"Square early"

[Henry Law]

I was lectured mercilessly by those who taught me to row that I must
square early (typically as my hands went over my ankles, in a sweep
boat). I harangue my coachees in like fashion.

But thanks to the ActiveTools people (the ones that make the adjustable
shoes) my attention was brought to a Rowing Biomechanics newsletter of
2009 (http://www.biorow.com/RBN_en_2009_files/2009RowBiomNews12.pdf)
which points out something that I'd always suspected: all that air
resistance from the square blade on the recovery, travelling bow-wards
much more quickly than the boat.

I think I'll change my practice to banging on at beginners and novices
about squaring early until they actually start to do it, but from then
on, and for more experienced crews, modify it slightly to "square early
enough to be sure of being really ready for the catch, but no earlier".

I'd be interested in comments from the mavens here, since my own maven
status is a long way off.

--

Henry Law Manchester, England

[James HS]

Henry,

I think that you are right that you want to square late enough to minimise air resistance (which is the point of feathering afterall) but early enough to be ready for a fast catch.

I think giving an instruction like over ankles is about having a crew boat ready at the same time.

How early is early enough - well, one needs to be ready with everything to catch quickly and take the load.

So, in a crew boat is it important to be in time with everyone else (and therefore square at the earliest need, or can you all be out of synch as you are readier than others in a shorter time?

Personally I think synch is probably more important - I certainly square earlier in the 2X because my partner does than I do in my single, and synchronicity seems to win us more boat speed than the increase in resistance, but in the single I square as late as I can while feeling settled enough to spear fish and take the catch :)

So - what he said, but how you coach a crew to get later and later in their square while remaining ready would be one for experimentation.

James

[robin_d...@hotmail.com]

heartily concur with all above, particularly the various ways you can get the crew to synchonise their actions into the catch, "ankles", calling the square rather than the catch (the catch is always a fixed interval after the square), doing variable catch strokes where they square on your call at quarter, half, 3/4, or full slide varying stroke by stroke etc.

While doctrine - particularly encountered with schoolboy rowers who have come to University and want to do a bit of regurgitation of what they learnt as 14 year olds - has people squaring early, I realised after a good long while that this is purely a device to ensure that beginners actually have got the blade squared and ready at the right height to take the catch on the way there, instead of the typical novice thing of skimming the blade along the water feathered, and then swooping down towards the ankles, diving the outer shoulder across the body and squaring up in the air to start pushing with the legs before the blade has engaged (resulting in skying and stopping the boat). The massive and sudden change of height necessary to get clearance for the square also results in horrific lurching of the boat from side to side. So - the early square (along with the even more basic "rowing square blades") impresses on the rower the need to maintain the correct height through the recovery AND get the blade squared before getting to the catch, but the wind resistance issues more than obviate the need to do this in anything other than technical sessions.

As they get a bit more experienced, as long as the blade is squared before the catch is initiated, that'll do me - but I will go through the other stages beforehand to get the stroke shape firmed up in the muscle memory BEFORE getting fancy with squaring closer and closer to the catch point.

[JK]

Yes, I agree with most of this....

Aren't most coaching drills an exaggeration of what is actually required so that when in the race comes the actual movements displayed are the coaches' desired result.... I'm very open about this when I coach and include phrases such as "exaggerated tap down"...

Mr Douglas writes profusely and eloquently on the myths and bad logic spouted in most coaching sessions... as a result I had to keep my mouth shut recently when hearing a BR coach talking about the "catch" and "backing it in"... explanations had wrong fluid dynamics logic but if those listening square earlier, reach further with correct posture, then we'll have a faster crew... I can re-educate them later about suction from the back of the spoon etc.!!

[Carl]

Let's inject a small sceptical spanner into the works, just for fun & to
see what it brings?

We've had previous discussions of the "Flip Catch", in which the blade
in effect squares as near as can be as it enters the water, & its
exponents do pretty well. And there's no obvious need, while the blade
is moving forwards over the water (which it is doing at all times
immediately preceding the catch) why it should be other than feathered
until the catch is being taken. I'll try to explain:

If you enter the water with the blade moving forwards you will
backwater, & it has to be moving slightly astern wrt the water, & thus
substantially sternwards WRT the boat, for this purpose.

There can be hardly any load on the catch (because you have nothing to
pull on until there is some engagement with the water), so it is logical
(but not necessarily easy) to want to retain the feather right up to the
instant at which the blade has a (very) slight net sternwards velocity
WRT the water. Which makes a theoretical case for squaring as you
enter. And this does not require you to dip your hands for extra water
clearance - not that the rather few centimetres between the end of the
shaft axis & the outermost bottom corner of the blade, necessitates much
increase of clearance even if you are feathering very close to the water.

That's the theoretical case, but of course we are of varying abilities,
so that ideal may not be easily attained by many. So we are drawn to
compromises & then to constructing plausible arguments to make the
compromise of an earlier square seem right of itself - which I don't
buy. Thus I don't buy James's argument that we need to square (early
enough) to be ready for a fast catch. In a good stroke there are no
separated actions but a smooth merging between actions, & what I fear
(perhaps wrongly) that I see in that statement by James is the idea that
we have to build ourselves up in order to make that catch fast.

We know that the load at the instant of engagement can't be other than
zero, & that the fast catch is not about speed of strike but the
combined speed of burying & loading - which are essentially low-pressure
actions, but building rapidly _under the water_ into the fully-loaded,
"fully-bent shaft" state. So pre-squaring, while it saves us from
making a mess of the catch if we are insufficiently adroit (as most of
us are), can be seen as an imperfection which carries with it the
potential to far too easily persuade your average to separate the last
part of the recovery from the first part of the catch.

Any thoughts?

Cheers -
Carl

--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing Low-drag Riggers/Advanced Accessories
Write: Harris Boatyard, Laleham Reach, Chertsey KT16 8RP, UK
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Email: ca...@carldouglasrowing.com Tel: +44(0)1932-570946 Fax: -563682
URLs: carldouglasrowing.com & now on Facebook @ CarlDouglasRacingShells

[Henry Law]

On 20/02/14 18:01, JK wrote:
> I'm very open about this when I coach and include phrases such as "exaggerated tap down"...

Me too. My crews pull my leg about my "mind things", i.e. things that
you imagine are happening, and which prompt you to better style, but
which (and I'm quite clear about this) aren't actually happening at all.

[Carl]

What's with the 'Mr.' bit?

Obviously I agree with you - most rowers have an awful lot to learn &
relatively few aspire to row at the very highest standard, so coaches
must find ways to herd them together into a form of rowing which feels
good enough to make it worth persevering with the activity.

But equally we should take more care, as you do but far too many don't,
to know & be ready to undo the fibs we feed to upcoming rowers as we see
these starting to hold them back. At the moment they are too often left
with a blind faith that what they've been taught must be right, which
ensures they'll go no further.

[Tor Anderson]

Regarding the flip catch you describe (which I like), how about catching even sooner:

I once ran into an old sculler that claimed you could catch earlier, if you slightly over squared the blades before catching. He claimed this allowed the catch to occur while the blades were moving towards the bow WRT the water. Once the drive was initiated, the grip was relaxed and to allow the sleeve to find the square of the oarlock.

Certainly this sounds really difficult to do reliably, but seems possible... Perhaps he just wanted to see me go for a swim. I have enough difficulty in perfecting a normal catch.

Has anyone seen or heard of anyone coaching this?

Best regards, Tor

[Carl]

On 20/02/2014 20:02, Tor Anderson wrote:
> Regarding the flip catch you describe (which I like), how about catching even sooner:
>
> I once ran into an old sculler that claimed you could catch earlier, if you slightly over squared the blades before catching. He claimed this allowed the catch to occur while the blades were moving towards the bow WRT the water. Once the drive was initiated, the grip was relaxed and to allow the sleeve to find the square of the oarlock.
>
> Certainly this sounds really difficult to do reliably, but seems possible... Perhaps he just wanted to see me go for a swim. I have enough difficulty in perfecting a normal catch.
>
> Has anyone seen or heard of anyone coaching this?
>
> Best regards, Tor
>

The nearest to this in my personal experience is the single-paddler
stroke for open canoes, in which you angle the blade forward and drive
downwards into the catch.

Yes, it could make sense to do as you describe. I've reckoned in the
past that your blade descends into the water at least 3x as fast as it
moves sternwards, & if you could do the over-square catch successfully
it might be a winner. Get it wrong & you might just be a swimmer ;)

The catch is really more complex than any of these descriptions
explains, since the blade (WRT the water) goes downwards, sternwards &
tip-first outwards while also rotating sternwards. When I get deep into
thinking about the complexities of flow around an oar-blade I may
succumb to a sudden urge to lie down & let it pass me by. Then someone
asks a question, & off we go again!

[sully]

I watched film of rowers in the 50s who were taught to flip catch, at racing speeds their oars were square entering the water, but their rollups were later
than was taught subsequently with macons.

I teach beginners to square early, elites to be able to square later according to conditions.

yes, you are correct that there is wind resistance against a square blade.

The irony is that Joe Burk went against convention to square earlier than commonly taught then which he believed allowed him to row higher rates. Wouldn't the wind resistance make it MORE difficult?

:^)

From a practical standpoint, when I teach beginners to row, a great majority of them will flip catch, have poor timing, and abysmal catches until they're taught otherwise. They also grip too tight, or sweepers dominate the inside hand. (hint for later).

The act of learning to square earlier improves catch timing immensely as it actually uncomplicates a lot of things happening at the same time at the catch.

an important factor about the rollup is what the hands are doing. When you drive, you want hands hooking the handle, not gripping it tight. Gripping is a waste of energy, tightens the forearms and upper body and breaks connection to the feet and impedes the quickness at the catch. relaxation helps quickness and power application.

the act of squaring the blade requires you to briefly grip the handle to initiate the feather. ideally, this can happen as the blade begins to drop,
but I don't teach ideal rollups until after people learn to catch well and time it properly with their hip movement in the boat.
so for both scullers and sweep, I teach to roll up before you lift the hands
to catch, to keep as few movements happening at the same time at the critical
catch area. This is roughly around the toes for full slide rowing, so I'll use that for ppl as it's a shorter clearer explanation and an easier cue in a busy boat.

When you're teaching beginners, it's distracting and confusing to get too technical, exact, and overly descriptive. You must know why and how everything works, but they don't need to know. Also, you can only teach one thing at a time effectively, focus on that, rotating your emphasis from week to week or day to day depending on the complexity of what you are teaching.

As JK said, which I agree with, that with most students we HAVE to use some exaggerated techniques to get them to learn something. Sometimes we do stupid stuff that works, and sometimes the stupid thing backfires. Connection is a good one, someone not using legs and horsing the upper body to futilely try to move the boat might be taught to shoot their butt just to get them to do something DIFFERENT than they're doing. I don't, but I get it. It works for some and others they just learn to shoot their butt! :^(

Good luck.

[James HS]

Carl Wrote >>>>>. Thus I don't buy James's argument that we need to square (early enough) to be ready for a fast catch. In a good stroke there are no

separated actions but a smooth merging between actions, & what I fear
(perhaps wrongly) that I see in that statement by James is the idea that
we have to build ourselves up in order to make that catch fast.

I guess I partly agree and disagree.

I completely buy (and use) the feathered extraction, so why wouldn't I buy the squaring catch - possibly because I have not found a way of coordinating it with my crewmate (so a skill level rather than necessarily a technique) and also possibly because I do ready myself for the catch by feeling the square of the blade in the collar - again, this may be a technique error, but it is part of my feedback mechanism (right or wrong) and I do have a mental check at that part of "the continuous sequence" that I am square (check) tension in the core (check) tension in the upper and lower limbs (check) - raise the hands and go :)

Possibly reflects the way I have been taught and compartmentalised - and also I am probably more fluid than that, but it is certainly the way I visualise it.


James

[Kit Davies]

On 20/02/2014 21:59, Carl wrote:
> The nearest to this in my personal experience is the single-paddler
> stroke for open canoes, in which you angle the blade forward and drive
> downwards into the catch.

Also, in Thames skiffs, where the shape of the button over-rotates the
blade slightly as it approaches the catch.

But I think both of these are to do with entering more cleanly rather
than minimising air resistance.

Kit

[ct]

I think the 'point' of the early square is that it simplifies things, and therefore more often than not allows the rower to relax and focus other things.

Although we all know it's a relatively simple action, it is still an action, hence why a decent novice rower who appears to of grasped the basics with square blades can completely fall apart when asked to go feathered, and even experienced crews will go from having a good platform to flapping all over the place, as it's that one extra thing.

By squaring "over the knee's" you've then got the entire leg compression to re-focus on timing, being relaxed (but not slack), and placing the blade. By squaring late, you simply make this skill more difficult.

So yes it is a matter of skill, and it's a choice. What do you focus on? Squaring at the optimum time? Placing at the optimum time? or both at the same time?

There's perhaps also some merit in getting the square "early" in low rate work so that it occurs around the same time at higher rate work. I'm not so sure about this, though it's often the reason given for early squaring.

We should take 2 evenly matched crews of novices, with the same supporting staff, coached with the 2 approaches, one early square, one theoretically optimum square. Supported by biometrics measure everything possible over x months. Then do a follow up study for a further y months where the early square's then focus on late square. Reckon BR would finance this? ; ).

[JK]

Mr Douglas, I have not personally met you yet.... when I do meet you, I hope to have a large wad of cash in my hand collecting my custom made single... I'll be happy to call you Carl from then on ;0)..... but the rate my children bleed my bank account it may be a long while coming.... so please keep bailing out the workshop for the time being...

cheers

James

[Steve]

I've had a tendency to square late. Not something I find easy to fix either.
The reason I square late I believe is that I'm very conscious of bringing a
squared blade too close to the water and catching it awkwardly and maybe
even losing my grip on a handle or both if I'm sculling. Feel a bit more
secure in a sweep boat with two hands holding and so I think I do square at
a more usual time in that scenario.

One thing bad about late squaring is that you have to do it faster which
means you're "snapping to the square" which I was taught is not good.
ideally a "roll" to square is what I was taught after going through the
novice state where I think the natural impulse is to "snap" to the square at
the last second.

While on a sculling course back over a year ago after getting back into the
sport after many years, I was told to begin the squaring process as your
hands passed over your knees. This seemed just a little too soon to me and
the mental block of having a fully squared blade moving towards the bow as
water is moving at speed in the opposite direction meant I just couldn't do
it! :)

In sweep, however, I tend to roll to the square going over my ankles.

No implied wisdom here I'm afraid other than to illustrate perhaps that
there's what's ideal and what you're comfortable with.

--

Regards

Steve
"Henry Law" <ne...@lawshouse.org> wrote in message
news:iNKdnXDtYd5QjJvO...@giganews.com...

[s...@ku.edu]

In following this thread, a question comes to mind: with the blades square just before entry, why wouldn't the blade act like a foil in the air just as it does when it enters the water with a similar angle of attack. I'm not thinking/suggesting that the squared blades just before entry provide any help in moving the shell, but isn't the air drag significantly less than the square blade perpendicular to the boat?

Steven M-M

[sully]

I like it! I heard it here on RSR first! :^)

(that the blade acts as a foil in the water I ALSO heard on RSR first).

[Carl]

Steven's right, but only when the oar is rotating sternwards (in the
horizontal plane) about the pin. Which is when it's taking an air-shot,
or too slow making its entry.

Otherwise it's all drag, just as it would be if you tried to push the
blade through the water towards the catch.

So I don't think we should regard that as more than a theoretical model
but of no practical relevance, perhaps not unlike those guys a couple of
centuries ago, who thought they could row hot-air balloons across the sky?

[Carl]

Re CT's post (easier to follow, however, if not top posted, but that's
enough pedantry!):

There was a US president of whom it was unkindly said he couldn't both
walk & chew gum. While we have to simplify things for the less expert,
that does not make it right to continue to separate each imagined stage
in the stroke as one acquires expertise. Thus the square & catch can &
should be overlaid on each other, unless we want to row by numbers or as
the so-called Russian band plays (each player can lay only one note &
waits to play his note whenever it comes up in the music). So please
don't let the necessary stepwise actions of the learning process become
the supposedly ideal model for the good stroke.

And what's this about "placing"? Are you saying you drop the blade in &
let the water take it, only applying any effort at some later stage?
I'm completely unsure what this achieves except a soft, delayed catch,
but maybe I've misunderstood?

[s...@ku.edu]

Agreed, Carl, all drag, but near the entry with the tip of the blade angled into the direction of the travel, how much? Surely less than at 'body-prep' position. To me a skilled sculler should be able to row on the square, square up early, and square at the last moment. In my experience rowing square with any speed or into a headwind produces palpable resistance; I feel nothing similar squaring before the entry. I have also rowed with many too many less skilled scullers who employ the 'flip catch.' In a 2x I feel like I'm taking most of the load at the entry while my flip-catching partner is using the top 1/4-1/3 of the drive to square up in the water.

Steven M-M

[Carl]

On 25/02/2014 08:51, s...@ku.edu wrote:
> Agreed, Carl, all drag, but near the entry with the tip of the blade angled into the direction of the travel, how much? Surely less than at 'body-prep' position. To me a skilled sculler should be able to row on the square, square up early, and square at the last moment. In my experience rowing square with any speed or into a headwind produces palpable resistance; I feel nothing similar squaring before the entry. I have also rowed with many too many less skilled scullers who employ the 'flip catch.' In a 2x I feel like I'm taking most of the load at the entry while my flip-catching partner is using the top 1/4-1/3 of the drive to square up in the water.
>
> Steven M-M

Yes, the angling of the blade towards the direction of travel does
(assuming a head wind or no significant tailwind) diminish wind drag on
the blade, but less exposure is always going to be better.

I'd like to think that your flip-catching partners are concentrating on
their flip at the expense of an early & swift catch - emphasising style
to the detriment of content. That's going to leave you holding the baby
at the catch - a miserable feeling. We always make compromises en route
to that impossible 'perfect stroke', but they should never get in the
way of what actually propel the boat.

I'm not an advocate of the flip catch, which can become a damaging
distraction, but except in a good tailwind I can see no case for
squaring any earlier that absolutely necessary. Nor can I see why
squaring should ever be seen as somehow a separate activity from any
other aspect of taking the catch & getting on with moving the boat.

As we row better I'd suppose that all the actions previously separated
by coaches in their efforts to get us to row at all should merge into a
smooth flow. In which case the catch becomes less evidently definable
except as that part of the action where we ignite the application of
power. However, in saying even that I fear I give the sense that the
catch is different when in truth every next part of the stroke is, if we
will allow it, only the inevitable consequence of all that preceded it.
So when you're approaching what we call the catch you're already
committed to what will happen during (not at) the catch, & when taking
the catch you are already committed to rapidly amplifying the load on, &
speed in, the hands which alone bend the shafts & load the blades to
sustain the motion of the rower/boat system against the continuous
resistance of the forces of fluid drag. And so on!

Cheers -
carl

[Charles Carroll]

Henry,

Whenever I hear someone tell me to square early my first impulse is to ask
why. How will I benefit from squaring early?

You point out the only answer I ever hear to this question — namely, that
squaring early ensures that you are prepared for blade entry. Of course this
ignores those coaches and gurus who advocate a sculler’s catch (Frank
Cunningham, Dr. Kleshnev, a lot of open water scullers, etc. etc. etc.)

Now ask, what are the drawbacks of squaring early?

In my first month of sculling I squared early in a strong headwind, that is,
a wind blowing against the direction of travel.

Mistake!

Squaring early just didn’t slow me down. It actually caused me to come to a
complete stop. And worse, I started moving sternwards, which is opposite the
direction in which I was trying to go.

Arrrrrrgh!

That settled the question for me. Square as late as possible …

Cordially,

Charles


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[Charles Carroll]

> I had to keep my mouth shut
> recently when hearing a BR coach talking
> about the "catch" and "backing it in"..

James,

The last time I was able to scull was late December of last year. At the
time I was thinking a lot about the catch and backing it in.

I had been working for months trying to do a “reset” of my technique — that
is, going back to when I first began sculling and starting all over from
there. My idea was to delete the muscle memory that was causing me to miss
water at the catch.

Virtually all my outings consisted of low rate/low pressure sculling. What I
learned from these outings is how to load the blades before pushing off the
stretcher.

Carl and others on RSR have many times advised us not to push off before the
blades are loaded. “You can't hit something hard which offers no
resistance.”

But for all the times I have encountered this advice, I cannot recall anyone’s
ever addressing the question, how do you load the blades. No, I take that
back. There is one exception — Tom Copeland last year. Tom posted one of the
most brilliant posts ever uploaded to RSR. In it, among many other things,
he described a hooking motion at the catch to load the blades.

Ok, so what does this have to do with “backing it in?”

From my experience sculling at low rate/low pressure I have come to think
that there are two ways to load the blades. First is passive and second is
active.

Passive is easy. Just immerse the blades and hold the oar handles in place
until you feel the handles press bowards in your fingertips. This tells you
that you have made that “essential tensile connection between the mass of
water behind the backs of the blades and the backs of the blades
themselves” — that is, the blades are loaded and will support the pressure
you apply to the oar handles.

Holding the oar handles in place after immersing the blades — that is,
passive loading — works very well at low rates/low pressure. But what
happens when you increase the rate and pressure? Do you have time to sit
with the blades immersed and wait to feel the oar handles press bowards into
your fingertips?

Even if passive loading only takes a few milliseconds, aren’t those
milliseconds wasted? Why wait? Why not try to find some way to load the
blades faster?

And here, it seems to me is where “hooking” becomes so important.

Hooking isn’t just immersing the blades and pulling on the oar handles
bowards.

Hooking, as I understand it, is a slight push against the oar handles in a
sternwards direction before pulling on the oar handles in a bowards
direction.

In other words, hooking is not just immerse/pull. Hooking is
immerse/push/pull. And isn’t that a bit of backwatering, albeit a very
slight, bit of backwatering? Some might even go so far as to think of this
as “backing the blades in.”

Now consider some data from the RBN February 2004. Valery Kleshnev compares
two crews. The faster crew increases force at the catch much more quickly
than the slower crew but has relatively lower maximal and average force
application. Also, while the boat speed and acceleration curves of the
faster crew have deeper negative peak at the catch, these curves show a much
quicker increase afterwards.

It seems to me that key here is the “deeper negative peak at the catch.”
Doesn’t this mean that the faster crew is checking the boat a little more
than the slower crew? I think so. I think this “deeper negative peak at the
catch” is what occurs when you actively load the blades at the catch — or,
if you will, when you “hook” the blades at the catch. But, of course, when
you hook the blades you load the blades faster.

Hence, Kleshnev’s concluding data: The Graph for Boat Acceleration shows
that the faster crew, in spite of showing a deeper negative peak at the
catch, is much quicker at reversing deceleration – that is, re-accelerating
the boat – than the slower crew.

So I wonder if by “backing it in” coaches are trying to tell you that you
should “hook the blades at the catch.” And if so, is this bad advice?

It seems to me that the problem, as always, is with language.

As Fairbairn suggests, you can’t really tell someone what rowing is. “One
can only illustrate in a boat what one thinks rowing is.”

[s...@ku.edu]

On Thursday, February 20, 2014 8:31:40 AM UTC-6, Henry Law wrote:

Charles,

I think a square entry is a sine qua non of a quick, effective catch. With regards to the catch it doesn't matter if you row square blades or square up just before the blades enter the water, you are still better off if you are square before the bottom of the blade touches the water.

I don't think there is a single top sculler of the last 75 years who took/takes the catch in the manner Frank Cunningham describes. Even some of his most successful rowers, like Jen Devine, didn't row that way. Go back and look at your videos of Ivanov; he is always square before the entry.

Steven M-M

[James HS]

Charles,

Good to have you in the discussion - hope you are well on the road to getting back in and trying it all out again :)

I don't think the snip was from my post - but I am afraid I also disagree with both of your scenarios.

(1) Dropping the blade in and still moving bow-wards would IMHO create tension on the wrong face of the blade, which you would then have to reverse.

(2) pushing the blade bow-wards so that you can then pull it stern-wards is so counter intuitive to me that I am just checking it as I re-write it.


My mental image is completely different. I pop the blades in (in my case normally fully on the square and as deep as my technique will allow) and then my initial loading before leg drive is a movement of hands towards the centreline (pecks) and then as discussed in another thread I think that there is a general tensioning of the system, which does include a slight bending of the arms - then leg drive.

All of this is designed to bend the blade ready for the leg drive which I can only see happening from the handle(s) travelling towards the bow.

Always ready to be corrected though :)


James

[Carl]

Sounds good to me.

It's also excellent that Charles is back into (virtual) sculling action
already, if only with one arm. How's it going, Charles? Keeping up the
physio, & lifting the whisky with the left hand without spilling?

We need to put our minds to generating appropriate analogies between the
"waters of life" and those we float boats over, just to keep the mind
sharp & your spirits up ;)

Cheers -
Carl

[s...@ku.edu]

Carl,

Out here in the west, we have a saying "Whisky is for drinkin; water is for fightin."
We fight over scarcity, but sounds like you are fighting over abundance.

SMM

[Carl]

Can we do a deal, Steven? We have a country-full of water which is
about the area of one of your smaller States. Should we tow (or row)
our XL-sized water bucket over to you, empty it out and then row it
back? What's it worth? But don't pay us in whisky, or we'll be fairly
described as 60m drunk clinging to a rock.

[sully]

count us in over in Cali. cities vs farms vs fisheries...

[John Greenly]

Hi Charles!

I hope you are progressing well!

You bring up something I have been working on: the observation that the best crews show a very short, sharp deceleration of the boat at the catch, compared with a longer, more gradual deceleration of less proficient crews.

May I give my interpretation of this, to invite correction from the experts?
(This has been seen by others as well as Kleshnev- Magnus has a very nice discussion as I remember.)

What is happening has nothing to do with pushing backwards with the blades. Good crews certainly do not do that. The deceleration of the boat is caused by the feet pushing on the stretcher to reverse the slide. The sculler has been pulling the boat to her with her feet during the recovery, and then has to make the reversal to pushing on the drive. The best crews do this very quickly. They do not gradually slow down the slide into the catch, but come up fast and reverse almost instantaneously. The boat gets shoved backwards because in fact the oars are not yet fully flexed when the feet start to push, so the forward pin force doesn't rise quickly enough to counter the backwards stretcher force in that first tiny fraction of a second. The preloading of the oars with the pecs is (probably not surprisingly) not enough to equal what the legs initiate. Nevertheless, the decrease in boat speed, which is the time integral of that deceleration, is smaller for the narrow sharp impulse of the best crews, so they lose less. Also, and probably even more important, they get the full drive force applied sooner, so they don't waste any of the beginning of the stroke. Effectively, they get a longer working stroke length.

I, in my frozen wasteland, slaving away on my erg, can see this very clearly. My oartec slider has a stroke length measure on the monitor, and I see that when I make the quickest reversal of slide that my useful stroke length immediately goes up- I'm not wasting as much distance at the catch. I get it best when I come into the catch fast and make the reversal of slide as quickly as ever I can by changing from pulling to pushing with my feet as instantaneously as possible, making sure that my core is solid so that the force is coupled directly through to the handle. The increased stroke length is the immediate indicator, but the indicated speed and power also go up significantly when I do it right. That's what I have been concentrating on this winter, and I hope to see good effects when I finally get back in my boat!


In reading your post, Charles, I'm wondering whether there might be a slight question in clarity of definition of the word "load", with respect to our oars. I'm not a great rower, but I am a rather good physicist, so I should be able to be clear about this- may I try?

To "load" something, in mechanical engineering lingo, is to exert a force on it. That's all. It's the engineer's term for the physicist's "force". Loads- forces- have a magnitude and also a direction: for instance, you can push or pull. Loads can be applied at a point, or distributed in magnitude and direction over an object. The engineer is often concerned with how materials respond to loads; they bend or twist, etc. Our oars mostly bend when we load them.

To propel our boats, we need to load- put a force on- our oars in the direction to move the boat forward. That is, we need to pull, not push. Immersing the blades in the water is necessary in order to couple our force to the water, but just putting the blades in does nothing to load them. They are usefully loaded exactly and only when we pull on them. As James said, if we push on them they are loaded all right, but in the wrong direction, which would just slow the boat down and waste time.

Does that help clarify the term "load"?

all best,

John G

[John Greenly]

On the subject of "hooking" the blade in, I'd be grateful for your opinions about this:

http://www.youtube.com/watch?v=DcX7qA3DxdQ

It's the London 1x final, and at 10:12 in the video there is slow motion of one stroke of Drysdale's from a nice viewing angle. If my understanding of the hooking motion is right, this looks like what I should be trying for: the blade is already on the way down toward the water while it is still moving bow-wards, then it touches the water surface just as it reaches its maximum bow-ward extension, and it makes a splash on both front and back sides, meaning it is entering while moving sternward to just about match the speed of the water past the boat. So the "hook" is that rounded path, bow-wards and down to the water, then sternwards into and under the water- yes?

--John

[sully]

I can't see the vid, but you describe what I would consider an excellent catch.

[Carl]

Completely correct. And it is the relative motion of blade skicing
through water which makes the largest contribution to the flow processes
which (but only in response to load) generate lift & prevent the blade
from moving face-first through the water.

We suffer in our interpretation of the stroke from our narrow 2-D,
side-on vision of what is actually happening. We see only the XZ view
(X being axial, Z being vertical), which is very important of course,
but do not see (except by our own power of interpretation) the XY view
(Y being in the plane of the water, perpendicular to the boat). That
side-on view denies us the rather important 3rd dimension in which we
see the hook that is Mahe's catch.

It would have been so much easier for rower to understand the factual
existence of the lift process, had they been able to see how the blade
cuts in a loop through the water. And although some of us have tried to
explain it, and there have been overhead photos available of the same
process since at least 100 years ago, this gets forgotten or ignored
when coaching from launch or bike.

[sully]

On Friday, February 28, 2014 2:46:38 AM UTC-8, Carl wrote:
> On 27/02/2014 16:26, John Greenly wrote:
>
> > On the subject of "hooking" the blade in, I'd be grateful for your opinions about this:

snip

>
>
>
> It would have been so much easier for rower to understand the factual
>
> existence of the lift process, had they been able to see how the blade
>
> cuts in a loop through the water. And although some of us have tried to
>
> explain it, and there have been overhead photos available of the same
>
> process since at least 100 years ago, this gets forgotten or ignored
>
> when coaching from launch or bike.
>
>

This is such an excellent point. Years ago I accidentally discovered this when
coaching competitive scullers from my single. In doing SS work, of course
I couldn't keep up with the athletes, and the work to do so required more
focus on my rowing than them.

So I set up between 2k to 3k course loop, back and forth for them, of which
I would only row the middle part, then I could stop and watch a sculler row
past me. From the bow close in, I got a much clearer view of the quality
and consistency of their catches, and a different view of the finish as well.

It didn't register that when I was coaching in a launch, the crews would
look SO much better from behind or from the side. :^(

[Charles Carroll]

> In reading your post, Charles, I'm wondering

> whether there might be a slight question …

> of definition of the word "load"
>

> To "load" something, in mechanical engineering
> lingo, is to exert a force on it. That's all. It's the
> engineer's term for the physicist's "force".
> Loads- forces- have a magnitude and also a
> direction: for instance, you can push or pull.

John,

Push or pull!

As usual you skillfully elucidate the difficulty I am having with the idea
of loading the blades.

Take a long plank balanced in the middle on a fixed support. A common seesaw
will do as an example. Have a child sit at one end and a second child of
similar weight sit at the other end.

Am I right to think that each child is tantamount to a load placed on their
respective ends of the plank?

And am I right to think that each load exerts a downwards force on the
plank? Can I think of this as a pushing force?

Now have one child sit at the end of the plank and anchor the other end of
the plank to a fixed bolt in the ground with a second bolt attached to the
bottom of the plank, and connect the two bolts with some strong elastic
material. The elastic is just strong enough to support the child such that
the plank is parallel to the ground.

Am I right in think that we have just established another kind of load on
the end of the plank? A load that holds the end of the plank in place by
pulling against the bottom of the plank as opposed to pushing against the
top of the plank?

Now here is where I am having my problem. I am confused about whether the
load on the blades is a pushing load or a pulling load. Or a bit of both?

When Carl writes about that “essential tensile connection between the mass

of water behind the backs of the blades and the backs of the blades

themselves,” I think of a pulling load rather than a pushing load. (cf Carl
Douglas, RSR, 3 May 2011, Subject: Anyone feel their hands move slightly
towards the stern during blade entry?)

For a long time now I have thought that it is a pulling load against the
backs of the blades that essentially holds the blades in the spot where we
put them? Am I wrong to think so?

“The oarsman should have a clear conception of what is required of him … He
should understand, and be quite sure that he does understand, that he is not
so much required to set water in motion and shovel it along past the side of
the boat, as to stick the blade of his oar as firmly as he can into a given
spot in the water and to lift the boat as far and as quickly as possible
past that spot. His attention must be concentrated on moving the boat, not
stirring up water.”
Sorry to be such a dimwit.

Warmest regards,

[John Greenly]

On Friday, February 28, 2014 12:29:29 PM UTC-5, sully wrote:
> On Friday, February 28, 2014 2:46:38 AM UTC-8, Carl wrote: > On 27/02/2014 16:26, John Greenly wrote: > > > On the subject of "hooking" the blade in, I'd be grateful for your opinions about this: snip > > > > It would have been so much easier for rower to understand the factual > > existence of the lift process, had they been able to see how the blade > > cuts in a loop through the water. And although some of us have tried to > > explain it, and there have been overhead photos available of the same > > process since at least 100 years ago, this gets forgotten or ignored > > when coaching from launch or bike. > > This is such an excellent point. Years ago I accidentally discovered this when coaching competitive scullers from my single. In doing SS work, of course I couldn't keep up with the athletes, and the work to do so required more focus on my rowing than them. So I set up between 2k to 3k course loop, back and forth for them, of which I would only row the middle part, then I could stop and watch a sculler row past me. From the bow close in, I got a much clearer view of the quality and consistency of their catches, and a different view of the finish as well. It didn't register that when I was coaching in a launch, the crews would look SO much better from behind or from the side. :^(

Yes!

That's why the one slow-mo of Mahe's catch really caught my eye in that video. It's the viewpoint nearly along the shaft of the oar at the catch that shows it so well.
I'm thinking of diagnosing my own catches this spring by mounting a video camera at the right place to get that view on my boat. The camera would be not all the way back at the stern, as people often do, but rather at a position on the deck looking out past one oarlock, at just about the angle of the oar shaft at the catch.

--John

[John Greenly]

On Friday, February 28, 2014 1:49:30 PM UTC-5, Charles Carroll wrote:

>I am confused about whether the load on the blades is a pushing load or a pulling load. Or a bit of both? When Carl writes about that "essential tensile connection between the mass of water behind the backs of the blades and the backs of the blades themselves," I think of a pulling load rather than a pushing load.

Hi Charles,

Eveything you wrote about the seesaw plank and its loads is just right, and very clearly stated!

Now for the blades in the water. First of all, we have, with your example, nicely established that the way to load the blade is to pull on the handle- just as the way to load the attached end of your seesaw is to have someone sit on the other end so the elastic stretches. Loading the elastic needs no skill or knowledge at all on the part of the sitter on the other end; their mere weight, load, does the job. Likewise, to load the blade in the water, we need no special skill or knowledge, just pulling does it. (I'm assuming that we do have the skill to have the blade nicely buried so air doesn't get into the act).

Let's start with the blade stationary in the water. The water, within a couple of feet of the surface, is only a little above atmospheric pressure, 15 pounds per square inch (psi) or so. This pressure is applied to all the surfaces of the blade, as it is to any object in the water. Pressure is exactly force per unit area: 15 psi exerts 15 pounds of force on each square inch of the blade. But the pressure is the same on both both front and back surfaces, and of course it is loading the blade in opposing directions, pointing into the surface on both sides, so all those forces in opposite directions add up to zero (I'm ignoring the net upward bouyancy force that floats the oar). There is no net load on the blade. The same is nearly true if you're moving, and just drop the blade in and let it go. It's a little more complicated because the oar is rotating with respect to the water as it goes by, and there is friction in the oarlock applying a little load, but basically there is nearly no net load on the blade as it moves along with the water.

Okay, now you start to pull. The blade exerts forces on the water, and the water exerts forces -loads- on the blade. These loads are still distributed over the area of the blade, both front and back surfaces. Now we are in the realm of fluid dynamics. Most fundamentally, what happens is that your application of force develops a flow pattern around the blade. The fundamental result is that this flow pattern always produces a pressure difference between the front and back sides of the blad. The pressure is always lower on the back side of the blade when you pull (and the opposite if you push). So, now the pressure and the total load on the front side is bigger than the pressure and the total load on the back side, and that difference is the net load in the direction that opposes your pull on the handle and drives the boat forward.

For instance, a blade of 100 square inch area with a pressure difference of 1 psi from front to back would have a net force of 100 pounds on it. With the ancient magic of the lever, that would mean a force of over 200 pounds at the handle, 400 pounds on the two oars. So 1 psi or so is enough to transmit the drive of even the most ferocious heavyweight sculler.

You might remember that in an earlier thread we established that Carl was simplifying to make a point, in talking about tension in the water. What he was emphasizing to an unreceptive rowing community was that the lower pressure on the back side means that atmospheric pressure air would eagerly rush into that area if it could get there, as with an inadequately immersed blade, and mess up the nice smooth water flow that produces that pressure difference efficiently. A 1 psi pressure difference can move a lot of air fast- a really good trombone player produces about that, fortissimo, and it's enough to blast you out of your seat: I can tell you, having been in the clarinet section right in front of them!

Anyway, in fact there is positive pressure loading -pushing- on both sides of the blade when you pull, but the flow produces a pressure difference that produces the net load. The further issues have to do with the hydrodynamic efficiency of producing that net force, and there the lifting regime is better than the stalled regime, as has been often discussed here, and I won't try to reprise now.

Does this help?

all best,
John

[Charles Carroll]

> a square entry is a sine qua non of
> a quick, effective catch.
>

> you are better off if you are square before the

> bottom of the blade touches the water.
>

> Go back and look at your videos of Ivanov;
> he is always square before the entry.

Steven,

I could not agree more.

And not only is Ivanov always square before entry, look at how high his
blades are off the water.

By the way, would you say he is squaring early or late?

https://www.youtube.com/watch?v=uDXBx_OFgi4&list=UUqox_JHnRozM76faCCLP1xg

Cordially,

[s...@ku.edu]

Charles,

"Late" and "early" are a little too prescriptive for me when describing one of the best. I will say that Ivanov begins to square up well before the catch and he tends to sky a little just before the entry. (That first stroke may be misleading and the water looks rough.) But, of course, you don't need to be perfect to be an amazing athlete. I prefer a more relaxed, gradual roll up to the more frantic, last moment square, but I can see how my approach may create a little more wind resistance. On the clip that John shared of Mahe, I so appreciated how relaxed and calm he looked even at end of the Olympic final against the best in the world. Often the best sculling/rowing looks almost lazy.

Steven

[Charles Carroll]

> Dropping the blade in and still moving
> bow-wards would IMHO create tension on
> the wrong face of the blade,
> which you would then have to reverse.
>

> pushing the blade bow-wards so that
> you can then pull it stern-wards is so counter
> intuitive to me that I am just checking it as I re-write it.
>

> my initial loading before leg drive is a movement
> of hands towards the centreline (pecks)

James,

It is my turn to eat humble pie

I was trying to think of ways to load the blades faster when I theorized
that maybe a tap in a bowards direction against the oar handles with just
the fingertips might speed up the tensile connection between the water and
the backs of the blades. As a bonus I wondered if it also might explain the
deeper negative peak velocity that is seen in faster crews in the initial
phases of the drive.

Unfortunately, however, as John Greenly has made obvious in another post,
such a maneuver has nothing to do with loading the blades. So I now have
another theory to retire to my book shelf of embarrassing hypotheses.

I once knew a man who was fond of saying, “It’s a full time job being me.”
He meant it was a full time job being himself. I never quite understood what
he was getting at, and whenever I asked he refused to say. He said, one day
I would know. It is moments like this that make me feel I may be getting a
little closer to knowing what he meant.

[Carl]

And that's the absolute essence of any job done well - the real expert
makes it seem easy, relaxed, maybe even artistic.

There's continuity even where, for tiny durations, very little seems to
move. Reversals of direction are not sudden & accelerations while
sometimes powerful, sometimes gentle, are never sudden, never jerky.

Such experts have taken the stroke & eliminated as far as they can every
action which does not enhance the process & are merely superfluous
stylistic baggage. But each one is different, in build & brain. And
maybe each could be even better....

Which is why, although we should learn from the real experts, we should
also understand the folly of trying to imitate them. As we cannot know
or appreciate how they feel or react throughout the cycle, to try to
slavishly copy them may even slow us down.

[John Greenly]

On Saturday, March 1, 2014 2:59:06 AM UTC-5, Charles Carroll wrote:

> I was trying to think of ways to load the blades faster when I theorized
> that maybe a tap in a bowards direction against the oar handles with just
> the fingertips might speed up the tensile connection between the water and
> the backs of the blades. As a bonus I wondered if it also might explain the
> deeper negative peak velocity that is seen in faster crews in the initial
> phases of the drive.
> Unfortunately, however, as John Greenly has made obvious in another post,
> such a maneuver has nothing to do with loading the blades. So I now have
> another theory to retire to my book shelf of embarrassing hypotheses

Charles,

I hope you know that your questions and thoughts are absolutely an inspiration! I, as you know well by now, am a teacher at heart; I love to try to see things from somebody else's viewpoint and try to help clarify understanding. There is a wonderful secret about teaching that you may know, and it is that you never really understand something yourself until you explain it to others, and especially to others who think about things quite differently than you do.
You are one of the most interesting and rewarding partners in dialogue I have met, so please keep those thoughts and questions coming!!

many thanks,
John

[John Greenly]

To get back to the original issue of this thread, there's an awkwardness I have with squaring the blades that I need help with. It's that in rolling up to the square, as my fingers curl downward I tend to move the handle downwards slightly, and that of course tends to sky the blades. That's working backwards to the initiation of the hooking motion I'm looking for, where the blade starts downward to the water while still moving bowwards, as I see so nicely in Mahe's catch. The only way I can see to avoid that is to raise the forearms and hands to compensate for the fingers curling down, but that seems to be hard for me to coordinate. So for me at present, that's a reason to square a bit early, to get that slight contrary motion done with. Any suggestions?

thanks
John

[Richard du P]

On Saturday, March 1, 2014 5:03:53 PM UTC, John Greenly wrote:
> To get back to the original issue of this thread, there's an awkwardness I have with squaring the blades that I need help with. It's that in rolling up to the square, as my fingers curl downward I tend to move the handle downwards slightly, and that of course tends to sky the blades. That's working backwards to the initiation of the hooking motion I'm looking for, where the blade starts downward to the water while still moving bowwards, as I see so nicely in Mahe's catch. The only way I can see to avoid that is to raise the forearms and hands to compensate for the fingers curling down, but that seems to be hard for me to coordinate. So for me at present, that's a reason to square a bit early, to get that slight contrary motion done with. Any suggestions?
> thanks
> John

John, here's one attempted answer, possibly rubbish but the best you have so far. Please bear in mind [a] that "it's all done from memory", because I've hardly actually DONE any of this in the current millennium, and [b] that my memories are of sweep rowing much more than sculling, because of acute short sight and consequent very poor peripheral vision.

It appears to me that, if you keep the hands set on the blade handle[s], without shifting your grip, during the full stroke + recovery cycle, then the wrists must drop quite low on the feather, and you can only bring the blade close to the water by raising the forearms a bit as you square - or am I missing something?

May I suggest that you shouldn't co-ordinate these actions by some process of analysis and integration - did someone once say something about paralysis by analysis? ..... but rather tell your body to learn how to do it ..... in stable conditions, engage in a repetitive exercise that I was subjected to in the 1950s ..... WITHOUT LOOKING AT YOUR BLADE[S], do repeated "come forward to a square entry"s through the air, in order to knock that imaginary small frog off that imaginary lilypad with your squaring blade without quite splashing the water?

..... or am I the only one here old enough to have been taught cruelty to imaginary frogs?
I'm probably far too old to be offering an opinion .....

Richard du P

[Charles Carroll]

John,

I extracted footage of Mahe Drysdale in slow motion at the 2012 Olympics,
enlarged it slightly, and then slowed it down even more.

https://www.youtube.com/watch?v=H44iiI40vq8

[alsto...@yahoo.com]

Dern. I just spent much of the day last Sunday practicing squaring early.

[John Greenly]

On Saturday, March 1, 2014 9:46:53 PM UTC-5, Charles Carroll wrote:
> John,
> I extracted footage of Mahe Drysdale in slow motion at the 2012 Olympics,
> enlarged it slightly, and then slowed it down even more.
> https://www.youtube.com/watch?v=H44iiI40vq8
> Cordially,
> Charles

Hey, thanks!! At this speed I can really see well. If you think of the fishhook of the blade's path as having a straight shank parallel to the water, with half of the curve and the barb underwater, Mahe's completing the rollup just at the end of the shank, just before the curve starts. That's just what I was suggesting for myself in my post! In fact, you can see the same thing- as he closes his fingers the handle does dip a little bit, but that is finished just before the hook curve starts as the hands start upward.
This looks natural and good to me, but it's not what I have been doing- I have been squaring later- not getting square until the farthest point of the hook curve, and that's what feels too complicated: trying to begin the hook and finish the square at the same time. So for me I think that's the answer to Henry's original question on this thread.

What I really want out of all this is just to get the blades moving smartly downward before they hit the water, for a quick entry, and Mahe's hook certainly does that beautifully. So, as Richard says, enough analysis, now I need to teach my hands to do it! Of course, first the temperature around here has to go up just a bit from its present -15C so I can get into a boat....

cheers,
John

[John Greenly]

On Saturday, March 1, 2014 7:13:24 AM UTC-5, Carl wrote:

> And that's the absolute essence of any job done well - the real expert
> makes it seem easy, relaxed, maybe even artistic.

Wonderful, yes. To me, most any human activity done at the very highest level of skill becomes indistinguishable from magic. So the world is full of wonder and magic if you pay attention.

John

[James HS]

Charles,

I am an architect and sometime inventor. In my mind and when asleep I come up with the most amazing designs and alterations - which burst into nothing when I draw them or write them down - to such an extent that I wonder how on earth they made any sense to me before I engaged in that process.

But they always move me on - mainly because they allow me to move onto the next impossible dilemma.

so NEVER worry about writing it here - I used to as I was corrected (gently) so often, but now I find it too useful.

Be reassured - I do eventually build stuff so some of my ideas work!! :)



However, I do have a personal problem with the backsplash coaching - and just having looked at your youtube channel again I see that you are a practitioner of that philosophy, yet your video clearly shows how it checks the boat and prevents you from getting the blade in before you can generate useful work.

My personal understanding (here we go) is that what we call the V splash is what we are looking for. The blade is travelling downwards as quickly as you can to get berried. Because you are going backwards there is going to be a bit of back splash, and because you are beginning to load the blade (by pinching the chest and bending the arms) there will be some small front splash also caused because you are popping something into the water.

That is what I have 'observed' to be the most efficient form of splash :)

But please - expose your thinking to the light as we all benefit from it's discussion!

James

[Kit Davies]

I don't know whether Jim Dwyer still frequents these parts, but he did
some GoPro shots from above looking down.
https://www.youtube.com/watch?v=4C44XxF1_ZA

Another useful viewpoint.

Kit

[Kit Davies]

And then of course there's this!!

https://www.youtube.com/watch?v=0XfL_2EzEHI

Though some might say there are enough drones in modern rowing already.

Kit

[James HS]

Interesting site - for a good view of the V splash look at this one http://www.youtube.com/watch?v=h2sQY0Mp4Q8&feature=share&list=UUmaIAqa0lAR5NDEgqcpWoNA&index=5 about 2:22 in.

James

[Charles Carroll]

> If my understanding of the hooking motion is right,
> this looks like what I should be trying for: the blade
> is already on the way down toward the water while it is
> still moving bow-wards, then it touches the water
> surface just as it reaches its maximum bow-ward extension,
> and it makes a splash on both front and back sides,
> meaning it is entering while moving sternward to
> just about match the speed of the water past the boat.

John,

I have been rereading this part of the larger thread this morning. I cannot
tell you how impressed I am with the discussion. You have very simply and
clearly, indeed elegantly, described what Drysdale is doing at the catch.

I am curious, however, about why Mahe is throwing so much water bowards. In
the slowed down video I put on YouTube you can see everything you have
described. But you can also see a spray of water spurting up behind the
blade and rising over his head and across his bow.

Any ideas about what may be causing this spurt of water? Is it speeding him
up, or slowing him down, or just irrelevant?

Mike, when you were coaching competitive scullers from your single and set
up the 2k to 3k course loop where you could watch your scullers from the bow
close in, did you ever see them throwing water bowards? And if you did, what
did you do about it? Ignore it? Or try to prevent it? Or something else
altogether?

By the way, I have not forgetting that “There's always a risk of spotting a
fault in a quick rower and thus justifying its existence in not so quick
rowers.”( Derek Clark)

[sully]

On Monday, March 3, 2014 10:42:50 AM UTC-8, Charles Carroll wrote:
> > If my understanding of the hooking motion is right,
>
> > this looks like what I should be trying for: the blade
>
> > is already on the way down toward the water while it is
>
> > still moving bow-wards, then it touches the water
>
> > surface just as it reaches its maximum bow-ward extension,
>
> > and it makes a splash on both front and back sides,
>
> > meaning it is entering while moving sternward to
>
> > just about match the speed of the water past the boat.
>
>
>
> John,
>
>
>
> I have been rereading this part of the larger thread this morning. I cannot
>
> tell you how impressed I am with the discussion. You have very simply and
>
> clearly, indeed elegantly, described what Drysdale is doing at the catch.
>
>
>
> I am curious, however, about why Mahe is throwing so much water bowards. In
>
> the slowed down video I put on YouTube you can see everything you have
>
> described. But you can also see a spray of water spurting up behind the
>
> blade and rising over his head and across his bow.
>
>
>
> Any ideas about what may be causing this spurt of water? Is it speeding him
>
> up, or slowing him down, or just irrelevant?
>
>
>
> Mike, when you were coaching competitive scullers from your single and set
>
> up the 2k to 3k course loop where you could watch your scullers from the bow
>
> close in, did you ever see them throwing water bowards? And if you did, what
>
> did you do about it? Ignore it? Or try to prevent it? Or something else
>
> altogether?

I haven't seen Mahe's vid yet. I keep reading this thread at a place
I don't fire up video.

I'll wait until I can see what you see.

[Charles Carroll]

> I'll wait until I can see what you see.

When have you ever not seen much more than I think I can see? You have a
much more educated eye, as well you should.

If anyone around you has a smart phone and access to WiFi, you can watch the
video. Just have them enter charlescarroll1 in their browser. This should
take you to my YouTube Channel. From there the slowed-down, enlarged video
should just be a couple of taps away.

[Charles Carroll]

James,

I cannot find words that adequately convey what your post and John’s post
means to me. I am horrified at the thought that I may be annoying people
with my questions.

Like you, with your amazing designs and alterations that come in your sleep,
I trouble myself with questions and fanciful notions in my sleep, and wonder
if I might not be on to something, only to discover in the clear light of
day that nothing I ask makes much sense.

But also, like you, the questions always seem to move me on. Post tenebras
spero lucem. After darkness, I hope for light.

I concede that in a video on YouTube I can clearly be seen taking the catch
with a lot of backsplash. So I need to emphasize that in the video any
backsplash is entirely inadvertent, not deliberate. I am not advocating
backsplash at the catch.

My questions begin with blade entry and load. Do these happen
simultaneously? Or do they happen in sequence?

Years ago Carl wrote: “Until there's load on the handles there's no point or
need for load on the stretcher.” This exactly describes what I experience
while I scull. I immerse the blades, and then have to wait until feel a load
on the handles. So it seems to me that blade entry and load are sequential.
I think of it as fully immersing the blades until they are nicely buried and
then waiting until I feel the oar hands press very lightly against my
fingertips.

In other words, it seems to me that there is always an interval between when
the blades are nicely buried (John’s words) and when I feel the load on the
handles. I want to stress two things about this interval. First, it is very
quick, a matter of a few milliseconds. Second, it is all but impossible to
feel at high rates.

But the important question is am I just dreaming up this interval? Is it
real? And if so, is there anything I can do at the catch that can speed it
up?

That is really the question I am dealing with. Assuming there is an interval
between blade entry and load, is there anything I can do to shorten this
interval?

But then I look at the video of Mahe Drysdale in very slow motion. By the
time the blade becomes visible it is already square. And this makes me think
of what Richard wrote to John.

“… you shouldn't co-ordinate these actions by some process of analysis and

integration - did someone once say something about paralysis by analysis?

..... but rather tell your body to learn how to do it .....”

Is Drysdale thinking about when to square the blades? Or does Drysdale just
do it, on time, because that is what his muscles remember to do?

In only write this because in a couple of weeks I hope to be back in my
amazing shell and on the water trying to create new memories in my muscles.

Ha!

Warmest regards,

[Carl]

On 03/03/2014 20:42, Charles Carroll wrote:
> My questions begin with blade entry and load. Do these happen
> simultaneously? Or do they happen in sequence?
>
> Years ago Carl wrote: “Until there's load on the handles there's no
> point or need for load on the stretcher.” This exactly describes what I
> experience while I scull. I immerse the blades, and then have to wait
> until feel a load on the handles. So it seems to me that blade entry and
> load are sequential. I think of it as fully immersing the blades until
> they are nicely buried and then waiting until I feel the oar hands press
> very lightly against my fingertips.
>
> In other words, it seems to me that there is always an interval between
> when the blades are nicely buried (John’s words) and when I feel the
> load on the handles. I want to stress two things about this interval.
> First, it is very quick, a matter of a few milliseconds. Second, it is
> all but impossible to feel at high rates.
>
> But the important question is am I just dreaming up this interval? Is it
> real? And if so, is there anything I can do at the catch that can speed
> it up?

Charles -
For some there is a clear delay between inserting blade into water &
applying load. But it is neither necessary nor desirable that it be so,
since that delay wastes stroke length where it is most valuable &
reduces the time you have in that stroke to do the work of which you are
capable

The water is moving past you & you have to catch it at the run. If you
stop to take the catch you won't be fast enough not to back-splash. So
don't even think of the mechanics of the entry, just how swiftly you can
be pulling. Contrary to what you imply, unless you pull there can be no
load; load is the reaction to your pull (just as lift is the
fluid-dynamic reaction to a load on a wing, sail or rudder, and pressure
on the soles of your feet is a reaction to the action of gravity on your
own mass). But maybe those analogies only confuse the issue?

What we see here is a problem caused by mentally splitting a stroke into
separate actions (e.g. squaring from catch, or catch from loading).

Suppose you want to jump over a high wall. Do you leap & hang from the
wall, then pull yourself up & over it? Or do you preserve your upwards
momentum by catching & simultaneously pulling down on the top of the
wall? Ideally you'd do the latter. There'd be no delay between the
hands first touching the wall and their already dragging you on upwards.
It's the delay which costs you so dearly.

You need to be back on the water - but do it gently at first, please!
And maybe you should go swimming first (not by accident!) using breast
stroke to give you relatively lightly loaded movement over not to wide a
range and without undue amounts of rotation. What do your physios think
about that?

[rke...@gmail.com]

I have thoroughly enjoyed reading this topic! I have given this idea hours upon hours of thought over the past couple years in trying to teach my crews how to have a "good" catch. Let's see if I got this somewhat right...

Backsplash is caused by the lifting of the hands as they are still travelling towards the stern. Lift too soon and you get a lot of water moving towards the bow causing a big check on the boat. Sternsplash is caused by moving the blade towards the stern while lifting the hands (driving before the blade has made much, if any, contact with the water) - picture many a novice crew trying to put some gusto on the catch. The perfect "V splash" then must have some components of each. The bow-side splash comes from lifting the hands at the latest possible moment as they are still moving sternwards. The sternward splash comes from (near) simulataneous drive as the blade is still being immersed.

The drills I have my crews perform would be pretty difficult in a single unless you possess great balance and control, which I do not. First, to work on the backsplash, I have them hold the oar/sculls very lightly. Lightly enough so that when the spoon makes contact with the water, the force of touching the water will cause the spoon to lay over on the water. I have the travel up the slide and, at their full reach, they lift their hands as if they were trying to get backsplash. But, of course, the spoon will flop over onto the water. I want them to visualize that the backsplash is caused by the bottom cm or two of the spoon as it travels bow-wards. So, if their spoon lays over and continues to move towards the bow, they have lifted too soon. If it doesn't lay over at all, they have lifted their hands too late. They will continue repeating until they find the "sweet spot" where they lift, the spoon flops, and everything stops. Then, keep it square and feel that amount of splash.

The sternward splash is harder. I will have them sit at full compression with the spoons about 1/3 buried. They will then drive, about 1/2 pressure at first, until their spoon is fully buried (lift the hands and drive the legs together). The goal is to accomplish this feat within the first inch of the slide. Longer than that means they need to lift their hands faster. More common is the "lift then drive" cheaters. They are easily identified by a quick upward jerk of the shoulders.

The last drill is to put the two together: last 1/4 of the slide, working on "driving through the catch."

In doubles, these are a little tricky for my high school rowers when stroke seat is doing the drills and bow seat is stretched out trying to balance the boat. I am always a little butt-clenched with a life preserver handy waiting for them to take a bath. (The Detroit River is pretty cold until about July.) I am not brave enough to have them try in singles! But, none of them have taken nearly as many strokes as you have, Charles.

[sully]

I've seen it now, yes, at the ratings that Mahe's likely at, 33-35, this would be a typical splash. The vid needs more contrast, there is actually a V splash but the bow splash is more pronounced.

But what I most pay attention to is from second 14 to 15, it is actually quite wonderful to look at such a powerful sculler have such a refined catch.

That's not true with most of his competitors.

From second 14, he's moving into stern and the change of direction of his body/slide doesn't happen until the clock turns 15, his blade is halfway buried.

In order to change directions on the slide, the slide, of course, must stop, but imperceptibly, logically of course you can't change directions until the
slide stops the direction it's going!

The blade tip hits the water right at 14.5 or so, and by 15 he's moving to bow slightly, the slide and back moving together out of the stern.

There are balances and tradeoffs to how we row. Look at where Mahe is when his blade is fully buried, his legs are still nearly fully compressed near his body, his legs are tighter angle than 90 degrees. I consider the blade
buried when the shaft hits the water, thats when the top of the blade is fully
covered and you have the full face acting as your lever point.

Yet, WHEN his blade is fully buried, his shaft is already loaded? Why is that?

because that inch of drive on the slide as the blade is dropping, you can see
Mahe's legs engaging, they aren't WAITING for the blade to "lock", but are taking advantage of the flow of the blade as it's burying and as it's being pushed outboard by the pin as it's burying.

The bow splash is an unfortunate byproduct of an awesome catch. It's unfortunate because that water flying around is some wasted energy, but to
avoid wasting that energy, you'll waste it elsewhere, mostly in pushing on the footboards with not enough water to drive against.

Imagine what you'd have to do to have a zero spash entry. As the boat travels
past the spot you want to drop the blade, you'd have to row the blade through some air, essentially, catching up to that imaginary puddle.

A characteristic of Mahe's catch is that it will likely be the same drop speed at a 24 as a 34, but the blade will enter more quickly because it's moving to bow more quickly. Not explaining it well, but at 20 spm, I would say his bow splash would be half size of the splash you see there.

Something else to note.

Mahe has a fantastic catch in part because of his very disciplined recovery.
Note that his arms get fully away and stretched, and he achieves his body angle by half slide of his recovery, so that all the movement into the catch is leg compression and hand separation following the handle path.

the flipside of that motion is to imagine reaching into the catch by stretching the arms, or leaning the body forward to blade entry. This greatly lessens the chances of getting good connection at full compression with the legs when the blade goes in.

Well done, Charles, I love this shot. Better to see about 5-6 strokes, but this is very good. I would wager there would be differences in just 5, 6 strokes in the splash heights, as much as 50%.

[James HS]

I agree that there is a 'percieved' wait - in reality you want to get leg power onto a loaded blade as soon as you can.

In my mind the wait is not a wait at all - it is the time that I am drawing my hands towards each other and slightly bending my arms - i.e. loading the blades without leg drive. So there is a 'wait' if we split up all the elements - but lets make them all simultaneous - sliding forward into the catch, rolling up, lifting hands, dropping in and loading and then reverse direction of the slide.

The lifetime's work is combining all those.

I like to think of the blade element of this as pushing a spinning merry go round. You have to catch a moving object and then impart load - pausing as you grab hold would throw you away :)

As it goes faster you have less time to grasp and push so everything has to be sharper.

I am coached that the insertion of the blade should be like spearing fish - it is an active and precise movement to get the blade covered as quickly as you can, but like pushing that merry go round - you need to be ready to apply force to those handles or it will run away from you :)

James

[magnus....@gmail.com]

I've always regarded the "perfect" catch as the final and almost uncoachable part of a sculler's or rower's repertoire, a sleight of hand. It happens too quickly to be able to think about what's going on, it's basically a reflex that has to be developed by constant practice and exercises.
I've been lucky enough to spend the larger part of my sculling racing career with a 2x partner who, when I rigged him up with my double-accelerometer set-up (one on seat, one on shell) in his 1x, showed a seat-direction-reversal and start of the shell's acceleration within hundredths of a second of each other: which no other scullers I tested came anywhere near even very good ones. Even Carl was impressed when I showed the graph to him (this is him http://www.slidingseat.net/accel/Accel_Chart_ExplainedBig.png)

In terms of what's mechanically going on at the catch I'm pretty sure I've referenced my article on this before, for those who haven't seen it it's http://www.slidingseat.net/howtorow/howtorow.html#catch

[John Greenly]

On Monday, March 3, 2014 3:42:45 PM UTC-5, Charles Carroll wrote:

> "... you shouldn't co-ordinate these actions by some process of analysis and

> integration - did someone once say something about paralysis by analysis?
> ..... but rather tell your body to learn how to do it ....."

> Is Drysdale thinking about when to square the blades? Or does Drysdale just
> do it, on time, because that is what his muscles remember to do?

Hi Charles,

This is something that I as a musician have thought a lot about. When I learn a piece of music, I take it apart, figure out its ingredients and their sequence, then I practice it slowly until that sequence is in my muscles. At the end, I have learned it in three ways, all of which I can use as I play it: first the muscle memory that requires no thought at all. Second, the aural memory- I know what it sounds like, and I can "listen ahead" in my mind to remember what to do. Third, the structural understanding, I know its parts and how they are put together, its architecture. If any one of these fails, I can use the other two.

We scullers have it easy in a way, we only have to learn one song, but it's complicated by the fact that we do it at variable tempo- the rate, and in different rhythms- the relative drive and recovery times. Mahe is certainly not thinking "okay, now it's time to square". First of all, conscious perception and thought is far too slow to do this. Your idea of waiting to perceive something consciously and then respond during the catch is absolutely not possible. We fool ourselves: it feels like milliseconds, but many experiments have shown clearly that it takes a couple of tenths of a second from when a stimulus reaches the brain for conscious thought to process it and deliver a resulting instruction to the muscles. That's way too slow. That's why we have to practice very slowly in the process of learning. But at normal speed it has to be all automatic. Mahe is certainly working on muscle memory. But, at least in training, he is also monitoring his motions using the other two kinds of memory- first, memory of the rhythms of how the parts of the motion play in their sequence; and finally, the knowledge and understanding of the structure of the stroke.

--John

[Charles Carroll]

Carl,

I think of slow motion video in the same way I think of a telescope or
microscope. All three are tools that reveal things which must be seen
otherwise than by ordinary sight.

Now why do I write this?

Because it seems to me that every video I have made of elite scullers moving
shells at extraordinary speeds all show the same thing whenever I recreate
the video in slow motion — namely, a clear delay between inserting the blade
into the water and applying load. The only difference between elite scullers
and the rest of us is that with elite scullers you cannot see this delay
with the naked eye. But it’s there when you slow down the video enough.

I have two questions about this. Why is the delay there? And what can I do
to shorten it?

I hope that everyone on logs into RSR, and especially the regular
contributors, understand that I am not a physicist and have never claimed
expertise in any of this. But this is not going to stop me from proposing an
explanation, if only to see how it is received in the clear light of day. As
James and John and you and others have pointed out, isn’t this how we learn?

Ok, so how can you explain this delay?

You have written about how the hull of a shell moving through the water
creates a boundary layer between the shell and the water. Would a blade
descending vertically through the water create a similar boundary level
between its two surfaces and the water? And if so, would this mean that the
water has to regain contact with the two surfaces of the blade before the
blade is able to resist any load put on the oar handles? (Is the V splash
above the water surface just an extension of this boundary layer?)

I am sure you see where I am going with this.

Elite scullers have very fast blade entries. So wouldn’t this mean that the
delay between inserting the blade into the water and applying load would be
shorter for them than it is for scullers with slower blade entries?

It seems to me that this hypothesis supports what you have been saying for
many years — namely, that fast blade entry is crucial to sculling fast.

Now for the second question: How do you reduce the delay between inserting
the blade into the water and applying load? I don’t know have any notion of
how to answer this question other than to refer to the previous paragraph —
fast blade entry is crucial to sculling fast.

But no matter how fast the blade insertion, it seems to me that a sculler —
any sculler — is going to have to accept that during the delay between
inserting the blades into the water and applying load, he is going to have
to be relaxed — meaning: even if the delay is so fast that it is impossible
to see with the naked eye, for those few milliseconds of delay the sculler
is going to have to refrain from hitting something hard and fast that can
offer no resistance.

Ok, I’ve got to go walk the dogs and then get on to physical therapy. But I
am interested if anything I have said makes any sense.

Warmest regards,

Charles

Ps Also, just to stay on topic, it seems to me that this is why it is so
important to have the blades fully squared at the catch. Doesn’t a fully
squared blade expedite faster blade entry? Just look at the slow motion
video of Mahe. Look at how early he seems to square.

[Charles Carroll]

> I've been lucky enough to spend the larger part
> of my sculling racing career with a 2x partner
> who, when I rigged him up with my double-accelerometer
> set-up (one on seat, one on shell) in his 1x, showed
> a seat-direction-reversal and start of the shell's
> acceleration within hundredths of a second of each other:
> which no other scullers I tested came anywhere
> near even very good ones.

Magnus,

How does it do that? Whenever I try I just end up hammering the catch and
shoveling water.

[Charles Carroll]

Sorry! The "it" should have been "he." Terrible typo!

But the question still remains. How does he do that?

[sully]

On Tuesday, March 4, 2014 10:48:55 AM UTC-8, Charles Carroll wrote:
> Carl,
>
>
>
> I think of slow motion video in the same way I think of a telescope or
>
> microscope. All three are tools that reveal things which must be seen
>
> otherwise than by ordinary sight.
>
>
>
> Now why do I write this?
>
>
>
> Because it seems to me that every video I have made of elite scullers moving
>
> shells at extraordinary speeds all show the same thing whenever I recreate
>

> the video in slow motion -- namely, a clear delay between inserting the blade

>
> into the water and applying load. The only difference between elite scullers
>
> and the rest of us is that with elite scullers you cannot see this delay
>
> with the naked eye. But it's there when you slow down the video enough.

If you just sat on an erg and slide forward and changed direction, recovery and drive, if you Slo-mo that enough there would be a delay!

But as I pointed out, Mahe's blade is loaded by the time it's first buried.
I'm seeing the shaft bent, as the top of the blade goes below the surface.

[John Greenly]

On Tuesday, March 4, 2014 1:48:55 PM UTC-5, Charles Carroll wrote:
> Carl, I think of slow motion video in the same way I think of a telescope or microscope. All three are tools that reveal things which must be seen otherwise than by ordinary sight. Now why do I write this? Because it seems to me that every video I have made of elite scullers moving shells at extraordinary speeds all show the same thing whenever I recreate the video in slow motion -- namely, a clear delay between inserting the blade into the water and applying load. The only difference between elite scullers and the rest of us is that with elite scullers you cannot see this delay with the naked eye. But it's there when you slow down the video enough. I have two questions about this. Why is the delay there? And what can I do to shorten it? I hope that everyone on logs into RSR, and especially the regular contributors, understand that I am not a physicist and have never claimed expertise in any of this. But this is not going to stop me from proposing an explanation, if only to see how it is received in the clear light of day. As James and John and you and others have pointed out, isn't this how we learn? Ok, so how can you explain this delay? You have written about how the hull of a shell moving through the water creates a boundary layer between the shell and the water. Would a blade descending vertically through the water create a similar boundary level between its two surfaces and the water? And if so, would this mean that the water has to regain contact with the two surfaces of the blade before the blade is able to resist any load put on the oar handles? (Is the V splash above the water surface just an extension of this boundary layer?) I am sure you see where I am going with this. Elite scullers have very fast blade entries. So wouldn't this mean that the delay between inserting the blade into the water and applying load would be shorter for them than it is for scullers with slower blade entries? It seems to me that this hypothesis supports what you have been saying for many years -- namely, that fast blade entry is crucial to sculling fast. Now for the second question: How do you reduce the delay between inserting the blade into the water and applying load? I don't know have any notion of how to answer this question other than to refer to the previous paragraph -- fast blade entry is crucial to sculling fast. But no matter how fast the blade insertion, it seems to me that a sculler -- any sculler -- is going to have to accept that during the delay between inserting the blades into the water and applying load, he is going to have to be relaxed -- meaning: even if the delay is so fast that it is impossible to see with the naked eye, for those few milliseconds of delay the sculler is going to have to refrain from hitting something hard and fast that can offer no resistance. Ok, I've got to go walk the dogs and then get on to physical therapy. But I am interested if anything I have said makes any sense. Warmest regards, Charles Ps Also, just to stay on topic, it seems to me that this is why it is so important to have the blades fully squared at the catch. Doesn't a fully squared blade expedite faster blade entry? Just look at the slow motion video of Mahe. Look at how early he seems to square. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com

Charles, I can comment usefully on only one thing- the "boundary layer" is the flow pattern in the fluid immediately adjoining a moving surface that is generated by contact with the surface (the famous "no-slip condition"). So when there's a boundary layer, that means the blade is in contact with, and moving with respect to, the water. Boundary layers are at the heart of fluid dynamics; in fact, the textbook for the graduate course in fluid dynamics I took decades ago was just called "Boundary layer theory". I can look over at my office bookshelf and see it right now. It brings back great memories of my excellent professor saying "turbulent thermal plume" in a nearly impenetrable Swedish accent. (...think about it!)

I must admit that I've never understood what you mean by waiting at the catch. And in one of your videos, your coach can be heard telling you to wait- "count to 20" I think he says (obviously exaggerating to make a point) But I don't have the faintest idea of what he means.

As far as I can understand, you have complete control over how fast the load comes on at the entry. The load comes on when you pull, and you can pull any time you want. The load is the pull, the pull is the load. If you pull too soon, of course, you'll shovel some water on the surface (or if you pull way too soon, you'll shovel air!), and if you pull too late, you backsplash, check your motion and waste time. As far as I can tell, and Carl, Magnus, Sully, James and all the pros are telling me, if I understand them right, it's all about quickness- the quicker you get the blades in, the sooner you can profitably pull. So Mahe's near-vertically moving blade entry with respect to the water at the apex of his hook looks like what I am aiming for.

By the way, Sully wins his bet- if you look at Mahe in other parts of that video, you see that the backsplash is quite variable. After all, even a 1" high ripple on the surface, with such a finely-grooved motion, will mean more water being caught right at the turnaround point of the hook.

yes?

John

[Carl]

I would suggest that we might be focussing too closely and these splashes?

If you drop an object into water with any vertical velocity, a splash
goes up in all directions. So it is with the edge & tip of an oarblade.
A splash-free entry will be a very slow entry in the vertical sense
(but not in the rotation-about-the-pin sense), but will still generate a
tip splash as the blade has velocity in that direction WRT the water.

So I'd suggest that splashing should bes roughly symmetrical, front &
back, but perhaps slightly more to the back. More importantly, since
that's just a symptom, that there should be the sense of an immediate
application of load - the blade seeming to be driven in, but since the
force can't be instantaneous & the vertical component of the entry will
be rapid, it will still engage well enough with the water. You won't be
able to load the blade faster than you can embed it, due to the
flexibility of the shaft.

[Carl]

On 04/03/2014 19:16, Charles Carroll wrote:
>> I've been lucky enough to spend the larger part
>> of my sculling racing career with a 2x partner
>> who, when I rigged him up with my double-accelerometer
>> set-up (one on seat, one on shell) in his 1x, showed
>> a seat-direction-reversal and start of the shell's
>> acceleration within hundredths of a second of each other:
>> which no other scullers I tested came anywhere
>> near even very good ones.
>
> Magnus,
>
> How does it do that? Whenever I try I just end up hammering the catch
> and shoveling water.
>
> Cordially,
>
> Charles
>

Your only problem, other than worrying too much about it, is that in
that film of yourself you were obviously far too slow in the vertical
direction, so you were missing your catch. Hence too much horizontal
&/or insufficient vertical velocity, hence the delay you felt in loading
& hence the "shovelling".

But now we know why - from the fact of your recent shoulder operation.
You were, AIUI, sculling to protect a bad shoulder & I don't know how
you managed it at all.

Now please remember to row for pleasure & relaxation. No examiner will
be marking you - for speed & technique. The only important test will
be: "was it a heap of fun?". If so, it might even become fast - the
icing on the cake. Don't let the worm eat the bud while you're
over-examining the plant, my friend.

You're a great sculler, you scull in tricky conditions some would find
too challenging & you've been through a sticky patch, but you handle
your boat well & will certainly scull better when you've been back in
your boat & covered a very relaxed few hundred miles, thinking of
nothing but the joy of slicing through water in a beautiful shell.

[John Greenly]

On Tuesday, March 4, 2014 6:21:39 PM UTC-5, Carl wrote:
>...when you've been back in your boat & covered a very relaxed few hundred miles, thinking of nothing but the joy of slicing through water in a beautiful shell.

Ohhhhhhh, yes....

I thank all for forbearance for my overwrought contributions to this discussion, it's my way of diverting my frustrated attention from the blasted
(-23C last night) waterways here that prevent that sublime image from realization for the forseeable future.

Polar vortex: Bah! humbug. Sometimes I wish we could repeal the laws of fluid dynamics.

Cheers,
John

[Carl]

I would never blame fluid dynamics, especially living here as I do on a
northerly off-shore island that is bathed & warmed by the Gulf Stream.

And if we cop a train of water-filled storms spun into our skies by the
jet-stream, we have no one to blame for the chaos resulting from our
unpreparedness but our scientifically illiterate politicians & our own
selves for electing them. They, knowing the price of everything but
clueless as to the lasting value of any of it, & financially insulated
from the pain felt by others, deliberately ignore the compelling
evidence all about them because they & their manipulative advisers have
persuaded themselves that whatever they wish to believe, & particularly,
like Lewis Carroll's Bellman, that what they have said three times, must
be true.

Without fluid dynamics where would rowers be? And where would be that
fluid mixing which, for now, buries excess atmospheric heat in the vast
thermal capacity of the oceans.

Grateful for small mercies -

[magnus....@gmail.com]

On Tuesday, March 4, 2014 7:16:21 PM UTC, Charles Carroll wrote:
> > I've been lucky enough to spend the larger part
>
> > of my sculling racing career with a 2x partner
>
> > who, when I rigged him up with my double-accelerometer
>
> > set-up (one on seat, one on shell) in his 1x, showed
>
> > a seat-direction-reversal and start of the shell's
>
> > acceleration within hundredths of a second of each other:
>
> > which no other scullers I tested came anywhere
>
> > near even very good ones.
>
>
>
> Magnus,
>
>
>
> How does it do that? Whenever I try I just end up hammering the catch and
>
> shoveling water.
>
>
>
> Cordially,
>
>
>
> Charles

I don't know. I very strongly suspect his extraordinary speed, especially over sprint distances and when he was in his full-training prime (we're both now over 50), is not unrelated to his catch-timing ability.
The fact he could only beat the national team hopefuls on the water and not on the erg, and never weighed more than 85kg ensured he never really got a look in to the Team Process.
But if you ask him how he achieves his catch, he just answers "dunno, it's just what I do". Also worth noting is that he's extremely relaxed when sculling, and seems not to notice waves that have most others, including me, tensing up and slowing down.

[sully]

Yes, this totally refutes my testimony that all good catches must be taught!

But I have seen it before as well.



.

[Kit Davies]

One idea that I think helps to develop quick catches is how well the
recovery/catch/drive blend into one smooth motion, and I believe stroke
rhythm plays a large part in that.

When Drew Ginn's "Will it make the boat go faster?" video did the rounds
last year, my pairs partner and I spent some time working on our
recovery technique and timing. He is a natural-born sculler too, and
"Will it make the boat go faster?" is a question he instinctively asks
all the time. Me, I like tinkering because you'll never know what works
for you until you try.

What we found was not that our tinkering made the boat go faster per se,
but that a controlled finish/fast recovery/catch is a much more natural
rhythm for the stroke. It feels more like a golf swing than "compressing
a coiled spring" (as the mantra goes), with the catch being the point of
impact (maybe a weak analogy since the water is moving relatively).
Nevertheless, a natural rhythm makes a quick catch and start of drive an
easy extension of the recovery, much more so than if you try to control
the approach to the catch. You don't "control" a golf down-swing, you
let it flow and work with it.

Kit

[s...@ku.edu]

On Saturday, March 1, 2014 10:06:33 PM UTC-6, John Greenly wrote:
> On Saturday, March 1, 2014 7:13:24 AM UTC-5, Carl wrote:
>
>
>
> > And that's the absolute essence of any job done well - the real expert
>
> > makes it seem easy, relaxed, maybe even artistic.
>
>
>
> Wonderful, yes. To me, most any human activity done at the very highest level of skill becomes indistinguishable from magic. So the world is full of wonder and magic if you pay attention.
>
>
>
> John

Relaxed, effective, powerful: http://www.youtube.com/watch?v=UTH_hRxU2j4

Steven M-M

[Charles Carroll]

> I must admit that I've never understood what
> you mean by waiting at the catch.

Hi John,

So how do I explain “waiting at the catch?”

Let’s begin with two ways of defining the catch. The first comes from Valery
Kleshnev and the second from Magnus Burbanks. Valery defines the catch “as
the furthest point of the handle towards the stern.” Simple enough!

Magnus uses more words. “At the end of the recovery, ‘into frontstops’, the
shell is decelerated/pushed by the feet until momentarily the rower and
shell are stationary relative to one another. At this point the catch starts
to happen, and some time later the shell “notices” the thrust exerted by the
oars and starts to speed up again. I have defined catch time as this time
from the moment of frontstops until the point that the shell deceleration
has been overcome by the start of the drive.”

It seems to me that both definitions help explain what is happening at the
catch. Furthermore it seems to me that when added together they make a
complete definition the catch. And lastly it seems to me that the video of
Mahe Drysdale in slow motion illustrates this perfectly.

I have uploaded to YouTube another slow motion video made with frame
interpolated technology of Mahe Drysdale. The video focuses exclusively on
the blade entry, from the time the tip of the blade starts to move down into
the water to the time the oar shaft starts to bend. This process normally
happens in milliseconds. The video looks at it over a period of about twelve
seconds. I don’t know if this would qualify as super-slow motion video, but
it is certainly interesting to look at.

I might add that I hesitate to say anything about a video until Mike and
Carl have had time to look at it. They always find things I miss. But fools
rush in where angels fear to tread.

http://www.youtube.com/watch?v=1quy1OJAq_8&list=UUqox_JHnRozM76faCCLP1xg&feature=c4-overview

To my eye the one surprise in the video is the speed with which Mahe is able
to load the blades. Mahe starts loading the blade the instant the blade is
completely buried. In very slow motion it takes Mahe about ten seconds from
the time the tip of the blade starts to move down into the water until the
time it is completely buried. And this is when a remarkable thing happens.
In roughly four frames his oar shaft starts to bend.

Watching this video makes a convincing case that in real time when you are
sculling well there is virtually no delay between the time that the blade is
completely immersed and the time that you can begin loading it. Isn’t this
something that Carl has been saying for years?

After watching this video how can I argue that a delay between blade entry
and load is unavoidable? Obviously it isn’t. For any good sculler the two
movements are sequential and instantaneous — sequential because the two
movements are separate and instantaneous because there is no delay between
them.

If Magnus could rig Drysdale’s shell with a double-accelerometer set-up, I
would love to see the graphs between seat-direction-reversal and start of
the shell's acceleration. I wonder if Mahe might come near the results of
Magnus’s 2x partner. One thing is for certain, Mahe Drysdale is just
blazingly fast at loading his oar handles.

On a more personal note, for me the question has become what is Mahe
Drysdale doing that I am not doing?

Look at Drysdale’s hands at the start of the catch. The separation between
them is huge. If memory isn’t deceiving me I seem to recall someone’s saying
that Mahe Drysdale spreads his oar handles over a meter apart at the catch.
I am not nearly as large as Drysdale and will never achieve that length of
spread between my oar handles. But aren’t there are plenty of large people
who can spread their oar handles far apart at the catch who do not scull
nearly as fast as Mahe Drysdale?

So what does Drysdale do that is so important?

Watch his hands as they lift the oar handles to immerse the blades. From
what I can see Mahe’s oar handles do not move even so much as a millimeter
apart during blade entry. So on completion of entry pressure has been
applied to all the surfaces of the blades and as a consequence the blades
are prepared to resist whatever load he puts on the oar handles. I believe
that you have explained this very well in a recent post.

By the way I don’t want to forget something Mike wrote. Mike points out that
when Mahe’s “blade is fully buried, his legs are still nearly fully
compressed near his body.” In other words, Mahe is still at the catch as
Magnus defines it. Furthermore Mahe is completely prepared to apply immense
pressure against the oar handles as quickly as possible.

Contrast this with my tendency to row the blades in — that is, my habit of
simultaneously pulling against the oar handles as I lift the blades. Carl
writes that this makes my blade entry very slow. In fact from videos of me
it looks as if I am two-fifths to one-third of the way through the drive
before my blades are completely buried. And at that point in the drive I am
far away from the catch as evidenced by my legs, which are anything but
“fully compressed near my body.

Is it any wonder that I observe a delay between blade entry and load?

After years of finding myself confused and frustrated about the catch, I
think I may finally have attained some insight into it, thanks to your help,
and Carl’s, and Sully’s, and Magnus’s, and James’s, et al.

I have always been fond of something Socrates said about discussion as a
means of learning. He compares the participants in a discussion to midwives
delivering infants. We’ll just have to go through the process, he says, to
find out whether we have delivered a healthy child or just a lot of gas.

Warmest regards,

Charles

[John Greenly]

Charles-

Excellent, thanks for the super-slow mo, and the discussion!

I'd like to hazard another observation, inviting the experts to weigh in. When I compare Mahe's catch to my own, I think the biggest difference is in what he does BEFORE the blades touch the water. Sully pointed out how important his body preparation during the recovery is to his catch, and I particularly am thinking of the way he starts the squared blades down toward the water while his legs are still compressing up to frontstops. That blade motion is the first half of the "hook", and it is what makes it possible for him to bury the blades so fast: they are already moving downward quickly by the time they touch the water, just as he reaches frontstops. For me that first half of the hook and its initiation before reaching the stops is the hardest thing to coordinate, and I would be very grateful for suggestions for drills for trainin to get this right. I tend, as I think many amateur scullers do, to not start to drop the blades until I reach frontstops-- Too late!

many thanks,
John

[sully]

I don't have good 'drills' for this, and I'll reiterate that I think learning
to catch correctly is very difficult, I've seen few in the sport that do it
as well as Mahe demonstrates on that one stroke snippet.

I'll also repeat that when we learn to improve something, quite often
as teachers we'll over exaggerate, simplify, do something whacky even, in
order to get the student to even do something different than they are used
to. For many things like teaching finishes, drive mechanics, releases, hand positioning, you can over emphasize and exaggerate and the boat or crew will
respond positively, IE give positive feedback to doing it.

Not so with the catch. With catching, we are almost all universally late. So
what do we do as coaches? We exaggerate by getting them to catch early.

The result of that NEVER gives positive feedback by the boat! You need a coach or a training partner with an eye to encourage that behavior while you're figuring out the timing.

I think I have an old RSR post about how to teach the catch.

The basic approach that I think is best is that you learn the sensation
at a very slow pace, cutting out all other factors. Get a double, a partner,
and just do static catches with boat stopped. go from half-slide to 7/8 slide
(not even full), only a travel of a few inches really, with eyes closed and
see if you can time the blade entry to when you stop your slide. This drill
should be done w/ no drive, that's why it's static catches. The boat's not moving so you don't have to worry about chattering blades on the catch.

Prepare, keep blades square, slide up, catch, stop. extract blades and repeat:

1. Prepare. (get all the body angle and arm extension that you will use at the catch/initial drive), be set up and prepared at 1/2 slide

2. keep blades square. keep feathering complications out for now. Make sure grip is loose, you're hooking handle - flat wrist.

3. slide up. the body position at "prepare" should be maintained exactly as you roll to stern except for the arc of the handle, whether sweep or scull.
Thus, essentially the only thing moving is the butt.

4. catch. lift the hands(more on this later) while hips are moving, when the blade enters, stop the hips. With eyes closed, you want to emphasize the sensation that the HIPS are putting the blades in the water, not the hands, focus on two things, where the hips/wheels stop, and the feel of the blade entry. They should be simultaneous. Eyes closed REALLY helps feel this, and
it is a nice tool to use later, close your eyes a few strokes during steady state to note catch vs /hip-wheel timing.

5. extract. No pulling at all, all motion should be to stern to learn that catch timing. take the blades out, re-position to 1., go again. You are in a vulnerable position, every 4-5 strokes, shake it out and twist and turn so that you aren't stressing your back while holding these positions.

On hand lift: On the catch, you aren't forcing/lifting the handle, what you are doing is controlling it's drop! Start at half slide and roll to the catch
w/ sq blade and just let go of your oars (don't be in a single). Note how quickly the blade drops. Yes it will spin and not catch, but the blade drop
will be very quick. This is why the emphasis on relaxation of the hands in
"preparation" above, you want to lift the hands to allow the blade to drop but light finger contact with the blade prevents it from spinning out of control.

So you are lifting the hands quickly, but not forcing the handle, light grip.

Next steps:

add drive to the short stroke. I go in a tweener stage. After the athlete
is catching well statically, then have them do "air strokes" in the exact
same range. Careful, as there's a tendency to lengthen and drive PAST half slide which messes with the preparation.

Eyes closed, go through 1,2,3, but not 5/6. at 4, they change direction and
push legs lightly to get back to 1/2 slide.

IMAGINE where the catch should be in that drill, drop it in with your minds
eye.

Then go to add the catch and add drive at 5, instead of extract.

For the first ten strokes of it, I like to stop the boat, prepare again, and do that front end stroke cycle, one stroke at a time. If you try to release
square before half slide, there tends to be a lengthening, you lose the preparation, the catches suffer.

I see a lot of crews do this front end work like this, but I don't see them
getting the catches in!

This doesn't answer your question on how to get the blade to 'seek the water' as Mahe does. When you go through those steps of learning in a static boat like that, you'll be able to row on the square very close to the water and will learn that it makes for quicker easier catches to be close.

My observation has been once an athlete learns the hip/blade entry connection and what that's supposed to feel like and how to do it, even if they don't get it right, the "skying" motion that so many of us do tends to go away.

The other aspect of "skying" starts at the finish. I assert that whatever the highest blade height you wish to have on the recovery (and that can vary by conditions), should happen at the release. If you never teach a rower to finish and release, they will simply row the oar out to half blade and
feather, holding the boat up with the blade momentarily where it's most vulnerable, then push down later in the recover to get the oar off the water.

In a sweep boat, this hand motion wreaks havoc with relaxation and balance,
as one person is pushing the handle down when someone on the other side isn't.

It's not quite so deadly in a sculling boat, as the rower pushing down
at mid stroke will do so symmetrically.

My observation with lots of new scullers is that once they push the hands
down in mid recovery to get their oars off the water, they'll tend to keep going down farther than needed to square the blade.

I teach dropped wrist recovery, fingers lightly on top, to square the blade you lightly squeeze and initiate the turn of the handle by straightening/lifting the wrist, then let go and allow the oar to settle itself into the flat lock.
position. Feathering in this fashion is consistent with lifting the hands to the catch, and it's during this feathering/lifting motion that you find the
ideal blade height for a quick and effective catch.

This motion can vary, elite rowers should be able to feather later in a head wind and still get effective catches, but the best catches I've seen, the blade is square before the drop.

[John Greenly]

Sully,

this is great!! many thanks for taking the time to write it, I'm sure others will benefit as well as me.

It has struggled up to +1C today here and the sun is shining brightly! The lake looks beautiful, there is a place on the shore with no ice, and if it wasn't windy I would have gotten out for my first row. Maybe pretty soon I can begin to try your suggestions out. I have my stable wooden wherry that I made, that I use when the water is dangerously cold, so I can work on these things without having to balance the boat.

Okay, just for fun, here's a video I made on my home lake- Cayuga- in my wherry in Jan. 2013 (with a snip from one of my first rows in my Maas flyweight). My handles clearly don't start to move up until I get to frontstops and reverse, and I was squaring very late in those beginning days in the Mass.

http://www.youtube.com/watch?v=hOiQyL_d8SI

You won't learn anything from this, except my way of staying safe, warm and dry on water at +1C, and also that I have a VERY long way to go to have a catch like Mahe's. I'm going to try though!!

thanks again,
John

[Carl]

By discussion we can, if rigorous & dispassionate, sift out the grain of
truth from bushel of fiction. I write this without having read the
other replies, so I might be repeating what they say, but here goes.

1. I can see no distinct point before which there's no flex & after
which a load is initiated. My sense is that the shaft starts to flex
from or even before the moment of first contact of edge of blade with
water. All I see is an increasing flexure. But I'm not surprised.
Even to reverse his scull's rotation about the pin requires some load on
the handles, those sticks are flexible, so they may already have some
pre-load.

2. From the moment that the hands are no longer moving astern the hands
can no longer be moving apart. To take a clean catch they must already
be moving together.

3. Mahe's catch actually hooks the water & at the speed of the water.
Your catch (before your operation) moved in the right direction in the
horizontal plane but lacked much movement in the 3rd (vertical) axis.
He expects an immediate sensation of a high load & doubtless piles the
force into maximising that loading & the rate of its application. You
don't (yet) know that feeling. His vertical movement for the blade
entry is far faster than his initial horizontal movement. Yours is far
slower.

4. I suspect you feel inhibited - that if you hit the water too soon
your blade might be overtaken by the water - so you try to caress the
blade entry. But in the catch position the blade doesn't need to move
nearly fast astern as it would if you took your catch square with the
boat, so the coordination is not so hard to do. Mahe slots swiftly into
a narrow imaginary aperture in the moving water & loads up rapidly (seen
in the progressive bending of the shaft).

5. I think Mahe gets his initial loading by rotation of the hands
towards each other - see the pleating appearing in his vest between his
left shoulder & collar bone.

6. I'd say that those actions which you describe as sequential are
actually entirely simultaneous - overlaid upon each other. Nothing can
be instantaneous in our movements, loadings, etc. The acceleration seen
in any movement is determined always by the relationships between the
forces we can apply, the speed at which we can ramp up those forces, the
masses upon which those forces are acting & any loads that oppose the
movement or acceleration of those masses.

7. Mahe couples his actions to the loading of the handles better than
almost any other rower. His movements through his stroke indicate that
everything is loading & being used right from the catch at close to its
maximum possible extent. His action is therefore very smooth.

8. There always is a check at the catch &, although it is theoretically
possible to eliminate it, in practice I doubt that a human being can
manage to do so. But we are not so interested in when the boat begins
to accelerate. That would be a little bit like worrying about whether a
runner's shoes are starting to accelerate. The rowing stroke involves
doing work first to increase the momentum & kinetic energy of the rower
WRT to a fixed reference frame, & not until the finish does the boat
attain the same speed as the rower. On the recovery, the rower is
moving over the water always slower than the boat &, if done well, the
rower's deceleration would perfectly match the energy dissipated by
friction on the boat from its moving at constant speed through the water.

9. In that case we do have the theoretical possibility of hooking the
blades into the water before we reach front-stops, & of loading them
before any load is applied to the stretcher (indeed before we cease to
pull on the stretcher!), the necessary force being applied by an
inertial interaction against the body mass. In reality this seems a
challenge too far, so there's a small hiatus as we take the catch & tha
causes the check.

[sully]

On Sunday, March 9, 2014 1:25:48 PM UTC-7, John Greenly wrote:
> Sully,
>
>
>
> this is great!! many thanks for taking the time to write it, I'm sure others will benefit as well as me.
>
>
>
> It has struggled up to +1C today here and the sun is shining brightly! The lake looks beautiful, there is a place on the shore with no ice, and if it wasn't windy I would have gotten out for my first row. Maybe pretty soon I can begin to try your suggestions out. I have my stable wooden wherry that I made, that I use when the water is dangerously cold, so I can work on these things without having to balance the boat.
>
>
>
> Okay, just for fun, here's a video I made on my home lake- Cayuga- in my wherry in Jan. 2013 (with a snip from one of my first rows in my Maas flyweight). My handles clearly don't start to move up until I get to frontstops and reverse, and I was squaring very late in those beginning days in the Mass.
>
>
>
> http://www.youtube.com/watch?v=hOiQyL_d8SI
>
>

What is that wherry? It looks like it might have sealed floatation? Does it?

I love the old pocock wherries I have for rough water, and touring. They
do flounder, though, and I floundered one on the Sacramento River half dozen
years ago, hitting a submerged tree with a very heavy water flow.

I was well prepared for the cold water and for a possible sinking, I knew
this could happen going in, but it would be nice that once I righted one
of my wherries, I could row it away.

The Maas boats are nice boats, but the wherry hull design and high freeboard is much better in rough water.

[sully]

> > the two movements are sequential and instantaneous -- sequential because

> > Contrast this with my tendency to row the blades in -- that is, my habit

Carl, can you clarify this some more? Not sure what you mean. I didn't
correct Charles' comment:

> > Watching this video makes a convincing case that in real time when you
>
> > are sculling well there is virtually no delay between the time that the
>
> > blade is completely immersed and the time that you can begin loading it.
>
> > Isn't this something that Carl has been saying for years?

My observation in my post was that when I deemed the blade to be fully buried, the oar was already loaded and shaft bent. There is a discrete, but very short period of time from where the blade strikes the water until it fully burys. The boat is moving during that time, AND Mahe is initiating his drive during that time. So it hadn't begun to load when the blade is buried, it had already begun!

and it's a BIG'UN. :^)

Charles did correctly note my comment that Mahe's legs were NEARLY compressed fully with blade buried. YES! But, note it's NEARLY compressed, not completely compressed. He's at full compression right the instant his blade
strikes the water.

There's a lot more to this, but I've got to go!

[John Greenly]

On Sunday, March 9, 2014 8:14:38 PM UTC-4, sully wrote:

> What is that wherry? It looks like it might have sealed floatation? Does it?
> I love the old pocock wherries I have for rough water, and touring. They
> do flounder, though, and I floundered one on the Sacramento River half dozen
> years ago, hitting a submerged tree with a very heavy water flow.
> I was well prepared for the cold water and for a possible sinking, I knew
> this could happen going in, but it would be nice that once I righted one
> of my wherries, I could row it away.
> The Maas boats are nice boats, but the wherry hull design and high freeboard is much better in rough water.

This wherry is one I designed and built myself. It's 18.5' long, made of 4 mm plywood, sheathed in glass and epoxy, and weighs 53lb rigged. I did put sealed flotation chambers in both ends and I can row it swamped, though that has never come close to happening in the wild. I wanted a boat to row safely on the lake when it is rough, and for ocean races like the Blackburn, (I did row it there in 2010) as well as for when it's cold, and I spent a lot of time thinking about it. The cross-section is inspired by a small boat found in one of the Viking ship burials, the so-called Gokstad faering. Mine's much narrower, though. It's a double-ender, V- bottom, three planks each side, 21" beam at the waterline and 32" at the gunnels. The V bottom makes it rather tender at first, but then with that large amount of flare above the waterline, it stiffens up progressively as it rolls. It's a fine sea boat, lively and pretty dry, about the only time I take in water is going downwind when it starts to surf and I run into the sea ahead and bury the bow. It's a lot of fun to row, and pretty fast. Those Vikings really knew how to make good boats!

Cheers,
John

[Carl]

On 10/03/2014 00:27, sully wrote:
>> 1. I can see no distinct point before which there's no flex & after
>> >
>> >which a load is initiated. My sense is that the shaft starts to flex
>> >
>> >from or even before the moment of first contact of edge of blade with
>> >
>> >water. All I see is an increasing flexure. But I'm not surprised.
>> >
>> >Even to reverse his scull's rotation about the pin requires some load on
>> >
>> >the handles, those sticks are flexible, so they may already have some
>> >
>> >pre-load.
> Carl, can you clarify this some more? Not sure what you mean. I didn't
> correct Charles' comment:
>

And I did say that I'd written without having seen what you said in
response to Charles.

What I was saying was that, if you have a stick, rod, oar shaft rotating
in 1 direction about an axis within & perpendicular to its length & then
apply a force at the handle end to change that direction of rotation,
that shaft has mass & rotational inertia so that force, & the resulting
accelerations, must bend it along its entire length. So some (fairly
slight) bend must have been induced even before the blade touches or
engages with the water.

You'd detect that with an appropriate strain-gauge setup (& I'm sure
it's been done). If the blade is still squaring as the load goes onto
the handle, that'll induce shaft flexure in varying directions as you
square, adding a rotational, whirling component about the shaft's long
axis - but that's a very 2nd-order effect so we needn't go there ;)

What this shows is how wary we should be of over-interpreting data from
one source when the signals are small & have to be visually assessed -
as here.

But what that slo-mo sequence does still show is how swift is Mahe's
application of load at the catch. I have always felt that delayed
catches come from thinking about nonsensical concepts such as 'poise',
'coiling up', 'getting into a strong position' or 'gathering' for the
catch. Each of those images serves to separate the catch from
everything preceding it - like separating the impact of the hammer head
from the down-swing, or when doing a continuous set of jumps between
full squat & up in the air it'd be like stopping to gather oneself when
in that full squat position.

A lot of that comes from the notion that at the catch you're like a
coiled spring which you can hold & wait to release. And some of that
comes from the fiction that you have just used _pressure_ against the
stretcher to 'slow yourself down for the catch' when reality is quite
opposite & you'll have been pulling against hull friction all the way to
front-stops. It takes very little energy to get into a static catch
position, so there can be minimal usable energy stored in that posture &
to hold it must carry its own energetic penalty.

But you should never have a 'catch position' since that implies stasis
in the midst of a continuous process, & Mahe shows us this (through
Charles's good work).

I much prefer to explain the catch by quite other means. It is a swift
application of hand & arm load during a reversal of hand movement (& the
addition of a large vertical velocity component) to which you were
already committed before you were half-way up the slide. It should not
be something you think about when you do it - you should have
pre-thought it & mentally completed it before the moment arrives. And
when taking the catch your thoughts should be focussed exclusively on
increasing the load on, & speed in, the hands through the middle of the
stroke. When in the mid-stroke you should be thinking not of that but
of how hard you will be pulling that finish.

Only at the finish do you have time for contemplation, that stroke
having been well done, before setting off into your next stroke by
thinking about the process of passing the hands over the knees. Etc.

[John Greenly]

On Sunday, March 9, 2014 2:26:03 PM UTC-4, sully wrote:

> 4. catch. lift the hands(more on this later) while hips are moving, when the blade enters, stop the hips. With eyes closed, you want to emphasize the sensation that the HIPS are putting the blades in the water, not the hands, focus on two things, where the hips/wheels stop, and the feel of the blade entry. They should be simultaneous. Eyes closed REALLY helps feel this, and it is a nice tool to use later, close your eyes a few strokes during steady state to note catch vs /hip-wheel timing.

This sounds like the key to me. I have been feeling the rhythm of the catch as blade drop with respect to leg drive, trying to feel the blades go a little before legs. That couples the catch to the drive instead of the recovery, and it doesn't make for a good flow through the whole motion. Feeling instead the blade drop while hips and slide are still moving, and then feeling the entry simultaneous with when they reverse is perfect. Now I have to unlearn my old habit and make a new one.

Thanks Sully,

John

[Steve S]

I've stared at the video of the 2012 race for hours trying to figure out what distinguishes Drysdale from the rest, and I don't think it is at the very front end. All six load up super fast. I suspect that is a prerequisite for getting into an Olympic A final.

To my eye the biggest difference is the length of his stroke and the depth, and the two are probably related. All six bury their blades beyond the depth taught conventionally, but Mahe's blades are way down there at their deepest.

Carl has been teaching us about this depth matter for years.

- Steve Schaffran

[Carl]

Steve - Mahe cheats by engaging his blades with the bed of the course
;)

[sully]

Indeed, I use it now. I used to teach the 'just a bladeful', and still do for brand new beginners. I think when teaching deeper drive, the rower should have already learned how to finish well.

Be careful, though, on drawing conclusions looking at scullers side by side in a race. One might simply be stronger, have a better energy system, etc.

As an extreme example take the women's olympic champion single and race her against a big strong erg monster who's an average sculler.

he'll probably go 7:25 beating her by open water.

She might be catching really well, he poorly, but because he's beating her
we conclude it's advantageous to miss water and row it in?

I'm not suggesting this the case with Mahe, but it can be a misleading
use of film.

[Charles Carroll]

> I'd say that those actions which you describe
> as sequential are actually entirely simultaneous
> - overlaid upon each other. Nothing can be

> instantaneous in our movements …

Hi Carl,

Sorry to be so slow in replying to your very thoughtful and well-argued
post. We have been having one of our minor crises at school and I had to
return to work full time and more.

I reread your post a number of times and find myself just astounded by how
much I agree with what you say in it. It is almost scary how well you
elucidate what I need to do to improve my technique.

But all praise aside, I do have one or two questions. But a brief story
first:

Two men are in a room by themselves sitting at a table. They are engrossed
in conversation. One is a mathematician, the other an engineer.

The door behind them opens and a young lady, rather pleasant to look at,
walks through it and shuts it behind her. She then very carefully places an
office chair against a wall, not too far from where the men are sitting, and
settles down to observe.

When she finally speaks some time has passed and the two men have become
once again engrossed in their conversation.

“Gentlemen,” she says, “I find myself absolutely spellbound by the things
you are discussing. Obviously you are extraordinarily brilliant and your
intensity is a complete turn-on. So I am offering myself to you. The first
one of you to reach me may have me, provided that you agree to comply with
one simple stipulation. All I am asking is that as you step towards me you
divide your next step by half the length of your previous step.”

“But I’ll never reach you,” exclaims the mathematician in despair.

“But close enough!” exclaims the engineer with great glee.

I know! It is a hoary old joke. But it seems to me that it makes an
important point. The engineer knows how it is possible to flummox yourself
over matters of little consequence.

I took the video of Mahe Drysdale’s catch in slow motion and made the motion
even slower. The result is a 36 second video of a process that in real time
occurs in milliseconds. Next I split this video at the frame in which Mahe
has completely buried the blade. Lastly, I added a few brief comments. The
title of the video is “A Study of the Catch — from Blade Entry to Load.”

https://www.youtube.com/watch?v=I_-Vtlk91Nc&list=UUqox_JHnRozM76faCCLP1xg

To my eye the video makes the points I am trying to get across, so I’ll let
the video speak for itself, except to say that I can find nothing
complicated or mysterious about Mahe’s catch. It is simple, straightforward,
and elegant. Furthermore, try as I might, I can find no evidence in the
video of Mahe’s multitasking the catch. I just cannot I see him lifting the
oar handles while simultaneously pulling them in a horizontal plane.

But what the video clearly shows is Mahe’s catch divided into two simple
components — entry and load. The components are in sequence, each component
requires a different movement, and Mahe appears to give his undivided
attention to completing each movement without being distracted by trying to
blend other movements into it.

The first task is to place the blades deep enough that they have the
capacity to resist the pressure Mahe will to apply to the oar handles. As
you say, you can't hit something hard which offers no resistance. Am I
wrong, then, to think that the capacity to resist must precede, not follow,
application of pressure? Isn’t this a corollary to your proposition that you
can’t hit something hard that offers no resistance?

The second task is to apply pressure as quickly as you can after the blades
are completely immersed. And doesn’t this task point directly to the lesson
the engineer gives the mathematician?

In slow motion units of time we can see clearly a delay between blade
immersion and application of power. As you write, “Nothing can be
instantaneous in our movements.”

Now consider the standard dictionary definition of instantaneous: “… done,
occurring, or acting without any perceptible duration of time.”

I submit that in real time there is no perceptible delay between Mahe’s
having completely immersed the blades and the start of application of
pressure.

So my last question is why can’t we think of Mahe as the engineer who
exclaims with great glee, “But close enough?”

Warmest regards,

Charles

Ps. I see my doctor next Thursday. I am hoping that he will give me the OK
to go to Sausalito the following day. I can hardly wait to get out on the
water.

[mruscoe]

I think you've now got the video too slow to see changes - I think you
can see it better in your previous video. Obviously the blade is moving
around the pin as it is being buried, and there's a bit of lift in his
body and change of shin angle. It's not the best camera angle to see the
body movements.

Have a look at about 9:15 onwards on Xeno's video here too.

http://www.youtube.com/watch?v=QweFknZg4IA#t=551

[John Greenly]

Hi Charles,

I have to defend Carl's and Sully's earlier comments. I agree with mruscoe about this new video, and also I would point out that somehow this superslow video has compressed the image frame horizontally quite a lot, which makes the horizontal motion and the shaft bend even harder to see. Your original snip from the race video (many thanks for doing that!) gives a much easier view:

https://www.youtube.com/watch?v=H44iiI40vq8&list=UUqox_JHnRozM76faCCLP1xg

you clearly see the handle moving in a continuous curved "hook" , and the blade is clearly flexed and the seat is moving away from stops before the blade is buried all the way: the loading and the immersion are happening together as a continuous and simultaneous action, as Sully and Carl pointed out.

--John

[Charles Carroll]

John,

Let me start with the business of this continuous curved hook.

Whether you move the handles up or down, or towards or away from one
another, won’t the motion always be curvilinear? Am I wrong to think the end
of a straight line, which is attached at the other end to a fixed point, can
only describe curvilinear motion?

As for moving the handles continuously, I have no difficulty with that. It
is easy to understand.

The hooking motion, on the other hand, is something I have never understood.
If you keep the handles the same width apart as you move them vertically
along the X-axis, don’t they by necessity have to move in curvilinear motion
away from the stern? Isn’t this just simple Euclidian Geometry? And if so,
then isn’t this the same thing as a hooking motion? For this reason it seems
to me that putting the two words together in the phrase “curved hook” is a
tautological overlay.

Now let’s return to the videos. In the first video, what you call the
original snip from the race, I agree with you. It really does appear in this
video that Mahe is rowing the blade in. But how seriously should we take the
video? Don’t forget that it was made from interpolated technology. There is
a lot of muddiness and ghosting of images in the video. Take, for example,
the wobbliness of the oar shaft. In real time do oar shafts really look so
wobbly? I have the advantage of being able to look at the video frame by
frame. In no frame can I see the ghosting and wobbliness that I see when the
frames are collected together and viewed as a video.

And yes, Mahe’s catch is so fast that in real time it looks as if he is
rowing the blade in. But in slow motion he gets his blades completely buried
before he applies any meaningful pressure to the oar handles. Or so it looks
to me.

Let me repeat again that the definition of instantaneous is no perceptible
delay. So it should look as if he is applying pressure while he is immersing
the blade. But when I look at the video frame by frame I just don’t see any
movement of the seat or pulling in of the hands until the blade is
completely buried.

And this brings up my last question, something that I suspect you are
uniquely qualified to answer. How do you calculate the capacity of the blade
to resist pressure during entry? If you immersed just the tip of the blade,
say a mere millimeter of the blade, am I right to think that it would have
very little capacity to resist a load put on the oar handles? So how deep do
you have to immerse a blade in order for it to have the capacity to resist
the extraordinary load someone like Mahe Drysdale can put on the oar
handles?

What would be the point of trying to load the oar handles before they had
the capacity to resist the load?

As I asked Carl, am I wrong to think that the capacity to resist must
precede, not follow, application of pressure? If you want to put a lot of
pressure very quickly, shouldn’t you focus on having the capacity to resist
this pressure already in place?

Cordially,

Charles

[Charles Carroll]

> you've now got the video too slow to see changes

> I think you can see it better in your previous video.
> Obviously the blade is moving around the pin as
> it is being buried, and there's a bit of lift in his body and change of
> shin angle. It's not the best
> camera angle to see the body movements.

Hi Mark,

Yes, I agree that it is not the best camera angle. This is why I limited
focus to two questions: 1) can any movement of the seat be seen and 2) do
the hands start to come together? I observe neither until after the blades
are completely buried. But am I looking at the right things? I concede that
I don’t completely trust my eyes. I am not the best observer.

I love Xeno’s video. In the video Xeno does comment that Mahe “rows it in a
little bit.” Isn’t this what Carl and John and others are advocating? Maybe
they’re right. That is after all what we are discussing.

Xeno also makes another comment that I find fascinating. He notes that Mahe
"opens up his back with very little travel of the seat" and says that this
"did not help with any boat speed." But Xeno goes on to say that what is
really good is Mahe's push with the legs. “That is what makes him an Olympic
Gold Medalist … once the legs start pushing they are going down … every time
I click on a frame his legs keep going … there are people who I can go frame
by frame … all of the sudden I click an image but the knee is not going
anywhere … [but with Mahe] you can really see the continuity of the leg
drive.”

The continuity of the leg drive is unquestionably important. But for the
purposes of this discussion it seems to me that Xeno makes an even more
relevant comment when he suggests that sometimes it is only possible to see
things when you go through a video frame by frame.

Warmest regards,

Charles

[John Greenly]

On Sunday, March 23, 2014 7:10:32 PM UTC-4, Charles Carroll wrote:
> John

> Let me start with the business of this continuous curved hook.
> Whether you move the handles up or down, or towards or away from one
> another, won't the motion always be curvilinear? Am I wrong to think the end
> of a straight line, which is attached at the other end to a fixed point, can
> only describe curvilinear motion?

> As for moving the handles continuously, I have no difficulty with that. It
> is easy to understand.
> The hooking motion, on the other hand, is something I have never understood.
> If you keep the handles the same width apart as you move them vertically
> along the X-axis, don't they by necessity have to move in curvilinear motion
> away from the stern? Isn't this just simple Euclidian Geometry? And if so,
> then isn't this the same thing as a hooking motion? For this reason it seems
> to me that putting the two words together in the phrase "curved hook" is a
> tautological overlay.

Hi Charles, I hope others will correct me, but here's how I think of (and, more importantly, feel) the hook. Of course the oar is pivoted at the lock so the handle is constrained to move in a curved path. The path of the handle is mostly a circular arc in the horizontal plane, with small excursions (also, of course, circular and centered on the lock) in the vertical direction. In fact, the motion is actually constrained to be on the surface of a sphere with center at the oarlock.

All that has nothing to do with the hook. Speaking mathematically, we can map that spherical surface onto a two-dimensional plane, just the way a map maker makes a projection of the spherical earth onto a flat map. In our case, we want our map with one dimension the direction of horizontal motion of the handle, and the other dimension the vertical direction. That's the plane that the hook lives in. The point of view of the camera in this video of Mahe does a nice job of showing that projection. The hook in this view starts with the handle traveling from left to right in the horizontal direction (sternward), then it begins to rise smoothly in a curve until it is going straight up in the vertical direction just at the time the blade first touches the water, and it then continues upward and begins to move from right to left (bowward) to complete the smooth curve of the hook. Just watch Mahe's left hand in the video. That's it. So, thinking back on the sphere now, as soon as the hooking motion begins to move to the left in the picture, his hands are coming inwards toward each other. That begins just as the blades touch the water at the apex of the hook.

> Now let's return to the videos. In the first video, what you call the
> original snip from the race, I agree with you. It really does appear in this
> video that Mahe is rowing the blade in. But how seriously should we take the
> video? Don't forget that it was made from interpolated technology. There is
> a lot of muddiness and ghosting of images in the video. Take, for example,
> the wobbliness of the oar shaft. In real time do oar shafts really look so
> wobbly? I have the advantage of being able to look at the video frame by
> frame. In no frame can I see the ghosting and wobbliness that I see when the
> frames are collected together and viewed as a video.

Sorry, I don't understand this. The video I'm talking about is the original one from the olympics that had the one stroke shown in slow motion. You excerpted that clip (thank you!) so we could look at it easily:

https://www.youtube.com/watch?v=H44iiI40vq8&list=UUqox_JHnRozM76faCCLP1xg

it is very clear, there's nothing confusing, it's very easy to watch, and you can stop it at any frame you want, to take a close look. It is slow motion that they put in to go along with the commentary after the race finished. I agree that the even slower ones you made later have problems, especially the horizontal compression that distorts the motion by reducing the horizontal component compared with the vertical.

> And yes, Mahe's catch is so fast that in real time it looks as if he is
> rowing the blade in. But in slow motion he gets his blades completely buried
> before he applies any meaningful pressure to the oar handles. Or so it looks
> to me.

I'm afraid I do agree with Sully and Carl on that: by the time the blade is fully buried the shaft is already quite noticeably flexed.

> Let me repeat again that the definition of instantaneous is no perceptible
> delay. So it should look as if he is applying pressure while he is immersing
> the blade. But when I look at the video frame by frame I just don't see any
> movement of the seat or pulling in of the hands until the blade is
> completely buried.

just not true- it may be the distortion of your slowed videos, reducing the horizontal component, that is fooling you. Both seat and hands are moving bowward as the blade is going in. Go back to the original video and look, it is quite clear.

> And this brings up my last question, something that I suspect you are
> uniquely qualified to answer. How do you calculate the capacity of the blade
> to resist pressure during entry? If you immersed just the tip of the blade,
> say a mere millimeter of the blade, am I right to think that it would have
> very little capacity to resist a load put on the oar handles? So how deep do
> you have to immerse a blade in order for it to have the capacity to resist
> the extraordinary load someone like Mahe Drysdale can put on the oar
> handles?

I'm not qualified to answer that- it's much too complicated with the free surface between water and air! All I can say is that there is a continuous increase in resistance between none when the blade is in the air, to lots when it is fully immersed.

> What would be the point of trying to load the oar handles before they had
> the capacity to resist the load?
> As I asked Carl, am I wrong to think that the capacity to resist must
> precede, not follow, application of pressure? If you want to put a lot of
> pressure very quickly, shouldn't you focus on having the capacity to resist
> this pressure already in place?

Mahe is not shoveling a lot of water sternward; that means he has got his hook and the timing of his increasing pull just about perfect to bring on the pressure to get the blade loaded by the time it is buried, without wasting a lot of energy splashing water on the way down. Carl and Sully described the continuity of this very nicely, he is not waiting for the blade to be fully immersed, the immersion and the application of load are simultaneous and continuous: the deeper the blade, the more the force he applies. As Sully said, it is quite wonderful to see so refined a motion when such large forces are available!

Cheers,
John

[Carl]

Hi Charles -

When we hang on the words of champion scullers, we should remember that
these are, or were, superlative athletes. It is in the nature of the
supremely successful to attribute part of their success to favoured
niceties of technique, even to the extent of mild obsession.

In a champion, what determines their success includes, in a loose & less
than mathematically rigorous fashion, the ratio of what they get right
to that tiny proportion which they don't quite get right, multiplied by
their athletic potential, their individual determination not to come 2nd
to anyone &, maybe, a black cat not crossing their path that day.

I would respectfully venture that we see, in those 2 quoted comments,
Xeno's own technique preferences surfacing. That's fine, but I would
seriously doubt that Mahe's opening of the back is detrimental, or that
the perceived continuity of his leg drive is a clincher, for his
success. I think there's a far more to it, and Mahe is not Xeno, nor
vice-versa - they are very different people.

I recall so many great scullers who would probably like to attribute
part of their success to aspects of their own very different techniques.
But, really, how can we possible compare the techniques of Joe Burke,
Alberto Demiddi, Vyachyslev Ivanov, Sam MacKenzie, Peter-Michael Kolbe,
Xeno, Mahe, Uncle Tom Cobley & all? Each (excluding the latter
fictional character) was a superlative athlete. And that's only the
heavy men. Each had superlative fitness, strength, motivation - enough
to over-ride whatever they "did wrong". And each had developed their
own physique around their technique. I'd hazard a guess that few, if
any, of them knew much about fluid dynamics or ergonomics, but just did
what they thought was right at the time, helped in that belief by being
able to beat all of their opponents.

What I would suggest is that few if any would have got the basics of
blade-work wrong. And I'd also caution against over-interpretation of
video frames - they may tell us what it _seems_ to look like, but give
too few clues as to how it actually felt in the body & mind of the sculler.

Now let's have your arm & shoulder update, when you've a moment.

[Rainer]

I've been impressed by the excellent contributions by various individuals on many topics on this newsgroup over the years. This is only my second contribution, so your patience is requested.

Two thirds of the contributions to this thread refer to Mahe Drysdale's technique, specifically the catch. Before Charles published the clip of the one stroke in slow motion, I made a series of 108 screen shots for the same stroke cycle, similar to those on the Inverness Rowing Club website at http://invernessrowingclub.org.uk/strokecycles.php of other high profile scullers.

My first impression viewing the screenshots and the clip of the one stroke in slow motion is that this is one of Mahe's less stellar strokes, namely "down on starboard" - I'm putting my neck on the chopping block. Compare the amount of backsplash in the stroke that has been analyzed to those found in the original video from 2:00 to 2:15.

Here are some observations, perhaps incorrectly interpreted:

1) The great amount of back-splash is not typical of other strokes from the video. I suggest he may have been somewhat off balance, and the left blade contacted the water sooner than desired.

2) There is about two times as much vertical handle movement on the left compared to the right during the time from when the left blade bottom edge touches water to top edge fully buried.

3) There is about one and a half times as much vertical handle movement on the left compared to the right from the time when the left blade touches water to the deepest burial before mid-stroke and is coupled with a noticeably higher left shoulder - suggesting a deeper blade on the left during the drive - this greater depth would impart a righting action up from starboard and would help correct any imbalance over the course of a few strokes.

4) The right hand leads the left away from the body on the recovery, another attempt to help correct "down on starboard" by bringing weight of the arm earlier out to the port side of centerline.

I'm open to correction, instruction, and further insights by others. Looking forward to your responses.

-Rainer

[John Greenly]

On Thursday, March 27, 2014 1:53:03 PM UTC-4, Rainer wrote:
> I've been impressed by the excellent contributions by various individuals on many topics on this newsgroup over the years. This is only my second contribution, so your patience is requested. Two thirds of the contributions to this thread refer to Mahe Drysdale's technique, specifically the catch. Before Charles published the clip of the one stroke in slow motion, I made a series of 108 screen shots for the same stroke cycle, similar to those on the Inverness Rowing Club website at http://invernessrowingclub.org.uk/strokecycles.php of other high profile scullers. My first impression viewing the screenshots and the clip of the one stroke in slow motion is that this is one of Mahe's less stellar strokes, namely "down on starboard" - I'm putting my neck on the chopping block. Compare the amount of backsplash in the stroke that has been analyzed to those found in the original video from 2:00 to 2:15. Here are some observations, perhaps incorrectly interpreted: 1) The great amount of back-splash is not typical of other strokes from the video. I suggest he may have been somewhat off balance, and the left blade contacted the water sooner than desired. 2) There is about two times as much vertical handle movement on the left compared to the right during the time from when the left blade bottom edge touches water to top edge fully buried. 3) There is about one and a half times as much vertical handle movement on the left compared to the right from the time when the left blade touches water to the deepest burial before mid-stroke and is coupled with a noticeably higher left shoulder - suggesting a deeper blade on the left during the drive - this greater depth would impart a righting action up from starboard and would help correct any imbalance over the course of a few strokes. 4) The right hand leads the left away from the body on the recovery, another attempt to help correct "down on starboard" by bringing weight of the arm earlier out to the port side of centerline. I'm open to correction, instruction, and further insights by others. Looking forward to your responses. -Rainer

Rainer,
the clips on the Inverness website have been very valuable instruction to me ever since I discovered them a while ago, thanks so much for making them, are you going to put up the ones of Mahe?

I agree with all your observations, except I think Mahe was always leading away with his right hand, you can see it in other views during the race, for instance around 7:40 in the original race video

https://www.youtube.com/watch?v=DcX7qA3DxdQ

And, also you can see the kinds of variations between the two hands that you nicely describe, sometimes the right hand moves more vertically, sometimes the left, and that certainly is compensating for the set of the shell. Look for instance at 8:09-8:18 in the race video.

Nevertheless, the observations people have made about this one stroke have helped me very much to clarify my image of what a fine catch should look and feel like, and I hope it might have served that purpose for others too- I hope so, otherwise I apologize for having pointed this discussion at it in the first place!!

thanks,
John

[Rainer]

Hi John,

To clarify, I did not make or post the clips on the Inverness Rowing Club site. I only made a series for my own edification, emulating the others. Charles' video clips are very informative, only one can't readily derive time or percentages for the various parts of the stroke cycle (of special interest to me is blade furthest to bow until complete immersion). Yes, I did notice that the right hand tended to lead the left on the recovery, but it seems more so in the slow motion cycle.

I too have benefited from the observations of others in this discussion, thank you for bringing it up. As a result I have examined my own catches while on the water and reviewed some footage of me. I think the key to eliminating pronounced skying at the catch by some of the scullers I coach is to have them carry the blade as high as practical soon after the release/feather. That way there is no way but down at the catch, minimizes "rowing the blades in" and eliminates extraneous skying which I think acts as a limiter to higher rating.

Thank you for your response.
Rainer

[John Greenly]

On Thursday, March 27, 2014 6:43:54 PM UTC-4, Rainer wrote:
> I think the key to eliminating pronounced skying at the catch by some of the scullers I coach is to have them carry the blade as high as practical soon after the release/feather. That way there is no way but down at the catch, minimizes "rowing the blades in" and eliminates extraneous skying which I think acts as a limiter to higher rating.

This seems to me like a very good idea: no way but down, yes. Getting the blades moving down toward the water before coming to front stops I think will remove a rating limiter for me, just as you say. This is something I'm looking forward to working on, that is if it ever warms up here and I can get on the water this year!

--John