Adding weight to sculls for rough water

[Paul]

We often race and train on some pretty extreme harbour water.
Has anyone tried adding weights to the ends of your sculls? I was
thinking some kind of lead, maybe solder, where the blade meets the
shaft to help balance the boat? I was thinking about 100g would be a
good starting point. Opinions?

[Phil]

Having extra weight outboard would probably exacerbate the problem -
but by all means experiment.
Best to practice keeping your blades covered for as long as possible
IMHO.

Phil.
(currently 1x in Bristol Harbour, have raced & won in Penarth &
Mumbles....)

[James HS]

I agree - no weights. From my experience the thing that adds stability is learning to balance the boat with the feet and bum - and way less with the sculls which should ideally follow through on a levelled platform .... I possibly am not describing this well.

The other thing I have experimented with (a lot on the tideway which also cuts up pretty rough) is
a) generally keeping a higher stroke rate through rough water (it seems to give me stability through a sort of giro effect)
b) keeping the blades in longer and making sure I come out square ...... to avoid a differential in the amount of water coming out with each blade ... though I generally agree with feathering out in good conditions
c) keeping it bright (goes with higher rate) - i.e. more tap down with the elbows and emphasising the height of the blades during recovery

I don't think extra weights on the scull handles would dampen the movement and might encourage a lower recovery stance.

Just my murmuring though.

James

[Carl]

How did you get on with rules 1-1-4, 4-1-2, 5-2-5c, 3-2-1a and 4-1-2? ;)
Sorry, it's that Mornington Crescent moment.

But you're right: the higher the proportion of time that the blades stay
immersed, the more stable the boat will be. When immersed your blades
(& the parts of the shafts that are covered) provide righting moment &
stability. When the blades are out of the water you're astride a
tightrope, with the buffeting forces of wind & waves far stronger than
anything you can do with feet & bum.

That's why a higher rate helps - by giving longer with blades in the
water & less time on recovery.

Now to the concept of balance by foot & hand pressure:
What we do by pushing on one foot or hand is 2-fold - a dynamic impulse
followed by a static imbalance. The sudden application of pressure
immediately reacts the rather inert body mass with its high rotational
moment of inertia (MI) against the boat's low mass & low axial-rotation
MI - on a milliseconds time-scale. This has to be followed by a
resulting relative net displacements of body & boat - pressure on the
left foot must result in bodily displacement WRT the boat &
countervailing off-centre loads on, say, the seat.

This is a tricky area for discussion here, being too hand-wavy & hard to
nail down without more time & maths than I have immediately to hand, but
others are welcome to join in the fray.

What resolves whatever starts going right or wrong while the blades are
in the air is, fortunately, resolved for us when the blades re-enter the
water - as long as we keep both hands at equal levels (but not
necessarily at constant levels. That said, I'll dare to suggest (pace,
James!) that concepts like tap-down & square finishes are not
particularly relevant or helpful?

Cheers -
Carl

--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing Low-drag Riggers/Advanced Accessories
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[davie...@gmail.com]

On Thursday, May 23, 2013 10:00:42 AM UTC+1, James HS wrote:
>
> I agree - no weights. From my experience the thing that adds stability is learning to balance the boat with the feet and bum - and way less with the sculls which should ideally follow through on a levelled platform .... I possibly am not describing this well.
>
>
>
> The other thing I have experimented with (a lot on the tideway which also cuts up pretty rough) is
>
> a) generally keeping a higher stroke rate through rough water (it seems to give me stability through a sort of giro effect)
>
> b) keeping the blades in longer and making sure I come out square ...... to avoid a differential in the amount of water coming out with each blade ... though I generally agree with feathering out in good conditions
>
> c) keeping it bright (goes with higher rate) - i.e. more tap down with the elbows and emphasising the height of the blades during recovery
>
>
>
> I don't think extra weights on the scull handles would dampen the movement and might encourage a lower recovery stance.
>
>
>
> Just my murmuring though.
>
>
>
> James

OP was talking about putting them out near the spoons though. Is this not equivalent to sculling with heavier shafts, because that is definitely helpful for balance (well, it is for me anyway). AIUI, this is akin to the pole used by the tightrope walker to lower his CoG and create inertia against tipping. I am still wondering whether Carl's comment re. being "on a tightrope" when the sculls are out of the water wasn't a sly reference to this?

Kit

[Phil]

On May 23, 11:32 am, Carl <s...@sss.jjj> wrote:
> On 23/05/2013 09:31, Phil wrote:
>
>
>
> > On May 23, 5:05 am, Paul <moreno.p...@gmail.com> wrote:
> >> We often race and train on some pretty extreme harbour water.
> >> Has anyone tried adding weights to the ends of your sculls? I was
> >> thinking some kind of lead, maybe solder, where the blade meets the
> >> shaft to help balance the boat? I was thinking about 100g would be a
> >> good starting point. Opinions?
>
> > Having extra weight outboard would probably exacerbate the problem -
> > but by all means experiment.
> > Best to practice keeping your blades covered for as long as possible
> > IMHO.
>
> > Phil.
> > (currently 1x in Bristol Harbour, have raced & won in Penarth &
> > Mumbles....)
>
> How did you get on with rules 1-1-4, 4-1-2, 5-2-5c, 3-2-1a and 4-1-2? ;)
>   Sorry, it's that Mornington Crescent moment.
>

SNIPPAGE> - Show quoted text -

..long enough ago that points cards &c. did not enter into it!
Still don't mind the rough water though.
We used to have water-skiing here in Bristol, I quite used to look
forward to the racing-start sprint back to the clubhouse once the
harbourmaster gave us the all-clear on the hour.

Phil.

[James HS]

The finishes thing is a direst observation - possibly linked to my poor technique, but also observer in coaching, that the left and right often come out at different times - if they come out square it is unbalanced enough, but when feathered out the blades then have a few CC of water on them and I have watched the left blade 'drag' down that side of the boat - so squaring out tends to lessen this.

Unusually i did also mean rate - if I sit still and "cut the cake" when I do it slowly I can topple - whereas when I do it fast I can keep going, blades off the water, back and forth, back and forth - in my head (an often confused place) I link this to a giro effect.

Do we think that a tightrope walker would hang 10Kg weights at either end of his pole and benefit from the inertia?

James

[Carl]

On 24/05/2013 07:51, James HS wrote:
> The finishes thing is a direst observation - possibly linked to my poor technique, but also observer in coaching, that the left and right often come out at different times - if they come out square it is unbalanced enough, but when feathered out the blades then have a few CC of water on them and I have watched the left blade 'drag' down that side of the boat - so squaring out tends to lessen this.
>

I understand what you are saying, but some degree of feather at the
finish does not need to result in scooping water out of the pond. That
will only happen if you rip the blade out of the water.

We are talking about the last few milliseconds of the stroke, when
almost no work can be done & the blades should have unloaded - or that's
the ideal. So why would they need to extract square? If they slightly
feather (say by 30-deg) they'll rise naturally out of the water, they
won't try to butt you, they won't drag & there'll be no scooping. If
they extract square you must keep them moving astern & your hands moving
to the bow, & beyond the point at which you are doing anything useful,
so you increase your length of action without increasing your stroke
length, & give yourself the increased chance of backwatering.

It's another of those tricky concepts that get swept over by an
all-pervading (but not necessarily clearly considered) orthodoxy.

> Unusually i did also mean rate - if I sit still and "cut the cake" when I do it slowly I can topple - whereas when I do it fast I can keep going, blades off the water, back and forth, back and forth - in my head (an often confused place) I link this to a giro effect.
>

Years ago I also proposed the gyroscopic effect, & made a mathematical
twit of myself in the process, so I won't go back there right now ;) .
The reason a higher frequency gives you more stability is simply that
you have less time to topple either way. And remember that the toppling
process starts from nothing & accelerates over time, so the less time
you allow before the next contact with water, the very much less
toppling will have occurred.

> Do we think that a tightrope walker would hang 10Kg weights at either end of his pole and benefit from the inertia?
>

Pass. My guess is not. Any tightrope walkers out there?

[A. Dumas]

Carl wrote:
> On 24/05/2013 07:51, James HS wrote:
>> Do we think that a tightrope walker would hang 10Kg weights at either
>> end of his pole and benefit from the inertia?
>
> Pass. My guess is not. Any tightrope walkers out there?

I am not but my guess is no, with regard to increased inertia, but yes,
with regard to further lowering the centre of gravity.

[davie...@gmail.com]

On Friday, May 24, 2013 7:51:53 AM UTC+1, James HS wrote:
> Do we think that a tightrope walker would hang 10Kg weights at either end of his pole and benefit from the inertia?
>
>
>
> James

Apparently they do.
http://suite101.com/article/why-tightrope-walkers-carry-long-bent-poles-a185632

Kit

[James HS]

Ahhhh - nice one - so I suckered myself into that by comparing a system that would help the 'analagy' - i.e. we DAFTLY imho liken sculls to a tightrope walker's pole, when they are no such thing - they are split in the middle and we move them backwards and forwards.

So unless the hands are touching and stabalising each other they are nothing like the pole (i.e. do not help with the "moment of inertia".

I should have asked the question differently. If a tightrope walker held out a stick either side for balance, would he/she sling a 10Kg weight on it!

As the answer in the tighrope walkers case was 'yes if it lowered the centre of gravity' I would postulate that just weighting the sculls would not lower the centre of gravity - but it does possibly explain why I 'like' to have the sculls lower in terms of travel on the recovery - because higher requires better balance/more skill. So I would postulate that more weight on a correctly positioned scull would make it harder to balance :)

Carl - I do completely agree that a correct feathering out should not pull up more water - what I observe (and used to do) was shovel out - when the blade becomes sticky from the water it scoops and the (forgive language) stick of the water behind. I am using square out as an over exaggeration to get a proper feather out.

I have long resisted the coaching that I have received to actually feather out as when I see people do this as instructed, the sudden release of load looks to me like it 'surprises' the sculler and they are not then stable to go into the recovery - so another example of me poorly explaining something I think I understand

Thanks for sharpening my pencil!

[zeke_hoskin]

Erstwhile physicist, low-level juggler, ex-open-water-racer, and failed attempted unicyclist here.
(1) Adding mass to the end of your oars would certainly make it easier to balance by waggling them in the air.
(2) Adding volume to the ends of the oars would increase stability from buoyant forces - and make it harder to row deep enough.

[John Greenly]

On Friday, May 24, 2013 4:25:21 PM UTC-4, zeke_hoskin wrote:
> On Wednesday, May 22, 2013 9:05:23 PM UTC-7, Paul wrote: > We often race and train on some pretty extreme harbour water. > > Has anyone tried adding weights to the ends of your sculls? I was > > thinking some kind of lead, maybe solder, where the blade meets the > > shaft to help balance the boat? I was thinking about 100g would be a > > good starting point. Opinions? Erstwhile physicist, low-level juggler, ex-open-water-racer, and failed attempted unicyclist here. (1) Adding mass to the end of your oars would certainly make it easier to balance by waggling them in the air. (2) Adding volume to the ends of the oars would increase stability from buoyant forces - and make it harder to row deep enough.

I row in open water all the time, in an open-water boat- Maas Flyweight. Using the oars for balance while they're out of the water is badly compromised by the fact that the water surface is all over the place- on one stroke up on one side, on another on the other side. On one stroke you might be left-hand-over-right, and on the next, the opposite (for that reason, I, and many others, rig without height offset). The chaotically varying vertical excursions you have to make with the blades to clear the wave tops and then get them into the water at rapidly changing heights unavoidably destabilize the boat. For that reason, I think the lightest possible blades are probably the best for these conditions- they rock the boat as little as possible as you move them vertically. So, you just have to set the boat at the finish as best you can, and then get the oars back in the water as soon as possible. Carl's suggestion of upping the rate- shortening the recovery- to do that is what the good open-water rowers do. I try to do that without shortening up the drive, but don't always succeed- that's what distinguishes the really fast open-water rowers: they can get the rate up and still keep long without losing balance.