Sculling Boats With Rudders?

[Steve]

Hello All,

I've often wondered whether using a rudder on doubles and quads is something
to be considered. Doctrine seemingly has it that 2x's and 4x's when properly
configured are rudderless. However, having recently got back on the water in
a 2x after many years, it occurred to me how much easier it would be - at
least personally speaking, to have a rudder rather than having
to alter stroke length and/or pressure on one side or the other which I find
can be disruptive to rhythm.

Is it more or less effective, I wonder, to have use of a rudder than the
current methods used for steering control in sculling boats?

This subject was also brought back to mind when seeing Carl mentioned his
AeRowFin steering foil for sculling boats recently in another thread, so it
was about time I threw this question out
there to find out what others think.

--

Regards

Steve

[thomas....@googlemail.com]

It's a good question, in the past I've raced doubles at particularly windy head races and left the rudder on to make life easier. It certainly made it easier to get round particularly tight bends

With regards to your pressure vs rudder question, that's something I've wondered about before as well, and not just in sculling boats but sweep as well. Conventional wisdom (at least here in the UK) is that you should use the rudder to steer as little as possible, and ideally only steer with pressure. I wonder if that is correct tho as as you point out, changing pressure in that way can be quite disruptive to the rhythm in a crew, and it makes you wonder just how much a rudder slows a crew

[SingleMinded]

Quads? Really? I've never seen a 4x without a rudder.

[stew...@gmail.com]

I can't imagine a rudderless 4x being anything other than a disaster - I would think them too long and heavy to steer by hand pressure alone, particularly over a head racing course.

IMO having to steer a 2x by hand pressure is daft when you can add a rudder for minimal drag penalty (if you fit CD AeRowFin, probably beneficial!) and I have never seen a convincing argument to the contrary. As to a rudder slowing you down - I would say having to change your rhythm, stroke length and arm pressure to get around a bend is almost certain to slow you down more! A properly designed and fitted rudder should add no drag when set straight and minimal drag when turning if applied properly.

I'm not sure where this idea comes from that you should 'steer with pressure', and that it's somehow superior or faster than proper use of a rudder. I strongly suspect it's another piece of rowing dogma that's based on some very strange ideas from a long time ago.

Stewie

[gsl]

I don't see much or any disadvantage to being rudderless in straight line sprint races, at least if there is not much of a cross wind.
Certainly doing a head race in a 4x that has anything but minimal turns seems completely ridiculous.

My clubs 2x is rudderless and hard to steer. However, I don't like applying power while steering with my foot and I'm not the only one who feels that way. Still I sure that a rudder would make the boat faster in head races.

Learning to power turn with minimal disruption of power is a skill that one can learn. One needs to do it in a single after all.

Borrow a Hudson 2x last year for a head race that had a rudder and my partner who steered seemed to liked it, and I appreciated not having to think about powering on one side at all. I'm going to see if I can get support from other to spend the money to convert our best double to one with a rudder.

[johnf...@gmail.com]

On Monday, January 14, 2013 5:14:01 PM UTC-8, gsl wrote:
> Certainly doing a head race in a 4x that has anything but minimal turns seems completely ridiculous.
>

Every year approximately 60-100 4x's race the Head of the Charles, which includes a 90 degree and a 180 degree turn. They probably don't think it is ridiculous.

[robin_d...@hotmail.com]

Doubles & Quads without steering are my pet hate. Being strictly accurate, the thing I really hate is when a boat has a properly set up steering set-up, you leave it for a few weeks (a year old baby means that I don't have time to do weekly maintenance sessions) and come back to find that some "experienced" rower has removed the steering and tied it in a knot under the footstretcher because some former coach at a previous club has told them "sculling boats don't need steering" - and more pertinently, they have spread this rumour among the novices so that they think that steering should always be messed with if present.

An even worse myth is "the rudder was why the boat wasn't going straight". When you watch the crews that make these complaints, invariably as the person with the steering shoe approaches the catch, owing to a lack of flexibility the knees flop out sideways instead of lifting in a single plane as the torso approaches the catch position, sometimes asymmetrically (particularly if the person involved rows sweep regularly). Shoe rotates, rudder turns, hey presto, boat doesn't run straight. At the end of the outing, this is blamed on the steering, so it gets removed. A 6mm wingnut & bolt put through a hole drilled in the steering shoe mount and footplate to lock the steering out when crews don't want steering activity is a simple cure - but how many rowers go to get the spanners or wire cutters (!) instead?

[davie...@gmail.com]

On Tuesday, January 15, 2013 12:02:24 AM UTC, stew...@gmail.com wrote:
> As to a rudder slowing you down - I would say having to change your rhythm, stroke length and arm pressure to get around a bend is almost certain to slow you down more! A properly designed and fitted rudder should add no drag when set straight and minimal drag when turning if applied properly.
>
>
>

> Stewie
On the other hand, a rudder works by creating drag that pushes the stern sideways, reducing overall power. In contrast, applying pressure unevenly actually increases power. Also it seems to me that because the extra 'pushing' occurs towards the middle of the boat, the sideways movement of the hull through the water during turning is less than when the stern is being pushed sideways (I am willing to be corrected on that though).

[Carl]

Let me try to explain the science of steering:

It is a common misapprehension, especially in rowing, that rudders
should work by generating off-centre drag, & many shell rudders do just
that. But only the most inefficient of rudders work that way.

An efficient rudder works by generating a side-force, AKA 'lift', and
induces almost no (effectively = zero) drag at all. The general name
for such a device is 'foil', & foils work like wings - in fact wings are
foils - to generate large or small side-forces which are directly
proportional to the amount of input/rotation applied to them.

So, with a proper foil (e.g. our AeRowFin steering foil) the steering
action is entirely without energetic cost.

There is, however, another source of loss which is common to all shells
when steered. It's called leeway drag. But it arises whether you steer
efficiently with a well-designed steering foil, or the usual
mutually-conflicting separate fin & rudder set-up we mostly see, or with
the oars themselves.

When you make any course change you achieve this by first swinging the
stern to one side, so the boat now points in the new, intended
direction. However, the combined momentum of boat & crew continues to
carry it in the original direction, so the boat is now travelling
somewhat sideways. Shells are built long & narrow to provide a minimum
drag hull-form. However, when travelling even slightly in a direction
not aligned with their axis the water drag on the hull rises
dramatically. This drag is important for your course change, since it
slows the boat in the original direction which the crew pulls hard to
get the boat moving in the new direction, but in any other sense it is a
total dead loss.

Every time you steer, by whatever means, & whenever you are in any kind
of cross-wind, your boat is to some extent moving sideways. In marine
terms, it is making leeway. With leeway comes increased hull drag, &
with increased hull drag comes significant speed reduction. Typically
as much as 10% on a modest river bend, sometimes even more. So you want
to minimise the amount of steering & of steering correction (even
correcting your course for over-steer incurs further drag).

That's why it is so beneficial to have a steering system which applies
science to the task of shell control - i.e. precisely calibrated 'lift'
rather than the usual very variable combination of highly uncertain lift
& ill-directed drag (which is the cause of steering delays & consequent
over-steer). I hope I have made that point with sufficient clarity, but
will be more than happy to clarify any misunderstandings and fill in any
gaps I've left in the explanation.

Which brings us to the problem of leeway drag. An eight might be
17-18cm deep below the waterline but >55cm in waterline beam, so its
immersed cross-section is very saucer-shaped & not at all the sharp
knife-like object we suppose it to be, so it has relatively little
resistance to making leeway.

That's where our HyperSteer� twin-foil shell control system comes in.
Anyone wishing to know more about HyperSteer is very welcome to contact
me, but I think this short animation does a reasonable job of
demonstrating what the HyperSteer system does for a racing shell:
www.carldouglas.co.uk/downloads/HyperSteer.mov

Of course, we do get folk asking if the foil system adds drag - rowers
are always more concerned about whether a proven performance aid might
slow them down than they are interested to see if it could make them
faster ;) But the answer is, no it won't slow you at all. No shell
goes dead straight, even on a still day, since we are humans who will
pull slightly differently on every stroke & just one twitch on your
course will cost you more in speed than the vestigial drag of any
well-designed foil.

Cheers -
Carl

--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing Low-drag Riggers/Advanced Accessories
Write: Harris Boatyard, Laleham Reach, Chertsey KT16 8RP, UK
Find: tinyurl.com/2tqujf
Email: ca...@carldouglas.co.uk Tel: +44(0)1932-570946 Fax: -563682
URLs: carldouglas.co.uk & now on Facebook @ CarlDouglasRacingShells

[davie...@gmail.com]

> That's where our HyperSteer™ twin-foil shell control system comes in.

>
> Anyone wishing to know more about HyperSteer is very welcome to contact
>
> me, but I think this short animation does a reasonable job of
>
> demonstrating what the HyperSteer system does for a racing shell:
>
> www.carldouglas.co.uk/downloads/HyperSteer.mov
>
>
>
> Of course, we do get folk asking if the foil system adds drag - rowers
>
> are always more concerned about whether a proven performance aid might
>
> slow them down than they are interested to see if it could make them
>
> faster ;) But the answer is, no it won't slow you at all. No shell
>
> goes dead straight, even on a still day, since we are humans who will
>
> pull slightly differently on every stroke & just one twitch on your
>
> course will cost you more in speed than the vestigial drag of any
>
> well-designed foil.
>
>
>
> Cheers -
>
> Carl
>
>
>
> --
>
> Carl Douglas Racing Shells -
>
> Fine Small-Boats/AeRoWing Low-drag Riggers/Advanced Accessories
>
> Write: Harris Boatyard, Laleham Reach, Chertsey KT16 8RP, UK
>
> Find: tinyurl.com/2tqujf
>
> Email: ca...@carldouglas.co.uk Tel: +44(0)1932-570946 Fax: -563682
>
> URLs: carldouglas.co.uk & now on Facebook @ CarlDouglasRacingShells

Thank you, Carl.

In relation to steering by oars v. steering by rudder, would steering by oars cause more of less leeway movement than by rudder? Or similar? (My gut instinct is less but that's been proved unreliable many times on this board already!)

[Carl]

>> That's where our HyperSteer� twin-foil shell control system comes in.

>>
>> Anyone wishing to know more about HyperSteer is very welcome to contact
>>
>> me, but I think this short animation does a reasonable job of
>>
>> demonstrating what the HyperSteer system does for a racing shell:
>>
>> www.carldouglas.co.uk/downloads/HyperSteer.mov
>>
>>
>>
>> Of course, we do get folk asking if the foil system adds drag - rowers
>>
>> are always more concerned about whether a proven performance aid might
>>
>> slow them down than they are interested to see if it could make them
>>
>> faster ;) But the answer is, no it won't slow you at all. No shell
>>
>> goes dead straight, even on a still day, since we are humans who will
>>
>> pull slightly differently on every stroke & just one twitch on your
>>
>> course will cost you more in speed than the vestigial drag of any
>>
>> well-designed foil.
>>
>>
>>
>> Cheers -
>>
>> Carl

>

> Thank you, Carl.
>
> In relation to steering by oars v. steering by rudder, would steering by oars cause more of less leeway movement than by rudder? Or similar? (My gut instinct is less but that's been proved unreliable many times on this board already!)
>

Kit, that's a really good question! And if "being wrong" is what you
like to call it, isn't that how we get things better understood? It's
not about winning or losing arguments but how we all learn off each
other & thus get closer to better answers.

One might suppose that, because the extra pull on one side is turning
the boat it must reduce the leeway. I reality I think it works no
better than an efficient rudder, & the leeway will still happen.

It is possibly more efficient than a conventional rudder to steer by oar
pressure, but theres a personal price to pay. We are already pulling as
hard as it is economic to do, & pay a high fatigue price for any small
increment in that load, or we let off the load on the other side.
Either way we pay a performance price.

An example might be that you could steer a twin-prop launch by varying
engine power, but would it make sense if you have a decent steering system.

So I think the argument stacks up in favour of good steering gear over
oar steering.

[LakeGator]

We have 2 quads with no rudders and certainly no AeRowFin but the preferred one has AeRoWing riggers. We find these do quite nicely in steering in our river which does have some sharp curves. The only time there is challenge is on the tightest of turns like a couple that are 90 degrees with a river width of 20 meters or less.

A few weeks ago we were given a fun challenge when we lost the fin (skeg to us colonials) up river about 17 KM from the boat house. The beast skidded on almost any attempt to correct the course and, of course, were starting in the tightest and most twisty part of the river. We were able to learn how to work together to make very slight course corrections and made it home in only a little longer than normal time.

[Peter Ford]

I do intend, when I find a RoundTuit, to get in contact to ask about your various steering systems (although I see no mention of Janousek 8s in the list on your website :-( ) and how they might behave in our (Cambridge Bumps) somewhat unusual racing situation. However, the following statement bemuses me:

On Tuesday, 15 January 2013 12:55:22 UTC, Carl wrote:
> So, with a proper foil (e.g. our AeRowFin steering foil) the steering
> action is entirely without energetic cost.

I know that you go on to describe the (presumably rather larger?) drag associated with 'crabwise' motion of shells while cornering, and that your posts necessarily involve simplifications, but I don't understand what this sentence is trying to convey.

Certainly the style which involves the fin and rudder being separated by several metres, and is common on pairs, is disastrously ineffective. However, I've never seen that setup on eights, and only sometimes on fours; rather they tend to have a pair of flat plates separated by a gap of (hopefully...) less than a millimetre. I don't debate that this setup will be energetically more costly than a designed steering system, but it looks to me that the difference is only a matter of scale, and also that the difference may well be swamped by the 'leeway drag'. Working at the 'wrong' end of fluid dynamics, I lack the expertise to quantify these claims, but I would greatly appreciate any estimates of such numbers!

Returning to the original question, I also think that the idea of steering 'just with the rudder' is misleading. As soon as the boat is turning, if the 4 blades are to continue to catch and finish at the same time adjustments must be made to stroke lengths, and the simplest way to achieve this (assuming both scullers have spent plenty of time in singles) is to call for pressure on the outside of the corner and leave the rest to their experience. Then you have to do something to keep the boat level once the blades are out of the water... the notion of sculling or rowing normally and "just applying rudder" will never lead to fast cornering.

I've been fortunate enough on a few occasions to race a double on the Cam with a very good sculler, both with and without a rudder. My (purely intuitive) conclusion was that it felt that rudderless might have been faster, but we were racing with the ridiculous under-foot fin, stern-mounted rudder setup described above. It seemed that this meant having the rudder attached made it hard to move the stern sideways through the water, and therefore led to moving the bow further through the water. Leaving the rudder off allowed us to turn about a point nearer the centre and have the shallower-buried bow and stern moving sideways.

Thanks,
Peter

PS All this leaves me skirting around the question I've always been stuck on: What do we even mean by "efficiency" for the hull+rudder+fin+rowers system? If system A allows us to corner 1% faster than system B at the same total power provided by the rowers, but requires bowside to work 15% harder than strokeside for the duration of the corner, do we think this is more efficient?
If anyone can provide a definition of efficiency which could even in principle (ignoring the practical difficulties of measuring input power and (extra hard on a corner) boat speed) be measured in an eight, I'd be delighted to hear it!

[Henning Lippke]

My club now owns a CD-X double with AeRowFin.
It's great fun to zip around corners without the need to apply different
pressure. Keeps finishes much more precise as well.
I'm fortunate enough that my partner does the steering and he got quite
good at it and now I rarely notice him applying the rudder.
It takes some practice to take full advantage but then you don't want to
miss it.

Funny, there were people at the club talking like 'oh, a steered double,
that's prohibited by FISA'. If you can't grasp it, presume it's
forbidden anyway. The person in question got heavily beaten by that
white killer double in a head race some weeks later ;-)

[Carl]

On 15/01/2013 17:24, Peter Ford wrote:
> I do intend, when I find a RoundTuit, to get in contact to ask about your various steering systems (although I see no mention of Janousek 8s in the list on your website :-( ) and how they might behave in our (Cambridge Bumps) somewhat unusual racing situation. However, the following statement bemuses me:
>

Whenever you get the inclination, give us a call Peter. And, as it
happens, we have a genuine Round Tuit at home.

> On Tuesday, 15 January 2013 12:55:22 UTC, Carl wrote:
>> So, with a proper foil (e.g. our AeRowFin steering foil) the steering
>> action is entirely without energetic cost.
>
> I know that you go on to describe the (presumably rather larger?) drag associated with 'crabwise' motion of shells while cornering, and that your posts necessarily involve simplifications, but I don't understand what this sentence is trying to convey.
>

I'm saying the AeRowFin is the first steering device in rowing history
to generate no additional drag upon & around itself when steering.
That's because, for reasonable amounts of lift (steering effect, for
those uncomfortable with the term 'lift' being applied laterally) the
AeRowFin operates within the lowest part of the 'drag bucket' - that
zone of operation in which fluid drag on a foil is virtually unaffected
by changes in camber (steering input) & lift.

That's not to say that swinging the stern - with any rudder - doesn't
itself incur a drag penalty. It does. But with our HyperSteer system
that too is greatly reduced since the stern swing no longer takes the
whole darned boat crabwise with it.

> Certainly the style which involves the fin and rudder being separated by several metres, and is common on pairs, is disastrously ineffective. However, I've never seen that setup on eights, and only sometimes on fours; rather they tend to have a pair of flat plates separated by a gap of (hopefully...) less than a millimetre. I don't debate that this setup will be energetically more costly than a designed steering system, but it looks to me that the difference is only a matter of scale, and also that the difference may well be swamped by the 'leeway drag'. Working at the 'wrong' end of fluid dynamics, I lack the expertise to quantify these claims, but I would greatly appreciate any estimates of such numbers!
>

You are recognising the importance of leeway drag & that's good, since
until very recently you'd never, ever, have heard that term used in
rowing. But all drag components are additive, so the extra drag on a
poor steering system is additional to the leeway drag resulting when the
boat is steered. And here is the cruncher: if you steer with a poorly
responsive system you do a whole lot more steering, because it takes
time to get the required result, & after that lag there's every chance
that you'll then over-steer & have to steer again to correct that, & so
on. Then there's the matter of side-winds, or the guy at #2 who takes
an easy stroke every so often & then a stonking great stroke to make up
for it. So there is constant demand for steering - which is best done
by an efficient, low-drag system - and with a sloppy system you spend
more time slewing sideways & making leeway this way & that.

You want an estimate for what you might gain form using an AeRowFin, but
that's hard to provide since conditions will vary from boat to boat,
crew to crew & with conditions & course. I made a very modest estimate
for one coach who asked me this question at a regatta: over 2k straight
with a little side-wind & a slight chop, I said it might be around 2
seconds but could be more. He wandered off before returning with
triumph in his eyes to tell me "My crew could pull 2 seconds faster!"
Yes, I replied, and we'll still give you another 2 seconds, which makes
4. He couldn't work that one out and never came back. Think how many
crews would give their eye teeth for a 2 second gain? I'm not talking
about the hyperbolic & completely unfounded claims we heard when the
first cleaver oars appeared - that they'd be worth 7 seconds. That's be
a truly astonishing gain, but a couple of seconds is pretty handsome, &
much more justified.

> Returning to the original question, I also think that the idea of steering 'just with the rudder' is misleading. As soon as the boat is turning, if the 4 blades are to continue to catch and finish at the same time adjustments must be made to stroke lengths, and the simplest way to achieve this (assuming both scullers have spent plenty of time in singles) is to call for pressure on the outside of the corner and leave the rest to their experience. Then you have to do something to keep the boat level once the blades are out of the water... the notion of sculling or rowing normally and "just applying rudder" will never lead to fast cornering.
>

I can't easily comment on this because it is fairly subjective & I
wasn't there to see what was going on. I could easily accept that lousy
steering gear could put you at a disadvantage since it is not unlikely
to prevent you from steering well by foot & make it harder to steer by oar.

> I've been fortunate enough on a few occasions to race a double on the Cam with a very good sculler, both with and without a rudder. My (purely intuitive) conclusion was that it felt that rudderless might have been faster, but we were racing with the ridiculous under-foot fin, stern-mounted rudder setup described above. It seemed that this meant having the rudder attached made it hard to move the stern sideways through the water, and therefore led to moving the bow further through the water. Leaving the rudder off allowed us to turn about a point nearer the centre and have the shallower-buried bow and stern moving sideways.
>
> Thanks,
> Peter
>
> PS All this leaves me skirting around the question I've always been stuck on: What do we even mean by "efficiency" for the hull+rudder+fin+rowers system? If system A allows us to corner 1% faster than system B at the same total power provided by the rowers, but requires bowside to work 15% harder than strokeside for the duration of the corner, do we think this is more efficient?
> If anyone can provide a definition of efficiency which could even in principle (ignoring the practical difficulties of measuring input power and (extra hard on a corner) boat speed) be measured in an eight, I'd be delighted to hear it!
>

Here's a first stab at your question, Peter:
What you do when you have to pull 15% harder, even for a couple of
strokes, is to greatly increase the level of fatigue in the muscles
involved. Imagine adding 15% to the weight of a bar which you can lift
100 times before weight was added. How many times can you lift it with
the added weight? Many fewer, I suggest. So you sabotage your
endurance as soon as you exceed "rated load" & you also impair your
overall speed for the full distance.

[usbrit]

>
> Quads? Really? I've never seen a 4x without a rudder.

You've obviously not rowe in the US!!
Having been an umpire in the UK and now a Referee in the US, its interesting watching 4x's races here in contrast to over there :-). If a crew needs to correct their course instead of the steersman apply a little rudder to get the boat back straight, 4 scullers will apply uneven pressure to get the boat back on course. More often than not said 4 scullers will apply varying amounts of pressure clearly making the boat roll, sometimes shipwreck and usually slow down. I'm always advocating rudders for 4x but I seem to be a voice in the wilderness (Incidently for the Brit readers here, there's more or less no 4- rowing/racing in the US beyond the internationals or aspirants)

[Carl]

Every shell benefits from some kind of fin or skeg, because the drag per
unit surface area is much lower near the stern than at the bow. This
has the effect that if the boat goes even slightly off line, under the
inertia of the boat + crew the stern starts to swing forward as the bow,
experiencing much higher areal drag, feels held back. So a couple
develops which sets the boat turning & takes effort to constantly keep
correcting.

Consider those little kayaks used for canoe polo. They never go
straight & keep turning around on themselves at the drop of a hat - &
that's why.

If we're comparing bad integral shell control with no integral shell
control the difference is not so stark but you waste time & effort
trying to keep the boat going straight. That said, on a calm day it can
tell a sculler a lot about their finishes if the fin is missing. If you
have very well-together finishes you'll set the boat off straight at
each finish & it won't build up much if any spin before the catch,
whereas unmatched finishes will give you plenty to think about.

[pma5...@gmail.com]

Carl,

This thread has got me wondering why it is boats are steered with rudders at the stern ? The vast majority of wheeled vehicles have the turning wheels at the front - is there a fundamental reason why you couldn't swap your setup round and have the turning fin at the front and the fixed one at the back ?

(Clearly fitting something like that to any existing shell would be a lot of work, so I'm not seriously considering it, even if it wasn't a really bad idea for other reasons...although adding the CanardFin to our AeRowFinned Vespoli eight is definitely a possibility)

[johnf...@gmail.com]

On Tuesday, January 15, 2013 1:11:42 PM UTC-8, pma5...@gmail.com wrote:
> Carl,
> This thread has got me wondering why it is boats are steered with rudders at the stern ? The vast majority of wheeled vehicles have the turning wheels at the front - is there a fundamental reason why you couldn't swap your setup round and have the turning fin at the front and the fixed one at the back ?

I suspect it has to do with drag penalty. Flow in the first 5m of the boat is (hopefully) laminar, and having a rudder there might disturb the flow and impose a drag penalty even when there is no steering input.

I think in this discussion we have to consider that shells are basically designed for straight courses, not for curving head races. So the intent is for the boat to want to go straight and resist anything more than small changes in direction. For this type of racing (assuming no rudder) a foil-shaped fin/skeg might be preferable to a flat plate since changes in the angle of attack would create a lifting force which would tend to turn the boat back onto the same course)? For head racing (again assuming no rudder) a flat plate might be preferable because it stalls out at loweer angles of attack and permits one to turn the boat??

Of course a rudder might be desirable for straight racing in crosswind conditions, as Carl points out.

I have been puzzling over a steering question: if one has the choice, is it better to make a sharp change in course (and suffer a larger energy loss due to leeway but over a shorter period of time) or to turn gradually, so that there is less sideslip but over a longer period of time. Obviously some river configurations force one to make gradual turns, but if there is a choice, is it wiser (from an energy-loss perspective) to try to make a quick turn and then track straight if one can????

Another thought: would it be helpful to have a self-centering rudder system?? So that when one is NOT intentionally applying rudder, it goes to dead center? Seems to me one could lose a lot if small steering inputs were constantly inadvertently applied??

[thomas....@googlemail.com]

As a point to the interchangeable fin point above, I do know several scullers (Filipino owners) who have both a flat metal fun and carbon "wing" fin, and switch from the metal in the head season to the carbon for the regatta season

[thomas....@googlemail.com]

Also some boats I have steered have had a "ball and socket" arrangement where the centre point of the footplate has a notch that Engages and holds the steering straight, to steer you apply a little more pressure than normal and it pops out do you can steer normally, wasn't really taken with it myself as it made it difficult to do minor tweaks to the steering.

Carl can correct me if I am wrong but his aerofin, due to the way it is designed with the rudder part being connected to the fun has a "self centering" action when you used it, I certainly have a memory of feeling the plate slightly resist when I used the steering and then return to centre when I stopped applying pressure

[johnf...@gmail.com]

On Tuesday, January 15, 2013 3:08:20 PM UTC-8, thomas....@googlemail.com wrote:
> Also some boats I have steered have had a "ball and socket" arrangement where the centre point of the footplate has a notch that Engages and holds the steering straight, to steer you apply a little more pressure than normal and it pops out do you can steer normally, wasn't really taken with it myself as it made it difficult to do minor tweaks to the steering.
>
>
>
> Carl can correct me if I am wrong but his aerofin, due to the way it is designed with the rudder part being connected to the fun has a "self centering" action when you used it, I certainly have a memory of feeling the plate slightly resist when I used the steering and then return to centre when I stopped applying pressure

I've used the detent type and disliked it for exactly the reason you pointed out.

I was thinking about a centering system involving elastic cords, but obviously either of these arrangements could be problematic if not adjusted properly, i.e. if they bring the rudder to a position which is NOT centered!! Self centering would be better.

[Steve S]

At the 2012 USA Masters' nationals, I was part of a 4x crew the stroke of which was inexperienced in rowing with the shoe control for the rudder. We spent almost the entire 1k on the port buoy line and lost out on what should have been an easy win.

At the Canadian Masters' nationals two weeks later, I noticed that almost all of the 4x teams had pulled their rudders and rowed the course with only a fixed fin to give them directional stability.

My conclusion: from now on, if I am at a Masters' 1k regatta, I will follow the lead of the Canadians and pull the rudder.

But for anything resembling the curviness of the HOCR head race, the rudder is back in the boat.

- Steve

[Carl]

This thread has brought excellent contributions all round & the problem
is only where to start.

I would gently disagree that shells are or have been designed for
straight courses. The shape & size of eights has barely changed in 100
years, & through most of that period eights were raced largely on river
courses. My question, rather, is over the extent to which eights were
or have yet been 'designed', but we can go there another time. I would,
however, agree that they are tricky beasts to steer with the sort of kit
generally on offer.

Leo Lazauskas may well step in to correct me, but my view is that we
won't get laminar flow on a typical eight for much over the first couple
of metres. In the bow the flow is influenced by the very shallow depth,
the locally high ratio of water line to wetted surface & the unsteady
flow conditions due to waves & boat surge.

As for steering the bow: this has been done in sailboats, but maybe a
better-informed sailor than me will be able point us to any rare cases
where bow steering foils are used successfully at the moment. Any
canoeist is familiar with the use of a paddle as bow rudder during
slalom & shore landing manoeuvres; an 18 or 21ft open canoe can be made
to move diagonally for a rapid landing during a marathon race portage.
But for steering an eight I think the resulting slewing of the bow,
where the specific surface drag due to thin boundary layer & resulting
high shear forces & to the flow disturbance & "shovelling up" of the
water by the sharp edges of the bow, might act not just to steer but as
an unwelcome brake on progress.

We don't offer our AeRowFin foil as a self-centring option or aid. it
does, pretty much centre itself but there should be no sense of this
happening & no check on motion around that point. Anyone who had ridden
a bike with pitted head bearings knows how inconvenient it is when the
requisite smooth steering action is interrupted as a ball in the bearing
hits a pit in the race.

I agree that inadvertent steering inputs (when foot-steering) are
undesirable, but sit tight and we'll soon have a solution to that
problem. Watch this space! For coxed steering we have only to educate
coxes to know that gross steering inputs - the kind they have to use to
get a necessary response from conventional kit - are going to produce
correspondingly excessive reactions with proper steering foils. It's
like coming from steering a tractor or a jalopy, where only large inputs
take up the slack & get a result, to driving a modern car with its
immediate, nuanced steering responses.

My view is that shells should ideally be steered at all times - there
being no period when a steering system has nothing to do. Thinking
about it a bit more, how often are we in a crew in which every person
pulls exactly the same as the others, or exactly the same between
strokes, & how often are the no extraneous influences (cross-winds,
waves, etc)? Probably never would be my guess. Sure, we often make a
pretty good job, but that's more of a continuous compromise than a case
of needing no steering. Racing or training without a competent rudder
is what we do because most steering systems are incompetent, so we may
choose the lesser of the 2 evils. But I would respectfully suggest that
not having access to or experience of the merits of precision steering
is probably not a good way to judge the desirability of having & using it.

That said, I do think it's not a bad idea for crews to train -
occasionally & under well-controlled conditions - without rudder.
Before the 2000 GBR eight received their AeRowFin the late, great Harry
Mahon used that boat's relative unsteerability to show the crew, rowing
in pairs at a time, how much their individual strokes differed in their
effects on the boat's course & thus to bring them better together so the
boat wandered much less. Inspired coaching to use a defect as a
training tool!

I can't think that a sudden turn is really a good idea. With
conventional steering it's hard to make such a turn, unless you've got a
heavy bowman so the bow digs in & the boat slews, which certainly sounds
like a bad idea. With AerowFin steering (with or without HyperSteer)
I'd always opt for the smoothest course, consistent also with staying in
the right part of the stream & avoiding any known local shallows (these
can really slow you down).

I hope I've covered most points in that lot?

[Carl]

On 15/01/2013 23:08, thomas....@googlemail.com wrote:
> Also some boats I have steered have had a "ball and socket" arrangement where the centre point of the footplate has a notch that Engages and holds the steering straight, to steer you apply a little more pressure than normal and it pops out do you can steer normally, wasn't really taken with it myself as it made it difficult to do minor tweaks to the steering.
>
> Carl can correct me if I am wrong but his aerofin, due to the way it is designed with the rudder part being connected to the fun has a "self centering" action when you used it, I certainly have a memory of feeling the plate slightly resist when I used the steering and then return to centre when I stopped applying pressure
>

I'm tickled by your earlier suggestion that in the Phillipines they have
a particular choice over fins for courses ;)

As i've said in my reply to John's post, while AerowFin does return
pretty much to centre that is a handy but unintended consequence of it's
being symmetrical & having an elastic element in the articulation of its
steering tab. You wouldn't want steering to have an inbuilt bias, but
nor would you want a centring action with any kind of detent element.
Steering should be a smoothly continuous process.

[Steve]

I had always thought that the steering shoe assembly should be designed such
that there is a centered position that requires the users to apply a small
conscious pressure on to move either way and then as the foot returns to
where the user thinks centre is, the shoe "clicks" into position, thus
confirming that perfect centre has been arrived at and leaving the shoe back
in place so that a small pressure is once more required to apply rudder.
Sort of like those rotary switches on some car radios that allow you to feel
where dead centre is and require a little more force to continue the
rotation one way or the other.

I had pondered this many years ago when I was steering pairs and fours
regularly, but had forgotten all about it until seeing your message.

A simple idea perhaps, but one I always thought should maybe become an
innovation in ongoing development of the sport.

--

Regards

Steve
<johnf...@gmail.com> wrote in message
news:451fae8f-fbab-4669...@googlegroups.com...

On Tuesday, January 15, 2013 1:11:42 PM UTC-8,

[ -- SNIP --]

pma5...@gmail.com wrote:
>Another thought: would it be helpful to have a self-centering rudder

>system?? So that when one is NOT ntentionally applying rudder, it goes to

[wmar...@gmail.com]

On Monday, 14 January 2013 17:45:54 UTC-5, Steve wrote:
> Hello All,
>
>
>
> I've often wondered whether using a rudder on doubles and quads is something
>
> to be considered. Doctrine seemingly has it that 2x's and 4x's when properly
>
> configured are rudderless. However, having recently got back on the water in
>
> a 2x after many years, it occurred to me how much easier it would be - at
>
> least personally speaking, to have a rudder rather than having
>
> to alter stroke length and/or pressure on one side or the other which I find
>
> can be disruptive to rhythm.
>
>
>
> Is it more or less effective, I wonder, to have use of a rudder than the
>
> current methods used for steering control in sculling boats?
>
>
>
> This subject was also brought back to mind when seeing Carl mentioned his
>
> AeRowFin steering foil for sculling boats recently in another thread, so it
>
> was about time I threw this question out
>
> there to find out what others think.
>
>

> Regards
>
>
>
> Steve
Well...
I've seen a fellow in NZ whose father built boats (they've stopped in the last decade) but he worked at his father's shop, and put a rudder in his single. (argh, I forget the name of the boat builder... Hermann. OH that's it Kreutzmann (I think)...) He'd taken a basic aluminium fin (may have been stainless) and put a rudder post just astern of and contacting the fin. The steering mechanism was held in the centre by bungy cords which held the foot centered. The sculler would use it to enable him to steer in to the Karapiro cross-head or cross-tail, while pulling evenly and staying in the middle of the lane. Yes, it's rare to see doubles with steering and even more rare to see singles, but if you train on a site where there's a prevailing cross breeze - why the heck not?
Cheers,
Walter

[thomas....@googlemail.com]

As mentioned earlier in the thread fillipi (spelt right this time) do offer a footplate with what can only be described as a ball and socket joint. Imagine a tent pole that has a ball in one pole and a socket in the other so when the pole is put together the ball slots into the socket and the pole is held in place. That is the system that we had on the fillipi.

the eventual conclusion from the steers people at my club was we didn't like it and eventually taped the ball in so it didn't catch and it worked like a normal footplate, it was felt that a smoother application of rudder and being able to quickly micro correct the steering was a better option

[stew...@gmail.com]

On Thursday, January 17, 2013 7:50:49 AM UTC, thomas....@googlemail.com wrote:
> As mentioned earlier in the thread fillipi (spelt right this time) do offer a footplate with what can only be described as a ball and socket joint. Imagine a tent pole that has a ball in one pole and a socket in the other so when the pole is put together the ball slots into the socket and the pole is held in place. That is the system that we had on the fillipi.

You're nearly there - it's Filippi!