https://www.youtube.com/watch?v=2k1nUIi6dis

On Friday, May 5, 2023 at 12:46:41 PM UTC+12, Charles Carroll wrote:
> https://www.youtube.com/watch?v=2k1nUIi6dis
Hey Charles - that's quite a video.
I fear I've lost your email address... so nice to see your name again.
Rebecca

Hey Rebecca - It is always good to hear from you. It's been years! I'll try sending you my email address. And I conmcur that it is quite a video.

Here is a bit of the takeaway:

Teach The Athlete To Watch The Blade As It Enters:
The eyes inform the body. Have the athlete develop an awareness of what they are doing. Show the athlete that he needs to coach himself. Once this happens and the athlete begins to do just that, I've pretty much accomplished what I need to accomplish. (Steve Gladston's paraphrasing Steve Fairbairn)

Drills Without Pressure Are Worthless:
You can drill all day long. But if there's no pressure on the blade, the drill is worthless because it's not real. It's not dynamic. So pressure’s the key. Now think about applying pressure on the blade and how to increase the pressure, and you will soon understand that there is only one place power emanates from — the legs! So make sure the blade is engaged, then get hold of it, then use the legs to drive out against it. And after you finish with it, let it go. Let the boat slide up underneath. It's not complicated. Remember that every stroke you take is a stroke you don't get back, so do each one with intent. Jim Lemmon, the Head Coach at Cal, used to say races are not won on race day. Winning is 99% preparation. (Steve Gladstone)

On Monday, 8 May 2023 at 01:45:22 UTC+1, Charles Carroll wrote:
> Hey Rebecca - It is always good to hear from you. It's been years! I'll try sending you my email address. And I conmcur that it is quite a video.
>
> Here is a bit of the takeaway:
>
> Teach The Athlete To Watch The Blade As It Enters:
> The eyes inform the body. Have the athlete develop an awareness of what they are doing. Show the athlete that he needs to coach himself. Once this happens and the athlete begins to do just that, I've pretty much accomplished what I need to accomplish. (Steve Gladston's paraphrasing Steve Fairbairn)
>
>
> Drills Without Pressure Are Worthless:
> You can drill all day long. But if there's no pressure on the blade, the drill is worthless because it's not real. It's not dynamic. So pressure’s the key. Now think about applying pressure on the blade and how to increase the pressure, and you will soon understand that there is only one place power emanates from — the legs! So make sure the blade is engaged, then get hold of it, then use the legs to drive out against it. And after you finish with it, let it go. Let the boat slide up underneath. It's not complicated. Remember that every stroke you take is a stroke you don't get back, so do each one with intent. Jim Lemmon, the Head Coach at Cal, used to say races are not won on race day. Winning is 99% preparation. (Steve Gladstone)

Love all of these!

On Wednesday, May 10, 2023 at 1:16:32 AM UTC-7, James HS wrote:
> On Monday, 8 May 2023 at 01:45:22 UTC+1, Charles Carroll wrote:
> > Hey Rebecca - It is always good to hear from you. It's been years! I'll try sending you my email address. And I conmcur that it is quite a video.
> >
> > Here is a bit of the takeaway:
> >
> > Teach The Athlete To Watch The Blade As It Enters:
> > The eyes inform the body. Have the athlete develop an awareness of what they are doing. Show the athlete that he needs to coach himself. Once this happens and the athlete begins to do just that, I've pretty much accomplished what I need to accomplish. (Steve Gladston's paraphrasing Steve Fairbairn)
> >
> >
> > Drills Without Pressure Are Worthless:
> > You can drill all day long. But if there's no pressure on the blade, the drill is worthless because it's not real. It's not dynamic. So pressure’s the key. Now think about applying pressure on the blade and how to increase the pressure, and you will soon understand that there is only one place power emanates from — the legs! So make sure the blade is engaged, then get hold of it, then use the legs to drive out against it. And after you finish with it, let it go. Let the boat slide up underneath. It's not complicated. Remember that every stroke you take is a stroke you don't get back, so do each one with intent. Jim Lemmon, the Head Coach at Cal, used to say races are not won on race day. Winning is 99% preparation. (Steve Gladstone)
> Love all of these!

I do love it as well. But it raise old question, doen't it?

Steve Gladstone Says That Rowers Should Think About Applying Pressure On The Blade And How To Increase The Pressure. What does he mean? Is Gladstone asking rowers to think about how to accelerate a shell during the Drive? The words suggest that he is advising rowers to try pulling harder all the way through the stroke. Jimmy Hastie said to Steve Fairbairn, “Take hold of it as hard as you can, row it through harder, and finish it out hardest.” Is this how Gladstone wants his crews to row?

Is there another way to think about how to increase pressure? Charley Butts says that Kris Korzeniowski “... gave us a different way of thinking about rowing — that you didn't have to work so hard early in the stroke, that it was more important to maintain pressure throughout its entirety."

Aren’t these two contradictory opinions? Should rowers concern themselves with how to increase pressure? Or should they concern themselves with how to maintain pressure? Don’t just think about pulling harder through the stroke. Think instead about how to put pressure on the blade earlier and hold on to pressure longer.

Warmet regards
Charles

On Wednesday, May 10, 2023 at 1:16:32 AM UTC-7, James HS wrote:
> On Monday, 8 May 2023 at 01:45:22 UTC+1, Charles Carroll wrote:
> > Hey Rebecca - It is always good to hear from you. It's been years! I'll try sending you my email address. And I conmcur that it is quite a video.
> >
> > Here is a bit of the takeaway:
> >
> > Teach The Athlete To Watch The Blade As It Enters:
> > The eyes inform the body. Have the athlete develop an awareness of what they are doing. Show the athlete that he needs to coach himself. Once this happens and the athlete begins to do just that, I've pretty much accomplished what I need to accomplish. (Steve Gladston's paraphrasing Steve Fairbairn)
> >
> >
> > Drills Without Pressure Are Worthless:
> > You can drill all day long. But if there's no pressure on the blade, the drill is worthless because it's not real. It's not dynamic. So pressure’s the key. Now think about applying pressure on the blade and how to increase the pressure, and you will soon understand that there is only one place power emanates from — the legs! So make sure the blade is engaged, then get hold of it, then use the legs to drive out against it. And after you finish with it, let it go. Let the boat slide up underneath. It's not complicated. Remember that every stroke you take is a stroke you don't get back, so do each one with intent. Jim Lemmon, the Head Coach at Cal, used to say races are not won on race day. Winning is 99% preparation. (Steve Gladstone)
> Love all of these!

Hi James,

I am sure that Steve Gladstone has forgotten more about rowing than I will ever know. But even so, it seems to me that he raises an old question.

Gladstone says that rowers should think about applying pressure on the blade and how to increase the pressure. Is he actually advising rowers to accelerate a shell through the Drive? Isn’t this what the words suggest? As Jimmy Hastie said to Steve Fairbairn, “Take hold of it as hard as you can, row it through harder, and finish it out hardest.”

Or is there another way to think about how to apply pressure against the blade? Charley Butts says that Kris Korzeniowski “... gave us a different way of thinking about rowing — that you didn't have to work so hard early in the stroke, that it was more important to maintain pressure throughout its entirety."

Should rowers concern themselves with how to increase pressure? Or should they concern themselves with how to maintain pressure? Don’t just think about pulling harder through the stroke. Think instead about how to put pressure on the blade earlier and hold on to it longer. No mindless rowing!

Warmest regards,
Charles

On 25/05/2023 01:37, Charles Carroll wrote:
> On Wednesday, May 10, 2023 at 1:16:32 AM UTC-7, James HS wrote:
>> On Monday, 8 May 2023 at 01:45:22 UTC+1, Charles Carroll wrote:
>>> Hey Rebecca - It is always good to hear from you. It's been years! I'll try sending you my email address. And I conmcur that it is quite a video.
>>>
>>> Here is a bit of the takeaway:
>>>
>>> Teach The Athlete To Watch The Blade As It Enters:
>>> The eyes inform the body. Have the athlete develop an awareness of what they are doing. Show the athlete that he needs to coach himself. Once this happens and the athlete begins to do just that, I've pretty much accomplished what I need to accomplish. (Steve Gladston's paraphrasing Steve Fairbairn)
>>>
>>>
>>> Drills Without Pressure Are Worthless:
>>> You can drill all day long. But if there's no pressure on the blade, the drill is worthless because it's not real. It's not dynamic. So pressure’s the key. Now think about applying pressure on the blade and how to increase the pressure, and you will soon understand that there is only one place power emanates from — the legs! So make sure the blade is engaged, then get hold of it, then use the legs to drive out against it. And after you finish with it, let it go. Let the boat slide up underneath. It's not complicated. Remember that every stroke you take is a stroke you don't get back, so do each one with intent. Jim Lemmon, the Head Coach at Cal, used to say races are not won on race day. Winning is 99% preparation. (Steve Gladstone)
>> Love all of these!
>
> Hi James,
>
> I am sure that Steve Gladstone has forgotten more about rowing than I will ever know. But even so, it seems to me that he raises an old question.
>
> Gladstone says that rowers should think about applying pressure on the blade and how to increase the pressure. Is he actually advising rowers to accelerate a shell through the Drive? Isn’t this what the words suggest? As Jimmy Hastie said to Steve Fairbairn, “Take hold of it as hard as you can, row it through harder, and finish it out hardest.”
>
> Or is there another way to think about how to apply pressure against the blade? Charley Butts says that Kris Korzeniowski “... gave us a different way of thinking about rowing — that you didn't have to work so hard early in the stroke, that it was more important to maintain pressure throughout its entirety."
>
> Should rowers concern themselves with how to increase pressure? Or should they concern themselves with how to maintain pressure? Don’t just think about pulling harder through the stroke. Think instead about how to put pressure on the blade earlier and hold on to it longer. No mindless rowing!
>
> Warmest regards,
> Charles
>

Hi Charles, & all those (few) who, like you, still visit RSR with a
critical mind.

It's hard to argue against maximising force throughout the stroke, but
life is complicated by the cyclic complexities of the rowing process,
the limits imposed by our fixed oar/pin relationship, the excessive
focus on moving the boat (to which we are mechanically attached at all
times, so it goes "where" we go but not necessarily "as" we go, & cannot
accelerate away from us), & the inconvenient fact that we're doing this
while floating on water

I see too little (i.e. near zero) study of (or interest in) these
interactions, & too many unfounded assertions - despite the huge
investments by rowers in hard work & coaches in amplified & motorised
encouragement:
1. Water & blade - complex non-steady-state fluid dynamics, involving 2
disparate fluids separated (before each stroke) by a
gravitationally-sustained interface & with an oar-blade doing
"interesting" things to inject energy & thus disrupt same.
2. Inertial interactions between body mass & boat, with cycles of
kinetic energy storage & return subjecting the much lighter boat to
velocity-dependent fluctuations in fluid drag.
3. Strain energy storage in, & subsequent release from, the flexible
oarshaft from catch to finish & how this) affects the rate of
application of propulsive force & the stroke's propulsive efficiency.
Also how this affected by rower technique - feet or hands first, square
tap-down versus feathered finish.

In short, rowing focusses on technique without really understanding the
underlying processes. And we're offered a cornucopia of mental imagery,
some of which is probably bunk (despite sometimes producing desirable
effects contrary to reason & the explanations proffered). My question
is, "Why?"

I'm deliberately stirring the pot, but why not? Of course, I might just
settle for abolishing those demands to "accelerate the boat", since for
every acceleration there must be a compensating deceleration if you &
boat are to reach the end of the race together, & since constant boat
velocity offers the least fluid drag.

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: carl@carldouglasrowing.com Tel: +44(0)1932-570946 Fax: -563682
URLs: carldouglasrowing.com & now on Facebook @ CarlDouglasRacingShells

> It's hard to argue against maximising force throughout the stroke, but

Hi Carl,

Yes, I agree. Indeed it is hard to argue against maximising force. But I cannot resist. What is the old saying? Fools rush in where angels fear to tread?

Let me begin with a question. Should rowers think about maximising force? Or should they think about applying less force earlier?

Look at the graph below. Doesn’t F4 show that you get the same amount of power with roughly half the peak force if you apply force earlier and hold on to through the entire stroke?

https://photos.google.com/album/AF1QipMKBu_s87U8CyxqzLtIW1f3FuQ5iWn88dmphncI/photo/AF1QipPRmb8OediI6VT58_DernhhtgxocCFUpLAMXqma

Warmest regards,
Charles

Ps It is good to hear from you.

Carl,

I am having second thoughts about my reply. You write: “It's hard to argue against maximising force throughout the stroke …” If I had taken the time to be more careful about what you were saying, I would have realised that the phrase “force throughout the stroke” refers to power, not force. So in effect aren’t you and I talking about the same thing — that is, maximising power, not force?

This makes me think of Steve Fairbairn's account of the lesson he learned from his boxing instructor.

“An oarsman and the crew are nothing but a human hammer driving the boat with a hit. A hit is not a mere tap-and-withdraw action. When I was taught to hit by my boxing instructor, he took hold of my left glove and told me to advance it steadily, and as it landed on his face to lift my front foot and push with the other. So the beginning must have a push in it; not merely the momentum of the body being thrown at the water and vanishing in it, but a full-powered drive beginning with that momentum as the blade takes the water, and carrying it through with a drive from the stretcher.” ( “Rowing Notes,” Third Edition 1930, p. 156)

The hit and the follow-through are coefficients that unite in action to produce in Fairbairn’s words “a full-powered drive.”

What oarsman wants to row with less than a full-powered drive?

Warmest regards,
Charles

Carl,

I am having second thoughts about my reply. You write: “It's hard to argue against maximising force throughout the stroke …” If I had taken the time to be more careful about what you were saying, I would have realised that the phrase “force throughout the stroke” refers to power, not force. So in effect aren’t you and I talking about the same thing — that is, maximising power, not force?

This makes me think of Steve Fairbairn's account of the lesson he learned from his boxing instructor.

“An oarsman and the crew are nothing but a human hammer driving the boat with a hit. A hit is not a mere tap-and-withdraw action. When I was taught to hit by my boxing instructor, he took hold of my left glove and told me to advance it steadily, and as it landed on his face to lift my front foot and push with the other. So the beginning must have a push in it; not merely the momentum of the body being thrown at the water and vanishing in it, but a full-powered drive beginning with that momentum as the blade takes the water, and carrying it through with a drive from the stretcher.” ( “Rowing Notes,” Third Edition 1930, p. 156)

The hit and the follow-through are coefficients that unite in action to produce in Fairbairn’s words “a full-powered drive.”

Whether rowing leisurely or racing for gold, what oarsman wants to row with less than a full-powered drive?

Warmest regards,
Charles

On 31/05/2023 02:24, Charles Carroll wrote:
> Carl,
>
> I am having second thoughts about my reply. You write: “It's hard to argue against maximising force throughout the stroke …” If I had taken the time to be more careful about what you were saying, I would have realised that the phrase “force throughout the stroke” refers to power, not force. So in effect aren’t you and I talking about the same thing — that is, maximising power, not force?
>
> This makes me think of Steve Fairbairn's account of the lesson he learned from his boxing instructor.
>
> “An oarsman and the crew are nothing but a human hammer driving the boat with a hit. A hit is not a mere tap-and-withdraw action. When I was taught to hit by my boxing instructor, he took hold of my left glove and told me to advance it steadily, and as it landed on his face to lift my front foot and push with the other. So the beginning must have a push in it; not merely the momentum of the body being thrown at the water and vanishing in it, but a full-powered drive beginning with that momentum as the blade takes the water, and carrying it through with a drive from the stretcher.” ( “Rowing Notes,” Third Edition 1930, p. 156)
>
> The hit and the follow-through are coefficients that unite in action to produce in Fairbairn’s words “a full-powered drive.”
>
> Whether rowing leisurely or racing for gold, what oarsman wants to row with less than a full-powered drive?
>
> Warmest regards,
> Charles
>

Charles -

The pleasure is all mine - & best to you both from Jan and me. Much to
discuss privately - it's been too long.

Now to business - rowing!
There are 2 over-arching aspects to the net propulsive effect of the
rowing stroke:
1. The amount of work that you do during the stroke which, simply put,
is the sum (the integral) of the force that you apply at any instant
multiplied by the distance moved in that instant by the point of
application of that force (the hands)
2. The efficiency with which the work that you do is converted into
useful (propulsive) work.

That very simple depiction gets complicated very easily, so let's tread
carefully. One reason is the sheer complexity of the inertial
interactions between the rower's body (which weighs far more than the
boat), & how one best to manage the relative motion of body & boat.
Another reason is that the efficiency of the interaction between blade &
water is far from simple, varies continuously through the stroke & is
very difficult to analyse.

I feel, & see, little evidence that rowing wishes to study or understand
(or even acknowledge) these 2 aspects, preferring to think in stylistic
& stimulating but non-scientific terms - because it is very difficult to
do otherwise. Yet the time, effort & expense invested into rowing,
especially at top levels, could suggest that we should do more to study
those 2 factors listed above. Not to do so is like investing without
understanding the significance of risk & rate of return.

It's late after a busy day, so please treat the above as a place-holder
& I'll return in a day or so, over a cuppa, to elaborate. But let me
leave you with this thought, which I've expressed before:
that swirling puddle contains all of the energy input at the blade which
did _not_ move the boat.

Cheer -
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: carl@carldouglasrowing.com Tel: +44(0)1932-570946 Fax: -563682
URLs: carldouglasrowing.com & now on Facebook @ CarlDouglasRacingShells

On 02/06/2023 23:23, carl wrote:
> On 31/05/2023 02:24, Charles Carroll wrote:
>> Carl,
>>
>> I am having second thoughts about my reply. You write: “It's hard to
>> argue against maximising force throughout the stroke …” If I had taken
>> the time to be more careful about what you were saying, I would have
>> realised that the phrase “force throughout the stroke” refers to
>> power, not force. So in effect aren’t you and I talking about the same
>> thing — that is, maximising power, not force?
>>
>> This makes me think of Steve Fairbairn's account of the lesson he
>> learned from his boxing instructor.
>>
>> “An oarsman and the crew are nothing but a human hammer driving the
>> boat with a hit. A hit is not a mere tap-and-withdraw action. When I
>> was taught to hit by my boxing instructor, he took hold of my left
>> glove and told me to advance it steadily, and as it landed on his face
>> to lift my front foot and push with the other. So the beginning must
>> have a push in it; not merely the momentum of the body being thrown at
>> the water and vanishing in it, but a full-powered drive beginning with
>> that momentum as the blade takes the water, and carrying it through
>> with a drive from the stretcher.” ( “Rowing Notes,” Third Edition
>> 1930, p. 156)
>>
>> The hit and the follow-through are coefficients that unite in action
>> to produce in Fairbairn’s words “a full-powered drive.”
>>
>> Whether rowing leisurely or racing for gold, what oarsman wants to row
>> with less than a full-powered drive?
>>
>> Warmest regards,
>> Charles
>>
>
> Charles -
>
> The pleasure is all mine - & best to you both from Jan and me.  Much to
> discuss privately - it's been too long.
>
> Now to business - rowing!
> There are 2 over-arching aspects to the net propulsive effect of the
> rowing stroke:
> 1. The amount of work that you do during the stroke which, simply put,
> is the sum (the integral) of the force that you apply at any instant
> multiplied by the distance moved in that instant by the point of
> application of that force (the hands)
> 2. The efficiency with which the work that you do is converted into
> useful (propulsive) work.
>
> That very simple depiction gets complicated very easily, so let's tread
> carefully.  One reason is the sheer complexity of the inertial
> interactions between the rower's body (which weighs far more than the
> boat), & how one best to manage the relative motion of body & boat.
> Another reason is that the efficiency of the interaction between blade &
> water is far from simple, varies continuously through the stroke & is
> very difficult to analyse.
>
> I feel, & see, little evidence that rowing wishes to study or understand
> (or even acknowledge) these 2 aspects, preferring to think in stylistic
> & stimulating but non-scientific terms - because it is very difficult to
> do otherwise.  Yet the time, effort & expense invested into rowing,
> especially at top levels, could suggest that we should do more to study
> those 2 factors listed above.  Not to do so is like investing without
> understanding the significance of risk & rate of return.
>
> It's late after a busy day, so please treat the above as a place-holder
> & I'll return in a day or so, over a cuppa, to elaborate.  But let me
> leave you with this thought, which I've expressed before:
> that swirling puddle contains all of the energy input at the blade which
> did _not_ move the boat.
>
> Cheer -
> Carl

Part 2: How the work that you do is dissipated, & therefore wasted, in
the water. Let's have some definitions:-

1, Newton's 2nd Law of Motion: "Force applied to a body equals the mass
of that body multiplied by the acceleration induced", or F = m x a,
where 'F' is the force(e.g. Newtons, lb force, kg force, etc) to the
mass, 'm' (e.g. lb mass or kg mass), and 'a' is the resulting
acceleration of that mass (its rate of _change_ in velocity, measured as
feet or metres per second per second - no repeating the per second is
not a typo!)

2. Newton's 3rd Law of Motion: "Every action has an equal & opposite
reaction". If I push you, the force that you apply is the force that I
feel &, if we're of equal mass & both standing on frictionless ice, then
we will each move but in opposite directions at equal velocities.

3. Kinetic Energy: The energy stored in any moving body of mass 'm'
moving at velocity 'v' by virtue of its mass and velocity. This K.E. is
theoretically capable of being completely recovered when bringing the
moving object to a halt. In mathematical terms, this is defined as E =
0.5 x m x v^2/g, where 'g' is the gravitational constant (the rate of
acceleration of a body in free fall under gravity - ~9.81 metres/sec/sec
or 32.2 feet per sec per sec. To double a mass's velocity requires
quadruple the energy that was required to get it moving at its original
velocity.

4. Momentum: This is defined as mass times velocity - M = m x v

It is upon these fundamental relationships that boat propulsion depends.
But first understand that all mechanical (including fluid-mechanical)
processes are to some degree inefficient - part of the work invested is
inevitably lost/dissipated on the way, so your blade can never convert
100% of your work into propelling the boat. In fact what we can term
propulsive efficiency is depressingly low & with deficient technique may
even be 50% or less. For comparison, screw propulsion for ships tends
to be 60-70% efficient.

So how is so much of your input work/energy lost? Some of it disappears
because, to paraphrase Newton #3, to push the boat forward against the
frictional drag on its hull means that something else must be pushed
backwards - & that something is a "lump" of water. Since energy is
always conserved (can't be made, can't be destroyed), whatever is moved
backwards has gained a bundle of kinetic energy, which is a price paid
that can't be recovered - it's a total waste, a dead loss, but makes a
lovely puddle.

Which begs the question - how can we minimise that loss % thereby
increase the propulsive efficiency of our stroke?

Let me just say that this is where momentum comes into the calculation.
The force applied is proportional to the momentum gained by the mass
against which you are reacting. So you have an increase in momentum,
which is proportional to the thrust, which in turn is proportional to
the mass of water moved by the blade & the change in its velocity
(assumed to start from zero at the catch). And you have a simultaneous
increase in the kinetic energy of that mass of water, which is
proportional to that same mass of water and to the _square_ of its
increase in velocity.

I'll leave the there, to be resumed in my next posting. Some may
already see where this is heading...

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: carl@carldouglasrowing.com Tel: +44(0)1932-570946 Fax: -563682
URLs: carldouglasrowing.com & now on Facebook @ CarlDouglasRacingShells

On Sunday, 4 June 2023 at 20:50:00 UTC+1, carl wrote:
> On 02/06/2023 23:23, carl wrote:
> > On 31/05/2023 02:24, Charles Carroll wrote:
> >> Carl,
> >>
> >> I am having second thoughts about my reply. You write: “It's hard to
> >> argue against maximising force throughout the stroke …” If I had taken
> >> the time to be more careful about what you were saying, I would have
> >> realised that the phrase “force throughout the stroke” refers to
> >> power, not force. So in effect aren’t you and I talking about the same
> >> thing — that is, maximising power, not force?
> >>
> >> This makes me think of Steve Fairbairn's account of the lesson he
> >> learned from his boxing instructor.
> >>
> >> “An oarsman and the crew are nothing but a human hammer driving the
> >> boat with a hit. A hit is not a mere tap-and-withdraw action. When I
> >> was taught to hit by my boxing instructor, he took hold of my left
> >> glove and told me to advance it steadily, and as it landed on his face
> >> to lift my front foot and push with the other. So the beginning must
> >> have a push in it; not merely the momentum of the body being thrown at
> >> the water and vanishing in it, but a full-powered drive beginning with
> >> that momentum as the blade takes the water, and carrying it through
> >> with a drive from the stretcher.” ( “Rowing Notes,” Third Edition
> >> 1930, p. 156)
> >>
> >> The hit and the follow-through are coefficients that unite in action
> >> to produce in Fairbairn’s words “a full-powered drive.”
> >>
> >> Whether rowing leisurely or racing for gold, what oarsman wants to row
> >> with less than a full-powered drive?
> >>
> >> Warmest regards,
> >> Charles
> >>
> >
> > Charles -
> >
> > The pleasure is all mine - & best to you both from Jan and me. Much to
> > discuss privately - it's been too long.
> >
> > Now to business - rowing!
> > There are 2 over-arching aspects to the net propulsive effect of the
> > rowing stroke:
> > 1. The amount of work that you do during the stroke which, simply put,
> > is the sum (the integral) of the force that you apply at any instant
> > multiplied by the distance moved in that instant by the point of
> > application of that force (the hands)
> > 2. The efficiency with which the work that you do is converted into
> > useful (propulsive) work.
> >
> > That very simple depiction gets complicated very easily, so let's tread
> > carefully. One reason is the sheer complexity of the inertial
> > interactions between the rower's body (which weighs far more than the
> > boat), & how one best to manage the relative motion of body & boat.
> > Another reason is that the efficiency of the interaction between blade &
> > water is far from simple, varies continuously through the stroke & is
> > very difficult to analyse.
> >
> > I feel, & see, little evidence that rowing wishes to study or understand
> > (or even acknowledge) these 2 aspects, preferring to think in stylistic
> > & stimulating but non-scientific terms - because it is very difficult to
> > do otherwise. Yet the time, effort & expense invested into rowing,
> > especially at top levels, could suggest that we should do more to study
> > those 2 factors listed above. Not to do so is like investing without
> > understanding the significance of risk & rate of return.
> >
> > It's late after a busy day, so please treat the above as a place-holder
> > & I'll return in a day or so, over a cuppa, to elaborate. But let me
> > leave you with this thought, which I've expressed before:
> > that swirling puddle contains all of the energy input at the blade which
> > did _not_ move the boat.
> >
> > Cheer -
> > Carl
> Part 2: How the work that you do is dissipated, & therefore wasted, in
> the water. Let's have some definitions:-
>
> 1, Newton's 2nd Law of Motion: "Force applied to a body equals the mass
> of that body multiplied by the acceleration induced", or F = m x a,
> where 'F' is the force(e.g. Newtons, lb force, kg force, etc) to the
> mass, 'm' (e.g. lb mass or kg mass), and 'a' is the resulting
> acceleration of that mass (its rate of _change_ in velocity, measured as
> feet or metres per second per second - no repeating the per second is
> not a typo!)
>
> 2. Newton's 3rd Law of Motion: "Every action has an equal & opposite
> reaction". If I push you, the force that you apply is the force that I
> feel &, if we're of equal mass & both standing on frictionless ice, then
> we will each move but in opposite directions at equal velocities.
>
> 3. Kinetic Energy: The energy stored in any moving body of mass 'm'
> moving at velocity 'v' by virtue of its mass and velocity. This K.E. is
> theoretically capable of being completely recovered when bringing the
> moving object to a halt. In mathematical terms, this is defined as E =
> 0.5 x m x v^2/g, where 'g' is the gravitational constant (the rate of
> acceleration of a body in free fall under gravity - ~9.81 metres/sec/sec
> or 32.2 feet per sec per sec. To double a mass's velocity requires
> quadruple the energy that was required to get it moving at its original
> velocity.
>
> 4. Momentum: This is defined as mass times velocity - M = m x v
>
> It is upon these fundamental relationships that boat propulsion depends.
> But first understand that all mechanical (including fluid-mechanical)
> processes are to some degree inefficient - part of the work invested is
> inevitably lost/dissipated on the way, so your blade can never convert
> 100% of your work into propelling the boat. In fact what we can term
> propulsive efficiency is depressingly low & with deficient technique may
> even be 50% or less. For comparison, screw propulsion for ships tends
> to be 60-70% efficient.
>
> So how is so much of your input work/energy lost? Some of it disappears
> because, to paraphrase Newton #3, to push the boat forward against the
> frictional drag on its hull means that something else must be pushed
> backwards - & that something is a "lump" of water. Since energy is
> always conserved (can't be made, can't be destroyed), whatever is moved
> backwards has gained a bundle of kinetic energy, which is a price paid
> that can't be recovered - it's a total waste, a dead loss, but makes a
> lovely puddle.
>
> Which begs the question - how can we minimise that loss % thereby
> increase the propulsive efficiency of our stroke?
>
> Let me just say that this is where momentum comes into the calculation.
> The force applied is proportional to the momentum gained by the mass
> against which you are reacting. So you have an increase in momentum,
> which is proportional to the thrust, which in turn is proportional to
> the mass of water moved by the blade & the change in its velocity
> (assumed to start from zero at the catch). And you have a simultaneous
> increase in the kinetic energy of that mass of water, which is
> proportional to that same mass of water and to the _square_ of its
> increase in velocity.
>
> I'll leave the there, to be resumed in my next posting. Some may
> already see where this is heading...
>
> 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...@carldouglasrowing.com Tel: +44(0)1932-570946 Fax: -563682
> URLs: carldouglasrowing.com & now on Facebook @ CarlDouglasRacingShells

I am waiting for the next instalment ......

but - my reading so far, is;

we are aiming for the boat to have as constant a speed as is possible - because this reduces 'drag' and therefore is the most 'efficient' use of the input.

The blade efficiency (and possibly biomechanical force production capability) vary through the stroke cycle - I think I remember that the blade efficiency is greatest at the beginning and the end of the cycle, and biomechanically we are probably (muscle cross section) looking at the most force production availability in the early portion of the drive (up to perpendicular with the pin, when most knees are down and hip swing part way through?)

On 05/06/2023 09:55, James HS wrote:
> On Sunday, 4 June 2023 at 20:50:00 UTC+1, carl wrote:
>> On 02/06/2023 23:23, carl wrote:
>>> On 31/05/2023 02:24, Charles Carroll wrote:
>>>> Carl,
>>>>
>>>> I am having second thoughts about my reply. You write: “It's hard to
>>>> argue against maximising force throughout the stroke …” If I had taken
>>>> the time to be more careful about what you were saying, I would have
>>>> realised that the phrase “force throughout the stroke” refers to
>>>> power, not force. So in effect aren’t you and I talking about the same
>>>> thing — that is, maximising power, not force?
>>>>
>>>> This makes me think of Steve Fairbairn's account of the lesson he
>>>> learned from his boxing instructor.
>>>>
>>>> “An oarsman and the crew are nothing but a human hammer driving the
>>>> boat with a hit. A hit is not a mere tap-and-withdraw action. When I
>>>> was taught to hit by my boxing instructor, he took hold of my left
>>>> glove and told me to advance it steadily, and as it landed on his face
>>>> to lift my front foot and push with the other. So the beginning must
>>>> have a push in it; not merely the momentum of the body being thrown at
>>>> the water and vanishing in it, but a full-powered drive beginning with
>>>> that momentum as the blade takes the water, and carrying it through
>>>> with a drive from the stretcher.” ( “Rowing Notes,” Third Edition
>>>> 1930, p. 156)
>>>>
>>>> The hit and the follow-through are coefficients that unite in action
>>>> to produce in Fairbairn’s words “a full-powered drive.”
>>>>
>>>> Whether rowing leisurely or racing for gold, what oarsman wants to row
>>>> with less than a full-powered drive?
>>>>
>>>> Warmest regards,
>>>> Charles
>>>>
>>>
>>> Charles -
>>>
>>> The pleasure is all mine - & best to you both from Jan and me. Much to
>>> discuss privately - it's been too long.
>>>
>>> Now to business - rowing!
>>> There are 2 over-arching aspects to the net propulsive effect of the
>>> rowing stroke:
>>> 1. The amount of work that you do during the stroke which, simply put,
>>> is the sum (the integral) of the force that you apply at any instant
>>> multiplied by the distance moved in that instant by the point of
>>> application of that force (the hands)
>>> 2. The efficiency with which the work that you do is converted into
>>> useful (propulsive) work.
>>>
>>> That very simple depiction gets complicated very easily, so let's tread
>>> carefully. One reason is the sheer complexity of the inertial
>>> interactions between the rower's body (which weighs far more than the
>>> boat), & how one best to manage the relative motion of body & boat.
>>> Another reason is that the efficiency of the interaction between blade &
>>> water is far from simple, varies continuously through the stroke & is
>>> very difficult to analyse.
>>>
>>> I feel, & see, little evidence that rowing wishes to study or understand
>>> (or even acknowledge) these 2 aspects, preferring to think in stylistic
>>> & stimulating but non-scientific terms - because it is very difficult to
>>> do otherwise. Yet the time, effort & expense invested into rowing,
>>> especially at top levels, could suggest that we should do more to study
>>> those 2 factors listed above. Not to do so is like investing without
>>> understanding the significance of risk & rate of return.
>>>
>>> It's late after a busy day, so please treat the above as a place-holder
>>> & I'll return in a day or so, over a cuppa, to elaborate. But let me
>>> leave you with this thought, which I've expressed before:
>>> that swirling puddle contains all of the energy input at the blade which
>>> did _not_ move the boat.
>>>
>>> Cheer -
>>> Carl
>> Part 2: How the work that you do is dissipated, & therefore wasted, in
>> the water. Let's have some definitions:-
>>
>> 1, Newton's 2nd Law of Motion: "Force applied to a body equals the mass
>> of that body multiplied by the acceleration induced", or F = m x a,
>> where 'F' is the force(e.g. Newtons, lb force, kg force, etc) to the
>> mass, 'm' (e.g. lb mass or kg mass), and 'a' is the resulting
>> acceleration of that mass (its rate of _change_ in velocity, measured as
>> feet or metres per second per second - no repeating the per second is
>> not a typo!)
>>
>> 2. Newton's 3rd Law of Motion: "Every action has an equal & opposite
>> reaction". If I push you, the force that you apply is the force that I
>> feel &, if we're of equal mass & both standing on frictionless ice, then
>> we will each move but in opposite directions at equal velocities.
>>
>> 3. Kinetic Energy: The energy stored in any moving body of mass 'm'
>> moving at velocity 'v' by virtue of its mass and velocity. This K.E. is
>> theoretically capable of being completely recovered when bringing the
>> moving object to a halt. In mathematical terms, this is defined as E =
>> 0.5 x m x v^2/g, where 'g' is the gravitational constant (the rate of
>> acceleration of a body in free fall under gravity - ~9.81 metres/sec/sec
>> or 32.2 feet per sec per sec. To double a mass's velocity requires
>> quadruple the energy that was required to get it moving at its original
>> velocity.
>>
>> 4. Momentum: This is defined as mass times velocity - M = m x v
>>
>> It is upon these fundamental relationships that boat propulsion depends.
>> But first understand that all mechanical (including fluid-mechanical)
>> processes are to some degree inefficient - part of the work invested is
>> inevitably lost/dissipated on the way, so your blade can never convert
>> 100% of your work into propelling the boat. In fact what we can term
>> propulsive efficiency is depressingly low & with deficient technique may
>> even be 50% or less. For comparison, screw propulsion for ships tends
>> to be 60-70% efficient.
>>
>> So how is so much of your input work/energy lost? Some of it disappears
>> because, to paraphrase Newton #3, to push the boat forward against the
>> frictional drag on its hull means that something else must be pushed
>> backwards - & that something is a "lump" of water. Since energy is
>> always conserved (can't be made, can't be destroyed), whatever is moved
>> backwards has gained a bundle of kinetic energy, which is a price paid
>> that can't be recovered - it's a total waste, a dead loss, but makes a
>> lovely puddle.
>>
>> Which begs the question - how can we minimise that loss % thereby
>> increase the propulsive efficiency of our stroke?
>>
>> Let me just say that this is where momentum comes into the calculation.
>> The force applied is proportional to the momentum gained by the mass
>> against which you are reacting. So you have an increase in momentum,
>> which is proportional to the thrust, which in turn is proportional to
>> the mass of water moved by the blade & the change in its velocity
>> (assumed to start from zero at the catch). And you have a simultaneous
>> increase in the kinetic energy of that mass of water, which is
>> proportional to that same mass of water and to the _square_ of its
>> increase in velocity.
>>
>> I'll leave the there, to be resumed in my next posting. Some may
>> already see where this is heading...
>>
>> Cheers -
>> Carl
>>

>
> I am waiting for the next instalment ......
>
> but - my reading so far, is;
>
> we are aiming for the boat to have as constant a speed as is possible - because this reduces 'drag' and therefore is the most 'efficient' use of the input.
>
> The blade efficiency (and possibly biomechanical force production capability) vary through the stroke cycle - I think I remember that the blade efficiency is greatest at the beginning and the end of the cycle, and biomechanically we are probably (muscle cross section) looking at the most force production availability in the early portion of the drive (up to perpendicular with the pin, when most knees are down and hip swing part way through?)
>
> What I am going to postulate ('cos I only learn by having my thinking picked apart) is that even within this cycle, with these caveats, there is a dis-benefit to over-doing the acceleration early in the cycle (drag, fluid dynamics, blisters, tendons etc) and more benefit to an application of force that maximises the efficiencies here, and then holding that force through the stroke to the end where it becomes more efficient?)
>
> So I guess, to crudely summarise, I am a "hang and hold" rather than a "hang and bang".
>
> James
>

> Forget the rower for the moment, & just consider the relationships
> between thrust, momentum and kinetic energy:-

Carl,

Am I wrong to think that key to the argument is the rate at which momentum is acquired?

Peak force produced earlier and held onto through the entire stroke can provide as much momentum as twice the amount of peak force acquired late and let go early. Isn’t this what the graph in my earlier post shows?

Warmest regards.
Charles

On 20/06/2023 02:21, Charles Carroll wrote:
>> Forget the rower for the moment, & just consider the relationships
>> between thrust, momentum and kinetic energy:-
>
> Carl,
>
> Am I wrong to think that key to the argument is the rate at which momentum is acquired?
>
> Peak force produced earlier and held onto through the entire stroke can provide as much momentum as twice the amount of peak force acquired late and let go early. Isn’t this what the graph in my earlier post shows?
>
> Warmest regards.
> Charles
>
Hi Charles -

We must be careful because, so far, I've only discussed a quasi
steady-state situation - of stalled flow passing around, above & below a
blade which is at that stage roughly perpendicular to the direction of
that flow. This roughly defines the mid-stroke phase, & I've been
trying to indicate where & why conventional wisdom might conflict
disadvantageously with physical reality.

It matters to discuss this phase because, in part, of the prevailing
myth that this is where the stroke which most effectively propels the
boat (folk spout about the driving force being "orthogonal" - that Greek
geometric term granting them a veneer of quasi-scientific authority). My
other reason is that it's where the stroke generates the puddle & has
its lowest propulsive efficiency (see my earlier comment about the
puddle containing the energy which did _not_ move the boat).

In the rowing process momentum is imparted to a diffuse slug of water
all around the blade. The rate of momentum acquisition is proportional
to the force applied to the water by the blade (which matches the
reaction felt at the blade), & one problem is that we're dealing with a
fluid (water) which, as all fluids, is devilishly slippery. So we
cannot even define the limits of that slug of water, all of it being
affected to different extents. What an absolute mess! So no one in
rowing feels up to tangling analytically with the physics - easier to
stick with the old myths & mantras, as long as everyone else does the same?

What your questions seek, Charles, is to broaden the present discussion
to cover the entire stroke, including the catch & finish phases. But
when you ask about rate of loading the blade you run into the
interesting business not only of the very different flow regimes through
which the blade must pass but also the vital issues of how propulsive
efficiency varies through the stroke arc, & how a chunk of work done
around the catch goes not into propulsion but into bending the oarshaft
(it is a spring, storing strain energy), & how that strain energy
reserve is (or is not) fed back into the strokes towards the finish.

You ask an easy question which only has difficult answers. Maybe we can
fumble our ways to some kind of answers here, but only if RSR still
retains enough of its historically engaged and informed readership.
Otherwise we're talking in a darkened room. I'm treating this topic as
a test of whether RSR still has life.

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: carl@carldouglasrowing.com Tel: +44(0)1932-570946 Fax: -563682
URLs: carldouglasrowing.com & now on Facebook @ CarlDouglasRacingShells

Hi Carl -

It appears that the rsr brain trust has all but disappeared. I am not surprised. The only constant in life is change.

You are quite right to admonish me for asking easy questions that only have difficult answers. But that’s how we learn, isn’t it? What follows is a small meditation on science and artistry and rowing. Maybe it will give you a chuckle as you read it.

Best to Jan,
Charles

Does it make sense to think of a racing shell as being either fast or slow? No it doesn't for the simple reason that as a means of transport a racing shell is not self-propelling. For propulsion it depends entirely on an independent engine, the rower. For this reason a racing shell, in and of itself, can neither be said to be either fast or slow. But a racing shell with the correct hull geometry can do less to slow a fast rower down.

The preceding statement is important because it introduces a relationship between science and artistry. Many imagine inescapable conflict in such a relationship. Without much thought they are given to hypothesize the superiority of one over the other.

But doesn’t this beg a question? Is the relationship between science and artistry necessarily antagonistic?

While it is undeniably true that there is science in rowing, it is also undeniably true that there is artistry in rowing. Science is learned through careful observation and thought. Artistry, on the other hand, is cultivated through practice. Isn’t this why “mileage makes champions” is an idea so beloved by coaches and rowers? Artistry in rowing is gained and refined through mileage. One does not spend thousands of hours pulling against an oar handle to learn the science of rowing, but rather to acquire and perfect the artistry of rowing.

So the artistry of rowing is about fast rowers rowing boats that do less to slow them down. And the science of rowing is to equip rowers with such boats and other necessaries to accomplish this.

An old Roman saying - there are no fast chariots, only fast horses.

dw

On Monday, July 3, 2023 at 4:46:57 PM UTC-4, Charles Carroll wrote:
> Hi Carl -
>
> It appears that the rsr brain trust has all but disappeared. I am not surprised. The only constant in life is change.
>
> You are quite right to admonish me for asking easy questions that only have difficult answers. But that’s how we learn, isn’t it? What follows is a small meditation on science and artistry and rowing. Maybe it will give you a chuckle as you read it.
>
> Best to Jan,
> Charles
>
> Does it make sense to think of a racing shell as being either fast or slow? No it doesn't for the simple reason that as a means of transport a racing shell is not self-propelling. For propulsion it depends entirely on an independent engine, the rower. For this reason a racing shell, in and of itself, can neither be said to be either fast or slow. But a racing shell with the correct hull geometry can do less to slow a fast rower down.
>
> The preceding statement is important because it introduces a relationship between science and artistry. Many imagine inescapable conflict in such a relationship. Without much thought they are given to hypothesize the superiority of one over the other.
>
> But doesn’t this beg a question? Is the relationship between science and artistry necessarily antagonistic?
>
> While it is undeniably true that there is science in rowing, it is also undeniably true that there is artistry in rowing. Science is learned through careful observation and thought. Artistry, on the other hand, is cultivated through practice. Isn’t this why “mileage makes champions” is an idea so beloved by coaches and rowers? Artistry in rowing is gained and refined through mileage. One does not spend thousands of hours pulling against an oar handle to learn the science of rowing, but rather to acquire and perfect the artistry of rowing.
>
> So the artistry of rowing is about fast rowers rowing boats that do less to slow them down. And the science of rowing is to equip rowers with such boats and other necessaries to accomplish this.