Re: Advanced Sculling Technique

On Jun 27, 8:47 pm, Carl Douglas <c...@xxxxxxxxxxxxxxxxx> wrote:
Charles Carroll wrote:
Dear All,

Not that anything Daniel Boyne has to say about "Advanced Sculling"
hasn't already been said or at least alluded to on rsr, but Dan puts it
together nicely, and says it rather well, and I found it fascinating.

http://www.hemus.nl/coaching/advanced.html

Cordially,

Charles

In general, good stuff. I like his emphasis on smoothness & relaxation,
with nothing to excess.

Only point which simply can't hang to gether is this one:
"A curved back, with the shoulders used as a counterbalance to the
overall layback, helps execute the correct motion. When you get it down
right, your body moves out of the bow with ease, with no need to pull on
the foot stretchers."

The drag on the hull at peak speed (= finish speed) is well in excess of
10kg force. Your body mass experiences a similar force towards the bow
(Newton: every action has an equal & opposite reaction). And that force
is delivered from the stretcher, putting the legs in tension. Even to
move the body relative to the boat, your legs _must_ pull harder than
that force.

Cheers -
Carl


I had been pondering this question for a while, mostly because it is
such a larger part of many coaches' approaches, and clearly can't make
sense. The only conclusion I had come to is that the motion which
coaches are requesting when they say that is: Gaining a substantial
amount of horizontal sternwards momentum relative to the boat before
leaving backstops, thereby minimising the force with which it is
necessary to pull sternwards during the rest of the recovery. The
merits of this style are then a separate question.

I'm surprised you didn't have more to say about

"Maintaining this pressure helps sustain the cavity or "divot" of
water just behind the blade from which it can be easily plucked from
the water."

While this, as stated at least, cannot be true, what are the physical
factors which make it desirable to have pressure still on the blades
in order to produce a clean finish (other than the direct reason that
there's no point having the blade in the water unless you're
accelerating the system)?

Peter
.

Relevant Pages

  • Re: Advanced Sculling Technique
    ... Peter Ford wrote: ... water just behind the blade from which it can be easily plucked from ... factors which make it desirable to have pressure still on the blades ...
    (rec.sport.rowing)
  • Re: When to push off the stretcher
    ... When people talk about pressure building up "in front" of the blades in this context, ... The "front" of the blade from the point of view of the boat, i.e. the side facing the front of the boat, is the /back/ of the blade when you're talking about the blade itself. ... When you pull a blade that's in the water, the stuff in front of it simply moves aside, so little pressure can built up on the face, but the water behind the blade has nowhere much to go, so it clings to the back of the blade. ... Water is very hard so it doesn't give; when the blade tries to move away from the water behind it, at first that water behind it develops internal tension, exactly enough across the area of the blade to balance the applied load, & its pressure _falls_. ...
    (rec.sport.rowing)
  • Re: When to push off the stretcher
    ... When people talk about pressure building up "in front" of the blades in this context, ... The "front" of the blade from the point of view of the boat, i.e. the side facing the front of the boat, is the /back/ of the blade when you're talking about the blade itself. ... When you pull a blade that's in the water, the stuff in front of it simply moves aside, so little pressure can built up on the face, but the water behind the blade has nowhere much to go, so it clings to the back of the blade. ... Water is very hard so it doesn't give; when the blade tries to move away from the water behind it, at first that water behind it develops internal tension, exactly enough across the area of the blade to balance the applied load, & its pressure _falls_. ...
    (rec.sport.rowing)
  • Re: Sculling Finish
    ... That pressure is wholly inadequate for the task, which is principally done by the fluid tension existing across the blade's back. ... And this applies even in the mid-stroke stall phase of the stroke provided teh blade is kept sufficiently buried to rpevent hole formation. ... The flow of water across the convex side of the blade is what provides the "low pressure zone" that reduces drag for both squared and feathered releases. ... You can get substantial hydrodynamic lift without there being any increase in pressure over any part of the concave face of the blade. ...
    (rec.sport.rowing)
  • Re: ex-cell power washer
    ... of high pressure water and then it just pisses out. ... trigger the motor bogs down for a second and then idles normal (i guess ... pull the trigger while aiming at whatever you're power washing, ...
    (alt.home.repair)