Getting rid of that CHECK !!!!!

Getting rid of that CHECK !!!!!

Post by Planke, Jason » Tue, 12 Sep 1995 04:00:00


I have rowed for six years now. 4 years in High School and
2 years in College. So over this 7 year period I have heard of
about 1000 different ways to stop the check in a shell. The problem
goes like this: The Men's Varsity Eight that I row in has tried looking
for a lunge by the rowers at the catch, all the way to curling the toes
up on the recovery. But still the boat feels checked.
Please just write down any suggestions you might have.
5 - Man
 
 
 

Getting rid of that CHECK !!!!!

Post by Ken You » Wed, 13 Sep 1995 04:00:00


Quote:
>I have rowed for six years now. 4 years in High School and
>2 years in College. So over this 7 year period I have heard of
>about 1000 different ways to stop the check in a shell. The problem
>goes like this: The Men's Varsity Eight that I row in has tried looking
>for a lunge by the rowers at the catch, all the way to curling the toes
>up on the recovery. But still the boat feels checked.
>Please just write down any suggestions you might have.
>5 - Man

One of the problems of solving "check" is that coaches and rowers
seem to define it in may ways.  Of course we all agree that "check"
makes the boat go slower.

First the laws of physics say that you and the boat must slow down
between strokes.  The center of mass of you and boat immediately starts
to slow
down after the release.  Since you slide your mass relative to the boat,
you can keep the boat speed up after the release and even speed the boat
up.
However, you don't get something for nothing.  At the end of the
recovery
your body must come to rest momentarily before driving.    Just at that
moment,
the boat and you are going the slowest.  No matter what technique you
may use,
this is unavoidable.  You will notice this in the wake.

However, you can slow the boat even more and waste a lot of energy if
you
start your drive [either with your legs or your hips ]  BEFORE you have
completely buried your blades.  The boat speed will decrease
dramatically
if you do this.  This is what one should mean by "check".  You lose
average boat
speed because you will be wasting part of your drive by not "locking"
your
blades in.  The boat wake will look very different from the good case
and your cox will feel his/her head jerked forward.

To learn the difference in feel between the natural necessary
decceleration
and the mistimed catch, you should try the usual stroke but with a pause
at the
catch.  You should see the wake pattern with the boat slowing down.
Then compare
this with the wake pattern when you go right into the stroke.  You might
even mistime
your catch deliberately and see the result of this.

I find that check isn't a problem except when I'm too e***d and
mistime
my catch.  It's a mind thing... to bury the blades really fast then
start
the drive.

Good Luck,
Ken Young
  :
--

Ken Young                                Tel: 206 543 4186
Dept of Physics Box 351560               FAX: 206 685 9242


 
 
 

Getting rid of that CHECK !!!!!

Post by Hcrun » Wed, 13 Sep 1995 04:00:00

I've been thinking about check lately and asked my old college coach, Dave
Vogel at Yale, about it. All he said--more or less--was that the great
old-time English coach Steve Fairbairn had dismissed check as irrelevant
to a boat's motion, saying that the important thing was to get all
possible forward drive out of everyone in the boat.

Of course, getting all possible drive means not missing any water at the
catch, and missed water ("rowing it in") is the most likely cause of
check, for the reason given in the preceding response to your query: If
you start your body back toward the bow before your blade's in the water,
you're literally kicking the boat backward with your legs. Just work for a
good entry at full reach, *followed* (very quickly) by application of
force via the legs. If you can achieve that *and* get everyone moving
together, whatever the details of the style, you should be in good shape.

It's worth keeping in mind, too, that rushing on the slide is a common
cause of rowed-in blades--it tends to make you freeze at the catch,
because it takes so much more effort to stop your sternward motion when
you're moving fast on the slide. So try having everybody concentrate on a
carefully controlled slide with no acceleration toward the catch. That
will help you get a good quick entry with no missed water.

That'll be two cents, please. Good luck!



 
 
 

Getting rid of that CHECK !!!!!

Post by Jeffrey A. Festia » Wed, 13 Sep 1995 04:00:00

One of the biggest causes of a check in a boat is when the crew is
starting their leg drive before the oar has been placed in the water.  It
seems like the entire crew I have rowed with in the past has had this
problem.  When a crew does this it transfers the energy of the leg drive
in the direction of the stern until the blade is put in the water.  Let
me put it to you this way...
        Imagine all eight of you sitting in the boat and going through the
motions of rowing with out an oar in any of your hands.  Now, the recovery
will not have much affect on the movement of the boat, but when all eight
of you come up to the catch position and explode with the leg drive you
will inevitably jerk the boat toward the stern (what I call negative
energy) I argue that the same thing can happen even if the rowers do have
oars in their hands.
        If the rowers' blades are not buried before the leg drive is
started the same thing happens.  Of course the blades are going to enter
at some point of the drive.  Maybe after missing half a foot to a
foot of water but by then energy has been lost in pushing the boat backwards
in the form of a check and stopping momentum.  Then as the blades do enter
the water the boat starts its forward momentum again until the crew comes
up for the next catch and the process repeats itself.
        One tell tale sign that this is what is happening is that at
catch there is no backsplash off the blades.  And if there is a
tremendous foresplash this is most definately the problem.  Another way
to check for this problem is to ride along side of the shell and watch
for the movement of the blades.  If the blade is out of the water it
should only be moving toward the bow and not toward the stern.  If the leg
drive is being started before the blade is buried you will see the blade
move toward the stern for a fraction of a second before it is buried.
This will cause a significant check in the boat and might be your problem.
        This is somewhat of a novice solution but sometimes these things
are overlooked by even the best of us.  Just remember that the instant
you are fully compressed to start your leg drive the blade should be in
the water before you pull.
        If anyone has any comments on this please write me back and let
me know what you think.

Jeff Festian

 
 
 

Getting rid of that CHECK !!!!!

Post by Hcrun » Wed, 13 Sep 1995 04:00:00

I've been thinking about check lately and asked my old college coach, Dave
Vogel at Yale, about it. All he said--more or less--was that the great
old-time English coach Steve Fairbairn had dismissed check as irrelevant
to a boat's motion, saying that the important thing was to get all
possible forward drive out of everyone in the boat.

Of course, getting all possible drive means not missing any water at the
catch, and missed water ("rowing it in") is the most likely cause of
check, for the reason given in the preceding response to your query: If
you start your body back toward the bow before your blade's in the water,
you're literally kicking the boat backward with your legs. Just work for a
good entry at full reach, *followed* (very quickly) by application of
force via the legs. If you can achieve that *and* get everyone moving
together, whatever the details of the style, you should be in good shape.

It's worth keeping in mind, too, that rushing on the slide is a common
cause of rowed-in blades--it tends to make you freeze at the catch,
because it takes so much more effort to stop your sternward motion when
you're gathering speed on the slide. So try having everybody concentrate
on a
carefully controlled slide with no acceleration toward the catch. That
will help you get a good quick entry with no missed water.

That'll be two cents, please. Good luck!

Howard Runyon
Chicago

 
 
 

Getting rid of that CHECK !!!!!

Post by Larrysha » Wed, 13 Sep 1995 04:00:00

I have a copy of the video tape of the '95 worlds in Indiana. I watched
the gold medal men's 8+ in stop action. The total time of the swing, from
full compression to full layback was around 24 frames (at 1/30 sec per
frame). From full compression to the catch took between 4 and 5 frames,
the drive in the water was about 14 or 15 frames, and the time between
release and full layback (the hands have reached there farthest position
toward the bow) between 4 and 5 frames.  During all of the race, the
stroke rate was above 40 strokes per minute.

What can be learned from this?  If it is conceeded that this particular
crew was pretty good, then the catch does not happen at full compression,
but at about 1/5 of the way into the stroke. Likewise, the release (which
is much more difficult to see on video tapes because of the spray) happens
well before the end of the swing back.  Take a look at any video of a good
crew and you will see that there is plenty of leg drive before the catch
(by which I mean that water is suddenly piled up on the face of the blade.
Larry

 
 
 

Getting rid of that CHECK !!!!!

Post by John P. Wangerma » Wed, 13 Sep 1995 04:00:00



Quote:
>    Imagine all eight of you sitting in the boat and going through the
>motions of rowing with out an oar in any of your hands.  Now, the recovery
>will not have much affect on the movement of the boat, but when all eight
>of you come up to the catch position and explode with the leg drive you
>will inevitably jerk the boat toward the stern (what I call negative
>energy) I argue that the same thing can happen even if the rowers do have
>oars in their hands.

It's simply conservation of momentum.  When the oars are out of the
water, the boat and crew act as a system with almost no external forces
applying. With no external forces the total momentum of the system is
always conserved.  When the crew starts a recovery the forward speed of the
_oarsmen_ decreases compared to what it was at the release.  For
momentum to be conserved the velocity of the boat must increase.  This
is the surge that you can see a boat make at the release.

Now if the crew stops when they reach front stops with their blades out
of the water then their forward velocity has increased again, so the
boat slows a bit to maintain momentum.  (For thos who want an equation
        Ptotal = Mcrew x Vcrew + Mboat x Vboat)
If nothing else has happened, the boat will return to the speed it had
at the release.  However, if the crew drives down on their stretchers,
Vcrew has suddenly increased, so Vboat must decrease to maintain the
total momentum.  This is the check.  Hence, why the blade should be
backed in as the _last action of the recovery_ - it should not be pulled
in as the first action of the drive.

Totally agree with all Jeff's good comments about backsplash etc.

Pablo Wangermann
Carnegie Lake RA

 
 
 

Getting rid of that CHECK !!!!!

Post by A.J. Pot » Thu, 14 Sep 1995 04:00:00

Yeah, but Fairbairn crews also hung terminally at the catch compared to
what we now think of as orthadox. And they belted it up the slide and
walloped into front-stops. And had silly shaped oars.

But they all did it perfectly together, and hence won lots of things. But
not, of course, the 1908 Olympics :

Cambridge Univ. (rowing Fairbairn style), as GB II, knocked out by Belgium
in the semis on the Henely reach; Final: GB I v. Belgium. Belgium have won
the Grand the year before (first foreign winners yuck pooh); GB I have an
average age of about 45 and row _very_ orthodox ie. swing swing together.
GB WIN!  against the dastardly Belgiums. Belgiums sulk; GB hobble off on
their walking-sticks except coxswain Gilchrist Maclagan who goes off to
join the army and gets killed at Ypres in 1915.

Maclagan coxed Eton, then Oxford Blue Boat four times (a record?) winning
twice;  thence to Leander where he won the Grand seven times (definitely a
record) and, of course, the Olympics.

GB win again in 1912 - havn't won Olympic eights since :(

Sorry, this has nothing to do with catches. A random wibble, methinks.

AJP

 
 
 

Getting rid of that CHECK !!!!!

Post by Sullys Ma » Thu, 14 Sep 1995 04:00:00


Quote:

>I have a copy of the video tape of the '95 worlds in Indiana. I watched
>the gold medal men's 8+ in stop action. The total time of the swing, from
>full compression to full layback was around 24 frames (at 1/30 sec per
>frame). From full compression to the catch took between 4 and 5 frames,
>the drive in the water was about 14 or 15 frames, and the time between
>release and full layback (the hands have reached there farthest position
>toward the bow) between 4 and 5 frames.  During all of the race, the
>stroke rate was above 40 strokes per minute.

the gold medal 8 in 95 rowed over 40 the whole race?  someone
verify?

Quote:

>What can be learned from this?  If it is conceeded that this particular
>crew was pretty good, then the catch does not happen at full compression,
>but at about 1/5 of the way into the stroke. Likewise, the release (which
>is much more difficult to see on video tapes because of the spray) happens
>well before the end of the swing back.  Take a look at any video of a good
>crew and you will see that there is plenty of leg drive before the catch
>(by which I mean that water is suddenly piled up on the face of the blade.
>Larry

First of all, thanks for posting the observation.   It is extremely
valuable.  having  done miles of video, and 16 mm film and 8 mm film
with tons of coaches and athletes, I've learned there is a method of
observing film that must be learned, and I trust not others
observations until I've seen the video myself.

next, I have observed nearly every kind of rowing fault by world
champs.   Observing a phenomenom and concluding that the phenom is
good by the success of the crew is not valid.

Again, I emphasize the value of posting the observation here.
Bravo.

mike

 
 
 

Getting rid of that CHECK !!!!!

Post by Sullys Ma » Thu, 14 Sep 1995 04:00:00


Quote:

>Yeah, but Fairbairn crews also hung terminally at the catch compared to
>what we now think of as orthadox. And they belted it up the slide and
>walloped into front-stops. And had silly shaped oars.

>But they all did it perfectly together, and hence won lots of things. But
>not, of course, the 1908 Olympics :

>Cambridge Univ. (rowing Fairbairn style), as GB II, knocked out by Belgium
>in the semis on the Henely reach; Final: GB I v. Belgium. Belgium have won
>the Grand the year before (first foreign winners yuck pooh); GB I have an
>average age of about 45 and row _very_ orthodox ie. swing swing together.
>GB WIN!  against the dastardly Belgiums. Belgiums sulk; GB hobble off on
>their walking-sticks except coxswain Gilchrist Maclagan who goes off to
>join the army and gets killed at Ypres in 1915.

>Maclagan coxed Eton, then Oxford Blue Boat four times (a record?) winning
>twice;  thence to Leander where he won the Grand seven times (definitely a
>record) and, of course, the Olympics.

>GB win again in 1912 - havn't won Olympic eights since :(

>Sorry, this has nothing to do with catches. A random wibble, methinks.

no.  It should help prevent us Yanks from invoking Fairbairn,
though.
Mike