sculling oarlock height

[mislav]

I am currently setting sliding seat unit with outriggers and oarlocks from
Gary Piantedosi for my home built recreational rowing shell (by CLC of
Annapolis, MA). Piantedosi instructions suggests that one oarlock should be
placed higher. Many other sources found on web and in this newsgroup
recommend the same.

However Graeme King in his series of Kingfisher articles published in
WoodenBoat magazine suggests that both oarlocks should be placed at the same
height and that the sculler should roll the boat slightly in the middle of
the stroke to achieve the crossover. He claims that scullers that row with
one oarlock higher have tendency to level their hands, therefore roll the
boat, at both the catch and release. While rolling the boat during the
stroke does not seem to create any major problem, King claims that rolling
at the catch (and perhaps release too) might have significant impact on
stability.

I wonder what is general opinion on this topic and in what way people
usually set up oarlock height.

[mart...@carr12331.freeserve.co.uk]

Most scullers I know tend to scull with one gate washer difference
which makes one gate about 1/2 centimetre higher. (most are rigged with
the bowside/starboard gate higher)

I'm note sure though what you mean by an intentional roll of the boat
mid stroke?

[andy....@ps.ge.com]

Wouldn't you be more likely to dig the left blade...?

Just shorten the inboard so there is no crossover :)

I have mine set so that the left is 1cm higher than right, and then
have the left hand slightly higher and slightly in front (well behind
if you want to get picky, but it's in front the way I'm looking at
it...).

I think I catch and finish level though, I definately don't try to
reach more with the left at the catch and I don't finish shorter with
the left, but the boat still seems to go straight.

There's not a lot of difference in position with the left handle about
45 degrees forward and up of the right, so I don't think it makes too
much difference as long as you don't catch the handles whilst crossing
over. Do what is most comfortable.

[mislav]

> I'm note sure though what you mean by an intentional roll of the boat
> mid stroke?

If the oarlocks were at the same height then the only way to cross hands
left over right would be to tilt the boat to the port side. If that happened
at the catch or release (as a result of supposed improper reaction to
oarlock height difference by leveling hands) then it would obviously
introduce some pitch difference between the oarlocks, while during the
midstroke it wouldn't.

[andy....@ps.ge.com]

> only way to cross hands
> left over right would be to tilt the boat to the port side

Or have one hand in front of the other...

[Carl Douglas]

mislav <mislav....@alfakompjuter.hr> writes

Typical difference in hand height at the crossover would be around
4.5cm, give or take. If the object is to keep the blade immersed up to
the neck at mid-stroke (& I'd advocate somewhat deeper than that), then
to row the boat level throughout the stroke implies an oarlock height
differential of close to 3cm.

Few scullers use much over 1cm height differential, so we must assume
that the boat rolls by ~3/4 degree around the crossover point on each
stroke.

Rolling like that is not ideal, because it causes the fin/skeg to cut
diagonally first one way and then the other, which must put a bit of a
wiggle into your course as well as generating a little bit of extra
drag.

However, that's what scullers do. At least, I've only once encountered
a sculler who rigged for the full 3cm differential, the use of which
implies either that they catch & finish with their hands almost 5cm
different in height or, failing that, the catch & finish with the boat
tipped down on bowside/starboard - with the same problem I've already
indicated.

HTH
Carl
--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
Email: ca...@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)

[vet...@hotmail.com]

I've always understood that the reason scullers have to cross their
hands is so that their 'gearing' (yes, I know that's probably not the
right word) is correct;
1. If you shorten the inboard, gearing is too high
2. If you shorten the inboard and the length of the scull, gearing is
too low.

Why, with modern technology, can we not use a 'Big-Big' blade to
achieve appropriate 'gearing' ?

Paul W

[Neil Wallace]

Carl Douglas wrote:
(snip)

>
> However, that's what scullers do. At least, I've only once
> encountered a sculler who rigged for the full 3cm differential, the
> use of which implies either that they catch & finish with their hands
> almost 5cm different in height or, failing that, the catch & finish
> with the boat tipped down on bowside/starboard - with the same
> problem I've already indicated.

When we discussed Olaf Tufte's stroke cycle here last year, many thought he
was rigged with about 3cm diff.

for the crossover shot see
http://www.invernessrowingclub.co.uk/personal/tufte/images/tufte37.jpg

and for the full cycle
http://www.invernessrowingclub.co.uk/personal/tufte/tufte.html

[mislav]

> HTH
> Carl

Definitely. Thanks Carl. Strange how such an experienced shell builder like
King didn't mention fin lift effect resulted from rolling the hull. So the
conclusion is that general practice is infact a compromise between the two:

given that left hand is above the right at crossover:
1. same height + rolling at mid stroke to port
and
2. different height + the danger of rolling at catch/release to starboard

One might suspect that this combination of two implies both rolling at mid
stroke and at catch/release, but I guess that's life.

[mislav]

> and for the full cycle
> http://www.invernessrowingclub.co.uk/personal/tufte/tufte.html

Interesting, but it's hard to see whether the shell is tilted constantly
from this perspective. If anything, from the difference in angles between
oars and water level I would say that it's definitely tilted to port at the
catch.

It's also interesting that his left hand is both above and slightly in front
of the other.

[Neil Wallace]

mislav wrote:
> It's also interesting that his left hand is both above and slightly
> in front of the other.

Have a look at picture 3 on page 6 of this PDF.
http://www.rowingcanada.org/files/RowingSummer01.pdf

The Canadian view of what happens at the cross-over.

[mislav]

> Have a look at picture 3 on page 6 of this PDF.
> http://www.rowingcanada.org/files/RowingSummer01.pdf

Thanks for the article Neil. This is exactly what I was taught to do - upper
(left) hand follows the lower (right).. But not what I see in Olaf's
pictures. You can clearly see that his right (lower) hand follows the left
in both stroke and recovery.

[IPS]

But not what I see in Olaf's
pictures. You can clearly see that his right (lower) hand follows the
left
in both stroke and recovery.

That's the classic Norwegian style, as demonstrated by the champion
double of Frank and Alf Hansen in the seventies and eighties.

[paul_v...@hotmail.com]

A very clear shot of hand position with less required Oarlock
difference, and no "rolling of the boat".

http://www.nlroei.nl/Fotoboek-display-39831.html

- Paul Smith

[mislav]

>A very clear shot of hand position with less required Oarlock
> difference, and no "rolling of the boat".

Nice shot Paul. It's hard if not impossible to guess the oarlock height
without measuring. I believe this is 4x and that it would be quite difficult
for a four men crew to "roll the boat" simultaneously. I never rowed in 2x
or 4x, but I know from 4 and 8 that for any serous rowing a crew boat must
be perfectly stable, otherwise everyone thinks the other 3 (or 7) are to be
blamed.

[paul_v...@hotmail.com]

It's the others fault in a 2x too. [;o)

- Paul Smith

[Henry Law]

On 19 Jul 2005 06:10:49 -0700, paul_v...@hotmail.com wrote:

>It's the others fault in a 2x too. [;o)

And the major problem with my performance in the 1x is the guy who's
doing the sculling.
--

Henry Law <>< Manchester, England

[Walter Martindale]

Hmmm. with a flexible fin.. would rolling the boat make it work like
swim flippers? Hmm. How long before whippy fins with a rock 'n roll
balance profile become the new fad? 8-)
W

[Ewoud Dronkert]

On Wed, 20 Jul 2005 05:27:58 GMT, Walter Martindale wrote:
> How long before whippy fins with a rock 'n roll
> balance profile become the new fad? 8-)

Very old stuff, doesn't work. Tim Finn et al. (1983) - There's a fraction
too much friction.

--
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[mislav]

Googling around I found this:

http://dps.twiihosting.net/fisa/doc/content/doc_7_657.pdf

This is supposed to be FISA Intermediate Rigging booklet.