Technology vs hype in rowing
Carl Douglas
now America's Cup grinder, Greg Searle's report in today's Independent
newspaper (UK)
http://sport.independent.co.uk/general/story.jsp?story=346282
of the strange mix of bullshit & technical aversion which affects our
sport. I quote:
"After having the same conversation as I had on arrival about why
we rowers didn't look after our boats better, a few of our Olympic
sailors and our chief designer, Derek Clark, were off into serious
techno-speak ranging from why rowing boats aren't longer to the
use of other materials on the hull. Matthew's ultimate answer was
that if you're winning already, then why chase your tail looking
down blind alleys? The sailors are still mystified as to why we
don't make life easier for ourselves with technology, but I
remember fondly the old days when performance came down to pulling
the stick harder than the other guy."
Our sport, although highly mechanical, is remarkably science-averse.
I've had so many correspondences, on & off this newsgroup, with rowers
who while studying for science degrees at famous Universities
don't/won't try to understand how buoyancy works (Archimedes' Principle
is introduced at year 8 in UK schools!), or that oars don't work by just
pushing water away, or that you can't build fast racing shells on the
principle of minimum wetted surface (you get very slow woks), or that
wind & water drag on rigging slows boats & can be reduced, or that boat
design matters, or that a paint colour doesn't equate to success. So
Greg's new appreciation of the gulf between sailors' & rowers' attitudes
to their equipment was a most refreshing breath of clean air.
BTW - technology does not reside within a material, or a shape, but in
how intelligently the product's working environment is understood, how
intelligently the designs are prepared, how intelligently the products
are put together & then how intelligently they are used.
Discuss :-)
Cheers -
Carl
PS On the recurring topic of Archimedes, his 2250-year-old Principle &
the dangers of rowing in a science-free zone:
A well-known UK shell builder recently wrote to me on shell buoyancy to
say that whereas "You have your theories", he had done "many years" of
practical testing.
I had to reply that:-
1. Archimedes' Principle is no mere "theory" (its proper analytical use
allows complete prediction of the flotation & trim characteristics of
any vessel under any combination load & flooding conditions).
2. It's use is essential, routine & mandatory in the design of vessels
of every kind (which includes racing shells!).
3. Man-made tests only test the chosen test process, whereas real life
tests everything.
4. And that all those purported tests had signally failed to predict the
real life vulnerability of certain shells to sudden sinking during
swamping, with awful & fatal consequences.
C
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)
Neil Wallace
"Carl Douglas" <ca...@carldouglas.co.uk> wrote in message
news:J4Jr5LAt...@rowing-cdrs.demon.co.uk...
SNIP
>Our sport, although highly mechanical, is remarkably science-averse.
> BTW - technology does not reside within a material, or a shape, but in
> how intelligently the product's working environment is understood, how
> intelligently the designs are prepared, how intelligently the products
> are put together & then how intelligently they are used.
>
> Discuss :-)
>
Good thread Carl,
as an relative newcomer, I think I can speculate as to a couple of reasons.
1. Money - those at the top of our sport are on peanuts compared to others.
Research and development is horrendously expensive, can rowing compete with
formula one or the America's cup?
On a smaller scale - suppose there was a very expensive, but revolutionary
new very lightweight oar.... would FISA allow it, or jump to the defence of
smaller nations again (AKA sliding riggers).
Sponsorship also means that teams become tied to a manufacturer. Further
narrowing the rights for innovation.
2. Conversely, whilst boat design has remained relatively static, there have
been big advances due to the application of sports science to training
methodology. A good use of technology.
Surely increasing your power/weight ratio is important?
This priority may change with time.
3. Pinsents point along the lines of "we keep winning....why change?" does
seem to be a good argument. Of course, they did change their shell after
being given a spanking by Tomkins and Ginn (spelling?). A lesson learnt?
4. This ruling on strict patents not being allowed for any genuine
innovation (discussed here 3 months ago). Why spent thousands of man hours
developing and testing only to have your rivals nick the idea?
5. Ignorance. As you imply, many rowers (myself included) do not know the
first thing about what moves or slows a boat. This means that the boat
builders have a free run.... They say things like - "wing riggers don't
work"... "krew-klips have yet to be proved"..... "titanium has no
place"..... "a sculling submarine - you're bonkers".. Most of it on this
forum!!!
or am I missing something?
Regards
Neil
alexorig
Looking at Gliding {Segelfliege} (another sport with low funding and yet
highish technology lightweight carbon fibre aerodynamic craft) in Germany
for at least 40 years engineers and engineering departments have been
designing and manufacturing their own planes.
The students therefore well understand the principles behind their sport.
Indeed they trust their lives to their own designs or certainly used to. It
is a shame the same isn't true in rowing (not the trusting your lives bit).
I think the only difference is the culture that has grown up around the
sport and that could take some time to change.
In the UK (and yes I am bound to say this) rowing is very large at
Universities. Cambridge, Oxford, Oxford Brookes, Bristol, Durham,
Birmingham, UEA, UCL, IC and many more have notable squads of rowers. In
Cambridge I know for a fact engineers do 4th year projects into rowing
technology. 4th year projects often result in some very successful (small)
companies ( www.rowdata.com ). If this option was more readily available at
Universities across the UK surely many of the rowing squad members would
snap at it and it could produce great advancements in the technology of our
sport.
Whether this is a good thing or not is a whole other debate. c.f. F1
As a Physicist (and rower and paperaircraft enthusiast) I am very interested
in drag, aerodynamics and hydrodynamics. All of these are being taught at a
low level in my course this year with further option to specialise. I am
going to seriously consider following that course just to learn more about
my sport and largest past time.
Alex
--
Captain of Boats Magdalene College 2002/3
www.magdaleneboatclub.com
www.paperairplanes.co.uk - former yahoo website of the week and bbc radio 2
site of the day
www.cocktailmaking.co.uk
Nothing is so good that somebody, somewhere, will not hate it.
"Neil Wallace" <rowing.golfer@*nospam*virgin.net> wrote in message
news:ihwv9.1359$bn.8...@newsfep1-win.server.ntli.net...
Ewoud Dronkert
>oars don't work by just pushing water away
They don't?!
Jon Anderson
>>oars don't work by just pushing water away
> They don't?!
Have you noticed how it is usually your boat that moves, rather than the
water?
Jon
--
Durge: j...@durge.org http://users.durge.org/~jon/
OnStream: acco...@rowing.org.uk http://www.rowing.org.uk/
[ All views expressed are personal unless otherwise stated ]
Tim Granger
Jon Anderson <j...@durge.org> wrote:
>Ewoud Dronkert wrote:
>>>oars don't work by just pushing water away
>> They don't?!
>
>Have you noticed how it is usually your boat that moves, rather than the
>water?
But what about all the water that ends up inside the boat? That moves...
Tim
Steven Maynard-Moody
about boat designs for every class and that many innovations must pass
committee review before they are allowed to race. My impression is that
sailing has the same dilemma as rowing in that you want to balance the
importance of crew skill and execution with technical advances in boat
design.
--
Best, Steven
"Carl Douglas" <ca...@carldouglas.co.uk> wrote in message
news:J4Jr5LAt...@rowing-cdrs.demon.co.uk...
Henning Lippke
> how intelligently the product's working environment is understood, how
> intelligently the designs are prepared, how intelligently the products
> are put together & then how intelligently they are used.
You can read my mind :-)
I've just joined a discussion in a german rowing forum, where someone came
up with something like 'wooden boats are slow. period'. You gave some nice
additional arguments. It's becoming quite funny since most of the
contributors there tend to become agressive after they've fired their few
arguments. And then a very polite and reasoned reply is a very nice thing.
-HL
Nick Suess
"Carl Douglas" <ca...@carldouglas.co.uk> wrote in message
news:J4Jr5LAt...@rowing-cdrs.demon.co.uk...
>... Our sport, although highly mechanical, is remarkably science-averse.
> I've had so many correspondences, on & off this newsgroup, with rowers
> who while studying for science degrees at famous Universities
> don't/won't try to understand how buoyancy works (Archimedes' Principle
> is introduced at year 8 in UK schools!), or that oars don't work by just
> pushing water away, or that you can't build fast racing shells on the
> principle of minimum wetted surface (you get very slow woks), or that
> wind & water drag on rigging slows boats & can be reduced, or that boat
> design matters, or that a paint colour doesn't equate to success. So
> Greg's new appreciation of the gulf between sailors' & rowers' attitudes
> to their equipment was a most refreshing breath of clean air.
>
> BTW - technology does not reside within a material, or a shape, but in
> how intelligently the product's working environment is understood, how
> intelligently the designs are prepared, how intelligently the products
> are put together & then how intelligently they are used.
>
> Discuss :-)
Yes, sir.
The interesting thing is that whilst the rowing world is indeed
technology-averse, it's very far from trend-averse, so when something new
starts to catch on (eg the wing rigger) everyone's got to have it, and they
all rush out to buy, regardless of any proven performance benefit or lack of
it.
However, Carl, you may have observed by this advanced stage of your life
that we live in an imperfect world. And one of its imperfections is that
technology costs money, and lots of technology costs lots of money,
generally with a law of diminishing returns on what percentage improvement
you get for the next dollar, pound, euro or shekel. So there are balances to
be struck in pursuing performance benefits, especially when one remembers
that these are seldom if ever whole percents of boat speed and more often
are at best of the order of a tenth of a percent, which is 2 metres in a
2000m race. How much are you prepared to pay for that 2 metres? In an
Olympic (TM) final maybe quite a lot, but in a club, state, or even national
regatta there will be tight budgetary limits.
I was taught to row by a grandson of the legendary Jack Kelly, who told me
that boats didn't win races, rowers did. And indeed a rower as good as Kelly
would probably have won in a hollowed out log (but not at Henley, as they
banned him, ostensibly for being working-class, but really because he was
too bloody good). Yes, technology may give you a slight edge, but you've got
to be good enough to be in contention in the first place, and that applies
in any sport. Parents all over Britain are being bankrupted by having to buy
their boys Beckham shirts and Beckham boots, but it doesn't mean they'll
ever get to captain England or booff Posh Spice, and that's the reality of
it.
So now I sit back and watch bemused as despite my vote and few other voices
of reason my own club has gone crazy crazy crazy and bought for a lot of
loot the slightly tired Vespoli eight which won the Oz guys silver at a
Sydney. I can see men no longer young dreaming their dream that at some
future date the young men we don't even yet have at the club will suddenly
go a whole lot faster in this craft. This of course is bollocks (did I
really write that?). They may go a very tiny bit faster, but with very
limited resources available, in dollars for distance at the finish line, the
deal doesn't look too red hot to me. Of course, that's only my opinion.
So having discussed, and hopefully been awarded a Beta plus or even Alpha
minus by the professor, I contend in conclusion that whilst technological
advances have benefitted our sport down the years, the better education of
coaches, few of whom have the foggiest idea of how a boat is really
propelled, will give better return for money at club level than buying
seriously expensive high tech hardware.
Neil Wallace
"Nick Suess" <ni...@scull.com.au> wrote in message
news:3dbf7811$0$33...@echo-01.iinet.net.au...
SNIP
>
> So now I sit back and watch bemused as despite my vote and few other
voices
> of reason my own club has gone crazy crazy crazy and bought for a lot of
> loot the slightly tired Vespoli eight which won the Oz guys silver at a
> Sydney. I can see men no longer young dreaming their dream that at some
> future date the young men we don't even yet have at the club will suddenly
> go a whole lot faster in this craft. This of course is bollocks (did I
> really write that?).
took a little longer than usual... but you got the "b" word in.. well done.
>They may go a very tiny bit faster, but with very
> limited resources available, in dollars for distance at the finish line,
the
> deal doesn't look too red hot to me. Of course, that's only my opinion.
>
>
Of course - they may actually go slower if they can't balance the bugger and
get the work on due to the possibility of being slightly worse oarsman than
the Aussie 8.
BTW - remind us who won gold in Sydney Nick ;o).
nospam
news:J4Jr5LAt...@rowing-cdrs.demon.co.uk...
'Archimedes' Principle is introduced at year 8 in UK schools.'
Floating and Sinking is experienced at some stage up to KS3, year9, but A's
Princ.?
If you mean, for a body wholly or partly immersed in a fluid, the upthrust
is equal to the weight of fluid displaced, with the upthrust acting up
through the centre of gravity, I haven't taught that since 1987!
Caroline Smith
A's
> Princ.?
my mother's class of 4 and 5 year olds do floating and sinking! ;)
Think I did Archemides principle at primary school with those "Eureka cans"
finding volumes of lumps of plasticine by the volume of water they displace.
And did it again at about 14.
> If you mean, for a body wholly or partly immersed in a fluid, the upthrust
> is equal to the weight of fluid displaced, with the upthrust acting up
> through the centre of gravity, I haven't taught that since 1987!
certainly did that for GCSEs in 1997.
And in more depth for forces on ball bearings falling through oil and
reaching terminal velocity at A-level.
But I'll be quiet and get back to my geophysical fluid dynamics for now...
(and making my crew hats for the Fours Head. Hehe)
nospam
"Caroline Smith" <carolin...@somerville.oxford.ac.uk> wrote in message
news:apoj2u$e9$1...@news.ox.ac.uk...
>
> > If you mean, for a body wholly or partly immersed in a fluid, the
upthrust
> > is equal to the weight of fluid displaced, with the upthrust acting up
> > through the centre of gravity, I haven't taught that since 1987!
>
> certainly did that for GCSEs in 1997.
That would have been as a physics GCSE option or because your teacher wanted
to do it. A's P is not National Curriculm.
> And in more depth for forces on ball bearings falling through oil and
> reaching terminal velocity at A-level.
Again, I suspect, as an A level option or because it is necessary for
measuring TV in this case.
Enough off thread talk, by me anyway.
Carl Douglas
>> Floating and Sinking is experienced at some stage up to KS3, year9, but
>A's
>> Princ.?
>
>my mother's class of 4 and 5 year olds do floating and sinking! ;)
>Think I did Archemides principle at primary school with those "Eureka cans"
>finding volumes of lumps of plasticine by the volume of water they displace.
>And did it again at about 14.
>
>> If you mean, for a body wholly or partly immersed in a fluid, the upthrust
>> is equal to the weight of fluid displaced, with the upthrust acting up
>> through the centre of gravity, I haven't taught that since 1987!
I'm rather surprised & disappointed about that. My mate in Malmesbury
says they cover it as I indicated, despite now working in a building
owned by Group 4 & rightly described on TV as resembling a prison (well,
prisons & security are that firm's main line of business, so why not?).
They need lights on all day, the place has such lousy windows, & can't
teach upstairs when it rains because the noise on the tin roof is too
great. There's a fine example of a PFI at work! No, secondary
education in the UK is not in a very happy state right now :-(
OTOH, just remember that you can become 'important' in ARA safety
circles without ever having heard about Archimedes. Which gives you
licence to blame dead rowers for the fact that their boat didn't float.
>
>certainly did that for GCSEs in 1997.
>And in more depth for forces on ball bearings falling through oil and
>reaching terminal velocity at A-level.
>
But that's all about viscous flow & Stokes' Law - although, yes, there's
a buoyancy effect to be considered due to the difference in SG of the
oil & the steel balls - which reduces their effective weight when
immersed in the oil (not their mass, of course) by about 13.5%,
And, like certain under-buoyant & therefore sinking shells, although
Archimedes' Principle does provide uplift in both cases it is
insufficient to prevent the continued downward motion under gravity of
both shell & (steel) balls.
>But I'll be quiet and get back to my geophysical fluid dynamics for now...
An excuse for a quick trip to Sicily?
Cheers -
Carl
Carl Douglas
<use...@sculling.de> writes
Sad to say, correcting them with sweet reason really annoys some folk.
Just go out in that new, rather beautiful & quick wood-composite single
of yours & beat all comers. That might just show them the error of
their thinking, but probably they'll pretend it never happened.
BTW, Henning - I did get some nice snaps from the Vechtrace (including
some of you in your new boat). I just need a couple of free hours to
get them sorted & posted up......
Cheers -
Carl
Carl Douglas
>I don't closely follow sailing, but I thought they had very strict rules
>about boat designs for every class and that many innovations must pass
>committee review before they are allowed to race. My impression is that
>sailing has the same dilemma as rowing in that you want to balance the
>importance of crew skill and execution with technical advances in boat
>design.
>--
It varies from class to class:
Some have rigid one-design rules so, ideally, all race equal equipment.
That never works: the rich guys always have the latest, newest & most
advanced sails, masts, etc. It's fun to sail past them in rough old
stuff by superior skill, but really it's all rather dreary.
At the other end there's 'development' classes, like the International
14ft dinghy & International C-class catamaran, to name 2 extremes.
Their class rules can be pretty simple - length, beam, sail area, number
of trapezes, number of hulls - with the rest free & including, in C-
class (of which we have some experience), choice of types of sail (cloth
or solid airfoil), use of lifting foils, canting rigs, etc.
And there are all sorts of classes in between including, for big boys'
toys, the America's Cup Class.
In all classes money aids performance. Even in highly restricted
classes (in which they race major championships in 'committee boats'!) -
sailors bring their own fancy sails & masts. And there are real
problems on your way up the ladder in getting your own half-decent hull.
Different hulls from the same maker perform differently, affecting your
chances of selection, because highly standardised classes encourage poor
building standards.
Rowing equipment is incredibly cheap & durable (well-built stuff can
last 30 years), so the principal costs of our sport lie elsewhere. Yet
we cheerfully kid ourselves that novel designs must automatically be
very costly (why?) or 'unrowable' (they'd have said that about single
sculls at one time). And we invent techno-babble about how slapping an
uncalculated bit of magic fibre 'Z' into a mould makes a boat of the
same shape so much faster.
And, anyway, we don't have a clue how it all works! Not even how & why
it floats (or, with some builders & rowers, why it might suddenly not
float).
So we won't analyse the performance of what we use, nor how we use it,
but in true galley-slave fashion we cheerfully flog crews half to death
(& call it seat racing) in ritual searches for the fastest crews. After
all, we already know that we must have bought the fastest boat, blades,
riggers, etc. - or protest that these things are all equal & can't
possibly affect performance - don't we? So there's never any need to
competitively test, or rationally analyse our equipment - is there? And
the best way to go fast is to (ineptly) copy how faster crews row, &
their set-up, & their equipment, rather than exercise the brain to work
out why we should or should not do it that way - isn't it?
All very odd.
Does that stir anything up?
Cheers -
Carl
PaulS
hollowed out log. (Gosh, that reminds me of the wood boats we rowed
while in University. They seemed to work fine.) I like hardware that
is well designed, durable and reliable, then practice, practice,
practice.
- Paul Smith
"Nick Suess" <ni...@scull.com.au> wrote in message news:<3dbf7811$0$3343@echo-
Ed Fryer
> So having discussed, and hopefully been awarded a Beta plus or even Alpha
> minus by the professor, I contend in conclusion that whilst technological
> advances have benefitted our sport down the years, the better education of
> coaches, few of whom have the foggiest idea of how a boat is really
> propelled, will give better return for money at club level than buying
> seriously expensive high tech hardware.
Yes, but it's very interesting that it (the considered application of
technology) doesn't seem to happen at any level, which is what Derek
Clark was getting at. Were Pinsent & Cracknell running their Athens
campaign the same way that, say, Ben Ainslie is running his Finn
(Olympic one-man dinghy) campaign, no stone would be left unturned, to
the extent getting a boat and blades designed and built for them in
particular. (In the Finn, huge amounts of time are spent designing,
building, and adjusting masts, tuned to the sailor and his sails). I'm
no naval architect, but surely gains could be made by tuning a hull to
a particular weight, rating, degree of vertical occilation (of bow and
stern) of its crew - by fine-tuning the prismatic coefficient, length,
wetted surface etc. Or have they done this? Is their new boat a
standard Empacher? If they're not thinking about this sort of thing,
then why not? Surely it leave a gap in their armour, that could be
exploited?
A.Hodgkinson
> Have you noticed how it is usually your boat that moves, rather than
> the water?
Agreed. Your argument could be countered, of course. A rocket moves
because it throws stuff out of the back end quickly, which thanks
to Newton's 2nd, means the rocket itself moves the other way. By the
same token, a boat could move because the oar throws water backwards
quickly. But that's not the way it works, of course, unless you're
washing out an awful lot, in which case it might be the only reason
you're moving at all (that's my excuse and I'm sticking to it) =8*)
--
Andrew Hodgkinson, Rowing Secretary Cambridge '99 Rowing Club
Tel: +44 1223 518 560 (day) The Boathouse, Kimberley Rd, Cambridge,
+44 1223 369 408 (evening) CB4 1HJ, U.K. Tel: +44 1223 367 521
WWW: http://nines.rowing.org.uk/
Jon Anderson
> Agreed. Your argument could be countered, of course. A rocket moves
> because it throws stuff out of the back end quickly, which thanks
> to Newton's 2nd, means the rocket itself moves the other way.
As opposed to rowers putting their oar in something and pulling on it.
Rockets have nothing to push off except explosions.
I *know* there is some slippage but rowers try to minimise this.
Moving water is not our goal and that was all I wanted to say. :-)
Neil Wallace
SNIP
> BTW, Henning - I did get some nice snaps from the Vechtrace (including
> some of you in your new boat). I just need a couple of free hours to
> get them sorted & posted up......
>
> Cheers -
> Carl
>
Carl,
I hope you don't have a couple of free hours!
well not until after November 30th anyway....
;o)
BTW - the C-Clip rigger height adjusters are dandy thanks...... and good
value. I wouldn't begrudge you 5mins of your time to put those on your
website. After all, every rigger should have a set IMHO.
Neil
Henning Lippke
> Sad to say, correcting them with sweet reason really annoys some folk.
And in that certain ridiculous discussion it's really funny...
> Just go out in that new, rather beautiful & quick wood-composite single
> of yours & beat all comers. That might just show them the error of
> their thinking, but probably they'll pretend it never happened.
Sad thing is that there are so few rowers out on the water.
> BTW, Henning - I did get some nice snaps from the Vechtrace (including
> some of you in your new boat). I just need a couple of free hours to
> get them sorted & posted up......
Nice. I'm going to write my experiences I got in Holland down, inspired by
Mike's nice Rose-Report.
On a more serious note & back to topic:
The main reason against wooden boats you hear is always: 'Too heavy'.
I have some FISA weight limits in mind, don't they already apply to nearly
all top level boats, regardless of the material?
And if there are lighter boats, who is really able to take the best out of
them? We have a very light CDRS double here, and only very few crews are
able to make use of this 'benefit'. It really needs almost perfect technique
to keep a light boat running, so shouldn't some more strength based rowers
try out a slightly heavier boat?
-HÖ
Henning Lippke
> is well designed, durable and reliable, then practice, practice,
> practice.
Reminds me of my oars. I had to buy a new set, because they are for my own
use.
I had some experience with my preferred make, and now I had to chose whether
I would have those funny edges or not. I decided to get them, but not to be
few mm/h faster, but to make use of the blade protecting property.
And some have already asked me if these oars perform well. I always answer
that I don't know exactly, I have no comparison. And the manufacturer says
they are not slower. But they have very good protected tips. :-)
They often seem to be dissappointed by this answer, but that's it. The only
difference I know is that compared to macons allow some kind of a more lazy
catch... but if I want to go fast with macons, I can be as fast as with the
new blades...
-HL
(running out of words for today)
Steve Brown
Can you produce a boat for me which will go faster than all the others at an
acceptable cost ?
Steve
Carl Douglas
<brown...@btinternet.com> writes
It is not boats which are fast. Boats can't help making drag & slowing
you down. But boat drag can be reduced.
I believe, confidently, that we already build a boat which will enable
you to go faster than in the rest. But however good you are, we never
give boats away or buy favours with them. We have no need to, so we
don't.
I also believe, with equal confidence, that if demand is there we can, &
will in due course, build something more radical in which you would be
able to do even better.
And I don't see cost as an ever being an issue.
Cheers -
Carl
Nick Suess
> Caroline Smith <carolin...@somerville.oxford.ac.uk> writes
> >> If you mean, for a body wholly or partly immersed in a fluid, the
upthrust
> >> is equal to the weight of fluid displaced, with the upthrust acting up
> >> through the centre of gravity, I haven't taught that since 1987!
Upthrust acting through the centre of gravity?????
BOLLOCKS!!!!!!!!
Who on earth ever taught that?
Imagine a long watertight box of constant cross-section, made of a
lightweight material, and containing a big lump of lead fixed at one end.
Its centre of gravity will be very much towards that end, OK? Partially
immerse it in water in so that its long axis remains horizontal. Centre of
buoyancy will be at the centre of the box, NOT at its C of G. QED.
Nick
Nick Suess
"Neil Wallace" <rowing.golfer@*NOSPAM*virgin.net> wrote in message
news:MLNv9.1040$pI2....@newsfep1-win.server.ntli.net...
>
> BTW - remind us who won gold in Sydney Nick ;o).
Bugger it, I forgot we're not allowed to mention that alleged regatta that
arguably did or did not take place between August and October 2000 at a
location named after a town in the north west of England, at the western
extremities of the capital of New South Wales. I think I managed not to
mention any of the forbidden words there.
Neil Wallace
And of course, back on thread, that glorious GB men's eight that pushed the
Aussies into Silver did actually give some credit to some technology they
were using.....
A reduced drag combined fin and rudder system designed by some guy in
Staines, who allegedly also made the riggers!!
So right back at you there Carl!!
Anu Dudhia
> "Carl Douglas" <ca...@carldouglas.co.uk> wrote in message
> news:wCg2eBA1...@rowing-cdrs.demon.co.uk...
> > Caroline Smith <carolin...@somerville.oxford.ac.uk> writes
>
> > >> If you mean, for a body wholly or partly immersed in a fluid, the
> upthrust
> > >> is equal to the weight of fluid displaced, with the upthrust acting up
> > >> through the centre of gravity, I haven't taught that since 1987!
>
> Upthrust acting through the centre of gravity?????
>
> BOLLOCKS!!!!!!!!
>
> Who on earth ever taught that?
"... upthrust acting through the centre of gravity [of the displaced fluid]"
is what I assume they meant.
It's all in the intonation.
Nick Ablitt
boat go faster by developing a boat that isn't available to others.
The only specifications I would seek in terms of a boat are for it to
be as efficient/reliable etc as that of my other competitiors. As long
as I'm not at a disadvantage then it's a fair compeition and winning
is down to the more physical aspects of the sport, not the workshop.
Obviously a boat builder is going to spend more time thinking about
how best to design and manufacture a boat but it's not what inspires a
competitive rowers mind.
To 'flog crews half to death' is in part what it is all about. Those
that will push themselves harder mentally and physically will be
rewarded over those that won't. It's not about investing in
development and new boats, it's about getting more out of yourself
than you thought was possible, taking it further.
In the same manner that I'm not interested in supplememnts either
banned or not which offer me an "unfair" advantage which is not
available to others. For instance taking creatine is not hard, it may
not do any harm. But while it is still questioned I would not take it
as I'm looking for a cheap advantage which does absolutely nothing in
terms of my development. I'm not trying to start a discussion on
Creatine by the way, it would be quite dull.
I don't disagree with you being interested in the development of boats
and being proud of your products, it's your job and probably your
hobby. I don't have that much experience of them but the riggers seem
quite pleasent. It's the seemingly patronising manner in which you
question why we're not spending all our time doing the same.
Development of boats is not my hobby, rowing and competing at rowing
(not boat development) is mine.
Quite a long winded answer but you're not shy of long answers
yourself.
| * __ | / Nick Ablitt
|\ | | | |/ Imperial College, London
| \| | |__ |\ ni...@ablitt.net
| | | \ http://nick.ablitt.net
Carl Douglas <ca...@carldouglas.co.uk> wrote in message news:<jSRyKJAw...@rowing-cdrs.demon.co.uk>...
Bob McMillen
>
> As opposed to rowers putting their oar in something and pulling on it.
> Rockets have nothing to push off except explosions.
> I *know* there is some slippage but rowers try to minimise this.
> Moving water is not our goal and that was all I wanted to say. :-)
>
> Jon
On the contrary, moving water back is exactly our goal (well, I guess
our first priority is to move the boat as fast as possible with a
given effort). The only way to move the boat forward is to move water
backwards. Whether it fits your definition of lift, drag, or slippage,
the crew that moves the most water back (preferable below the water
surface) at the greatest rate will have the most propulsive force.
Very simple physics.
Bob
Lin DeNoyer
I would love to enter this one...
If the upward thrust is not acting through the center of
gravity, you've got one spinning box.
Rowers' Mom
Roger
Can I just say Olympic
alexorig
That does not move the road backwards to move the cyclist forwards.
I am afraid I agree with Carl and Jon "oars don't move by just pushing the
water away"
There might however be a happy medium between moving the water and levering
past the water.
Alex
--
Captain of Boats Magdalene College 2002/3
www.magdaleneboatclub.com
www.paperairplanes.co.uk - former yahoo website of the week and bbc radio 2
site of the day
www.cocktailmaking.co.uk
Nothing is so good that somebody, somewhere, will not hate it.
"Bob McMillen" <bobmcm...@comcast.net> wrote in message
news:6977105f.02103...@posting.google.com...
Lin DeNoyer
says...
>
>Think about a bike.
>
>That does not move the road backwards to move the cyclist forwards.
Of course it does! Road, nation, earth, the whole works.
Momentum rules,
Anu Dudhia
> Think about a bike.
>
> That does not move the road backwards to move the cyclist forwards.
Actually, it does.
Anu Dudhia
>
> Can I just say [deleted]
Aaargh! now you've done it.
OK, everyone, get your last few posts in to rec.sport.rowing before they close us down. Oh, and one
more thing...
ATTENTION ALL LAWYERS !!!!!
I just want to point out that although I have occasionally frequented the same newsgroup as Roger,
I in no way condone his gratuitous use of justifiably appropriated "special words" and wish to
completely disocciate myself from his actions.
Edd Edmondson
> Think about a bike.
> That does not move the road backwards to move the cyclist forwards.
> I am afraid I agree with Carl and Jon "oars don't move by just pushing the
> water away"
> There might however be a happy medium between moving the water and levering
> past the water.
As others have pointed out, a better analogy might be that a cyclist
doesn't go forward by spraying grit out behind him.
--
Edd
Edd Edmondson
> In article <3dc0ad2e$0$47...@echo-01.iinet.net.au>, ni...@scull.com.au says...
>>
>>BOLLOCKS!!!!!!!!
>>
>>Who on earth ever taught that?
>>
>>Imagine a long watertight box of constant cross-section, made of a
>>lightweight material, and containing a big lump of lead fixed at one end.
>>Its centre of gravity will be very much towards that end, OK? Partially
>>immerse it in water in so that its long axis remains horizontal. Centre of
>>buoyancy will be at the centre of the box, NOT at its C of G. QED.
>>
>>Nick
> I would love to enter this one...
> If the upward thrust is not acting through the center of
> gravity, you've got one spinning box.
Yes, you have, since you've put a box with uneven mass distribution
underwater whilst keeping it horizontal.... so it will spin. What point
were you trying to make?
--
Edd
David Biddulph
news:aps0dc$g9h$2...@news.ox.ac.uk...
But of course it won't spin continuously; we haven't invented the perpetual
motion machine yet. It will reach equilibrium with the CG below the CB (and
of course will approach that equilibrium position with oscillations whose
amplitude will decrease at a rate depending on the viscosity).
--
David Biddulph
Rowing web pages at
http://ourworld.compuserve.com/homepages/david_biddulph/
http://www.biddulph.org.uk/
Jon Anderson
> Whether it fits your definition of lift, drag, or slippage,
> the crew that moves the most water back (preferable below the water
...going into moving water instead of moving the boat yes.
The blade, *ideally*, doesn't slip at all through the water. It's like
rowing on an ice rink with a spike on the end of the oar. You dig the
spike in, and lever the boat past that point.
> Very simple physics.
Another simple analogy if I may.
Try stepping off a skateboard. Then stick chocks under the wheels and
tell me you go quicker forwards when the skateboard moves quicker
backwards. You wouldn't, clearly. Substitute water for skateboard and
your boat for you. The less the thing you're pushing off moves the more
you move.
This is clear in my mind anyway. Maybe I'm rubbish at explaining? :-)
Jon Anderson
> It's all in the intonation.
That came across very clearly over the Internet I must say. ;-)
Carl Douglas
There is not a lot of really simple applied physics.
It matters hugely whether, in you effort to provide a propulsive
reaction force, you accelerate a small amount of water by a large
velocity change, or a large amount of water through a rather small
velocity change. The former wastes a huge amount of your input work,
the later wastes hardly any.
Thus, high propulsive efficiency demands that you row in the manner
which imparts the least velocity change (& turbulence) to the largest
possible amount of water.
Carl Douglas
>Do we have to know 'why it floats'.
No, to row it you don't. But if you administer safety in the sport you
should have the very clearest understanding of why boats float & what
affects that property. Especially if you are going to obstruct rational
buoyancy-based safety measures.
> For me it's not how can I make the
>boat go faster by developing a boat that isn't available to others.
>The only specifications I would seek in terms of a boat are for it to
>be as efficient/reliable etc as that of my other competitiors. As long
>as I'm not at a disadvantage then it's a fair compeition and winning
>is down to the more physical aspects of the sport, not the workshop.
>Obviously a boat builder is going to spend more time thinking about
>how best to design and manufacture a boat but it's not what inspires a
>competitive rowers mind.
So why row? If you don't want to see evolutionary progress why not just
skiff (per Thames skiffs?). But, of course, those are evolved craft, so
it would be fairer if we all just sat on (equal) logs.
>
>To 'flog crews half to death' is in part what it is all about. Those
>that will push themselves harder mentally and physically will be
>rewarded over those that won't. It's not about investing in
>development and new boats, it's about getting more out of yourself
>than you thought was possible, taking it further.
Notwithstanding the fact that seat racing so often has far too much to
do with the personal politics of who wants to row with whom? There are
better ways. My point was that to try to assess crews but to ignore the
differences between equipment is, for a club which wants to win races,
irrationally blinkered.
>
>In the same manner that I'm not interested in supplememnts either
>banned or not which offer me an "unfair" advantage which is not
>available to others. For instance taking creatine is not hard, it may
>not do any harm. But while it is still questioned I would not take it
>as I'm looking for a cheap advantage which does absolutely nothing in
>terms of my development. I'm not trying to start a discussion on
>Creatine by the way, it would be quite dull.
Creatine is also, very probably, a stupid thing to take, like so many
other so-called supplements.
>
>I don't disagree with you being interested in the development of boats
>and being proud of your products, it's your job and probably your
>hobby. I don't have that much experience of them but the riggers seem
>quite pleasent. It's the seemingly patronising manner in which you
>question why we're not spending all our time doing the same.
>Development of boats is not my hobby, rowing and competing at rowing
>(not boat development) is mine.
Not patronising, just questioning. And you'll know that I'm more
interested in content that style. It certainly got you going, & many
others, which is dandy.
>
>Quite a long winded answer but you're not shy of long answers
>yourself.
You're free to answer at whatever length you wish. Or not. The object
should be to play the ball, not the man.
Nick Suess
"David Biddulph" <da...@biddulph.org.uk> wrote in message
news:aps4e6$1f9$1...@venus.btinternet.com...
Excuse me. Read the words. My Big Fat Greek Buddy Archimedes and I are
talking about "a body wholly or partly immersed in a fluid". That's the
precise wording the original correspondent "Nospam" used, and with which we
are all familiar. This does NOT state the specific instance of a body
floating freely in fluid. So I can manually or otherwise force my long box
with the lead at one end to some unspecified level of immersion into the
fluid so it still remains horizontal, and it will experience the upthrust as
described. That's Archimedes. If it is released it will of course bob like a
fishing float with its axis vertical, and in calm conditions any floating
body will attain equilibrium with its centre of mass and centre of buoyancy
in the same vertical line. Note that the centre of mass may then be above,
below or coincident with the centre of buoyancy.
alexorig
rest of the world. The bike does of course impose backwards momentum on the
earth to obey the law of conservation of momentum. As Ed shows in his post
my point was clear even if my method of explaining it was not.
How about thinking of rowing as hooking onto the rungs of a ladder and
pulling yourself upwards. The maximum velocity will not be acheived by
breaking of bits of ladder and throwing them backwards to impart velocity.
Or being a cross country skier who pushes themselves along on their sticks
(not using their legs for some reason). Do they move by throwing/kicking up
huge amounts of snow.
OK fair enough pedants of the world unite. Perhaps Bob was being pedantic
too but the overall comment from Jon earlier I understood as saying
splashing water backwards won't make us move. From that comment I assumed
Bob was arguing Jon was wrong and I was trying to agree and point out that
"splashing around" won't move a boat along QUICKLY. I am in my third year of
physics at Cambridge so I do have some understanding of the law of
conservation of momentum.
Alex
--
Captain of Boats Magdalene College 2002/3
www.magdaleneboatclub.com
www.paperairplanes.co.uk - former yahoo website of the week and bbc radio 2
site of the day
www.cocktailmaking.co.uk
Nothing is so good that somebody, somewhere, will not hate it.
"Lin DeNoyer" <lk...@cornell.edu> wrote in message
news:aprop2$ah4$1...@news01.cit.cornell.edu...
Anu Dudhia
> Thus, high propulsive efficiency demands that you row in the manner
> which imparts the least velocity change (& turbulence) to the largest
> possible amount of water.
Yet, as Galileo once said under his breath, "eppur si muove".
Anu Dudhia
> fishing float with its axis vertical, and in calm conditions any floating
> body will attain equilibrium with its centre of mass and centre of buoyancy
> in the same vertical line. Note that the centre of mass may then be above,
> below or coincident with the centre of buoyancy.
Attain equlibrium with the centre of mass *above* the centre of buoyancy?
Show me that and I'll buy you a beer (and your pal Archie if he's around).
Neil Wallace
"Anu Dudhia" <dud...@atm.ox.ac.uk> wrote in message
news:3DC24F40...@atm.ox.ac.uk...
Gyroscope? (let the flame begin)
Bob McMillen
>
> It matters hugely whether, in you effort to provide a propulsive
> reaction force, you accelerate a small amount of water by a large
> velocity change, or a large amount of water through a rather small
> velocity change. The former wastes a huge amount of your input work,
> the later wastes hardly any.
>
> Thus, high propulsive efficiency demands that you row in the manner
> which imparts the least velocity change (& turbulence) to the largest
> possible amount of water.
>
> Cheers -
> Carl
Carl,
my comment was simple. You can't move the boat without moving water.
The ideas of lift and low slippage have been hyped to the extent that
apparently some rowers believe that the blade is actually "anchored"
in the water. The concept of lift (perpendicular to the blade length)
reguires moving water perpendicular to the blade length.
cheers,
bob
Jon Anderson
> my comment was simple. You can't move the boat without moving water.
> The ideas of lift and low slippage have been hyped to the extent that
> apparently some rowers believe that the blade is actually "anchored"
> in the water.
It's not thixotropic so yes I agree slip will occur but it's not our
aim, surely? You did say it was, hence my vigorous reply. :-)
Henning Lippke
> The ideas of lift and low slippage have been hyped to the extent that
> apparently some rowers believe that the blade is actually "anchored"
> in the water.
You are right, but we can try to maximise the effect of an anchored blade
through the stroke. The stall during the middle phase of the stroke will
prohibit this, but we can try to delay this stall as much as possible. And
of course regain lift soon after the stall.
The water moved is more something like exhaust-water :-)
> The concept of lift (perpendicular to the blade length)
> reguires moving water perpendicular to the blade length.
?
Flow in line with wing, lift perpendicular.
Did you really want to write: perpendicular flow, perpendicular lift?
-HL
Carl Douglas
<dud...@atm.ox.ac.uk> writes
anyone important had overheard him. Of course, the Vatican now realises
that was an unfortunate administrative error, just one of those things,
no one's fault, couldn't have happened to a nicer guy, bit of well-
intentioned administrative overkill, & so on. The friars were in frying
mood, so for Galileo it was a bright career move not to try to wait
until his accusers saw reason but to recant there & then. It's no fun
to be righteously kippered & then be forgiven a few centuries later.
But I'm sure that you know, Anu, what I was on about?
For those who don't, it's all down to kinetic energy. You'll generate
the same propulsive impulse by accelerating 1000kg of water to a
velocity of 1mm/sec as by accelerating 1 kg of water to 1metre/sec. But
the kinetic energy (KE) imparted to the 1 tonne mass will, because of
the law:
KE = M x V^2 / 2
(M = mass, V = acquired velocity)
be only 1/1000 part of the kinetic energy you'd lose to that notional
1kg water mass.
Which is why a poorly buried blade which scoops up a small quantity of
water is so darned inefficient, while burying the blade so that you even
have a noticeable part of the loom in the water is no bad thing - you
entrain less air, your blade slips less & you spend less of your work on
simply moving the water.
The argument advanced earlier about always moving the earth is
inapplicable overall. Every impulse you give to Mother Earth with your
blade is exactly cancelled by the countervailing forces on same arising
from fluid drag on you & the boat.
Roger
Of course our friend the "professor of pedantics" is correct. Perhaps
we should have read the first note more clearly. If you nail the box
in a horizontal plane and then submerge it the c of b is in the
middle. I forget the original point to all this though
Ed Fryer
> Attain equlibrium with the centre of mass *above* the centre of buoyancy?
> Show me that and I'll buy you a beer (and your pal Archie if he's around).
Roger
Thought you were talking about water
Iain Langridge
Says the man at the selling end of the process ! ;-)
Iain
"Carl Douglas" <ca...@carldouglas.co.uk> wrote in message
news:G1HLjUAV...@rowing-cdrs.demon.co.uk...
> In article <appo4k$em6$1...@helle.btinternet.com>, Steve Brown
> <brown...@btinternet.com> writes
> >So therefore Carl getting down to brass tacks............
> >
> >Can you produce a boat for me which will go faster than all the others at
an
> >acceptable cost ?
> >
> >Steve
> >
> Getting the pedantry out of the way first:
> It is not boats which are fast. Boats can't help making drag & slowing
> you down. But boat drag can be reduced.
>
> I believe, confidently, that we already build a boat which will enable
> you to go faster than in the rest. But however good you are, we never
> give boats away or buy favours with them. We have no need to, so we
> don't.
>
> I also believe, with equal confidence, that if demand is there we can, &
> will in due course, build something more radical in which you would be
> able to do even better.
>
> And I don't see cost as an ever being an issue.
Carl Douglas
> Carl,
> my comment was simple. You can't move the boat without moving water.
>The ideas of lift and low slippage have been hyped to the extent that
>apparently some rowers believe that the blade is actually "anchored"
>in the water. The concept of lift (perpendicular to the blade length)
>reguires moving water perpendicular to the blade length.
>
Sorry - I'd missed this post when posting just a few moments ago.
Lift does not require moving water, & certainly not perpendicular to the
blade (you may not have meant it like that?). It does require relative
motion of blade & water, which results from the combined effects of the
forward motion of the pin relative to the water & the consequent
rotation & outsweep of the blade after the catch (& insweep near the
finish).
Depending upon the blade's shape & its alignment on the shaft (the
latter being also affected by load-induced bending of the shaft), when
'lift' is being generated the blade may move either with the appearance
of slip (sternwards) or lift (bow-wards) through the water relative to
the line of the shaft. What is actually happening may not be easily
discerned, but can certainly be measured (e.g. in a water tunnel or
channel).
It is the same for an aircraft wing. An asymmetric airfoil (upper
surface not a mirror image of lower surface) can usually generate useful
lift even when it does not appear to be angled upwards in relation to
the line of motion (i.e. with an angle of attack). Thus it will generate
lift at seemingly zero or even negative angles of attack.
An oar is just one of the examples of rowing equipment which has not
been optimised for performance. It moves relative to the water in a
highly complex 3-D fashion (vertical, rotational & on both horizontal
axes). In so doing it passes rapidly from 'lift' (attached flow) to
'stall' (separated flow) & back to 'lift' modes, with never any
classical fully-developed flow regime having the time or distance of
steady travel to become established. And in that way it presents a
quite fascinating succession of flow-transient situations.
Because oar fluid-mechanics is so complex, rather little effort is made
to properly understand them, & effectively none of it by rowers of
coaches who prefer to adhere to convention which, dare I say it, is not
always well informed. So folk make sweeping assumptions about physical
effects they can't be bothered to measure & base advice on those
assumptions. And oars of different shapes are altered in proportion &
gearing not until performance is optimised - which must mean that the
way & feel of a stroke is significantly altered (requiring significant
technique adjustments by the user) - but until they 'feels like an oar
is supposed to feel'.
I hope that wasn't me coming on too heavy? It certainly wasn't meant to
be, but you raised an interesting issue which seemed worth expanding.
I'm not saying the problems are insoluble. Nor that we lack insights
which could help us to get better performances by adjusting what we do.
But we do need to have open minds - it would be a good idea, instead of
always saying 'this is how it works' (exactly as for the last 150 years
- & I do mean exactly), for us to try to explore what really happens out
there in the water - by purely practical means if no other.
Neil Wallace
> But we do need to have open minds - it would be a good idea, instead of
> always saying 'this is how it works' (exactly as for the last 150 years
> - & I do mean exactly),
So what happened in 1852?
1829 = first Oxford-Cambridge race
1846 = outrigger (Oxford)
1856 = removal of keel (Oxford)
1871 = rolling seats
surely you don't mean 1852, the first Yale-Harvard race, and with it the
launch of the good ol' US of A into boat design???
pray tell................
Ewoud Dronkert
>An asymmetric airfoil (upper
>surface not a mirror image of lower surface) can usually generate useful
>lift even when it does not appear to be angled upwards in relation to
>the line of motion (i.e. with an angle of attack). Thus it will generate
>lift at seemingly zero or even negative angles of attack.
How can aeroplanes fly upside-down? Do they need this positive angle
of attack and therefore must keep the nose high, tail low? And/or do
they rapidly lose altitude, and so must rather quickly roll right-way
up again?
Henning Lippke
First of all, only very few can. Take an Extra 300 for example, its wing
profile is quite 'flat', with up- and downside almost equal. It flies almost
exactly in the direction where you head its nose to.
You can even take an advanced PC simulator to test this. Try to roll a B737
(which has a very complex shaped wings) upside down and keep the angle of
attack at about 0. It will fall like a stone. And even raising the nose
doesn't give enough 'lift' to regain altitude, you can hardly keep it.
-HL
PaulS
> > I like hardware that
> > is well designed, durable and reliable, then practice, practice,
> > practice.
>
> Reminds me of my oars. I had to buy a new set, because they are for my own
> use.
>
> I had some experience with my preferred make, and now I had to chose whether
> I would have those funny edges or not. I decided to get them, but not to be
> few mm/h faster, but to make use of the blade protecting property.
>
> And some have already asked me if these oars perform well. I always answer
> that I don't know exactly, I have no comparison. And the manufacturer says
> they are not slower. But they have very good protected tips. :-)
>
> They often seem to be dissappointed by this answer, but that's it. The only
> difference I know is that compared to macons allow some kind of a more lazy
> catch... but if I want to go fast with macons, I can be as fast as with the
> new blades...
>
> -HL
> (running out of words for today)
I was on the phone getting ready to order a couple new sets of Macons
from the same outfit of which you speak, I just wanted to know if they
were using Carbon fiber for the Macons as well (Lighter blade and I
can balance them as I like). The person on the phone said to me,
"Macons, you know they are slower don't you?". Too which I replied,
Nope I hadn't noticed, and I don't care for the feel of asymetrical
blades, too floppy for my taste. He didn't seem to happy with that,
but I think they will still accomodate me. I wonder if I should get
some tip protectors on them. [;o)
- Paul Smith
Henning Lippke
> some tip protectors on them. [;o)
Yup. They are free. Even retrofitting is free, at least here. (Because they
don't want to see the edges on other makes, they don't give them away)
-HL
Carl Douglas
It's certainly cheaper & less painful to try this on a simulator than on
the actual 737 ;^)
Wings for commercial aircraft are specifically optimised for economical
flight with their passengers comfortably (?) in their seats. (The
inverted option spills the drinks, sends the peanuts flying &, although
rather exciting, is frowned on as some on board may not share the joke).
These wings tend to have flattish under surfaces, with upper surfaces of
pronounced convexity (camber). They also have large extendable control
surfaces which, among their other functions, both increase the apparent
wing area & existing camber & asymmetry to further enhance lift & reduce
stall-sensitivity for the lower-speed parts of the operating envelope,
e.g. landing & take-off.
The wings on stunt & fighter planes tend to be quite differently shaped.
Their upper & lower surfaces are more symmetrical &, for stunt planes,
are often quite thick. Being more symmetrical, they can generate useful
lift even when inverted - essential for planes that must be highly
manoeuvrable - but may require somewhat higher angles of attack to
generate lift in normal level flight (dependent upon velocity). The
thicker wings on stunt planes do increase drag but are much more
tolerant of slow speeds & high angles of attack, whether in normal or
inverted flight.
The blades rowers use are highly asymmetrical & highly cambered
(curved). They are very probably far from optimised for performance,
which is not altogether surprising in view of their empirical evolution
& given rowers' & coaches' reluctance to confront the true implications
of using more efficient blade forms (for one thing, higher efficiency
must mean the blade spends longer in the water & less time in the air
for the same stroke length & rating). However, any rower brave enough
to try rowing with their oar the wrong way round in the gate would soon
discover that the present range of oar shapes make far more sense than
their simple inverses, or even than plain flat blades. If anyone doubts
me, they really should give it a try - I can't see the reversed oarblade
ever catching on in competition!
Carl Douglas
Wallace <rowing.golfer@*nospam*virgin.net> writes
Neil - I refer not to any events in the last 150 years, but to the
written & sketched interpretations by rowing's 'experts' of how the oar
physically interacts with the water. These have barely changed
throughout that period, & they are plausible tosh. Especially the
classic one purporting to show how the oncoming water is split & turned
back on itself by the spine on the oarblade.
Cheers -
Carl
PS Before you make any further rude comments about my nocturnal habits,
didn't you realise that I always varnish my face before I hit the sack?
It maintains my perfect complexion & happy smile.
C
Jay
for.
As for technology vs hype, I think is can be summarized really easily by saying
that yes, a quick boat with reduced drag and fancy features that make it amazingly
quick might gain a rower a 5 seconds in a race. BUT in terms of psychological
advantage this boat creates it could easily be as much as 30 seconds (for us slow
pokes at the back). Which boils down to the old adage (used universally at
internationally in any sport) that sport is 30% physical and 70% mental...
So in the end it's nice to know that you have a fast boat, but it's much better to
KNOW that you are a better rower!
A.Hodgkinson
<URL:mailto:ca...@carldouglas.co.uk> wrote:
> [...] I can't see the reversed oarblade ever catching on in
> competition!
I dunno. I was once told that I could probably go quicker by backing
it down - not quite the same thing, but close. Ish. Now that I come
to mention it, given the Fours Head result I got on Saturday, the
coach was probably right... ;-)
--
Andrew Hodgkinson, Rowing Secretary Cambridge '99 Rowing Club
Tel: +44 1223 518 560 (day) The Boathouse, Kimberley Rd, Cambridge,
+44 1223 369 408 (evening) CB4 1HJ, U.K. Tel: +44 1223 367 521
WWW: http://nines.rowing.org.uk/
nospam
> BOLLOCKS!!!!!!!!
Now my headache has gone.
Consider the equilibrium of that part of the fluid which has the same volume
and shape as the part of the body to be immersed. It experiences a force,
through its centre of gravity, of the same magnitude as its weight, but
oppositely directed.
The upthrust through the centre of gravity of the displaced fluid. Sorry if
the 'intonation' was wrong. As I said I have not taught A's P since 1987.