Do boats go slower in winter?

Do boats go slower in winter?

Post by Steve Ke » Sat, 05 Oct 1996 04:00:00


Does anyone have any hard data indicating whether rowing boats in fact go
slower in cold water or not, and, if so, by how much? The change in
viscosity of water is large indicating that there should be some
interaction, and obviously the different training regimes in summer and
winter have an effect.

All I have seen in the literature is a remark in "Rudern" that water
temperature affects rowing boats, but they do not give an idea of by how
much, unlike for example their analysis of depth effects.

Regards,
Steve

 
 
 

Do boats go slower in winter?

Post by Kenneth Cooperste » Mon, 07 Oct 1996 04:00:00

Quote:

>Does anyone have any hard data indicating whether rowing boats in fact go
>slower in cold water or not, and, if so, by how much? ...

According to my trusty handbook, the viscosity of water approximately
doubles as its temperature drops from 80 deg. F. to 32 deg. F.

Ken Cooperstein

 
 
 

Do boats go slower in winter?

Post by Michael Woodmans » Mon, 07 Oct 1996 04:00:00

USRowing rules of racing (esp wrt national teams trials) include racetime
modifications for water temperature.

Mike

Quote:

> Does anyone have any hard data indicating whether rowing boats in fact go
> slower in cold water or not, and, if so, by how much? The change in
> viscosity of water is large indicating that there should be some
> interaction, and obviously the different training regimes in summer and
> winter have an effect.

> All I have seen in the literature is a remark in "Rudern" that water
> temperature affects rowing boats, but they do not give an idea of by how
> much, unlike for example their analysis of depth effects.

> Regards,
> Steve

--

                                     -Michael Woodmansee

 
 
 

Do boats go slower in winter?

Post by D1Will » Tue, 08 Oct 1996 04:00:00

in chicago they go very slowly in the winter......

 
 
 

Do boats go slower in winter?

Post by Richard D. Lew » Tue, 08 Oct 1996 04:00:00

  These modifications for regatta time effects
have been discussed before on this very page!  
These effects include water temperature, water
density (variable from temp & salinity), head
(or tail) winds, etc, etc.  What several noted
physicists determined was the severe correction needed
for the Eotvos effect.  Currently this is not applied
to regattas.  As a result, race times in different
parts of the world and different river or lake
elevations is like "comparing apples to oranges".
The Eotvos effect for a shell traveling at "V" knots,
at a bearing "A", and a latitude "P" is:

  E = 7.503 * V * cos P sin A + 0.004154 V**2

It doen't take a rocket scientist to plug in a few
numbers and see the real reason why rowing race times
will be so different at various locations on the
earth. Until the Eotvos corrections are applied
to race times or alternately conductioning the race
to minimize its effects, (this is possible !!!),
the comparison of different time from different
locations is a BOGUS endevour and should be
discontinued.  

Dr. Richard D. Lewis  PhD PE

 
 
 

Do boats go slower in winter?

Post by Kenneth Cooperste » Wed, 09 Oct 1996 04:00:00

Quote:

>in chicago they go very slowly in the winter......

---

I neglected to mention that the viscosity of ice, being a solid, is
infinite.  However, the coefficient of dynamic friction is low.
Therefore, in the winter in Chicago, scientific reasoning requires
that you switch to ice skating.  I hope you find this helpful.

Ken Cooperstein

 
 
 

Do boats go slower in winter?

Post by Jim Dwy » Thu, 10 Oct 1996 04:00:00


Quote:
>   These modifications for regatta time effects
> have been discussed before on this very page!  
> These effects include water temperature, water
> density (variable from temp & salinity), head
> (or tail) winds, etc, etc.  What several noted
> physicists determined was the severe correction needed
> for the Eotvos effect.  Currently this is not applied
> to regattas.  As a result, race times in different
> parts of the world and different river or lake
> elevations is like "comparing apples to oranges".
> The Eotvos effect for a shell traveling at "V" knots,
> at a bearing "A", and a latitude "P" is:

>   E = 7.503 * V * cos P sin A + 0.004154 V**2

> It doen't take a rocket scientist to plug in a few
> numbers and see the real reason why rowing race times
> will be so different at various locations on the
> earth. Until the Eotvos corrections are applied
> to race times or alternately conductioning the race
> to minimize its effects, (this is possible !!!),
> the comparison of different time from different
> locations is a BOGUS endevour and should be
> discontinued.  

> Dr. Richard D. Lewis  PhD PE

Richard:

What is the Eotvos effect?

--
Jim Dwyer
London, Ontario
Canada

 
 
 

Do boats go slower in winter?

Post by Anu Dudhi » Thu, 10 Oct 1996 04:00:00

Quote:


> > The Eotvos effect for a shell traveling at "V" knots,
> > at a bearing "A", and a latitude "P" is:

> >   E = 7.503 * V * cos P sin A + 0.004154 V**2

> Richard:

> What is the Eotvos effect?

> --
> Jim Dwyer
> London, Ontario
> Canada

I'd like to know, too! Unfortunately Richard doesn't
provide any units for his constants so I can't tell if
this "effect" is significant or not.
 
 
 

Do boats go slower in winter?

Post by David Prat » Thu, 10 Oct 1996 04:00:00

I smell smoke, being gently wafted up my nose.

David T. Pratt
Professor of Mechanical Engineering
University of Washington


Quote:
>   These modifications for regatta time effects
> have been discussed before on this very page!  
> These effects include water temperature, water
> density (variable from temp & salinity), head
> (or tail) winds, etc, etc.  What several noted
> physicists determined was the severe correction needed
> for the Eotvos effect.  Currently this is not applied
> to regattas.  As a result, race times in different
> parts of the world and different river or lake
> elevations is like "comparing apples to oranges".
> The Eotvos effect for a shell traveling at "V" knots,
> at a bearing "A", and a latitude "P" is:

>   E = 7.503 * V * cos P sin A + 0.004154 V**2

> It doen't take a rocket scientist to plug in a few
> numbers and see the real reason why rowing race times
> will be so different at various locations on the
> earth. Until the Eotvos corrections are applied
> to race times or alternately conductioning the race
> to minimize its effects, (this is possible !!!),
> the comparison of different time from different
> locations is a BOGUS endevour and should be
> discontinued.  

> Dr. Richard D. Lewis  PhD PE

 
 
 

Do boats go slower in winter?

Post by Richard D. Lew » Thu, 10 Oct 1996 04:00:00

Check any advanced Physics book or a good
advanced navigation text (before GPS).  Also
this phenom is a HUGE HUGE factor in orbiting
sats., so a physics of orbiting objects text
might also be consulted.  Sorry I could
not place the oomlauts over the o's.  
Ricahrd Lewis

Quote:
>Richard:

>What is the Eotvos effect?

>--
>Jim Dwyer
>London, Ontario
>Canada

 
 
 

Do boats go slower in winter?

Post by Richard D. Lew » Thu, 10 Oct 1996 04:00:00

V is in knots
A and P are in Radians
E is in Gals (after the guy who dropped the spheres
             from the tower!)

Cheers   Richard Lewis

 
 
 

Do boats go slower in winter?

Post by Richard D. Lew » Thu, 10 Oct 1996 04:00:00

SMOKE you say ?  It is high time that modern
physics (not classical mechanics) be placed
into rowing !!!!  If you think that the
difference in race times is not effected by
these important accelerations then prove it !!!!!!
The next thing that you will say is that Coxains
cannot be replaced by DGPS systems interfaced with
computors using NN and fuzzy logic !!!!  Are
you still using wooden shells and oars ???

Quote:
>I smell smoke, being gently wafted up my nose.

>David T. Pratt
>Professor of Mechanical Engineering
>University of Washington