Re: Digest Number 2171
--- Inbolger@yahoogroups.com, Chris Crandall <crandall@u...> wrote:
Heeling on a sharpie
> will present a v-shape to the waves, but it will not increase
waterline length.
Oh yes it will.....:-)
Peter Lenihan
Looking at Parker's "Sharpie" book, I'd say that the increase in
waterline length in due to heeling in a non-potbellied sharpie is
minimal. Depending on crew weight, I think my Light Schooner may
actually have a shorter waterline when heeled over. The other thing to
keep in mind is long, skinny, shallow drafted boats don't seem to
respect traditional calculations about hull speed; or at least the
light schooner and folding schooner don't seem to. The Light Schooner
has a waterline of about 22. Square root of 22 is about 4.7 x 1.7
(generous) giving a hull speed of 8 knots. Yet I've clocked going 8
knots and know I've gone even faster without planing.
YIBB,
David
waterline length in due to heeling in a non-potbellied sharpie is
minimal. Depending on crew weight, I think my Light Schooner may
actually have a shorter waterline when heeled over. The other thing to
keep in mind is long, skinny, shallow drafted boats don't seem to
respect traditional calculations about hull speed; or at least the
light schooner and folding schooner don't seem to. The Light Schooner
has a waterline of about 22. Square root of 22 is about 4.7 x 1.7
(generous) giving a hull speed of 8 knots. Yet I've clocked going 8
knots and know I've gone even faster without planing.
YIBB,
David
On Friday, September 10, 2004, at 09:21 PM, John B. Trussell wrote:
> Bruce--I'm not certain, but most sharpies have a little overhang at
> the bow and somewhat more overhang at the stern. As a sharpie heels,
> the chine sinks deeper in the water, and more of the overhangs become
> immersed. Wouldn't this increase waterline length? (Note, I'm
> referring to a New Haven style sharpie--not one of Bolger's double
> ended sharpies like Birdwatcher, Burgundy, or Windsprint.)
>
> John T
> ----- Original Message -----
> From: Bruce Hallman
> To:bolger@yahoogroups.com
> Sent: Friday, September 10, 2004 10:46 AM
> Subject: Re: [bolger] Digest Number 2171
>
>
>> ChrisC
>> It will not be true of a Bolger sharpie, for example. Heeling on a
>> sharpie
>> will present a v-shape to the waves, with it's added advantages and
>> disadvantages, but it will not increase waterline length.
>
> I recall someone claiming that when a Micro heels, it presents
> a greater waterline length. Wouldn't the buoyancy along the longer
> and narrower "V" chine of a Micro, be equivalent buoyancy to a
> shorter
> length along the wider flat belly?
>
> In other words, the average width of the boat is wider at rest than
> at heel.
>
> For the same displacement, a narrower boat must be longer than
> a wider boat. I'm not sure, I am just thinking aloud.
>
>
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> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
> - Pls add your comments at the TOP, SIGN your posts, and snip away
> - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930,
> Fax: (978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
> Yahoo! Groups Links
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Bruce--I'm not certain, but most sharpies have a little overhang at the bow and somewhat more overhang at the stern. As a sharpie heels, the chine sinks deeper in the water, and more of the overhangs become immersed. Wouldn't this increase waterline length? (Note, I'm referring to a New Haven style sharpie--not one of Bolger's double ended sharpies like Birdwatcher, Burgundy, or Windsprint.)
John T
John T
----- Original Message -----
From: Bruce Hallman
To:bolger@yahoogroups.com
Sent: Friday, September 10, 2004 10:46 AM
Subject: Re: [bolger] Digest Number 2171
> ChrisC
> It will not be true of a Bolger sharpie, for example. Heeling on a sharpie
> will present a v-shape to the waves, with it's added advantages and
> disadvantages, but it will not increase waterline length.
I recall someone claiming that when a Micro heels, it presents
a greater waterline length. Wouldn't the buoyancy along the longer
and narrower "V" chine of a Micro, be equivalent buoyancy to a shorter
length along the wider flat belly?
In other words, the average width of the boat is wider at rest than at heel.
For the same displacement, a narrower boat must be longer than
a wider boat. I'm not sure, I am just thinking aloud.
Bolger rules!!!
- no cursing, flaming, trolling, spamming, or flogging dead horses
- stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
- Pls add your comments at the TOP, SIGN your posts, and snip away
- Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
- Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
Yahoo! Groups Sponsor
ADVERTISEMENT
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Yahoo! Groups Links
a.. To visit your group on the web, go to:
http://groups.yahoo.com/group/bolger/
b.. To unsubscribe from this group, send an email to:
bolger-unsubscribe@yahoogroups.com
c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]
> at the speeds/horsepower they operated at,I think that is the same reason that a shorter
> wetted surface was more important that waterline.
> David
Spur II might be slightly better for a solo rower,
though Spur II is already great.
The intention with the Micro and other of PCB's "potbellied" sharpies
is to reduce wetted surface area in light conditions (when friction is
a big factor) and increase waterline in stiffer breezes (when hull
speed becomes more important.)
Wetted surface came up when I was in Glouster. Phil observed that the
big multi-man crew boats had gotten smaller (from about 60' to 45', I
think) in recognition that at the speeds/horsepower they operated at,
wetted surface was more important that waterline.
YIBB,
David
is to reduce wetted surface area in light conditions (when friction is
a big factor) and increase waterline in stiffer breezes (when hull
speed becomes more important.)
Wetted surface came up when I was in Glouster. Phil observed that the
big multi-man crew boats had gotten smaller (from about 60' to 45', I
think) in recognition that at the speeds/horsepower they operated at,
wetted surface was more important that waterline.
YIBB,
David
On Friday, September 10, 2004, at 10:46 AM, Bruce Hallman wrote:
>> ChrisC
>> It will not be true of a Bolger sharpie, for example. Heeling on a
>> sharpie
>> will present a v-shape to the waves, with it's added advantages and
>> disadvantages, but it will not increase waterline length.
>
> I recall someone claiming that when a Micro heels, it presents
> a greater waterline length. Wouldn't the buoyancy along the longer
> and narrower "V" chine of a Micro, be equivalent buoyancy to a shorter
> length along the wider flat belly?
>
> In other words, the average width of the boat is wider at rest than at
> heel.
>
> For the same displacement, a narrower boat must be longer than
> a wider boat. I'm not sure, I am just thinking aloud.
> ChrisCI recall someone claiming that when a Micro heels, it presents
> It will not be true of a Bolger sharpie, for example. Heeling on a sharpie
> will present a v-shape to the waves, with it's added advantages and
> disadvantages, but it will not increase waterline length.
a greater waterline length. Wouldn't the buoyancy along the longer
and narrower "V" chine of a Micro, be equivalent buoyancy to a shorter
length along the wider flat belly?
In other words, the average width of the boat is wider at rest than at heel.
For the same displacement, a narrower boat must be longer than
a wider boat. I'm not sure, I am just thinking aloud.
> Actually, when the boat heels, in general the waterline lengthThis is really only true of boats that are built to do this, and these
> increases.
boats are built with racing rules in mind, and the racing rules that
promoted this building style have more or less expired.
It will not be true of a Bolger sharpie, for example. Heeling on a sharpie
will present a v-shape to the waves, with it's added advantages and
disadvantages, but it will not increase waterline length.
> From: Bruce Hallman <bruce@...>Sure, I volunteer . . . Bruce.
> An index?
> Yes, I agree, perhaps someone would volunteer to do that? (hint,hint)
:-)
-Chris
Chris Crandallcrandall@...(785) 864-4131
Department of Psychology University of Kansas Lawrence, KS 66045
I have data convincingly disconfirming the Duhem-Quine hypothesis.