Re: Pontoon Boats, HP, Fuel economy (was: Delaware concept--trawler yacht)
--- "John Bell" <smallboatdesigner@m...> wrote:
graph.
I don't know whether a pantoon boat with a sharp no-wave-making bow is
an oxymoron. But if the bow makes no or little waves, then what
meaning does 1.34*SQRT(WL) have? Why would the WL then influence the
behaviour at the stern?
This issue is in the end very similar to my transom question on the
design list.
Stefan
> This correlates very well with the speed at which weWould be interesting to see photos of both situations, as well as your
> see water breaking cleanly from the transoms.
> Both before and after the break, speed is exactly linear
> to power applied.
graph.
> Therefore, I come to the preliminary conclusion that fairingHull speed is an effect of the bow wave.
> the sterns of the pontoons would definitely pay if you never
> operate above 1.34*SQRT(WL)
I don't know whether a pantoon boat with a sharp no-wave-making bow is
an oxymoron. But if the bow makes no or little waves, then what
meaning does 1.34*SQRT(WL) have? Why would the WL then influence the
behaviour at the stern?
This issue is in the end very similar to my transom question on the
design list.
Stefan
Still, built with flat bottomed pontoon, with a tad of rocker forward,
you should be able to make a fairly fast pontoon boat with good fuel
economy.
Consider Bolger's Fishcat, or Glen L's Huck Fin wooden pontoons, and of
course Bolger's Bantam houseboat, which is rockered. All will do well
with low hp requirements.
As for asthetics, Bantams windowed house is easy on the eyes.
Bruce Hector
http://www.brucesboats.com
For recent updates on the "Don't Miss It" 2005 Kingston Messabout.
you should be able to make a fairly fast pontoon boat with good fuel
economy.
Consider Bolger's Fishcat, or Glen L's Huck Fin wooden pontoons, and of
course Bolger's Bantam houseboat, which is rockered. All will do well
with low hp requirements.
As for asthetics, Bantams windowed house is easy on the eyes.
Bruce Hector
http://www.brucesboats.com
For recent updates on the "Don't Miss It" 2005 Kingston Messabout.
On Jun 29, 2005, at 9:58 PM, John Bell wrote:
hal
[Non-text portions of this message have been removed]
> I meant to include this in my previous post:Ugly, maybe, but it looks like it belongs in my driveway. :^)
>
>http://mistermoon.home.mindspring.com/pb27_2.jpg
>
> That way you can see the ugly for yourself!
hal
[Non-text portions of this message have been removed]
Yes, but the catamaran is a poor load carrier. And the hull shapes
they seem to use are crude at best. I doubt a worse configuration could
be chosen for the intended use.
I was on a pontoon boat once several years ago. On one hand I had to
hold back laughter due to the shockingly poor performance for both the
price and the amount of horsepower. On the other hand I wanted to cry
at all the fuel that was burnt.
I guess I'm not a fan of the design style. ;-)
RonB.
they seem to use are crude at best. I doubt a worse configuration could
be chosen for the intended use.
I was on a pontoon boat once several years ago. On one hand I had to
hold back laughter due to the shockingly poor performance for both the
price and the amount of horsepower. On the other hand I wanted to cry
at all the fuel that was burnt.
I guess I'm not a fan of the design style. ;-)
RonB.
On 30-Jun-05, at 8:23 AM, John Bell wrote:
> Fuel burn depends mostly on how fast you want to go and how much
> weight you
> want to carry.
Fuel burn depends mostly on how fast you want to go and how much weight you
want to carry.
want to carry.
----- Original Message -----
From: "Ron Badley" <badley@...>
To: <bolger@yahoogroups.com>
Sent: Thursday, June 30, 2005 10:38 AM
Subject: Re: [bolger] Pontoon Boats, HP, Fuel economy (was: Delaware
concept--trawler yacht)
> Why not build a barge style hull? Using that much fuel is crazy!
>
> RonB.
>
>
Why not build a barge style hull? Using that much fuel is crazy!
RonB.
RonB.
Actually, in looking at my chart of speed vs. engine rpms for my boat
(constructed just last week using a GPS) I see that the slope of power shows
a break at around 8.5 mph. Below 8.5 mph, the slope is somewhat lesser than
for above that speed. This correlates very well with the speed at which we
see water breaking cleanly from the transoms. Both before and after the
break, speed is exactly linear to power applied.
Therefore, I come to the preliminary conclusion that fairing the sterns of
the pontoons would definitely pay if you never operate above 1.34*SQRT(WL)
and it does not make a difference if you mostly operate above that speed.
Bruce Hector's pontoon houseboat Adagio does have faired transoms and it
most certainly needs them. With its 50 horse motor it is not capable of
getting up to 1.34*SQRT(WL), which is 8 knots. At best it can only do about
6-7 knots. I'm sure if it had squared off transoms, it wouldn't go that
fast.
(constructed just last week using a GPS) I see that the slope of power shows
a break at around 8.5 mph. Below 8.5 mph, the slope is somewhat lesser than
for above that speed. This correlates very well with the speed at which we
see water breaking cleanly from the transoms. Both before and after the
break, speed is exactly linear to power applied.
Therefore, I come to the preliminary conclusion that fairing the sterns of
the pontoons would definitely pay if you never operate above 1.34*SQRT(WL)
and it does not make a difference if you mostly operate above that speed.
Bruce Hector's pontoon houseboat Adagio does have faired transoms and it
most certainly needs them. With its 50 horse motor it is not capable of
getting up to 1.34*SQRT(WL), which is 8 knots. At best it can only do about
6-7 knots. I'm sure if it had squared off transoms, it wouldn't go that
fast.
----- Original Message -----
From: "John Bell" <smallboatdesigner@...>
To: <bolger@yahoogroups.com>
Sent: Thursday, June 30, 2005 9:12 AM
Subject: Re: [bolger] Pontoon Boats, HP, Fuel economy (was: Delaware
concept--trawler yacht)
>
> ----- Original Message -----
> From: "craig o'donnell" <dadadata@...>
> To: <bolger@yahoogroups.com>
> Sent: Thursday, June 30, 2005 8:09 AM
> Subject: Re: [bolger] Pontoon Boats, HP, Fuel economy (was: Delaware
> concept--trawler yacht)
>
>
> >
> > What baffles me is that every aluminum pontoon boat drags its transoms.
> > Well, I've seen *one* with conical ends on the stern. Since a pontoon
will
> > never plane, I don't get it.
> > --
>
> At any speed over about 9-10 mph, the water breaks away cleanly from the
> transoms as in a planing boat. Since the boats are usually have enough
> horsepower to operate well above the speed the at which the water breaks
> cleanly away I doubt it makes much difference whether or not the transoms
> pointy or flat. On a lower power boat the difference would be much more
> significant, I agree.
>
> Displacement speed for my boat is something like 7.8 mph, and we normally
> operate it at twice that.
>
>
>
>
> 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
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> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
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>
----- Original Message -----
From: "craig o'donnell" <dadadata@...>
To: <bolger@yahoogroups.com>
Sent: Thursday, June 30, 2005 8:09 AM
Subject: Re: [bolger] Pontoon Boats, HP, Fuel economy (was: Delaware
concept--trawler yacht)
>
> What baffles me is that every aluminum pontoon boat drags its transoms.
> Well, I've seen *one* with conical ends on the stern. Since a pontoon will
> never plane, I don't get it.
> --
At any speed over about 9-10 mph, the water breaks away cleanly from the
transoms as in a planing boat. Since the boats are usually have enough
horsepower to operate well above the speed the at which the water breaks
cleanly away I doubt it makes much difference whether or not the transoms
pointy or flat. On a lower power boat the difference would be much more
significant, I agree.
Displacement speed for my boat is something like 7.8 mph, and we normally
operate it at twice that.
John,
Its less ugly than Adagio, but that's not saying much!
Have you considered a "faux plywood" paint-job?
Bruce Hector
http://mistermoon.home.mindspring.com/pb27_2.jpg
Its less ugly than Adagio, but that's not saying much!
Have you considered a "faux plywood" paint-job?
Bruce Hector
http://mistermoon.home.mindspring.com/pb27_2.jpg
If you wind up doing a homebuilt pontoon, do not sacrifice bridgedeck
height. The 'toons don't lift to waves like a conventional hull. Hit a big
enough wave and it will sweep the deck. The higher the deck, the bigger the
wave you can hit. Another thing about pontoons is that they are very
sensitive to weight. Adding three adults and a full tank of gas cuts several
miles per hour off our top speed. So build light and be realistic about how
much furniture you put on board. Larger, more buoyant pontoons are better.
Mine are 25" diameter and I wish they were 27". Even PCB found this out with
BANTAM, so he wound up revising the plan adding 4" of depth to the hulls in
the form of glassed over foam.
What baffles me is that every aluminum pontoon boat drags its transoms.
Well, I've seen *one* with conical ends on the stern. Since a pontoon will
never plane, I don't get it.
--
Craig O'Donnell
Sinepuxent Ancestors & Boats
<http://freepages.genealogy.rootsweb.com/~fassitt/>
The Proa FAQ <http://boat-links.com/proafaq.html>
The Cheap Pages <http://www.friend.ly.net/~dadadata/>
Sailing Canoes, Polytarp Sails, Bamboo, Chinese Junks,
American Proas, the Bolger Boat Honor Roll,
Plywood Boats, Bamboo Rafts, &c.
_________________________________
-- Professor of Boatology -- Junkomologist
-- Macintosh kinda guy
Friend of Wanda the Wonder Cat, 1991-1997.
_________________________________
[Non-text portions of this message have been removed]
height. The 'toons don't lift to waves like a conventional hull. Hit a big
enough wave and it will sweep the deck. The higher the deck, the bigger the
wave you can hit. Another thing about pontoons is that they are very
sensitive to weight. Adding three adults and a full tank of gas cuts several
miles per hour off our top speed. So build light and be realistic about how
much furniture you put on board. Larger, more buoyant pontoons are better.
Mine are 25" diameter and I wish they were 27". Even PCB found this out with
BANTAM, so he wound up revising the plan adding 4" of depth to the hulls in
the form of glassed over foam.
What baffles me is that every aluminum pontoon boat drags its transoms.
Well, I've seen *one* with conical ends on the stern. Since a pontoon will
never plane, I don't get it.
--
Craig O'Donnell
Sinepuxent Ancestors & Boats
<http://freepages.genealogy.rootsweb.com/~fassitt/>
The Proa FAQ <http://boat-links.com/proafaq.html>
The Cheap Pages <http://www.friend.ly.net/~dadadata/>
Sailing Canoes, Polytarp Sails, Bamboo, Chinese Junks,
American Proas, the Bolger Boat Honor Roll,
Plywood Boats, Bamboo Rafts, &c.
_________________________________
-- Professor of Boatology -- Junkomologist
-- Macintosh kinda guy
Friend of Wanda the Wonder Cat, 1991-1997.
_________________________________
[Non-text portions of this message have been removed]
Man,
There is nothing ugly about THAT pontoon boat. Looks like quality
merchandise to me. It is large enough to hold a good size party on it.
Bryan Swinney
There is nothing ugly about THAT pontoon boat. Looks like quality
merchandise to me. It is large enough to hold a good size party on it.
Bryan Swinney
I meant to include this in my previous post:
http://mistermoon.home.mindspring.com/pb27_2.jpg
That way you can see the ugly for yourself!
http://mistermoon.home.mindspring.com/pb27_2.jpg
That way you can see the ugly for yourself!
----- Original Message -----
From: "John Bell" <smallboatdesigner@...>
To: <bolger@yahoogroups.com>
Sent: Wednesday, June 29, 2005 11:41 PM
Subject: [bolger] Pontoon Boats, HP, Fuel economy (was: Delaware
concept--trawler yacht)
| Finally! A boat too ugly for PCB. LOL!
|
| Our boat is no raving beauty, but it's darned comfortable. Also it does
| better than anything else on our wake-torn reservoir, neatly slicing
through
| the chop without beating its passengers to death.
|
Finally! A boat too ugly for PCB. LOL!
Our boat is no raving beauty, but it's darned comfortable. Also it does
better than anything else on our wake-torn reservoir, neatly slicing through
the chop without beating its passengers to death.
The only problem with my boat is that the motor is too big at 115HP. If I
had to do it all over again, I'd look for one with 60-75HP max. Our best
fuel economy is at about 1500 rpm at 6 mph and 3.7 mpg. Normal cruise is
3200 rpm at 14 mph and 2.7 mpg and wide open at 5000 rpm yields 23 mph and
1.8 mpg(!).
Moving to the bigger boat from my very economical 15 horse/15 mpg AF4 was
quite an adjustment to say the least. My only consolation is that just about
every 'big' boat on the lake does about as poorly on gas as mine. That and
we don't ever go very far at all.
If you wind up doing a homebuilt pontoon, do not sacrifice bridgedeck
height. The 'toons don't lift to waves like a conventional hull. Hit a big
enough wave and it will sweep the deck. The higher the deck, the bigger the
wave you can hit. Another thing about pontoons is that they are very
sensitive to weight. Adding three adults and a full tank of gas cuts several
miles per hour off our top speed. So build light and be realistic about how
much furniture you put on board. Larger, more buoyant pontoons are better.
Mine are 25" diameter and I wish they were 27". Even PCB found this out with
BANTAM, so he wound up revising the plan adding 4" of depth to the hulls in
the form of glassed over foam.
Our boat is no raving beauty, but it's darned comfortable. Also it does
better than anything else on our wake-torn reservoir, neatly slicing through
the chop without beating its passengers to death.
The only problem with my boat is that the motor is too big at 115HP. If I
had to do it all over again, I'd look for one with 60-75HP max. Our best
fuel economy is at about 1500 rpm at 6 mph and 3.7 mpg. Normal cruise is
3200 rpm at 14 mph and 2.7 mpg and wide open at 5000 rpm yields 23 mph and
1.8 mpg(!).
Moving to the bigger boat from my very economical 15 horse/15 mpg AF4 was
quite an adjustment to say the least. My only consolation is that just about
every 'big' boat on the lake does about as poorly on gas as mine. That and
we don't ever go very far at all.
If you wind up doing a homebuilt pontoon, do not sacrifice bridgedeck
height. The 'toons don't lift to waves like a conventional hull. Hit a big
enough wave and it will sweep the deck. The higher the deck, the bigger the
wave you can hit. Another thing about pontoons is that they are very
sensitive to weight. Adding three adults and a full tank of gas cuts several
miles per hour off our top speed. So build light and be realistic about how
much furniture you put on board. Larger, more buoyant pontoons are better.
Mine are 25" diameter and I wish they were 27". Even PCB found this out with
BANTAM, so he wound up revising the plan adding 4" of depth to the hulls in
the form of glassed over foam.
----- Original Message -----
From: <wmrpage@...>
To: <bolger@yahoogroups.com>
Sent: Wednesday, June 29, 2005 10:59 PM
Subject: Re: [bolger] Delaware concept--trawler yacht
| In a message dated 6/29/05 1:18:55 PM Central Daylight Time,
|smallboatdesigner@...writes:
|
| > For lounging around at anchor it's tough to beat a pontoon boat.
|
| Pontoon Boats! If Bolger had invented them, perhaps they would seem less
| declasse! A pontoon boat is certainly the sort of minimalist,
Occam's-razor type
| of solution that exemplifies Bolger's most distinctive designs, at least
to me.
| For usual uses in protected inland waters, it is difficult to find fault
with
| them on other than aesthetic grounds.
|
|