Re: Isometric of Bolger's Cartoon 31 "Ocean crosser"
--- In bolger@yahoogroups.com, "Eric" <eric14850@...> wrote:
>That is very muchspot -on accurate indeed !
>
>
> There is something many people do not appreciate. To maintain a boat to yacht standards requires the same cost for fiberglass, steel, and wood (plywood). (Take time to appreciate that, because conventional wisdom dismisses the statement as nonsense. Then look along the back rows of boat yards and appreciate the derelict fiberglass boats that have replaced the thirty year old derelict wood boats the buyers of those boats ridiculed.) The difference between fiberglass, wood and steel construction is, ignoring maintenance of a fiberglass boat is usually not as disastrous as ignoring maintenance of a steel or wood boat. An epoxy encapsulated wood boat like ROGUE falls somewhere between a wood and fiberglass boat regards maintenance.
> Eric
>
>
>
In a boat like this the hull cost would represent 25% or less the cost of the whole boat. Chine construction might or might not save some percent of that 25% figure. Not worth it. Use the hull construction that makes the best performance/maintenance sense. Epoxy fiberglass over strip planking has proved very strong, durable, maintenance free on ROGUE which has a curvaceous hull like Ocean Crosser. There is nothing wrong with the traditional planking called for in the short and long term if the skills necessary are available.
There is something many people do not appreciate. To maintain a boat to yacht standards requires the same cost for fiberglass, steel, and wood (plywood). (Take time to appreciate that, because conventional wisdom dismisses the statement as nonsense. Then look along the back rows of boat yards and appreciate the derelict fiberglass boats that have replaced the thirty year old derelict wood boats the buyers of those boats ridiculed.) The difference between fiberglass, wood and steel construction is, ignoring maintenance of a fiberglass boat is usually not as disastrous as ignoring maintenance of a steel or wood boat. An epoxy encapsulated wood boat like ROGUE falls somewhere between a wood and fiberglass boat regards maintenance.
Eric
There is something many people do not appreciate. To maintain a boat to yacht standards requires the same cost for fiberglass, steel, and wood (plywood). (Take time to appreciate that, because conventional wisdom dismisses the statement as nonsense. Then look along the back rows of boat yards and appreciate the derelict fiberglass boats that have replaced the thirty year old derelict wood boats the buyers of those boats ridiculed.) The difference between fiberglass, wood and steel construction is, ignoring maintenance of a fiberglass boat is usually not as disastrous as ignoring maintenance of a steel or wood boat. An epoxy encapsulated wood boat like ROGUE falls somewhere between a wood and fiberglass boat regards maintenance.
Eric
--- Inbolger@yahoogroups.com, "daschultz2000" <daschultz8275@...> wrote:
>
> Interesting for sure. Very conventional except the "torpedoes". I agree the boat could be rendered in plywood as a multichine. However, having read Ruel Parker's book about cold molding, that would be as easy to accomplish and would likely be a stronger craft. IMO the booms need to be braced against fore/aft stresses.
>
> For a long time, Bolger has favored a dry exhaust, and using Deutz diesels that are cooled by the lubricating oil and have an integral radiator for the oil thus appear to be air cooled. excellent reputation.
>
> Don
>
Interesting for sure. Very conventional except the "torpedoes". I agree the boat could be rendered in plywood as a multichine. However, having read Ruel Parker's book about cold molding, that would be as easy to accomplish and would likely be a stronger craft. IMO the booms need to be braced against fore/aft stresses.
For a long time, Bolger has favored a dry exhaust, and using Deutz diesels that are cooled by the lubricating oil and have an integral radiator for the oil thus appear to be air cooled. excellent reputation.
Don
For a long time, Bolger has favored a dry exhaust, and using Deutz diesels that are cooled by the lubricating oil and have an integral radiator for the oil thus appear to be air cooled. excellent reputation.
Don
Couldn't one use two bladders inside the same tank structure, one for fuel and the other for seawater?--- OnFri, 9/17/10, Christopher C. Wetherill<wetherillc@...>wrote: |
On 9/17/2010 1:01 PM, Fred Schumacher wrote:To solve the problem of fuel as ballast in shallow hulls, Max Gunning, designer of Dutch submarines and of the unusual Alcyone, Alcyone II, and Cormorant sailboats, decided to use the submarine method of letting sea water enter the tanks at the bottom as the fuel is removed from the top. The diesel floats to the top, and ballast trim changes only slightly with fuel use. Of course, a really good fuel polishing system would be essential.
On Fri, Sep 17, 2010 at 10:34 AM, Bruce Hallman<hallman@...>wrote:I am reluctant to post the whole article, as it is copyrighted. Look
to the Small Boat Journal #55 (June/July1987). Paraphrasing from the
write-up.
My old issues of SBJ are up at our permanent home in northern Minnesota 260 miles away, but the next time I'm there, I'll have to look for that issue.
It's interesting to look at this design and see how the PB & F problem solving methodologies evolved over time: from slack bilged, complex curves to hard chined hulls derived from sharpies; from a heavy engine deep in the hull to placing a light weight engine in the stern above the waterline; relying on gimbaled chairs and berths instead of trying to stabilize the entire hull. Col. Hassler, Tahiti, and Fiji represent the latter solutions.
To solve the problem of fuel as ballast in shallow hulls, Max Gunning, designer of Dutch submarines and of the unusual Alcyone, Alcyone II, and Cormorant sailboats, decided to use the submarine method of letting sea water enter the tanks at the bottom as the fuel is removed from the top. The diesel floats to the top, and ballast trim changes only slightly with fuel use. Of course, a really good fuel polishing system would be essential.
fred s.
> This must be one of his earlier designs.The conventional view is that the choice between round bottom and chine depends on the speed. You need a fast boat to make chines the better option. This boat is definitely in round-bottom territory.
> I think he would have used a chined design if he had redesigned it.
The trailerability requirement made this a very difficult spec. From what I ever heard from people who had boats designed for them, PCB asked what was important, and in what order, then he stuck to that. One of the things that made him so creative is that he was able ignore things low on the list (or not on the list) even if when it went against convention. In fact, the advice I heard was to make very sure that you were content to live with the list because that was what you were going to get. If you left off "good looks" you might not get good looks.
Peter
On Fri, Sep 17, 2010 at 4:05 AM, Fred Schumacher <fredschum@...> wrote:
to the Small Boat Journal #55 (June/July1987). Paraphrasing from the
write-up.
Wishlist: a cheap trailer capable safe powerboat with 3,000 mile range
with 30 days of storage.
16,000 lb displacement, deep keel and big well immersed propeller.
The exhaust isn't shown in the drawings, but the text says "The
exhaust would probably be dry, straight up ahead of the wheelhouse."
The pipe berths in the engine compartment are for in-port use. The
large forward engine room is to make access for motor work easy, and
it doubles as the head. Showers/washroom are intended to be done in
port in a tent on the afterdeck. Dingy to be stored on the housetop.
For armament he suggests flare gun and industrial ammonia for boarders
and a large rifle for a stand-off engagement.
Bolger thinks paravane gear has too much drag and propensity to
fouling, and his torpoedo tanks are his 'better idea'. PCB writes
that he spoke with Captain Beebe about this, and Beebe was skeptical
that it would work.
Bolger also writes of the problem of the ballasting, as during
passages the stores and fuel will ballast the boat and at other times
you need solid ballast to float to her lines as there is not room for
water ballast. (He suggest steel rebar bundles, bought and sold at
scrap metal prices as needed.)
The 27hp motor is rated at 12hp at 2,000 RPM, should allow 6.5 knots
making 9 miles per gallon, with 325 gallons of fuel in the tanks.
Or, 8 1/2 knots at 2,700 rpm and 5 3/4 mpg.
Also, Beebe said that the limit of 8 feet width (to make it trailer
capable) made the living cabin too small for a passagemaker.
In summary, Bolger has enough reservations that a satisfactory passage
maker which is also trailer capable might not be feasible, hence this
never made it past the cartoon stage of design.
My own thoughts about the plank on frame construction versus the hard
chined option. Plank on frame can be cheap, and on a passage maker
like this the reduction in the total wetted surface area drag for a
given displacement (versus hard chined) makes a noticeable difference
in the fuel efficiency, I think.
>I am reluctant to post the whole article, as it is copyrighted. Look
> This must be one of his earlier designs. I think he would have used a chined design if he had redesigned it. I'm also curious about Phil's choice of water filled torpedoes instead of birds and placing the paravane booms in front of the hull midpoint, whereas Beebe recommends placing them 28% of the distance from the stern. Bruce, do you have the original article and can you post it?
>
> fred s.
>
to the Small Boat Journal #55 (June/July1987). Paraphrasing from the
write-up.
Wishlist: a cheap trailer capable safe powerboat with 3,000 mile range
with 30 days of storage.
16,000 lb displacement, deep keel and big well immersed propeller.
The exhaust isn't shown in the drawings, but the text says "The
exhaust would probably be dry, straight up ahead of the wheelhouse."
The pipe berths in the engine compartment are for in-port use. The
large forward engine room is to make access for motor work easy, and
it doubles as the head. Showers/washroom are intended to be done in
port in a tent on the afterdeck. Dingy to be stored on the housetop.
For armament he suggests flare gun and industrial ammonia for boarders
and a large rifle for a stand-off engagement.
Bolger thinks paravane gear has too much drag and propensity to
fouling, and his torpoedo tanks are his 'better idea'. PCB writes
that he spoke with Captain Beebe about this, and Beebe was skeptical
that it would work.
Bolger also writes of the problem of the ballasting, as during
passages the stores and fuel will ballast the boat and at other times
you need solid ballast to float to her lines as there is not room for
water ballast. (He suggest steel rebar bundles, bought and sold at
scrap metal prices as needed.)
The 27hp motor is rated at 12hp at 2,000 RPM, should allow 6.5 knots
making 9 miles per gallon, with 325 gallons of fuel in the tanks.
Or, 8 1/2 knots at 2,700 rpm and 5 3/4 mpg.
Also, Beebe said that the limit of 8 feet width (to make it trailer
capable) made the living cabin too small for a passagemaker.
In summary, Bolger has enough reservations that a satisfactory passage
maker which is also trailer capable might not be feasible, hence this
never made it past the cartoon stage of design.
My own thoughts about the plank on frame construction versus the hard
chined option. Plank on frame can be cheap, and on a passage maker
like this the reduction in the total wetted surface area drag for a
given displacement (versus hard chined) makes a noticeable difference
in the fuel efficiency, I think.
This must be one of his earlier designs. I think he would have used a chined design if he had redesigned it. I'm also curious about Phil's choice of water filled torpedoes instead of birds and placing the paravane booms in front of the hull midpoint, whereas Beebe recommends placing them 28% of the distance from the stern. Bruce, do you have the original article and can you post it?
fred s.
fred s.
This is an amazing looking concept as is your isometric. I guess the
engine gets air from that large cowl in the bow. I wonder how the
exhaust is handled?
Nels
engine gets air from that large cowl in the bow. I wonder how the
exhaust is handled?
Nels
--- Inbolger@yahoogroups.com, Bruce Hallman <hallman@...> wrote:
>
>http://hallman.org/bolger/cartoon31/
>
> For those (like me) who have been fascinated by the thoughts and
> writings of Robert Beebee (Voyaging Under Power), it was especially
> interesting to study the PCB Beebe inspired SBJ Cartoon 31, a 30 foot
> diesel powered ocean crossing power cruiser. PCB achieves the roll
> damping stability using outriggers towing sea-water filled torpedoes.
> The main mass of the boat, the fuel tanks are located at the low
> center of the hull.
>
http://hallman.org/bolger/cartoon31/
For those (like me) who have been fascinated by the thoughts and
writings of Robert Beebee (Voyaging Under Power), it was especially
interesting to study the PCB Beebe inspired SBJ Cartoon 31, a 30 foot
diesel powered ocean crossing power cruiser. PCB achieves the roll
damping stability using outriggers towing sea-water filled torpedoes.
The main mass of the boat, the fuel tanks are located at the low
center of the hull.
For those (like me) who have been fascinated by the thoughts and
writings of Robert Beebee (Voyaging Under Power), it was especially
interesting to study the PCB Beebe inspired SBJ Cartoon 31, a 30 foot
diesel powered ocean crossing power cruiser. PCB achieves the roll
damping stability using outriggers towing sea-water filled torpedoes.
The main mass of the boat, the fuel tanks are located at the low
center of the hull.