Arrangement for trailerable powerboat ?

[fcfc]

Do someones have ideas for general layout for a trailerable powerboat in the 8' beam with an INBOARD engine with STRAIGHT shaft. The engine would then be a little aft the middle of the boat, and would certainly protrude from the floor.

Thanks.

[fcfc]

I have refined my own specs

Trailerable for me so :
max Beam 2.55 m (8' 4"), strict, not negotiable.
max weight on trailer 2200 kg (4800 lbs). strict, not negotiable.

CE design category : B able to survive to wind force of Beaufort force up to 8 (34 - 40 kts) and significant wave heights of up to 4 meter (13 ') for 4 person would be preferable.

Inboard diesel engine.strict, not negotiable.
Straigth shaft, power in the 40 - 60 hp range.

And then some comfort : suitable for a family of 4 for a week : parents and 2 kids. Separate head with shower (so headroom and hot water). Separate sleeping area. 12v electric fridge and microwave oven. Water for 3 days. Black tank and grey tank (3 days too) to allow "restricted area" anchorage. This is minimal comfort, not negotiable.

And a cruise speed around 11 kts, sustainable for 24 hours on most weather. (about 300 nm range).

Given the low canoe draft (low weigth) and engine height, the engine box will protrude from the floor.

Do the shamelessly modified layout from commuter 27 from parker marine or motorlauch 40 from van de stadt are correct tentatives ?

Are there existing boats with this kind of layout or better , still within what I want (all non negotiable points : size & weigth, comfort, engine type ?

And how far is this from option One ?

[altura]

I like it. I would decrease the beam to no wider then 8ft and leangth to 30-32feet.(tight fit into cargo container) and possibly a little taller. Maybe a little more aero dynamic look (modern for resale)

Change inboard diesel to outboard diesel (maybe yanmar diesel 37hp with a oversized prop) will increase cabin room and other areas etc. limit engine noise and vibration, with such a narrow beam its gona feel really cramped with an inboard right in the middle of the galley. Drive it right up on a sandy beach, really sucks to hit the prop, bent the strut and shaft while loading and unloading from trailer.

Should cruise at 12+knot non-stop and with a large fuel tank could cross the atlantic. With duel outboard diesels should cuise 18+ and top speed of maybe 20+.

Now just need a 2axis clamshell rotomachine 10meters x 3 using high density poly and can melt out 20 nearly complete boats per day at $3-4k for hull/cap, now where to find the $300k to start the project? :confused:

[marshmat]

If we are to consider containerable shipping, we are restricted to the standard ISO container's door dimensions of 2338 mm wide by 2583 mm high (approx 7'8" wide by 8'5" high).
Fcfc, I think you're on a good starting track, at least regarding the size and general layout you're looking at. Just chopping up and rearranging other boats obviously won't work in reality but it gives us an idea what you're thinking of, and I think you've got a good idea what you want already.
Longer and narrower will be more efficient and faster. But keeping the total weight down under 2.2 tonnes will be difficult.
If inboard diesel is your powertrain of choice, you'd be wise to consider a skeg to protect that prop. I presume you've ruled out twin-engine configurations?

[altura]

I saw somewhere sombody was tilting a 8.2ft+ beam, 34ft long into a container. I may have been one of the taller containers though, id need to check on that one.

A vessel of this type interests a lot of people i think. I live in california and like to go to catalina for the weekend. In my 26ft bayliner cabin cruiser it costs me about $220+ just to get there and back and cruise around a little bit, forget about even exploring as the cost of fuel would bust you. Going to the river is even worse. The yanmar diesel outboard uses about 1.5 gph, figure you could run the thing at max speed for 10 hours strait for a little over $50 compared to $300.

[marshmat]

A Bayliner 26 is a fat inefficient pig. No offence, altrua, but Bayliner never meant them to be used for long passages. Just like virtually all similar craft, it's built for maximum interior space in a given length when sitting at the dock.
I agree completely that there's probably a lot of interest in something longer, slimmer, more efficient. A boat like fcfc wants could probably be done such that there's a smooth, clean increase in speed as the boat climbs to a semi-plane state, without the horrific bow-rise and associated massive wake that conventional full-planing cruisers tend to have trouble with. And the smaller engine will be a huge advantage with fuel prices heading the way they are.

[Geoh]

Here is the project boat i am now working on. allweatherboats.com It is 26' by 8' and the extra length would make it usable for 4 people. 29 hp perkins cruises at 7 mph since full displacement hull speed is 6.4 knots you could get more speed with more length and more engine.
Take a look at the Degero 28 for interior concepts.

[Geoh]

Also go for more hull speed by eleminating the double ender and designing a different stern.

[Geoh]

just noticed date on original post...lol...were about a year late.

[thudpucker]

Now I'm coming in on this another year too late!
In the old days (days of my youth) there were a heckuva lot of boats just about the design this thread is about, made of wood.
Awful things to keep up with.

Most had Inline, small cube engines, right in the middle of the walking room.

You could take them right up on the beach because they had the big Skeg which protected the prop and rudder and most of the bottom.

I found out years later why that design. Cheap, efficient, and sturdy.
The design didn't need a lot of HP.
In fact you could take out the 25 Hp inline four and replace it with a barnstorming V-8 and still the boat would only make 10 Kts.

The math was easy. If you had a given distance, 10 Kts was the speed you had to cruise with so computing time, fuel, etc was something you could do in your head.

fcfc needs to go back in time and find a bunch of article's out of the 20's and 30's and he'll have his boat design.

[Pericles]

fcfc,

For consideration.

http://www.bateau.com/studyplans/FL26_study.htm?prod=FL26

http://www.bateau.com/studyplans/LB26_study.htm?prod=LB26

Pericles

[altura]

fcfc,

For consideration.

http://www.bateau.com/studyplans/FL26_study.htm?prod=FL26

http://www.bateau.com/studyplans/LB26_study.htm?prod=LB26

Pericles

Nice boats and designs, id like to see 30-32ft long with a 6.5-7ft beam. 60-80hp diesel engine, cruise 12 knots+. A "FL 26" elongated basically and maybe a bit of a taller.

[Pericles]

Altura,

Sure are good looking and the plans are excellent. I have them for the LB26 and DE25.

You could register and take part in the forum.

http://www.bateau.com/

You might be interested in the TW34 as well.

http://forums.bateau2.com/viewtopic.php?t=11743&highlight=tw34

Good luck,

Pericles

[FAST FRED]

If its going to fit in "the Box" a loa of 39 will cost not a bit more to ship, and allow a grand interior.

The boat with an extra 13 ft of loa will be faster with the same fuel burn and cost only a bit more to build.

It would still be trailerable , as weight is the limiter for most tow vehicles not length.

FF

[thudpucker]

39' long and only 7-8' wide?
Isnt that gonna limit the highth over all to something like 6'?
A hard top, only four feet off the water does not provide much distanc vision.
I didnt use any math there, just experience. Long skinny boats tend to roll a good bit.

[FAST FRED]

Isnt that gonna limit the highth over all to something like 6'?

WHY?

See Tad's fine example on his site of a nice cruiser with a folding deck house.

The limit would either be a bit under 9 ft to fit in a container or the hight on a trailer under 13.5 ft (in USA).

We have contemplated such a vessel for a long time , and the chance of a rolly harbor with swells from 2 directions would be handled by slipping a pole ( like a 4 inch spinnaker pole) into a socket that goes through the hull from side to side , and then attaching a dink (with similar heavy mounts) on the pole.

As a half ass'd catamaran she should be quiet enough for proper living aboard or sleeping.

FF

[marshmat]

The 8.5m trailer cruiser I'm playing around with right now (computer simulations and tow model, no actual boat yet) is about 7'3" wide and the top of the wheelhouse is about seven feet above the water. Calculations done so far indicate that its stability is just fine. Many of the powerboats in the local marina are sufficiently stable with a 17' high flybridge on a 10-12' beam (although those are utter crap when out on the water). The rolling can be alleviated by going with a fairly stiff hull form and keeping weight low. I see no reason why this boat couldn't have full standing headroom and great visibility with a 39' length and 7'6" beam. Yes, a long skinny boat will roll more than a long fat boat. But when we compare stability, comfort, speed, efficiency, etc. of boats with comparable displacement (and thus comparable cost), the long and skinny ones tend to come out ahead.... they suck on dock fees though, hence the appeal of trailerable.

[thudpucker]

The long skinny boats are more economical to run. No doubt about that. I've been on some of those long skinny buggers in a cross sea. It's a thrill at first and then its a chore.
Make your steering easy so you can make those quick changes at the top of the waves and the bottoms.

I will say that I've never been on a long skinny boat that turned over. Close, but I really dont think we were ever in danger.
If you load up the top of the bridge you might be in trouble. That's the kind of thing I was referring to when I said long skinny boats roll too much.

In Cook inlet AK, the old beach set net boats were long skinny fishing boats that can be beached, because they have the big Skeg.

They are 'muthabear' to get across the inlet in those quartering waves. That Skeg takes over and makes it almost impossible to turn the boat in a hurry.
You wind up getting slammed, and then dropped into a trough, with each wave. Lordy you get tired and short tempered on a ride like that.
But you guys are right, I never felt like we might roll.

[FAST FRED]

Make your steering easy so you can make those quick changes at the top of the waves and the bottoms.

Our plan is a vertical tiller in the pilot house as used on many lobster boats and YC launches. Modern line and large pulleys would keep weight and loads down.

Very rapid rudder movements are easy , but the added + is that a low cost tiller auto pilot should work just fine.

Guess I'm just cheap, as well as lazy.

FF

[fishingaz]

hi kcfc.i own something of the type of boat you are looking for so maybe a search of the arvor range might help you .we own an arvor20 designed for the north sea .so its great for me down here in australia.it is 20 ft
powered by a 85hp nanni diesel shaft drive semi displacement and has a tunnel type of hull aft of midships.and a keel center of that tunnel.and a fine entry at the bow
it is the best type of boat i have ever had but maybe just purpose built like for us .its a fishing boat and troll all day without breaking the bank.it only has a small wheelhouse good enough for three in a blow shut the door and hatches and feels very safe and dry.2 small bunks but not for family weekends.so if this helps you with ideas im glad.sorry i cant send link .i dont know how.so good luck.gary.www.arvor.com.au.

[fishingaz]

oh and it does 20knots at 2800 with clean hull ours is antifould and we get 18 knots

[tom28571]

To accommodate all of your comfort requirements dictates a fairly heavy boat. Parker's commuter, which is a lightweight planing hull is not suitable at all. You need to look at Sam Devlins designs in this size range to get an idea of what is necessary in a boat to provide all you want. Not meant to actually use one of them but to get an idea of how a good designer approaches this set of problems. Look at his displacements and power requirements although most are meant for higher speed.

A shower means something to store all the water needed, a means to heat it, a power water system and some means to store the grey water from it. Microwaves and fridges need their power sources. Four people for a week need a considerable blackwater holding tank too. I expect you know all that but have you figured out how to fit them in any of the designs you considered? Before looking at a design, try to compile the list of requirements and see how much room and what kind of displacement you need. I don't see much headroom on any of the models you show. Easy to get cabin fever, especially with kids for a week.

While you appear to be convinced on the engine in the cabin arrangement, look at what it does to the interior room. In summer, it means a lot of heat too. There are some pretty good IO diesel packages that consume a lot less room and allow much better steering and handling, plus the ability to run much shallower if need be.

I don't remember any shipping container requirements.

[FAST FRED]

I don't remember any shipping container requirements.

The "oversize" which still is very common and ships cheaply

The boat can be

7ft 6 inches wide 39ft long and just under 9 ft high.

Longer costs almost nothing to build in a skinny boat, since there is so little of it.

Flat bottom to stand inside , and load with simple pipe rollers should be considered.

FF

FF

[Bushy]

The Arvor seems like its very good fishing boat, and would suit my needs perfectly. Does anyone know of build kit or plans for something similar

Any help would be much appreciated.

Cheers