Cabin design

The majority of the area in question is down low. The effect of wind increases higher up so the same area at roof level would have a greater effect.
PAR is right that ANY box-like structure on the water is going to have enormous windage for its footprint already.
I think you've done well to style the box given that you have avoided excess wind-catching appendages. It shows you're aware that the problem could exist.
I see a lot of small pontoon-style houseboats that have cabin soles (floors) some distance above the water. I'd like to see a design (maybe a tri-hull) that has a central passage with a sole BELOW water level. It would be more stable due to a lower center of gravity and it would also reduce windage hugely due to its roof being a couple of feet lower.

 

Perhaps I'm a little late to the party but another book you might consider is Ian Nicholson's "Boat Data Book".

 

I designed a hull like that years ago Alan, it was a three hull pontoon, but the center hull was a box, the width of the floor space, not counting cabinets, berths, etc. This let me drop the sole over 2 feet and the outside profile was greatly improved as a result. This was a hand drawn design, I'll dig around and see if it's been digitized (I doubt it). If it is I'll post a profile.

 

I'd like to see it. About a 30"-36" aisle would be great, allowing access to the two sides which might be another 30" wide each. Toilet would have to be somewhere in that central aisle, and the dining table would be tricky. I'd like to see how you worked that out.

 

The head was off center and a couple of steps up to sitting headroom unfortunately, but not a bad compromise considering centerline entries. The center foot well was about 32", but tapered out to 36" at the cabinet faces. The counter tops were 30", the settee/dinette was a drop leaf near, but not on centerline. With the leaf folded down there was still 22" or so foot well space to get by. The centerline foot well limited accommodation arrangement a good bit, but solved more problems then it created.

 

All good ideas. I thought of the raised toilet, there'd be 5 ft or so. If you find the plan you should post it here. There's quite a bit of interest in these minimal houseboats.

 

There surely hand drawn, so I'd have to scan them in pieces, reassemble and post. To be honest, I'd almost rather do a new set if enough interest was there.

 

Would the center hull have to be a passage area to achieve that lowered center of gravity? Would moving equipment and accy. weight to that hull and moving the bottom lower than the other hulls achieve the same gravity goal? I know it will do nothing for wind.

I don't know why, but I'm finding it hard to grasp the knowledge in calculating my CG & CB when introducing a third hull? I've been doing land locked design too long. It's almost like designing 3 gable buildings upside down and supported by roofs with fluctuating support loads??? Arrrrgh!!

I know what the answer is, but I'm on a shoe string budget. What would one pay for an NA to review a design? No seal, just a review/suggestions.

 

Actually knowing the CG as a figure isn't so vital. A lowered central hull is far more stable than a two-hull base or a three hull where all hulls are alike.
The significant calculation would be to know how deep to sink the central hull to meet the displacement required. This may entail adjusting down the displacement of the outer hulls by raising them (in height) or giving them smaller cross sections.
If the central hull has a one foot deep draft, two and a half foot beam, and is 16 ft long, with most of the length being a fixed width box-section, it has a very high prismatic coefficient (say .75).
The displacement of that hull would be 2.5 ft x 1 ft x 16 ft x .75, or 30 cubic ft, translating to about 1900 lbs. The outer hulls could contribute another 300 lbs each displacement, making a total of 2500 lbs cruising displacement.
This deeper-in -the -middle design approach requires that the scantlings of the boat will be on the heavy side. This isn't a problem since the trailering weight will be managable at maybe 1800 lbs.
Dialling down the displacement is easy because you're starting with parallel sides on the main hull. Lowering the displacement is as simple as designing a lower prismatic central hull. Doing so would allow up to maybe 500 lbs displacement reduction, but interior walking space would be cramped in the ends severely limiting the very thing you're trying to achieve, which is dependant on intelligently placing such items as require full height (table, inside steering station, toilet, steps at each end to the decks, reaching the outer walls comfortably, etc.).

 

I've finally found and looked over my drawings. They're in fair rough shape and it was decided, when we were converting everything to digital a few years back, that this set wouldn't be. The design is still valid, it's just that I would do many things differently now (older, wiser, etc.), so I'm not going to post the drawing, even though I said I would.

Ddrdan, I'm not sure what you need, but I think templates can solve your problem with ergonomics. Other then the off track discussion about my three hull pontoon design, your basic needs can be addressed with just two pontoons, assuming you've done a reasonable weight assessment and will hit your target immersed hull(s) volume. Yes, it'll be a tall structure, but so are many like this. Your target speed range can tolerate this and passage making isn't the priority of this vessel, so it's not a big issue. Windage is always going to be a problem with floating houses, a bigger engine is the usual option.

 

Originally Posted by yipster
"if i understand correctly you want to check the ergonomy of the drawing?"

Originaly Posted by dskira
"They should use it on airplanes. They forget peoples has legs "

was just told they do think about that in airplanes, here the new "standingseats"
some short flight price fighters allready showed great interest in




sort of in this safety belt position, budyseats would be another option
but where did the upstairs swifel bar chairs went with the lonesome cowboy
that you could not even impress showing how big a fish you were talking bout

back to topic