Affordable, long-term liveaboard?

Something practical for a couple to live on, without breaking the bank, economical to build and operate, with solutions to the problems of staying on the water for weeks at a time, in protected water. Some areas for debate might be how much technology and of what kind, (watermakers, etc), sail/engine/motor sailer, etc.

 

Monohull or multi?

 

Yeah, that's another area for debate. My opinion? Mono for economical build, multi for comfortable living. But I wouldn't want to restrain the creativity. What is the concensus?

 

The Water Planet

I am working right now on designing and building a long term live aboard vessel. The way I describe the vessel is:

• it costs less than a house (<$150k)
• Very low maintenance costs
• 1000 square feet of living space
• Carries a mini car that can be off loaded on piers or shore
• carries a small inflatable tender
• super efficient
• 5-8 kts with short burst of 12 kts possible
• twin electric drive
• extremely maneuverable
• Can be piloted by a single operator
• Pollution free
• Very low fuel costs
• Hybrid energy sources (solar, wind, current, wave, biodiesel generator, direct from mains battery charging)
• Quiet
• No fumes
• Idiot-proof
• Bullet-proof

I plan to spend the $150 k to build this boat, it will be the first of its kind to make the water planet fully inhabitable with very low operational costs.

If I succeed in this project I want to start manufacturing these boats on a mass production scale. But first I have to be able to build the prototype for the money I have. I would welcome collaboration. Have already received a lot from BoatDesign.net with a particular thanks to Yipster.

Right now it looks like:

• Symmetrical Twin hulls
• 16 meters LOA (50 ft)
• 6 meters wide
• 20:1 L/B hull ratio
• Largest section 2/3 aft
• Cp 0.5 - 0.6
• Draft < 1 meter
• Displacement - approx 12 - 14 tons loaded
• 10,000 watts of photovoltaic panels on the gently curved roof
• 20,000 watts of battery storage
• 1500 watts of wind turbines (3 small turbines, rackmounted aft)
• 2 - 10HP Electric outboard drives, mounted amidships, one for, one aft
• Outboard drives can rotate 180 degrees as well as instant reverse
• Composting toilet
• Solar hot water and cabin heating
• Roof collects water
• Solar distillation for potable water
• 2 meter headroom in cabin
• 5 camera video rear view
• Possible GPS feedback system for maintaining station without anchor

I would like the boat to be very aerodynamically perfected, and built of very tough, no-maintenance materials. Any ideas? I would like an understated futuristic design, where form follows function. The boats below are a departure point.

 

Jonathan,

Have you considered light-weight (foamed) glass-reinforced concrete for the superstructure?

Yoke.

 

Yoke,

Actually, I know very little of the materials technology you mention. Foamed concrete - is it non porous? Does it require a coating on under water parts of the boat that needs to be maintained? I have been thinking about stainless steel (very expensive as a prototype) and HDPE (limitations on size of parts) because of their very high resistance to corrosion, abrasion, and impact damage. Do you have sources of information on the foam-concrete materials you are bringing to the discussion?

The (up to now) size limitation of about 20 foot long parts for HDPE only means that a larger oven and rotating jig need to be built. I am thinking that if you use symmetical cat hulls that are very thin, then the oven and rotating jig that creates both hulls may not have to be that tall or wide.
Another possible line of design might be to have four shorter hulls in a diamond configuration. I am not sure what down sides there may be to that approach.


Jonathan

 

Some of the things sound like very good ideas. But having a mini-car in the boat might be a problem. I know it's probably one of the most minor things but still. There has to be a way to secure it so that when the water gets rough the car will not slam into the hull. Otherwise it sounds great.

Tim

 

Jonathan,
Have you visited any of the websites of the well known multihull designers? Here is a link to a list of them... http://www.powermultihulls.com/misc/power_multihull_designers.htm

Of the few that I looked at, none managed to claim a displacement of 12 - 14 tons for a 50 footer - most were closer to 20 tons - and probably not fully loaded.... especially not with a car! Remember that cats are very sensitive to weight and you NEED to be pretty spot on with your weight estimates. Long-term liveaboards tend to be the heaviest too as stuff accumulates over time.

As far as your boat being "pollution free" goes, just where do you think the power comes from when you plug into shore power...... solar, wind? ... I doubt it, so whilst you may feel that you are doing the world a favour by going all electric, all you're really doing is transferring the muck to where it's out of sight...and out of mind.... Granted the other systems you talk about may edge you in the pollution-free direction (solar etc) but all that I've read (which admittedly isn't a great deal... ) suggests that you would still have to augment your power requirements by plugging in to shore power. And the biggest drawback to all these "new technologies" is that they are very expensive - which would defeat one of your primary design goals...

You may also want to think about the beam of the boat - at 6m are you going to be able to cost-effectively find somewhere to berth it?

Don't get me wrong, I'm all for the economical long-term liveaboard but if that's your primary design objective then I think you may need to reconsider some of the directions that you've currently suggested....

 

In any case, new ways of doing things are always met with skepticism. If God had wanted us to fly he would have given us wings.

 

Jonathan, I think your idea sounds feasible depending on what your performance requirements are for the boat. If you don't expect to exceed 5 kts or run more than 25 miles then a very modest all-electric propulsion system would suffice. The challenge will be in cost - $150K for a lightweight, 50 ft multihull is asking a lot.

The example catamarans you showed are designed for high speed operation - one of them operates here in Alaska as a high-speed ferry, and one of the others has a similar operation in the Caribbean. At low speeds the case for a multihull diminishes - ride performance and high-speed efficiency don't apply for your application - at low speeds multihulls can be less efficient due to additional wetted surface. And as WillAllison pointed out, load carrying capability for a liveaboard (with large battery bank) is greatly decreased for a multi, especially w/ a 20:1 L/B ratio. I'm a multihull advocate, but it appears that for your application a monohull might be more suitable.

 

I expect to cruise at 5-8 MPH and occasionally as fast as 12 MPH. If I cruise at 3 MPH on calm waters and sunny days, I can probably exceed 50 miles per day if all of the other solar electric multihulls are any indication.

True but you can't always travel at low speeds because currents, wind, and waves force you to be able to make headway against them. So you need the efficiency at the point where wavemaking starts to be a significant factor. It is most impoortant to have the efficiency under adverse conditions as opposed to calm water conditions. Otherwise you run out of energy when you need it most. I believe this is why virtually all builders of solar electric boats are utilizing cat hulls. Also, I like the comfort of a wide cat and the fact that they have way less roll. I actually have not personally had much problem with sea sickness, but some friends (especially female ones) have and I want my friends to be happy, instead of being stuck in a barf nightmare.

Well I may have to go more in the direction of 16:1 L/B.

As far as weight goes, 20,000 watts of flooded lead acid battery storage weighs about 5250 lbs. Actually that was 10 years ago. Its probably less than 5000 lbs by now. 800 square feet of frameless solar electric panels weigh about 2400 lbs. Two electric motor drives and controls weigh less than 1000 lbs. That's about 8400 lbs. That leaves 24,000 lbs for the rest of the boat. I have a quote from a boat builder/designer in the Netherlands who will build me a pair of 5 mm marine aluminum cat hulls for about $60k. The solar panels will cost about the same - $60k. The batteries will cost about $5k. The electric drives will probably cost $20k. The rest of the cabin structure I hope to build from a plywood foam sandwich for less than $50k which brings the cost as envisioned to nearly $200k. Still a great price if I can do it. But then, I am into innovative construction/manufacturing projects and I am hoping to get assistance from companies whose products I use, since this is a prototype. The idea is to prepare a design for large production runs and enter the houseboat market with a distinct and well differentiated product. Maybe I'm nuts, but we won't know for sure til we find out!

 

Here's the car for carrying on your boat: http://www.commutercars.com/

 

Jonathan,
1st of all my apologies - I certainly didn't mean to sound condescending On the other hand, there's no need to get on your high horse and start abusing those who are simply trying to assist you with your endeavours People like me are not "why we are drowning in the residues of burned hydrocarbon".
I don't care how much experience you have with solar power - I simply don't think your numbers stack up. You want to cruise at 5 - 8 mph, with occaisional sprints of 12, yet you talk of a range of 50 miles at 3 mph in calm, sunny conditions. What happens when the wind blows - since you 'lived for extended periods on multihulls" I assume you would have noticed that this happens quite regularly... so if you have a range of about 25 miles at 5 mph in calm conditions it will probably drop to something like 10 - 15 in any sort of chop and to substantially less than that in a decent blow. Wind turbines may help to offset this somewhat, but not enough to make any real impact.
I don't doubt that you've probably looked at more multi's than I have - but that doesn't alter my point - show me a sensible, liveaboard powercat that can carry a small car, that has a LOADED displacement of 12 tons.

Your original post listed affordability at the top of your design criteria, yet you've already blown the budget by 25%.... and that's before your wife gets involved with the interior decorating
Look - I'm sorry - I just don't believe that what you propose can be done for the price you suggest and at the displacement you talk of. If you can prove me wrong I'll be the 1st to congratulate you, but I believe that a slender (probably steel) monohull with a small, efficient diesel (maybe diesel-electric?), supplemented by other 'clean' energies is the only way that you will attain your ultimate goal of an affordable long-term liveaboard.

 

Hey, you are entitled to your opinion.

 

20:1 L/B hull ratio

This fine a setup is optimizing for speeds you will never see.

Probably 8-1 to 10-1 would have less drag at low speeds (5K to 12K)than a superfine hull that would radically increase the wetter surface.

FAST FRED