Big progress on my solar driven pontoon river boat

Solar electric pontoon river boat

My new boat-project is near completion. I would greatly appreciate your input.

Link to images: https://drive.google.com/open?id=0B4YZdoArin92fmNIWlRjZk9JTVhMcTdqRThsZlIzX0daSTJ0NXpSTVprMU4yZm4xa19ZU0U

Length: 800 cm
Width: 220 cm
Depth: 18 cm
Weight ex. persons: 800kg (it is possible to get the boat-weight down to 600 kg if necessary)
Frame: Aluminium
Cockpit: 2 person, plywood
Pontoon material: PE100
Pontoon diameter: 40 cm
Battery: 2x180Ah DUAL AGM EXIDE EP1500
Engine: Torqeedo Cruise 2KW
Solar: 4 x 327W SunPower
MPPT: Morningstar 60

Speed and manoeuvrability: Any idea, folks????

 

Hello Jon,

congratulations, its looks nice and a clean welding job is done. And I'm very interested in the electric propulsion data.

I don't know anything about speed and maneuvrability, sorry.

But I'm a bit worried about its stability. Calculating with your data, the pontoons (tubes) will be immersed 50 %. In good weather conditions and calm water there will be no problem.

In a case of a strong heeling moment one of the two tubes schould be able to bear the complete weight (800 kg + 150 kg crew + ? kg gear). This is not possible and the (only one) tube would be submerged and could not prevent capsizing.

 

Hello. This boat will only be used on the local river (no big waves) on nice (hopefully) sunny days. Spec. on the engine, can be found here: http://www.torqeedo.com/en/products/outboards/cruise/cruise-2.0-r/M-1230-00.html

 

Good luck, Jon!
I'm looking forward to your reports.

 

Honestly the specs indicate it is grossly overweight and lacks boyancy. Both are going to add substantial drag and drain speed badly.

For a cat this size I think an ideal weight would be around 100kg for the platform plus the gear weight. But this would require carbon construction. Figure somewhere in the 200kg weight for less expensive construction methods. At 800kg it's going to be pushing a lot of water.

 

Hi Greg. You're Probably Right. This is just a fun hobby project, but i hope the cruise speed will be 6 to 8 knots. We'll see

 

The pontoon diameter seem too small for the weight. 2*8 m have about 2 m3 volume. Thus at 1000 kg waterline will in the middle of the pontoons where you seem to have a floor for the batteries. Once this hits the water the drag will be very high. You should change the pontoons or install the floor clearly higher.

I don't know much about catamarans, but it looks like the pontoons are too close to each other and will cause wave interference.

6-8 knots is too much for 2 kW. You would be lucky to get 5 knots at that weight and design.

 

I have to agree with Stumble. You need to extend the hulls by almost a meter raise the platform and still keep the all up weight to under 1000 kilos. You might make six knots in flat water but I doubt it. If you were to use the Torqeedo Cruise 4 you would probably be alright but your solar array and battery capacity would be inadequate. This is just an opinion based on my own experiments attempting to design a somewhat similar craft. I look forward to the launch of your boat and hope that you will post performance figures that I can apply to my own efforts.

 

I see most of you tells me that the boat weight 800 kg. is too heavy. It is possible to get the weight down to 600 kg if necessary. LifePo instead of lead batteries, and replace woodwork with lightweight material. Water Depth: 15 cm

 

Jon,

Going to lifepo will cost a fortune. The cheap way is to just buy two old beach cats of the same design and join them aft to aft. It will be a pretty bad hull shape thanks to the double rocker, but will still weigh in far less than what you have.

Or buy two canoes and use them, or build simple skin on frame round tubes. Or almost anything. Those plastic tubes are grossly overweight and lack boyancy, both are going to be major drains on the design.

 

Just some update. This is how my boat ended up looking, and i am pleased to see it technically works great. It looks quite ugly, but its my own buildt machine!

Here are some images and videos.

Average on a sunny day the panels give 6-700 watts pr. hour to the batteries. The speed is poor, but that is how it is. Average speed at 1200 watts, are 3,5 knots. Top speed at 2200 watts around 5,5 knots. Total weight 650 kg.

 

Thank you, Jon!

 

If you fall over or step backwards will the netting save the panels? Looks a bit close to me.

 

It is just to tell people that this is no step zone. Children tends to walk on the panels when in harbor.

 

congrats on the completion. I think you could get substantial performance improvement with better hull shapes though. There are several ways to create the hulls quite easily.

XPS insulation foam with fiberglass over (thought it will mean lots of annoying sanding and some wasted epoxy). Plywood frames could be much better too and faster than lets say strip plank.