T-Pain Is On A Boat: Re: [Electric Boats] Re: house boat + hybrid

Thursday, November 4, 2010

Re: [Electric Boats] Re: house boat + hybrid

we are talking displacement speeds here so the weight will have more effect on acceleration than speed and he will need 40' of water line length to hit 8.47 knots so he will have lots of load capacity. I'm thinking 43' or so to keep him below hull speed and 2 - 10 hp motors that would run at 60% power most of the time and only put out max power for short burst to maneuver or accelerate. A light weight structure built out of aluminum and maybe a trampoline area like a big catamaran. Another advantage of slowing down the speed is that the genset will supply more of the power for movement. Some of the 40-50' house boats here on the lake idle at say 5-10 hp at 4-5 knots and at full throttle (140 hp) get all the way up to 7-8 knots. These are barge type hulls and develop resistance and skin drag really fast. Catamarans and Proas can beat the hull speed formula. If this boat is only going on the river and waves are less of an issue and it can be built to flex you could keep the weight down. I am thinking a proa might be a really fast electric boat design. If you took and old rowing shell and put an outrigger on it I think it might go pretty well on electric power. Anybody have an old shell they want to donate to try it out?

We should build a spreadsheet that we can through the numbers in and get some predictive results. Or does that spreadsheet already exist?

Capt. Bill

From: Steamboat Willie <stmbtwle@yahoo.com>
To: electricboats@yahoogroups.com
Sent: Thu, November 4, 2010 5:24:43 PM
Subject: Re: [Electric Boats] Re: house boat + hybrid

The problem with pontoons is they don't like extra weight, and adding a bunch of batteries is going to add that extra weight.

--- On Thu, 11/4/10, Bill Spires <spiresac@yahoo.com> wrote:

From: Bill Spires <spiresac@yahoo.com>
Subject: Re: [Electric Boats] Re: house boat + hybrid
To: electricboats@yahoogroups.com
Date: Thursday, November 4, 2010, 5:02 PM

Yep, I noticed. 8-10 knots is pretty fast and 3-4 hours would be a long time. This would require a very easily driven long hull. Maybe a pontoon boat with hulls shaped like a Hobie cat 18 only a lot longer. We have some house boats like that on the lake here. 6-8 knots for 5-6 hours would be easier to do and give you about the same range. Speed kills! (Power)

Capt Bill

From: danbollinger <no_reply@yahoogroups.com>
To: electricboats@yahoogroups.com
Sent: Thu, November 4, 2010 4:45:19 PM
Subject: [Electric Boats] Re: house boat + hybrid

Bill, Did you notice? Aaron said he is planning on 8-10 knots for 3-4 hours. Dan

--- In electricboats@yahoogroups.com, Bill Spires <spiresac@...> wrote:
>
> How are you going to use the boat? If it's every now and then when it's calm
> wind and water you want to move it that's one set of issues. If it's I want to
> go cruise this thing days at a time that's another set of issues. Once you know
> the hull type, length and weight you can get an idea of how much power you need
> to move it. Even a small amount of power will push a large vessel at slow
> speeds but it takes a lot of power to accelerate or stop it. Wind and currents
> can also require a lot of power to overcome. I think that once you know how you
> plan to use the vessel and what the layout and size of it is the question of how
> to power it will be easier to answer. The other question would be what are the
> reasons you want to go electric. Just to give you an idea; 5 hp would push my
> Catalina 30 4.5 kts. in calm wind and water. Weight was about 15,000 lbs. 15-
> 20 knot winds on the nose would stop it dead or blow it backwards. At very low
> speeds the shape and type of the hull does not matter as there is so little
> resistance or skin drag. As speed increases the effect of resistance and skin
> drag increase in importance.
>
> Thinking out where you want to go and how you want to get there is half the fun
> of a voyage.
>
> Capt. Bill
>
>
>
> ________________________________
> From: Aaron Costic <aaron@...>
> To: electricboats@yahoogroups.com
> Sent: Tue, November 2, 2010 6:21:28 PM
> Subject: RE: [Electric Boats] Re: house boat + hybrid
>
>
> You are right, I was thinking of an all electric drive rather than a
> hybrid. With a gen set as a back up to charge the batteries. It would
> probably take a pretty hefty battery bank & 2 large electric motors to
> safely power the houseboat. Top speed isn't important. A range of 3-4
> hours at 8-10 knots would be adequate. Do you think the technology is there
> now?
>
> Aaron Costic
> Elegant Ice Creations
> www.ElegantIce.com
>