| The Parsun will be a 10 hp, not 10 Kw. Determine prop shaft rpm and pitch for speed desired. If shaft speed is say 2200 rpm X 4" pitch = 8800" per minute X 60 = 528,000 inches per hour / 12 = 44,000 feet per hour / 5280 = 8.33 mph X 0.88 slip = 7.33 mph, easy, huh? Bob --- On Thu, 5/3/12, Keith Jacko <nrixez@yahoo.com> wrote:
|
I'm interested in building an electric house boat. The basic concept is an easily driven houseboat, strictly displacement speeds (6 - 7 mph), powered by an electric outboard. I'm thinking about a 10kw outboard. The boat as sketched would displace just a little under 6 tons to sit on her lines. Here are a few pictures of the boat sketch (and a .skp file if anyone wants to play around):
http://www.dwdogs.com/Fusion/
I'd love to go with a ~40 kwh LFP pack, but reality probably has me sticking to around 20 kwh. There is enough space on the roof of the boat to fit 2 kw of solar panels. More if I really stretch it, but I'm thinking 2 kw should be enough.
Basic boat dimensions: 32' x 8' with a 16" draft. At 12,000 lbs with the proper center of gravity, the bottom of the transom would just be touching the surface of the water.
I live in Minneapolis, and this boat would be for cruising on the upper Mississippi and St. Croix rivers. Fairly sheltered, and no currents greater than 4 mph (hopefully less most of the time).
The boat will be built with plywood covered in glass / epoxy. I do plan on having fairly thick cabin walls for a boat... 2x4 construction, with closed cell foam insulation / floatation in the walls, hull, and cabin roof.
Any feedback about the sketches or general idea? I'm designing this as a liveaboard, and I plan on living on the hook as much as possible.
About the outboard, I'm not really sure how to figure the proper prop size, pitch, and rpm to shoot for. I understand the general rule of thumb "bigger prop, slower rpm, better"... but I don't know much past that. Could an electric outboard like say the up and coming Parsun 10 kw efficiently drive a heavy displacement boat like this? Or would it be better to think about using an inboard instead, so I would have the flexibility to tailor the rpm to my liking? I really do like the overall project simplicity of an outboard, but if it's really less than ideal I could consider alternatives.
Thanks for your thoughts and feedback. Cheers!
-keith
Hey, I just noticed the boat is my Harmony 25 at the halfway point of the Wye Island Marathon. Thanks for posting it Myles.
Lots more pics at my website www.wolfeboats.com.
It's for sale, BTW.
Denny Wolfe
Hi Julian
Hi Steve- Thanks for the input.- The main reason for the 110-230 vac battery charger is she will spend a lot of time on English, French and German canals, and a lot of the time they have a 10-15 amp outlet you can plug into for a small or no mooring fee, so your battery top up is as good as "free".- The DC genset is looming as s huge problem, I simply can't get a quote or lead time from the 5 companies I've emailed, including PolarMarine.- I'm beginning to think it's going to be a 50 HP low rev diesel (in a noise cabinet) and 5-6 48 vdc alternators running at 80% output to drive the motors directly, and then as a battery charger to top up the bank when needed.- Sounds a bit primitive but it's technology I understand and can therefore fix, and it's still way cheaper and quieter than straight diesel drive.Cheers, JulianOn 1 May 2012 11:44, Steve Dolan <sdolan@scannersllc.com> wrote:
Jules,
Without the basics it's hard to deturmine what you need but as far as in general here's my inputDirect DC is preferred; it eliminates inverters to DC and simplifies the system. I have a AC genset and would much prefer a DC for simplicity however it really depends on the size of the system and whether the cost is justified for the more expensive DC genset. My genset has a manual variable output to manage the charging of the batteries. Something I have to pay attention to, the new gensets have an automatic start/stop which I'm a little leery of.
> it seems better to use a diesel generator to produce DC with a large enough capacity to power the electric drive motor(s) directly for the times when i need cruising speed.
> this will let me get away from the "usual" AC output genset that has to be converted to DC before being sent to the motor controllers(s).
Correct.
> add a battery bank of the same DC voltage as the generators output and the motor controllers input.
I'm not sure why you would want to go to single phase, a 240V will give you more amperage, a quicker charge and smaller wires. Depending on the battery type you also want a multistage charger.
> add a single phase battery charger for shore power top up.
Correct. I'm assuming this is a European boat. 120v for US system.
> add a 230 VAC output inverter to run the onboard appliances.
A genset with a heat exchanger is what I have and works great. I also have a 10 gal. HWH for the storage and heating during shore hookup.
> if i can get my hot water from the genset that about finishes the system?
Also plan on several switches so that you can't operate the genset and shore power at the same time as well as the inverter only when operating the genset.
> if i am heading in the right direction, i will bore you with the boat details, but i thought i would get the theory right before moving on to the practice.
> thanking everyone in advance
Hope it helped.
Steve in Solomons MD
Lagoon 410 SE--www.proto.eu.com ltdOffice: Unit 121, 21 Botanic Avenue, Botanic, Belfast BT7 1JJ, Northern Ireland, UNITED KINGDOMPhone; (+44) 02895 811251 - Mobile; (+44) 07427 696 796 - Fax; (+44) 0871 9898296
Company number; NI067673 VAT number; GB975375474
Jules,
Without the basics it's hard to deturmine what you need but as far as in general here's my inputDirect DC is preferred; it eliminates inverters to DC and simplifies the system. I have a AC genset and would much prefer a DC for simplicity however it really depends on the size of the system and whether the cost is justified for the more expensive DC genset. My genset has a manual variable output to manage the charging of the batteries. Something I have to pay attention to, the new gensets have an automatic start/stop which I'm a little leery of.
> it seems better to use a diesel generator to produce DC with a large enough capacity to power the electric drive motor(s) directly for the times when i need cruising speed.
> this will let me get away from the "usual" AC output genset that has to be converted to DC before being sent to the motor controllers(s).
Correct.
> add a battery bank of the same DC voltage as the generators output and the motor controllers input.
I'm not sure why you would want to go to single phase, a 240V will give you more amperage, a quicker charge and smaller wires. Depending on the battery type you also want a multistage charger.
> add a single phase battery charger for shore power top up.
Correct. I'm assuming this is a European boat. 120v for US system.
> add a 230 VAC output inverter to run the onboard appliances.
A genset with a heat exchanger is what I have and works great. I also have a 10 gal. HWH for the storage and heating during shore hookup.
> if i can get my hot water from the genset that about finishes the system?
Also plan on several switches so that you can't operate the genset and shore power at the same time as well as the inverter only when operating the genset.
> if i am heading in the right direction, i will bore you with the boat details, but i thought i would get the theory right before moving on to the practice.
> thanking everyone in advance
Hope it helped.
Steve in Solomons MD
Lagoon 410 SE
Hello all.
I hope this is not me! I am a 71 year old Cancer patient, and
hopefully survivor. I should know more in the next few months.
For a number of years I have been having ideas, Before I was
diagnosed, about self charging, all directional wind/electric boats.
As I got sicker, from Radiation treatments etc. I found that these
ideas kept surfacing and improving, especially after I met one of my
new neighbours who powers his home with a wind turbine and also drives
a Rav 4 that has been converted to all electric with Lith- Ion
batteries and a BMS. He gets about 100 mile range at this point. He
said that aiythng of interest he would be glad to send, through to
this forum or any individual here that wants it. . I have learned a
lot from him, and he has learned a lot from some of the discussions
between you guys that I have sent him.
He said that he is a member of several Elect Car forums, has lousy
internet service and doesn't have the time to sift through another
forum. So I try to do it for him. I have been in boats, until the last
7 years or so, since my family got its first. A 1947 1/12 HP Scott
Attwater on a 1947 Barbour 14 foot runabout, both NEW, when I was
about six years old.
I only learned to turn a computer on 1n 2007 when I commissioned to do
an extensive watershed assessment for the local volunteer group.
Needless to say" I ain't no expert!" I don't know what a " Blog Spot"
or a "Bot'' spot is, and really don't want to learn that stuff, unless
it is, through me, causing problems for anybody.here or anywhere else.
My friend knows NOTHING about boats, as I have mentioned, And up until
recently I knew very little about electricity and elect drives, etc.
So we are basically exchanging information that gives us a fresh, and
naive view of each other's problems. His main interest is the
understanding and development of different kinds of elect generation
and new ideas for drive lines that don't cost a fortune and may be
applicable in different situations. Like SALT WATER.
I only copy and paste the content, as much as possible, without
divulging contributor's ID's although I have't really been as careful
as possible, Perhaps.
PLEASE let me know ASAP, if I'm doing something wrong here, I'm Just
an old man trying to get better and this project keeps my mind off
some of my problems, some of the time. I'll fix what ever I need to
fix. If can't be fixed, or get off altogether if that's what it takes
I'd hate to have leave because I never realized how much more new
stuff this old dog can learn.
Thanks all for time and understanding
Ericr
