Hi Geoff,
I found the entry for the 41' houseboat in Boynton Beach. With two ibl360 motors, if they are running 48V systems, then they've got 34kW of drive power on tap (assuming 360A x 48V). With 34kW of drive in a 13 ton boat, they've got more than enough for displacement mode, I would be interested to hear if they can get past the bow wave into any sort of planing or semi-planing mode.
Since people show up asking if converting a houseboat to electric is feasible, it would be great if you could post any sort of watts to knots or top speed performance for this boat. With load to speed numbers, figuring the range is pretty simple for various size battery packs.
Referring to other posts, it takes very little power to move large floating objects at slow speed. Old school fitness guru, Jack LaLanne used to tow various things on his birthdays to show that he was still in shape. Here's a few of those events:
1957 (age 43): swam the Golden Gate channel while towing a 2,500-pound (1,100 kg; 180 st) cabin cruiser. The swift ocean currents turned this one-mile (1.6 km) swim into a swimming distance of 6.5 miles (10.5 km)
1974 (age 60): For the second time, he swam from Alcatraz Island to Fisherman's Wharf. Again, he was handcuffed, but this time he was also shackled and towed a 1,000-pound (450 kg; 71 st) boat. At least that's according to his website. However, according to an account of this event published the day after it occurred in the Los Angeles Times, written by Philip Hager, a Times staff writer, LaLanne was neither handcuffed nor shackled if each of those terms has the unconventional meaning of "tightly binding the wrists or ankles together with a pair of metal fasteners" although that's not how handcuffs or shackles work. Hager says that LaLanne "had his hands and feet bound with cords that allowed minimal freedom". But "minimal" clearly did not mean "no" freedom, since elsewhere in the article Hager describes LaLanne's method of propulsion through the water as "half-breast-stroke, half-dog paddle" which is how you swim with your hands tied.
1976 (age 62): To commemorate the "Spirit of '76", United States Bicentennial, he swam one mile (1.6 km) in Long Beach Harbor. He was handcuffed and shackled, and he towed 13 boats (representing the 13 original colonies) containing 76 people.
1979 (age 65): towed 65 boats in Lake Ashinoko, near Tokyo, Japan. He was handcuffed and shackled, and the boats were filled with 6,500 pounds (2,900 kg; 460 st) of Louisiana Pacific wood pulp.
1980 (age 66): towed 10 boats in North Miami, Florida. The boats carried 77 people, and he towed them for over one mile (1.6 km) in less than one hour.
1984 (age 70): handcuffed, shackled, and fighting strong winds and currents, towed 70 rowboats, one with several guests, from the Queen's Way Bridge in the Long Beach Harbor to the Queen Mary, 1 mile.
Obviously, his maximum power output in this configuration is pretty low. But for each of these stunts, while he wasn't fast, he did have the endurance to complete the swim (and a chase crew in case he got too tired).
This proves that small motors can move large boats in calm conditions, but for basic marine safety, we should have enough power to manueuver in adverse (not extreme) conditions. That's where this group's guideline of 1kW of power for each ton of displacement comes from. This will typically provide 90-95% of hull speed in calm conditions and seems to give reasonable power in less than ideal conditions. On the other hand, houseboats have considerable windage for their displacement and may need more power to handle crosswinds safely. So I'm really interested in hearing how the Boynton Beach houseboat handles in the real world now that it is electric.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@yahoogroups.com, "runneribe42" <geoffgamsby@...> wrote:
>
> Greetings David,
>
> I work with electric Yacht and we have "electrified" a 41' houseboat in Florida. We would be glad to give you some more info and help you figure out the best set-up for your boat.
>
> Here is a map of your customers http://eyacht.straightturn.net/node/8 you can search the webpage and find the info on the houseboat
>
> geoff
> www.straightturn.net/sailing
>
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