T-Pain Is On A Boat: Re: [Electric Boats] moving boats with little power

Sunday, April 7, 2013

Re: [Electric Boats] moving boats with little power

I guess that it's time to post this again. I posted this in January 2012 and again in August the same year.

".... Here's an excerpt from a post in this group from January this year that
discusses your point fairly well.

"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 85-95% of hull
speed in calm conditions and seems to give reasonable power in less than ideal
conditions."

Fair winds,
Eric
Marina del Rey, CA

--- In electricboats@yahoogroups.com, Carter Quillen <twowheelinguy@...> wrote:
>
> Orest,
>
> I'm glad it worked out for you and frankly amazed because I had my doubts when we first talked about it. But like I said, if you got the stuff laying around anyway, just put the thing together and see if it works.
>
> You have established a new benchmark, pushing 9 tons with less than 1.5 hp or about 1 kW. Even if it is just for trolling in good weather, that's awsome and it serves your purpose.
>
> And constructed primarily of recycled content to boot! You da Man now!!!!
> Carter
> http://www.shipofimagination.com/
>
> PS:Couldn't tell you anything about that golf cart motor but if you could get it to work at 1 kW too, you could run it directly off a six pack of golf cart batteries or even a 3 pack of 12V with 3 or 4 solar panels and run silently for free whenever the sun was shining.
>
>