In article ,
"Dan Listermann" wrote:

I need a boat for a very shallow river. Paddles, especially with stiff
rubber tips, seem like a good alternative and a riding lawnmower drive train
would give me reduction, reverse and a variety of gears. Anybody know of
some experience?

No personal experience, but there are a couple of vaguely similar
sounding designs on Svenson's free boat plans website (way down in the
bottom section)

http://www.svensons.com/boat/

I don't think a riding lawn mower transmission, at least of the
traditional tractor variety, is the best way to power things. Riding
lawn mowers have a differential as part of the transmission unit, which
I suspect would tend to be rather irksome on a boat. Also, they are
generally designed so as to have their input shaft on the top of the
transmission housing, belted up to a pulley on the underside of a
vertical-shaft engine; thus you would end up with the engine above the
shaft line of the paddlewheels unless you did some fancy multiple pulley
arrangement. Ideally, I'd think you'd want the weight of the engine
relatively low in the boat, although it should be adequately stable up
high with an appropriate hull design for the kind of protected waters
where you'd use such a boat.

The idea that someone posted about using a zero-turn hydrostatic
transmission setup does sound like a whole lot of fun, though, and not
too impractical as well. It wouldn't be overly efficient, and not
inexpensive unless you're good at scrounging up parts; but those may not
be important design considerations.

--
Andrew Erickson

"He is no fool who gives what he cannot keep to gain that which he cannot
lose." -- Jim Elliot

"Andrew Erickson" wrote in message
...
In article ,
"Dan Listermann" wrote:

I need a boat for a very shallow river. Paddles, especially with stiff
rubber tips, seem like a good alternative and a riding lawnmower drive
train
would give me reduction, reverse and a variety of gears. Anybody know of
some experience?

No personal experience, but there are a couple of vaguely similar
sounding designs on Svenson's free boat plans website (way down in the
bottom section)

http://www.svensons.com/boat/

I don't think a riding lawn mower transmission, at least of the
traditional tractor variety, is the best way to power things. Riding
lawn mowers have a differential as part of the transmission unit, which
I suspect would tend to be rather irksome on a boat. Also, they are
generally designed so as to have their input shaft on the top of the
transmission housing, belted up to a pulley on the underside of a
vertical-shaft engine; thus you would end up with the engine above the
shaft line of the paddlewheels unless you did some fancy multiple pulley
arrangement. Ideally, I'd think you'd want the weight of the engine
relatively low in the boat, although it should be adequately stable up
high with an appropriate hull design for the kind of protected waters
where you'd use such a boat.

Thanks for the link.

I did not intend to drive the paddles directly with the mower's axels. The
motor and transmission would be mounted as low as possible with belts
powering the wheels. It should not be too difficult to negate the
differential if by nothing else, just get power from one side. The belts
would be tightened with idlers so that the power could be disconnected from
the wheels for close quarter turning.