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Terry K Terry K is offline
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First recorded activity by BoatBanter: Apr 2007
Posts: 95
Default Low power sailing, was inexpensive diesel engines

Gawlea!

Shore sounds like a job for two or even three trolling motors in
wells, two aft and one foreward.

Azipods!

Hanging propellors off the ends of the boat is a sure way to whip up
the air while props are out of the water in waves.

I would use the one foreward, mostly, for easy days marina docking,
etc. Should be able to steer it from the v berth in the sun or rain,
or remotely, or lock it and and raise it and plug the hole when ready
to sail. A fishguard bottom plate could be affixed beneath the prop
for maximum convenience and trouble free transformations. A one foot
lift might retract the prop and smooth the bottom. If located
foreward in the cockpit, it might sit next to the bridge deck step and
be innocuous raised or lowered.

With two after azipods, crabwise docking could become an exercise in
balance, pushing a keel sideways and providing some redundancy.

Using all three might permit all sorts.

No tranny saves weight for batteries. The generator you will need
anyway, if it is a little larger. Spatial accommodations could
benefit, if range might suffer, as if fuel economy were most important
on a sail boat.

With wind no motor is needed, if tradition tells anything. With no
wind, auxiliary drive is just that. 3/4 hull speed is very
economical. Sailing is an adventure, fun, not many of our livings nor
sustenance nor work, but joy and pleasure only. As with golf (I am
told) the longer time spent at it the better.

Now, if one azipod could charge batteries under sail, you might
subsist with solar cells...

The windage design of the topsides must accommodate low power
manouvering under power or in a breeze. A well balanced low drag
topsides plan should be utilized. A comparatively low elevation would
be best, as it is in any sailing vessel. I kind of like the idea of
raised deck and hull side portlights (a glass bottom?) as opposed to a
dog house.

Will you ever want for air conditioning? Possibly using one of the
wells, a stovepipe heat exchanger with only a small automotive heater
radiator underwater and ducted air tubes could provide basic survival
cooling. It would stow for sailing, being plugged in and deployed
overboard for overnight comfort at anchor. A sump dip tube for the
bottom of the stovepipe overboard would evacuate condensed humidity
scavenged from the recirculated cabin air. An air to air heat
exchanger would provide fresh ventilation. It won't make ice, but such
a system could defend your sweaty sanity and restlessness on a muggy
night with little weight or energy penalty, requiring only a small fan
for air circulation.

I can almost envision such an air conditioner in a bag, like a kayak.

As well, using an azipod well for a "stick in the mud" anchor, as used
on the junks of the Yangtze, might be an additional bonus.

Ain't it wonderful, the way one small decision regarding an auxiliary
powerplant can affect so many options?

Terry K