"Bruce in Bangkok" wrote in message
...
On Sat, 29 Mar 2008 17:06:05 +0100, "Edgar"
wrote:


"Bruce in Bangkok" wrote in message
. ..
On Sat, 29 Mar 2008 01:12:17 GMT, Jere Lull wrote:
The tide and sling rig isn't logical and I can't believe ever existed.
If you are working on the boat at low tide just prop it up on the
beach. Heck, they been painting lobster boats that way for a couple of
hundred years, or more. Probably been cleaning those oyster tongers
down your way using the same scheme.

There is some logical use for such a device if you plan to do some major
work which you might not be able to finish on one low water session.


Look, if you are going to hang a boat in a sling then(1) you use a
travel lift or crane device and pick it up, or (2) you position the
slings and float the boat into them at high tide and when the tide
goes down you can work on it.

However using method (2) every high tide the boat has sufficient water
around it to float it. so why not just put it on the beach? Lash legs
in place and you have exactly the same situation - at high tide the
water covers everything up to the water line.

The slings also have the disadvantage of being rather costly. Have you
prices 15,000 lb. capacity slings recently? Better yet price 17,000
lb. slings, I want a bit of a safety factor on this project. Another
problem is what are you going to tie the slings to? Have you got a
couple of strategically located trees available? Or are you going to
build something?

Bruce-in-Bangkok
(correct email address for reply)

No, sorry,I did not make my scheme clear.
My idea was for a floating dock supported by air tanks so it could float
with a yacht in it.
Position the empty dock over the beach and flood the tanks so it sinks.
Side supports stick up above water so you can correctly position the yacht
above it.
Next low water the yacht will be sitting on it and you close the valves on
the tanks so the whole issue floats on the next tide and continues to float
the yacht on every tide until the job is finished.
Then you flood the tanks again and the yacht sails away.
You could build a thing like that comparitively cheaply as there is nothing
mechanical on it at all.