This is a method that we use often at the local boatyard but we have 2
tripods made with 1 inche steel tube and a very large plate at the bottom to
spread the load on the floor. This seems very important since you don't
know if you're on solid or not with some fiberglass boat. 1700/2 = 850 lbs
on each side so a 4x4 = 3.5 x 3.5 = 12.25 = 70 PSI. This is not a big
load for a static structure but unless you are sure the local structure can
take the whole 850 lbs is something else. Better have a large plate at the
bottom to spread the load.

Be very cautious if you build from 2x4 or 4x4 because they could have some
invisible defect and the loat will be great. A 4x4 is strong enough if well
built though but you need to make the attachment accordingly to the load.

André



"Paul Wiggins" wrote in message
...
I need to build a contraption to remove two large, old, heavy engines.
(1968 CC 427's).

The boat is on stands and there's no way I know of to get a boom up, over
and inside the wheelhouse.

So... I'm considering building tripods on either side of the wheelhouse...
running a metal I beam thru the windows over the engines... lifting...
placing them a wooden bed... sliding the engine back to the rear... where
a small crane can lift out.

The question I have is.. what to build the tripods out of... 4x4's our of
sistered 2x4's? Something beefier...

I recall reading somewhere they weight in at 1700lbs.

many thanks.