Thanks for all the kind replies.
To clarify, I would never lift from the gunwales only. That is very wrong. Keel lift only. Straps are always my first choice and safety
I should clarify her condition.
No Ballast is on the vessel. She is a partially complete boat. She is a fully complete empty wooden hull which several people have estimated to be around 10K. I think she is a bit less at 8500-8900. Thanks to all who clarified weights of the Marco Polo. Your right on at 39K fully finished and wet.
Let me go back to the beginning and add some drivers to consider.
The main objective here is I am looking for a smooth way to get the boat high enough for a Double Drop trailer to get under her and not have to use a hydraulic trailer. DD are very inexpensive. My first choice is a nice expensive $40K hydraulic Hostar, but can't find one for lease
. On contract
haul, it is a very expensive ride from North CA to Houston
TX. Hydraulic trailers are expensive. I know, I priced building one. Single
and DD's are in stock and everywhere.
For the Single
Drop or Double Drop to work, I just need the lift to be clear of the trailer when it backs under it. The rest is easy. My second issue is that I am going to need to lift her 2 more times (heavier) and haul her at least once more. If I can use what I build for that work, again it saves some cash later.
I guess my "out of the box" trailer jack idea is a bit of a curve ball, so I should should clarify what I was thinking.
Truck Trailer Jacks (Landing Gear
as they call it), are very capable of weights well in excess of my needs. e.g. I can get a 2 speed 20K pound jack for about $170. They can handle side loading up to 50% of rated max which is cool. They are simple, lift some 15-17", inexpensive and simply work. I am thinking of using 4 of them if I can work out a design which replaces the traditional chain falls. Straps will be used regardless. Sure, I am not against using 4 chain falls and I have used them routinely in over 100 lifts. I do want to consider a different approach due to final cost.
I have steel
sailboat cradle for a 40' vessel in the shop now. It is well made and would require little to beef her up for this boat. Likely another set of stanchions.
It appears I am becoming more committed to building, (again in my shop), a fast erecting collapsible gantry system. I would haul it there and erect in the barn. I have sketched out a design which would rate about 15 tons each lateral section. I would use two gantries, making a 4 point (two strap) lift at this weight (4 strap on heavier load). They would have about a 20' foot longitudinal spread and a 14' inside measure. I would use I-beam trucks if I am using chain falls, but always a strap lift.
My question is was there a cheaper way. Thus the jack idea. They only questions remaining are the cross beam (capable of rated load or just acting with spreader loads) and the lift mechanisms (jacks or chains). One consideration in favor of jacks is the weight of the gantry top beam. Everything needs to be manhandled as there is nothing there but a barn and concrete floor. The second issue is the lifting mechanism (jacks or chain falls). This is where the truck landing gear comes in.
I like simple, I like inexpensive and I like reusable. I just hope I am not making the discussion worse with this post. I don't think so.
If anyone can complicate something it's me. Just remember I have deal with her again at 39K pounds.
Thanks for all your time thinking of this and posting
your thoughts. I deeply appreciate it and consider it as a blessing.