Moving a boat.

[Fr J Hackett]

What about two substantial A frames carrying a longitudinal I beam with two roller carriages with chain hoists to fit the I beam that would hold two slings the boat could then be lifted and slid along the I beam which could be repositioned until the hulk sorry boat is in the shed sorry barn.

 

[GEM43]

Do as Leo did and build a shed over the boat?

 

[DownWest]

Did a 'yard trailer' for a 4.5t with RSJs and two truck axles. Chopped up some Acros for the side supports. Set it up so the long keel was about a foot off the ground. It worked, even over relatively soft surfaces. But that was towed around a bit, so likely a frame with long runners that could slide on other RSJs on the ground, better with rollers..

 

[Mister E]

Build his own private small railway then weld up a bespoke carriage for it to sit on.
Then it can be pushed or pulled in an out of the shed using a tractor or Land Rover .

 

[[194497]]

I think if I was planning this, the thing I'd really focus on would be creating some kind of track - either for rollers or just to slide on - that was really flat and smooth, with no steps or discontinuities. It could be RSJs, big timbers or whatever else, but I reckon the key to moving it easily would be a smooth, level surface.
For safety and simplicity I'd be inclined to slide it myself. Maybe some railway sleepers on the bottom of the cradle, sliding over well-greased RSJs?

 

[benjenbav]

This is probably a bad idea but how about digging a big hole outside the barn for the crane to sit in.

 

[alahol2]

As Downwest suggests, two (front) lorry axles, longitudinal RSJs possibly underslung to reduce height, a few cross members, some supporting uprights on outriggers and you have a fully maneuverable trailer that is easily pushed/pulled.

 

[Cerebus]

If the decision is made to use girders as sliders than according to a tv documentary where people in America moved silos and very large structures, such as whole buildings, SOAP was proven to be the best lubricant.

They actually used bars of soap to create a sliding platform when moving massive buildings upon crawler vehicles with hundreds of wheels.

 

[AntarcticPilot]

If the decision is made to use girders as sliders than according to a tv documentary where people in America moved silos and very large structures, such as whole buildings, SOAP was proven to be the best lubricant.

They actually used bars of soap to create a sliding platform when moving massive buildings upon crawler vehicles with hundreds of wheels.

The ancient Egyptians used water to lubricate dirty great blocks of stone. See Did slippery sand help Egyptians build the pyramids? – Physics World

 

[Wansworth]

Greasy ways