iam planning on building a 2 ton gantry crane for my RR shop, similar to the one in the photos below. It won't be real tall, maybe 8'-9' to the top of the beam.
My big question is how long should the cross beams be, at the bottom, where the casters mount?
There's recommendations for straight ladders, that the rise:run should be 4:1 .
That would suggest a 4 foot base (two ft from center) for an 8' hoist, but shorter would work
too (because you have nonrotating joints, which the ladder doesn't). It would be useful, too, to know
exactly which doors the crane has to potentially navigate, and which pickup or flatbed trucks,
might have a heavy item in the bed, before defining the full sizes of the project.
With the right design, a short-topbeam gantry can slide one leg under the truck bed, so needn't
straddle the full width.
I can tell you from experience that a bookcase taller than 75" and/or wider than 24" will sometimes
have problems getting through a door, or up a stair, or down one. Also, pallets and lifting points are your
friends.