[TheForge] bridge crane

[Ries Niemi]

Justin is thinking of a jib crane- a swinging arm, which the chainfall 
or hoist can roll back and forth on, giving you a circular coverage.
Usually these are limited to about a half ton, unless they are really 
stout.

A real bridge crane has elevated tracks on both sides of the shop, and 
a beam that rolls along these tracks, and then a hoist that rolls 
across this beam, giving you x-y axis coverage of the whole shop.

The biggest factor, in terms of weight, and cost, is how heavy an 
object do you need to lift?
If you are thinking 1 ton or less, you could use a 6" to 10" I beam, 
depending on span, and buy some trolleys from Jet or somebody similar, 
and just yank it around with a rope hanging down.
I was just in a shop of a blacksmith near tacoma who had a homebuilt 
system like this- probably good for around 1000lbs or 1500lbs max, as  
it was only about an 8" I beam. He could not use it to move his 300lb 
chambersburg in and out.

There are loads and loads of used bridge cranes out there, but they 
usually start at about 3 ton and go up from there- and used, from a 
dealer, figure 5 grand or up. This would include a motorised trolley 
for the hoist, and motorised trolleys for the beam, so the whole thing 
powered where you wanted.

Or you might find a deal on one at an auction. But since the main 
component is big steel beams, scrap value alone for a 30x40 ft setup, 
including posts, is gonna be a few grand alone, and a motorised 3 ton 
hoist is worth something too.

ries