[TheForge] bridge crane

[Justin Fellenz]

YOu know, I may have used the wrong term. The crane I was referring to
is anchored in pins at the floor and the ceiling of the shop with a
vertical, pivoting I-beam between them and the crane part cantilevered
out from the vertical post 4' down from the top or so. The outer end of
the horizontal I-beam that the chainfall hangs from is supported by a
heavy cable one one and a triangulating piece of i-beam on the other to
keep it from sagging. The cranes' horizontals pivot through a
quarter-circle from opposite corners of the shop, where the bench areas
are. From memory and eyeball (don't take this as engineering data) the
cranes are made from 5 or 6" x 3/16" i-beam, and he has 2-ton hoists on
them. I don't know how far out he can go at full load though.

The result is a nice compact system, easy to build (one rides on
bearings top and bottom, and it moves really easily; the other is just
on pins and it still works ok) and, for better *and* worse, it doesn't
cover the entire shop. THe better part obviously is that you can still
have air and electric lines and whatever else dangling from your bay
ceiling; the worse, equally obvious, is that you can't put something
just anywhere in the shop. 

Anyway, not arguing for one design or another, just thought his was a
good setup that took less expensive iron to build. And you can't tip it
over.

Cheers,

JRF

> I have considered a couple of gantry cranes on wheels.  They would be
> 
> easier and much cheaper to build.  But they probably wouldn't be an
> even 
> substitute.  So if I ave the choice I'll go with the bridge crane. 
> Of 
> course there may be times I'll wish I had both.  Of course I have
> seen a 
> gantry crane tip over with a 50# little giant hanging under it,
> scared us 
> half to death but didn't hurt the hammer.
>