[TheForge] Re: bridge crane

Sun Oct 2 09:16:33 EDT 2005

Hi Mike, Gantry cranes always seem to be in the way for tripping on or
hitting your shins on the legs parked against the wall.

Jibs are a good option but of course cover a radius......passing from one to
another allows going from door to certain areas, positioning, welding etc.

Bridge cranes are of course the best bet for total coverage, totally out of
the way, but also the most expensive to build or buy.  I've done a few make
shift cranes including helping a friend with the one you mention below.  He
only had a 9 foot ceiling height so we were trying to figure out how to hug
the ceiling and get at least enough hook height to lift all his plows,
mooring chains, and marine projects under it (figuring we needed to have 6-7
foot to work in.  It was a clever gadgit that ran off the wall on one side
and had a bipod wheeled end that ran down the center of the shop (which also
allowed it to be used as a sliding rack for tools).  It would only handle
1,000-1200 lbs max and it had a 13 foot span (a 5" beam was used).

To accomadate a 20-30 foot span and carry 2000-4000 lbs - the game changes
considerably.  The dam crane weighs as much as your pickup truck and doesn't
really move well by hand especially with 4000 lbs added and hanging from it
so most are motorized for a reason. The design of your shop becomes
mandatory to include the crane design into it.  You have to figure the hook
height you want to accomadate the work you'll be doing and the largest items
you wish to lift.  From there it determines what the wall height of the shop
has to be, the strength needed in beams to carry such loads, the wiring
which will motorize the travel, and all lighting needs to be recessed into
the ceiling (Or the walls need to be all that much higher).......and all
machine wiring must be in place in the floor in conduit to the outlets
needed as hanging drops to power machines is NOT an option any longer if
this is what you used to do in an older shop.

IF you buy a used one, you should have it on hand before building your new
shop - as you'll have to work the entire design of footprint of your
building, track assemblies, etc from the crane instead of trying to modify
the crane to fit the span your creating as stripping a crane apart and
getting all the dollies back square, and the drive shafts cut, rekeyed, and
set back again can be a decent enough project to try to stay away from
it.......unless you do it in a shop where they have a ceiling crane :-)
Anything is possible, but one can see why heavy weights, powered travelers,
and fitting it to a set of tracks, along with designing the tracks to carry
the weight (and not have it working off walls supporting snow loads on the
roof: is why there are companies who do this as a specialty.

I've found the option of doing a ceiling crane down the center of a bay and
letting the outside bays get fed by roll carts, or jib cranes to be the real
way to do the grass roots do it yourself kind of ceiling crane.  Trying to
cover the entire shop is the option you should get help with from someone
who knows what the loads will be and not be in the position to regret
investing poorly in something that deflects, doesn't move well, or doesn't
lift what you need to lift.

One thing I will mention about Jib booms is they can have a stiff leg placed
at the end of the beam and double the lifting capacity of the unit.......so
2 ton jib which is affordable, handy, and covers a decent 12 foot
span.......can unload a power hammer with a still leg when needed (IF the
area of jib coverage allows a vehicle to go under it (such as part of a
drive in bay).

I've built jibs, installed factory made jibs, made makeshift ceiling
cranes(on mostly short spans) and have lots of black and blue memories of
gantry legs slamming my shins. Both jobs I've been involved with where the
customer has wanted full building width ceiling crane lifting of heavy loads
we have panned it out to outside specialty companies who have done an
outstanding job, but one would expect that for $24,000 - 52,000 that each of
them cost.

Sure is nice to bring a tractor trailer load of steel in and pick it off and
sort it into working piles on the floor in a matter of minutes........but
you have to do a lot of work to afford a price tag like the one above.

Yes, you can build your own, and no I'm afraid I don't know of any used
bridge units at this time.  If I knew of any jibs at this time.......I'd be
owning it.  :-)

Ralph

-----Original Message-----
From: theforge-bounces at mailman.qth.net
[mailto:theforge-bounces at mailman.qth.net]On Behalf Of Mike Spencer
Sent: Tuesday, September 27, 2005 2:19 AM
To: theforge at mailman.qth.net
Subject: [TheForge] Re: bridge crane

> Has anyone on the list ever built a bridge crane? is it a do it
> yourself project or should I just plan to hire it done?

Ralph Sproul sent me some pictures of a bridge crane that ran on a
wall-track/trucks on one end and had a bipod on (15" car?) pneumatic tires
on the other.  He said it was good up to 1000#.  Looks to me like it
would be easy enough to jigger it up to take 3000# or so.

I betcha he's the guy to ask when he gets back on line.

I kinda wish I had planned one in.  I have my eye on an old one on
wheels but I'm not sure I need it bad enough to move it.  My problem
is that, altho I have a 30' wide shop, I have a center beam on (3)
posts so I'd be limited to one 15' bay at best and it would screw up
my lighting.

- Mike

--
Michael Spencer                  Nova Scotia, Canada       .~.
                                                           /V\
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^

--

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