REvise 2200 lb to 4200 lbs my typo

Ok, a repost due to invalid information…

Hi, I am in Alaska without a code enforcement consideration but I still want to be in a safe working condition in my shop. I have designed a top rolling single beam gantry crane that has an overall width of 26 feet and is 39 feet long by 15 feet high out of ASTM A36. It will have three 2 ton hoists, one on each end and one on the gantry. The posts are w10x45 with 1/2 bottom and top plates. The longitudinal beams are w12x35 @ 39 feet long. The transverse beams are set on top of the w12x35 and are w14x30 or 35. I plan on having post bracing of 4 feet made from w14 x22 beam material and six foot lateral top bracing made from w6x16.

The Posts will be centered in the 39 foot span and the center gantry will have 96" ends made from w14 x 22 to disperse the load. I have calculated that with a 4200 lbs. load (including hoist) in the center of the 26' span I will have approx .24 deflection (for 35#) to .28 deflection (for 30#). Input on this project and its working loads would be appreciated.

Please give a simple sketch to understand complete arrangement.

Your deflections seem to be in the right area if I understand you correctly.

Some things that I do not understand:

The posts are centered on the 39 foot span. What supports the ends of the W12X35 (or are there 3 posts along the span, one at each end, one centered at midspan?)

You mention post bracing of 4 feet. Is the post braced horizontally at 4 feet above the base? What does this mean? Are these diagonal braces?

You mention top bracing using a W6x16. What does this mean. What is being braced? Where is this bracing occurring?

There are three 2 ton hoists, one on each end (of what?) and one on the gantry. The hoist on the gantry (the w14X30) can move along the length of the w14X30, correct?

If you can clear these questions up perhaps we can be of assistance to you. As previously requested, a sketch would be the best.

Thanks,

Y/E

Just because the codes are not enforced, does not mean they are not in place. OSHA has some very specific requirements for cranes that are used for overhead lifting in the USA.

Working out the statics of the major elements is not difficult but what margin do you then use? What are the effects of starting and stopping the load or of crashing the bridge into the stops at the end? Are all the bolts in the joints applied correctly (shear vs tension)?

The people who manufacture these kind of cranes know all about these things. A way to save money on a stationary crane is to buy a used one that came out of a building that is no longer in use. Due to the way manufacturing is going in this country you might be surprised how many used stationary cranes are out there. The used equipment people can help. Just google used equipment, used crane, used gantry, etc. Of coarse Globalspec has good supplier search utilities.

I have had used equipment trucked across Canada to the US and had no problems.

Yes there are six w10x35 post (three along the span with one in the center), with four 3/4 inch bolts to the floor and four 1 inch bolts in the top bolted to the W12x35

The four foot bracing is in the upper corner of the post at 45 degrees in both directions on the end posts.

The top bracing I mentioned with the W6x16 is in the four corners in a top plan view.

The gantry beam, W14x34 can move along the length of the W12x35 (39'). There is also a W14x34 across both ends, hence the other two hoists. I will try and get a drawing posted.

The text reads in the above drawing from top to bottom;

W14x34 all three with trollies

W12x35 39' long

W10x45 with 1/2 top and bottom plates

Bracing is on both sides, front and rear

All beam ends caped and gantry stops placed here.