If my calculations are right (and it is possible they are not) you might consider this beam. If you have a beam of steel which has a basic permissible bending stress of about 23000 lbs per square inch, by the time you make allowances for the span and the lack of restraint, the actual bending stress that the beam can handle is down to about 6100 lbs per square inch under these conditions. My conclusion is that if the ends of the beam are not built in to something substantial, and if the top flange is not restrained, the major factor is keeping the bending stress to acceptable limits. I have not done steel calculations for a while, but I thought I'd have a go. In order to get round this problem, you have to go for a larger section.

If the top flange of the I beam is not restrained (ie prevented from moving sideways), and you have a clear span of 45 foot, the permissible bending stress for the beam will be far less that the nominal value for the steel. Unterhaus is right on the button with with comments on buckling. With the over head crain one person can move the material around.Dear Dennis,

If I happen to need to move something heavier i'll just use the forklift. I can make the trolly support wheels farther apart to spread the load. So I think a better estimate would be 2,200 lbs. max plus the winch, trolly, vacuum lifter, I think that will be another ~700lbs. Maybe my 3K lbs estimate is a little high. I will use it move granite slabs around, from the cart to the saw and so on. We ship all over the world including the United States, Canada, Indonesia, India, the United Kingdom, EU, and more.^^ I measured the shop and it is 45' not 50' so thats a plus. Note that we also sell Kart Kits which transform disassembled tri-adjustable gantries into wheeled carts making them exceptionally easy to move and store. All 5 lines are shown below for easy comparison. We have 5 different product lines and hundreds of models, including a 15-ton made-to-order gantry and the option to have a crane customized just for you. The comprehensive line of portable gantry cranes we have for sale is designed to fit every need and budget.

These cranes are sometimes also referred to as a-frame hoists, rolling cranes, or gantries because of the triangular (“A”) shape of their legs. All our gantries can be mounted with wheels and/or casters. Portable or mobile gantry cranes are free-standing gantries mounted onto wheels or casters so they can quickly and easily be moved from one location to another. With customers still ordering accessories for gantries built well over 60 years ago – they are an investment that pays for itself – many times over. They are built to last using our patented, pinned-joint design, heavy-gauge steel and aluminum, and plated bolts, pins, and hardware. Wallace gantry cranes are manufactured and assembled in the USA.

I beam load chart for hoist