Mine is nothing special, just a reach extension boom.
We made it last summer when we needed to rig some 12' diameter hexagonal frames we were building. My old shop didn't have a crane, so we needed to use the forklift to get the frames out into the parking lot, flip them, finish welding, and then deliver them to the customer. Fortunately they went to the brewery a few doors down so we were able to just drive them down.
Unfortunately these pics are all I have of that project. These are tank bases for wooden beer aging tanks that needed to be kept off the floor. They got a few more braces welded in, and extreme duty leveling feet. I think we made 12 of these frames all told.
As you can see my old shop had 10 pounds of **** in a 5 pound can, so it was VERY helpful to have this boom to facilitate rigging of large weldments and machines.
I had load tested this boom to at least 2000lbs, as it would easily move my Bridgeport. It is made of heavy wall rectangle tubing and an 8' length of 6" schedule 40 pipe. The plate on the end for the hook is 1/2" plate, and is sized to take a 1" pin shackle or that old crane hook that I have on it right now.
We had to add a second set of fork pockets when we got the new forklift. My old hilo had class 2 forks and the new forktruck has class 3, and they wouldn't fit in the old pockets. So we cut some lengths of 8" x 3" x 1/4" tube and welded them on the bottom of the old ones. Now it can run either size forklift.