Ok here's the question: Say I want to launch a boat that's aw,aw, say 155'long & has a beam of aw,aw,say 35'. The boat weighs around 425 tons (just a guess)
Ok I have to lift the boat using a spreader bar about 1-2 feet & CRAWL up on to a supporting platform , about 14" high (as the pressent soil cannot support this load -- weight of both crane & the boat),,,, the pads will sink as the crane crawls. I gotta crawl around 60 feet,than lower the boat into the water, about 6'below ground level.
Keep in mind the Spreader bar CANNOT hit the boom at any time during the lift & crawl. So the boom angle is very important. I don't know what the distance from the center of the load to the Crane "King Pin" is. It's 17-1/2' plus somthing.
Ok can this be done & if so, what size crane do I need.
I know a "Ringer" could handle the lift if it were straight up. But could it handle it @ the needed boom angle ???