I took one of two steel structures down for the ramp in the early 70s I think they could have been support legs but not sure and they would have been around 35/40 tons each as I ran with the Samson which took the other one so it must have been when they were building the roll on roll off dock I know it was Newton Chambers Chapeltown Sheffield who constructed the structures but is a long time since and I have done a lot of loads since
cheers Johnnie