thank you Derek never in 100 years would i have come up with the term "shearlegs"
hum?? interesting indeed shearlegs is the answer to lifting heavy things, now to ponder moving heavy things, the shearlegs are stationary so the parts have to be moved to the shearlegs. Unless the shearlegs rotated then it could be constructed next to the hull, rotate and pick up the frames then rotate them over the hull timbers and set them down.
it does make engineering logic to lay the keel set the floor timbers in place and construct the engine, then built the hull around the engine rather than build the hull first and lift up and lower the engine into the hull. But somehow the shearleg crane has to swing and pick the parts up off the ground and place them on the hull floors.