on raising the mast

This seems to be a matter of great concern to most f-boat sailors - and it should be. However, the risk of any accident or failure during this operation is greatly reduced by simply doing it twice at the same time. One needs to rig two independent sets of lines and blocks and use two winches to lift the mast. I have done this together with a friend as well as alone. Operating two self-tailing winches allows for this operation to be done without blood, sweat, or tears. Have a look at the sequence of events here. We are using inexpensive blocks (no snap-shackles, though) and genoa and spinnaker sheets.

There is no need for analysis of forces in the lines or on the blocks. It has been tried and tested many times. The magic word for success and safety is: redundancy.