What is the major advantage of a Forstmann boom?
Well, there's a major reduction in weight from all the cash that you won't have in your wallet anymore...
Seriously, the advantages that I see are:
- The blocks are recessed up in the boom to the maximum allowed so the boom-deck distance can be smaller.
- The blocks are on a continuously adjustable track (although the "as delivered" adjustment system isn't very convenient).
- The distance between the bolt-rope and the blocks is minimized by recessing the bolt-rope track down in the boom so it is right above the block-track. This minimizes the distance the boom moves off to the side when it loads up.
The last item may need some explanation. Imagine you had a 6" distance between the boom-blocks and the sail, and you had sheeted in so the deck and boom blocks were tight together. Without and side-load the boom would sit vertically 6" above the deck, but as the side-load increases, the boom would move out (and down) along an arc with a radius of 6" centered on the pivot where the deck-blocks attach to the hull.
This is also the reason you use a rigid riser-block to raise the sail up off the deck, rather than just easing the sheet.
Cheers,
Geoff S.
