The weight of the casting at the top of the mast to support the block up there (the A Class masts just have a foam plug at the top of the mast and something for the ring to hook onto), the halyard all along the mast, and a block at the bottom. The most important place to save weight is aloft...and the support structure at the top of the mast for that halyard is a good place to save weight, even if you have to add it back to the plaform to meet minimum weight.
Actually the F16's do not have any support structure up the mast for the halyard. All the Taipan and Blade masts have a foam block up there just like the A's. So no weight lost there. What we do have is a single standup block that has been blind riveted inside the sailtrack. weight = 20 grams or less (0.6 oz). The halyard is typically a 4 mm dyneema line = 13 grams per meter. In total 8.5 mtr is going up the mast the other 8 mtr is in the tramp pocket while sailing. 8.5 mtr weights 100 grams in total or 3 oz. Of course the other 8 mtr in the pocket will also weight about 100 grams.
But the total weight added to the mast while sailing will be 120 grams or 1/4 lbs. So I'm afraid that the halyard is not the best place to save weight on the mast. Currently that is the proctor spreader arms. Next in line is the mainsail itself. F16 does allow cuben fibre and kevlar to be used in the mainsail. Several mainsails still use fibre rods as battens over foam battens, another 500 grams (1 lbs) weight savings.
But any true weight savings are to be found in the mast material itself. If you go for a carbon mast then that will garantee you a weight savings aloft of no less then 4 kg (8 lbs). But there is a price tack attached.
Wouter
