Mast length for a Top Hat 25
Member Gary Pick drew up this (below) sail plan for a Toppie.
He was looking at a timber mast 220mm at the partners tapering to 100mm at the top, 9 metres long, which weighs in at 87kg (about 3.6% of the weight of a Toppie - Arne reckons 3% is ideal). Gary's already made it.
I thinking of going with the same, but I'm unsure about the length.
I've decided to go with a timber, keel-stepped mast right in front of the cabintop. That would give the mast 1.2m of bury, from the partners to the keel.
The sail, when it's made, will need to have a shorter lead to compensate - somewhat like Speedwell's (see pic), though not as far forward.
Graham Cox wrote of his experience with his JR Toppie Blue Moon: "The ideal place for a proper junk rig is just fwd of the cabin top, on the foredeck. Blue Moon has more lead in the sail design, 22-25%, to compensate, but it is not ideal. About 300-450mm further forward would be better. If you placed the mast right up against the fwd end of the cabin, on the foredeck, I think the position would be perfect for your (Gary Pick's) sail."
Graham also reckons 11m would be a good mast length Toppie.
Step 1 in my junk conversion, and the most difficult step for me, is getting the mast.
Time, space and skills mean I'm looking at having a mast made for me. I'm looking at a birdsmouth timber mast, 220mm at the partners tapering to 100mm at the top. Just like Gary Pick's. The only question is the length. I reckon i can manage fabricating partners and step, and bracing the underside of the foredeck, but a mast is beyond me.
So, how long should it be?
In my cruising grounds (Victoria, Australia) often as not the wind is 'fresh' - often too fresh. Given Toppie's reputation as initially tender, I think I'd rather err on the side of shorter, and keep weight aloft to a minimum.
Cheers,
Matt