MERLIN ROCKET FORUM

Topic : Advice sought re secondhand sails

I thought that I might buy some second hand sails for my NSM 1 but am having a little difficulty understanding the various Merlin rig dimensions:

My certificate gives a mainsail luff length of 5720mm, mainsail foot length of 2470mm and a headsail area of 2.87sqm for a total sail area of 9.96sqm. So far so good but this doesn’t correspond to most of the sails that I see for sale which often appear to have a mainsail foot length of 2503mm and a jib of 2.8sqm. Working back through the calculations in the rule book these dimensions also suggest a total sail area of 9.96sqm and a luff length of (approx) 5720mm so I assume they would fit my rig as well. Whether they would be cut to suit is a different matter as I am still working with a hog stepped aluminium mast but are my basic assumptions about the geometry and measurements correct?

One other point that has puzzled me concerns the description of various sails as “to suit a 21ft 6in rig” or similar. How is this measured? Am I right in thinking that one adds 680mm to the luff length and converts to imperial measurements? In my case giving a length of 21ft exactly.

Any clarification from one who knows would be most welcome.


Posted: 11/04/2012 13:03:02
By: Roy Poole
Yes and yes - you have a standard 21ft rig but with a slightly larger jib and smaller main than is now common.  If you put a main with a 2503 foot on your boom it is unlikely not to fit as we are only talking about 33mm.  You should be able to accommodate the jib within the extent of your present jib track.

BUT the sails will be cut for a much bendier mast with closer sheeting angle and lower sheet tension on the jib. Also you should get your measurement cert altered to suit as you are altering the rig dimensions. However if you keep the black band the same on the boom that probably doesn't apply. If you are intending competing in open meetings you should consider getting sails recut or fiddling with the rig. If you are doing some club races and just enjoying the boat I doubt anyone will get too bothered about it.

Andrew


Posted: 11/04/2012 18:43:08
By: Andrew M
Thanks Andrew, Most helpful. For the time being it's just some club racing for me but who knows what the future holds. If it's the same as the past perhaps a few Silver Tiller meetings. I was spectacularly unsuccessful then so it can't get any worse but whatever happens it's enjoying sailing the boat that's important now.


Posted: 11/04/2012 22:21:32
By: Roy Poole
My thanks to those who offered advice and sails. i have now found what I need for the time being and look forward to trying them out at the weekend.


Posted: 18/04/2012 20:04:24
By: Roy Poole

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