Correct forestay diameter?

[wysiwyg]

I intended to install a Harken Cruising Jib Reefing and Furling Unit 1 on a heavy displacement 33' boat. The spec. says it covers typical boat lengths of 28' - 36', max. forestay dia. of 5/16", and clevis pin 1/2" or 5/8".

I measured the forestay as 3/8" and the clevis pin as 1/2". These don't seem to match up - the forestay is stronger than the clevis pin!

I suspect that a previous owner put a larger diameter forestay on the boat.

How do I decide whether I can reduce the forestay down from 3/8" to 5/16"?

(West Marine give the breaking strengths as 14,800 and 10,600 lbs. A significant difference!)

Thanks.

[sailingdog]

It would help if you said what the boat was... since someone here may own the same boat or might know what the original specification for the forestay was.

Generally, as a rule, the more information you can give about your situation, the better the answeres you get will be.. Leaving out things like what kind of boat you have is a common newbie mistake.

[RickBowman]

Contact Harken tech support for the proper fit.

[Tartan34C]

First, a 3/8” headstay is a very large wire for 33 foot boat even if she is heavy. Second, a pin and wire usually have some relationship in size. The common rule of thumb is a pin is twice the wire size. Your instructions say 5/16” inch wire and a 5/8” pin or a 1/4” wire and a 1/2” pin and that bears this rule out.

What boat is this? I have rigging information for a lot of boats so I may have something on yours if you share this information.
All the best,
Robert Gainer

[sailingdog]

Rick-

I don't think the real problem the OP is trying to address is the furling unit, but the discrepancy in the sizing of the forestay and forestay clevis pin.

[wysiwyg]

Thanks for the replies.

The boat is a Tradewind 33.

I'm trying to decide whether I can reduce the forestay from 3/8" to 5/16" so that I can go ahead with the Harken furling unit (Unit 1).

I don't want the mast falling down!

[T34C]

I agree with Robert, 3/8 sounds big for a boat of that size. (Dumb question, but have you double checked your measurement?) I would say updating the standing rigging is never a bad idea, but does it need replacing? Have you looked to see if other furlers have a differnet range of wire diameters they will cover?

[Tartan34C]

That is a heavy boat. The company that built the John Rock designed Tradewind 33 is still in business. Give them a call at 44 (0) 1202 767412 or visit the web site at "www.tradewindyachts.co.uk". This is a question worth asking and it’s worth going to the source for this one. Either way 3/8” is larger then you need and in my mind the question is if you should use 1/4” wire and match the 1/2" pin or is there some reason to use 5/16” which I think is still a little bit large.
All the best,
Robert Gainer

[billangiep]

I have to agree with the rest of the gang here that 3/8" is way big and 1/4" as Tartan said is probably the correct size? As a general rule of thumb any two stays or shrouds should be able to carry the displacement weight.
Bill,