Running Rigging Sizing

[Don Lucas]

This seems a basic question, but I have not come across it it in the various books I have:

Is there some chart etc for sizing lines for your running rigging? The ones I've replaced so far I replaced with same as were on the boat, but who knows if those were correct to start with.

[MarkJ]

Is yours a Cal 39?
There should be a standard rigging chart in the user manual. If you don't have one perhaps there is a Catalina forum that will.
Those standard charts are a good starting point as the blocks may all run that bit easier with the manufacturers correct specs.

In particular don't go any heavier with the genoa sheets as they might not sit in self tailers correctly etc.

[Don Lucas]

I'll look in my owners manual (don't remember seeing anything like this). But the boat got raced etc over the years, sails changed etc. so who knows if this is correct. I was thinking there was a sizing chart based on sail area or such that someone might know of. I'm in no rush, got 5-1/2 months to figure it out.

[MarkJ]

Yes, racers tend to play with things! LOL

[GordMay]

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Tech Corner ➥ Harken Tech Corner

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[sailinmike]

Sailboat owner's dot com has a running rigging calculator in the online store. Lot's of boats listed with factory specs. Running Rigging Calculator

[Don Lucas]

Funny in that these calulators give smaller sheet lines than the boat currently has. But this is based on diameter size and in a way is meaningless as to me size should be measured as strength then diameter.

[gulfstar37]

I think most of us realize over the years the material for the lines have changed to allow using smaller diameter line for the same strengh. However several things need to be considered before changing the size.

Some include other hardware you have on the yacht. Clutches, self tailing winches, stoppers, and even how it feels in the hand. Most have ranges of line size that may be adjusted. The only thing that runs better with a smaller diameter is blocks. Hate to spend $200 on the line and find you need to spend another $1000 on upgrading the hardware it runs through. Also some of the newer high tech stuff allows to go very small but a 40 footer jib sheet of 1/4" won't feel good in hand when the wind kicks up.

Go to any of the cordage websites Yale, Newengland, Sampson etc. They give good advice on what will work.

[Sunspot Baby]

I have no doubt that with improving technology, newer lines could be of smaller diameter but when I replace I always go with the same diameter to be sure it fits the sheaves and winches.

George

[SkiprJohn]

On my boat it is what runs over sheaves, through blocks and feels good in my hands. The most important is what feels good in my hands. Any line that diameter is going to be plenty strong enough.
regards,

[Don Lucas]

Yeah I agree. Took my sails down today for storage and I think the genny sheets are at least 3/4" even though the calculator says 7/16" for them. The current lines fit the winch well but is tight in the block (I ran them outside it last season) but they fit our hands well and are easy to hold onto to. Maybe the cost of the oversize lines is offset by being able to use low tech materials as there isn't a need to have the lines so strong that the sail rips instead of the line.