IRC Heavy weather jib

jonjo · #1 24-11-04, 18:22

The IRC rating formula makes provision for something called a heavy weather jib which is distinct from a storm jib.

A yacht with a furling foresail is given a rating credit but this credit is reduced if a heavy weather job is carried. By my calculations an IRC heavy weather jib is about 2.5 times the size of a storm jib.

A sail maker told me these jibs plug the gap between 25knots and use of a storm sail but I question the scenarios in which it will be pragmatic to switch over to such a sail.

Typically a cruising yacht will not knowingly venture out into a force 6+ and on those occasions when the wind pipes up worse than expected I think most cruising crews will tough it out with a couple of extra rolls rather than unfurl a 135% genoa in a 28knots wind in order to switch to a heavy weather blade jib.

The only use-case I can think of is that I am sitting in a Poole marina on a Sunday and must get back to Gosport that day against a steady 25knot wind. In such a case I could switch sails on the furler in dock.

Maybe the proper solution is an inner forestay?

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powerskipper · #2 24-11-04, 20:40

or a power boat [img]/forums/images/icons/wink.gif[/img]

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Julie

AndCur · #3 24-11-04, 20:43

Yea but after a night in the pub could you afford the fuel!!

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powerskipper · #4 24-11-04, 20:47

erer no comment![img]/forums/images/icons/wink.gif[/img]

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Julie

bedouin · #5 24-11-04, 20:53

I have a number 3 jib that satisfies the requirements as an IRC heavy weather jib and I find it a very useful sail.

Once the boat begins to get overpowered with the full number 2 genoa on the wind (about 25 kts AWS) it is much more efficient to change down to the smaller sail than to try to make to windward with a part-furled genoa.

If I anticipate going up wind in a 5 or above I would use that sail, and can happily carry it with progressively less main up to F8. It also has the benefit that it is high-clewed and very flat cut, meaning that it can be part-furled without significant loss of efficiency so even though I (sometimes) carry a storm jib I can't imagine when I would use it

However I sail a fairly heavy/seaworthy boat and I'm quite happy to set off in F7

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StephenSails · #6 24-11-04, 21:57

I doubt that would rate either!

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jonjo · #7 25-11-04, 11:06

Is your No3 hanked onto a spare forestay or do you find it practical to swap the No3 onto the foil at sea.

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AndrewB · #8 25-11-04, 11:32

Like Bedders I also carry a heavy weather foresail as well as a storm jib, but for cruising in my case. The storm jib is really no more than a steadying sail, downwind or hove to in extreme conditions. Going out for a brisk thrash in Poole Harbour in an F7-8 (or any other stretch of well sheltered water) the heavy weather foresail and triple-reefed main is a good combination. Has stopped many a weekend from being entirely wasted.

It might also serve if I ever do have to claw off the proverbial lee shore, but that's never happened yet, and never likely to.

jonjo · #9 25-11-04, 11:55

Thanks I think I will order a heavy weather jib.

Do you know the relative sizes of your foresails?

My 100% fore triangle is 29m2 and the main is 39m2. IRC rules indicate a storm jib of 10m2 and a Heavy Weather jib upto 27m2.

My hunch is that 27m2 is still too much foresail for 28knots on a 5.7 ton hull even with a 2.2m keel.

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bedouin · #10 25-11-04, 12:42

Mine hoists on the furler, so does require the bigger Genoa to be dropped.

As I usually sail short or even single handed I am not a great fan of changing to a smaller Genoa underway so I normally try to chose the right size genoa at the start of the trip and stick to it (unless racing...).

The reason the heavy weather jib is so practical is that upwind it is as fast or faster than the number 2 down to wind speeds as low as F4, and can be carried (maybe partly rolled) in winds of F9 and above (not that I've tried the "above" bit).

Of course much depends on the boat - mine loves stronger winds and sailing in F7 is more fun than F3. A more modern design will have different handling characteristics.

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