Double Spinn Sheets

[johnsail]

As everybody's been saying, the point of twin sheets is to facilitate a dip-pole jibe by keeping a traditional spinnaker under control while the pole's moved from one side of the headstay to the other. The pole's arranged "cup up" with the pin on top. That way, when the outer jaw's opened and the topping lift is released, the pole end falls down and away from the spinnaker guy. Otherwise it would be caught on it.

But that's a concern for racers. I have to ask: why do you need a traditional spinnaker? You can do very nicely with an asymmetrical spinnaker -- essentially a big, nylon genoa jib set without a pole. The mainsail's so big on boats like the 8 Metre (I race on one) that you have plenty of sail area. All you need is a lightweight headsail.

Roll up the jib, set the A-sail with the usual two sheets, and you're in business with no worries about managing a spinnaker pole on that narrow foredeck. To jibe, just head off and let the sail fly out in front of the boat before trimming the sheet on the new leeward side. You can even run square before the wind by sailing wing-and-wing.

[mrkeith]

i guess that raises a good point. is there any advantage of having a symetrical spin vs an assymetrical spin? are symetrical spins now becoming obsolete? thank you

[sailingdog]

IMHO, the rise of asymmetrical spinnakers is mainly due to sailing short-handed. An asym doesn't require the number of crew, or level of coordination that a traditional spinnaker generally does. Traditional spinnakers aren't really obsolete, just serve a slightly different purpose.

Also, on non-racing boats, carrying a half-dozen headsails isn't really common, and an asym is a much more versatile sail in many ways.

[GER308]

Asy spi´s are used on cruising boats because they are easer to handle, on racing boats because modern light displacement (sport) boats make better VMG by sailing hotter angles. On a heavy non surfing boat like an 8mtr there is not enough speed gain to warrant the extra distance, therefore sailing deeper with sym. chute will be much faster.

Dip pole jibe: Jaws up so the old guy lifts out, make sure that the lazy sheet is over the guy, square pole, pull new sheet on, raise mast butt (mark on mast), open jaw and drop topper (mark on topper), guy lifts out (hopefully), release old guy, swing pole through clipping the new guy in. drop butt, raise topper, pull new guy in while easing the old sheet. Use the port and stb. sheets to fly the chute through the jibe. The topper and mast butt are marked so that you know that the pole is angled enough that it will pass through the foretriangle. Attach the guys so that the lazy guy can be removed in light air.

It takes ideally 1 person to do sheets, 1 to do guys, 1 for pit, 1 for mast, and 1 for bow . I have done it double handed on a 44 foot fractional rigged (with runners) IOR boat in 25 knots at 2am on the way to Hawaii, anything is possible.

[nolatom]

Originally Posted by mrkeith

i guess that raises a good point. is there any advantage of having a symetrical spin vs an assymetrical spin? are symetrical spins now becoming obsolete? thank you

I'm fairly new to assym. kites, but im my opinion they aren't all that good on a dead run, since they're tacked onto the bow and don't get out enough from behind the main. On a very broad reach or a run, give me a spinnaker on a pole.

[Giulietta]

There are assymetricals and assymetricals.

newer assymetricals actually allow dead runs...the point is that sometimes the dead run is not the fastest way to get there....

Assyms can be built to dead run..