Spinnaker Sheets - How long?

[Viking]

Brought a boat with a spinnaker (with pole), but no sheets. How long (rule of thumb) should they be? What size 8mm or 10mm thick?
Boat lenght 8.5 Metres - 29 feet, Mast head rig

 

[bedouin]

The usual recommendation is about 2.5 times boat length, that's what I've got (came with the boat) and so far I haven't needed them that long (twice boat length would probably do.

As for thickness, 10mm is a minimum for the sheet, and probably too small if you don't use separate guys (as I guess you don't)

 

[jamesa]

Length rule of thumb - 1.5*LOA.

Thickness depends on what sort of rope you use and how much pain you enjoy! I use 8mm dyneema on my sheets and 10mm on the guys (10m masthead cruiser racer) but gloves are a must. With braid-on-braid I'd go up a size or 2.

 

[Viking]

Thanks for the info??
So between 1.5 and 2.5 X boat length. Perhaps its a case of 'how longs a piece of string'
I had spin. sheets on my last boat but never throught to measure them.

 

[Twister_Ken]

If the clew of the kite rarely goes forward of the bow, and the sheet comes back to the quarter, does two or three turns around the bwinch and is taken forward to a trimmer standing near the shrouds, 1.5x might be a smidge short, whereas 2.5x is a bit too much string. Why not go for 2x which leaves the trimmer something to hold onto?

 

[bedouin]

Also depends a bit on the type of spinnaker, and how you use it. With an asymmetric, 1.5x is definitely too short. It is simply not long enough to reach from the quarter, round the forestay and back to the clew (when it is the lazy sheet). Nor could you really trim the chute from the weather shrouds. If you only have a symmetric, and trim it from the cockpit, then you might get away with 1.5x, and it would keep the cockpit less cluttered (the long tails certainly get in the way).

 

[hugh_nightingale]

All the recommended writings seem to suggest 2x boat length. This agrees with Twister Ken above.

1.5x is barely enough to allow a few turns on a winch. My boat came with about 1.25x and I don't know how they used them. At least one of the sheets must be long enough to reach around the forestay and back to where the spinnaker is worked at the bow, then on the other side, back to near the stern and forward to a winch. This is about 1.5x without turns on a winch. I have since bought some new 2x sheets but have not been able to try them. Once you've bought them too short you're just left with a set of ropes you can't use.

 

[LORDNELSON]

when you are alongside a suitable pier or pontoon on a still or almost still day, why not knot together a few ropes, hoist your spinnaker and see, with the foot of the sail streched out, what length of sheets you need? Alternatively ask a rigger - if you do ask a rigger you will not end up with the disaster of the newly brought sheets being too short!

 

[JimMcMillan]

Twister ken is right.The sheets never go past the forestay,so the length of the pole and the foot of the spin.determine the the length of sheet.So rig the pole with the uphaul take it forward to the forestay measure to your sheeting point and then to your winch and add enough to let a trimmer stand about the mast.