Spinnaker Tack Line

[Cathyalan]

What size block should be used for the spinnaker tack line attached to the bow sprit?

Alan

[Dan]

Are you flying a symmetrical spinnaker or an asym? Most likely it is an asym or screacher, and you're probably better off shackling the tack to the big bail on the bowsprit. The Asym, about 700 sq. ft IIRC, usually came with a spinnaker sock to douse it. The Screacher, about 400 sq. ft., usually came with a Schaefer wire luff furling drum system.

[Cathyalan]

It's an asym...manual says 400 sq.ft. I have been told I will get more performance out of the sail if I rig a tack line with a block on the bow sprit. I assume a 1000 pound block us quite sufficient??

Alan

[Dan]

Alan-

I don't think that is the Asym. IIRC, the screacher, not the Asym, is 400 sq. ft. It is also typically flown from a wire-luff furler unit, usually a Schaefer 650.

Yes, flying either using a tack block and line should help with performance, but I'd go with a block with a SWL of at least 1200 lbs. However, the tack line should run back to the cockpit so you can control it.

[Cathyalan]

This is what it says in my manual:
Asymmetric Spinnaker
The T2 spinnaker is roughly 400 square feet and made of 1.5 ounce sail cloth. The spinnaker sail is only rigged immediately prior to using the sail. To rig the spinnaker, first run the spinnaker sheets. Connect the snatch blocks to the padeye on each side of the stern outrigger deck. R un the lines forward to the foredeck.

It does seem bigger than that.
I definitely have an asym with sleeve/sock but you say 700 sq. ft. ???

Yes, I have a 1,200 lb block and 1/4 inch, 1,200 lb line.

Thanks
Alan

[Dan]

Alan-

I believe the section you're quoting is a typo. If you look at the screacher section, on the same page IIRC, you'll see the area of the Asym is listed at 700 sq. ft., not 400. The screacher is 387 sq. ft., but I rounded it off to 400. IIRC, I sent them an e-mail regarding the error and it was supposed to be corrected in a later revision of the manual. If yours came with the sleeve/sock, then it is most likely the Asym, since the screacher typically was sold with and mounted on a Schaefer 650 furler.

If the loads you are quoting are Safe Working Loads, then you're probably okay. The Asym (1.5 oz cloth) is probably good for up to 10 knots apparent wind, where the screacher (4.0 oz cloth) is good for 14 knots upwind and about 17 knots apparent off the wind. The load on the Asym at 10 knots is about 300 lbs., so a swl of 1200 lbs.is probably fine, but a BREAKING LOAD of 1200 is a bit low, since you generally want at least a 5:1 safety margin minimum.

This is what it says in my manual:
Asymmetric Spinnaker
The T2 spinnaker is roughly 400 square feet and made of 1.5 ounce sail cloth. The spinnaker sail is only rigged immediately prior to using the sail. To rig the spinnaker, first run the spinnaker sheets. Connect the snatch blocks to the padeye on each side of the stern outrigger deck. R un the lines forward to the foredeck.

It does seem bigger than that.
I definitely have an asym with sleeve/sock but you say 700 sq. ft. ???

Yes, I have a 1,200 lb block and 1/4 inch, 1,200 lb line.

Thanks
Alan

[Ron]

I've got both sails - asymetrical spinnaker with sock and roller mounted screecher. The screecher is substantially smaller than the asymetrical. 700 and 400 square feet sound about right. As Dan suggests - 1200 pound rated line and block are probably OK, but I'd also go heavier for a better safety margin. I think I'm using 3/8 stay-set and a 3000 pound swl block I was using on a 40 foot monohull. The limits, especially upwind, are partially based on what the bow sprit can take. If there is even a remote chance of exceeding them (and I have), I will set up a bob stay (using the trailer U-bolt on the bow).