Forestay tension for wood mast

[allene]

I desire less forestay sag when racing. Right now I limit my forestay tension to 1050 pounds for no apparent reason. What is a reasonable number? My boat is an L-36, 55 years old, box wood spruce mast 4.75x7 40.5 tall, single spreader. Thanks for the advice.

[Ian McColgin]

Isn't this the boat with frames spaced to hold a six packs snugly in the bilge bays? My memory is that the construction of these boats is utterly fantastic. Absent rot or damage, she ought to handle the tension you desire. That's the hull. You'll also want to be sure the stick can take the compression and the shrouds keep it in column.

If so and if you can measure the backstay tension on the hard beat where you have jib sag, that will give an idea of what's happening. I'd try tensioning to about that static and take another sail to see if you're leaking or hurting anything.

You may also want to consider a dynamic approach to rig tension like easing on the run and for sitting at the mooring, tensioning only for the beat.

That's the limited seat of the pants view. In WWI, each fighter off the assembly line had to be test flown to find the problems and correct them. Test flying those crates was incredibly risky and when my grandfather actually lived through a week of doing it, they made him permanent, cancelling his chance to get out of England and over to hunt the Red Baron. Grandfather said it was simple. Other test pilots took the plane up and shook it till something broke. Grandfather had the revolutionary idea to shake it till just befoe it broke.

Point is, there are too many inponderables with a old boat and old rig. I don't think you'll have much luck with predictive engineering, especially over the internet with no way to know the actual condition of the boat. But assuming you inspect your rigging so there won't be some stupid but catastrophic failure, like the backstay turnbuckle stud snapping, then you are safe to gently tweek tighter depending on wind and observe closely.

G'luck

[allene]

Yes, the L-36 has 13 inch spacing on the floors so a 6 pack can fit, at least that is the legend.

I see I should have expended some in my post. I would like to put 1400 to 2000 pounds on the forestay but am afraid. The hull is rock solid after the 5 new very much larger floors, new mast step, and new keel bolts. All I am worried about it the rig. I do relax the tension at the slip, btw.

I like the idea of testing the tension under sail and inching up. My shipright said to tighten it and look to see if the mast goes at all out of column when the boat hits a wave.

Another person said to tighten it until the mast breaks then back off a little. I am looking for better advice than that although I am told that is how the big boys do it.

Allen