Forestay Load Calculation for Toggle

[JSBKC]

I've been unsuccessful finding a website to calculate the rig loads on my forestay (O'Day 34, ~ 600 sq sail area, 9/32 wire). Specifically, I'm trying to determine if an Eye Jay Toggle (WestMarine # 453324 1/2" pin - rated at 3400 lbs) is strong enough. Any help greatly appreciated. -

[bhnautika]

Size fittings to a bit above the breaking load of the wire, 9/16 about 8000lbs

[RHough]

Originally Posted by JSBKC

I've been unsuccessful finding a website to calculate the rig loads on my forestay (O'Day 34, ~ 600 sq sail area, 9/32 wire). Specifically, I'm trying to determine if an Eye Jay Toggle (WestMarine # 453324 1/2" pin - rated at 3400 lbs) is strong enough. Any help greatly appreciated. -

The diameter of the hole in the forestay chainplate determines what will work. For 9/32 wire the pin should be 1/2" diameter.

Eye-Jaw toggles are built to carry the same working loads as the pin.

If the pin fits properly, the toggle should be fine.

I couldn't find the 3400# rating for that toggle. The rated break strength of 9/32 1/19 type 302/304 wire is about 10000# or about 8500# for type 316. If 3400# is the safe working load, it is in the 30-40% of breaking strength range. I can't imagine an Alexander-Roberts 1/2" toggle being rated at 3400# breaking strength.

[JSBKC]

Yes the Eye-Jaw toggle has 1/2" pin just like the forstay. The 3400 lbs load seems low to me.

[RHough]

Originally Posted by JSBKC

Yes the Eye-Jaw toggle has 1/2" pin just like the forstay. The 3400 lbs load seems low to me.

That has got to be a SWL number, not a breaking load number. I've never seen a eye-jaw toggle break before some other part of the assembly. I use bits from A-R all the time, no problems with the quality.