Damage to the main sail was discovered Saturday morning, June 19th, when we unfurled it to begin crossing Lake Michigan from Wisconsin to Michigan. We found a good number of tears in the main sail.
It is my thought that this occurred when we furled the main sail in 30 to 40 kt winds last Thursday, coming into Kewanee. We applied sail tape to prevent the sail from tearing further.
When we arrive in Frankfort, Michigan this evening we will do further damage assessment. At first glance, it’s not good.
Sail tape is for making temporary repairs. After applying the sail tape patches, we were confident that in today's moderate winds the tape would hold, and we could make the crossing without further damaging the sail. Our current plan is to continue our journey with the sail tape. We will look to find a loft or sailmaker to inspect and make the necessary repairs.
My current thinking on factors and causes of the damage are that we had high winds of 30-40 kts during furling and it was difficult to keep the bow of the boat head into the wind while furling the sail causing the sail to enter the slot at an awkward angle.
I need to know which way my furler turns and furl on the tack that does not bend the sail around the slot in the mast. (I should have known this already and consistently furled in this manner. What I got away with at 10-15 knots may have bit me at 30-40 kts).
We recently added a storm track on the port side of the furling slot on the mast. This track has cars with rings that stick out a bit. There’s also a hard shackle on a car connected to a line that holds the trisail tack down that’s a potential snag point. It’s possible that the sail was getting fouled on the rings or shackle as it was being furled.
When we get in this evening, we’ll check to see if the sail damage is at the same height as the rings and consistent with this failure mode to determine if this theory can be validated or rejected. If this looks like a causal factor we can furl on a starboard tack that would reduce this risk in the future. I think we’ll also replace the hard shackle with a soft shackle.
Post Damage Assessment
The shackle didn't line up with any of the damage. But, the damage lines up with the rings on the newly installed cars. The rings on the cars are smooth and you wouldn't expect them to create this type of damage to a sail, but sudden high winds can be extremely hard on a sail.
We made the decision to remove the cars from the track and store them with the trisail. If the trisail is needed, we install the cars at the same time.
Experience can be a cruel and expensive teacher.