⚠️ Our hydraulic Mainsheet Broke! Lessons from the Swiftsure Race 2025.
- Raymond Van Der Linde
- Jun 20
- 2 min read
Recently, while racing in the Swiftsure International Yacht Race onboard Cheekee Monkee, we got a surprise we weren’t expecting—the hydraulic mainsheet let go and snapped right at the sheave exit.
What Happened?
For some context: Cheekee Monkee is equipped with a hydraulic backstay, rigged in a 1:2 configuration. The hydraulic cylinder is mounted inside the boom at the forward end. The mainsheet dead-ends inside the boom on a pin, then runs through a block on the ram, and back aft to the exit sheave where it attaches to the traveller car.
We’ve been running a 9mm DSK78 Ultra core mainsheet with a Dyneema cover for abrasion protection. It was installed back in 2019, and truth be told—it was due for retirement. Unfortunately, it beat us to it and failed just before we got the chance.
What We Found
Upon examining the break, we noticed something clear:The core was significantly worn in a short section, about 1 meter in length. This area sees the highest loading when sailing upwind, and over time, it’s where the line has repeatedly cycled over the same load point. That friction led to progressive abrasion and ultimately the degradation of the strands in the core, reducing its strength below working limits.
As a general rule:
If more than 25% of the line is abraded or damaged, it should be replaced. In our case, we were well past that threshold.
As expected, further down the line—toward the dead-end—the fibers were 100% intact, showing that the load path itself isn’t the problem, just repetitive friction in a key area.
The Takeaway
Check your lines regularly. Chafe and wear aren't always visible from the outside—especially with covered cores. In some situations, like this, it’s worth taking an hour to open the eye splice and slide the cover back to inspect the core directly.
It’s a simple 1-hour service that could save you the hassle of jury-rigging a replacement underway—and more importantly, help prevent a failure that could cost time, safety, or worse.
A Final Note of Thanks
We also want to give a big thank you to Cheekee Monkee for inviting us to join the crew for this year's Swiftsure. It was an incredible opportunity to sail alongside such an incredible team, and we learned a lot—not just from the hydraulic mainsheet breakdown but from the whole experience. Despite the hiccup, the race ended on a high note:
'Second boat across the line at 11:23 PM! 🐒It was a speedy downwind run after rounding the Clallam Bay mark, and we hit a peak of 21 knots of boat speed.'
What a ride!
Want to talk more about rigging inspection? Or show us how you’ve handled mid-race failures?📩 Drop us a message or comment below—we love learning from the water, and from each other.:
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