This isn't really a new topic, but I have been in contact with Barton regarding the double block at the top of my keel hoist. One sheave broke into 3parts and shed all its bearings, the other is cracked across. I am assuming from the lack of response to my first mail, no-one else has had this problem as yet. Barton tell me that their ball bearing blocks are not suitable for static loads. Since I have owned Shivra she has been dry sailed, so the only time the blocks have been under load is during launching, since I've not used a drying anchorage or mooring,yet this has happened.

Incidentally PBO did a test on blocks a bit ago, and found little difference in performance between plain and roller bearing Bartons.

Jon, I just discovered your note. I use Barton ball raced blocks on my 275 keel. Suspecting that the plastic balls might not appreciate constant load, I had a new wire strip made with two loops on it. The keel is either all up, hanging on the strop, or half way down, hanging on the strop, or fully down resting on the bottom of the keel box. This has worked fine for two seasons now. It sounds like your blocks are also rarely under static load so I would have expected them to be as well behaved as mine. I'll keep a close watch in future.
Cheers-Ken

---