Auto ratchet block to replace one of the blocks on the boom
Chris, jdwoods,
There is alteady q§uite some material on this topic which I think it would be good for you to read. Under:-
Claass Rules - Queries & Suggestions > Mainsheet 57 mm ratchet block, Are auto ratchet blocks allowed
The topic addresses the pros & cons of using an auto-ratchet; not just on the toe=strap bracket but also on the boom, and whther it is class legal.
The priincipal motivation being to get more sailing with weak(er) hands.
Reply 20/05/2026 07:28:00
Jonathan Rickels
Posts: 120
I replaced the rear most block with a Harken 40mm 2159 Ratchamatic Carbo soft attach block. It works well. It has an auto ratchet which releases when the load comes off. I have been able to change to a thinner 7mm mainsheet and have no difficulty holding it in any wind strength. I use a 6 sail. I used to sail a Laser radial and had difficulty holding the thin mainsheet. This is much better.
I had to use the Spectra line that comes with the block to link to the dyneema loops from the boom. As a result it hangs slighty lower than the standard blocks. I couldn't think of a way to attach the block without the spectra. The dyneema loops are thicker and when I forced them through the central hole in the block they prevented the block from relaxing the auto ratchet when the load was off. The mechanism depends on up and down movement of the central pulley to release.
I asked the supplier of Ronstan blocks about the ratchet block that they make (RF46101 Series 40 RTA OrbitBlock,Auto, Single, Link Head). I was told it would work also. Similarly they recommended using the attachment cord to link to the Dyneema loops on the boom. I went with the Harken as it was a close match to the current blocks.
The Harken block was about £70.
Reply 19/05/2026 12:46:00
jdwoods
Posts: 8
Does anyone have experience with this. I'm not concerned about being class legal and i'm trying to have more friction before release in the system to take load off my elbow. The swivel block on the deck only contacts the mainsheet through about 90 degrees of turn where the blocks on the boom would have about 180. Cleating the mainsheet does not appeal as an option to me as i find i am tryimming upwind pretty constantly. Thanks for any info.
Reply 18/05/2026 18:35:00
Chris
Posts: 7
