Boom preventer

[Odysseus]

I have had this set up in the order of 50 years sailing it's easy to set up, easy to operate,  and vaue for money. £7

It's an abseiling fitting, (I got it from my navy days) set it up on your boom towards  the rear.

Thread rope from port side through hole in bottom of  midship cleat, to fitting on boom down to stb side midship cleat, back to cockpit cleat.

Once rope is tight the boom is fixed, I have mine just less than tight and if boom swings across it goes slowly. Trial and error for your boat, It works.

Hope this helps
Odysseus
Bav 38.

[The Other Woman]

Hi
I have the same on mine, it is hard to get the right tension, cost me £5 plus a spring shackle which I had in stock👍
Mick

[Salty]

Thanks Bill and Mick, thats a good tip.
When I bought my ex charter B36(2002) back in 2010, I noticed that the swivel pin for the boom was very badly worn, and it was one of the first things that I renewed. I also noticed that with just the main sheet tightened that the boom was always swinging a little to port and starboard, and that it was possibly this small movement that caused the wear on that swivel pin. Since then I have always tied the boom off to prevent that movement, and while that and some periodic lubrication seems to have significantly minimised the wear on the swivel, tying the boom off with rope that was now under tension was not such a neat and effective system as your abseiling device.

[sy_Anniina]

Thanks for this first-hand experience. I have been considering similar setup for a couple of years now - but have so far used a traditional preventer from boom-end. Your system is a genius low-cost version of the wichard boom brake.

Have you considered the boom bending forces in accidental broach when the end of the boom may become submerged? I have so far avoided attaching preventer to mid-boom having read one too many horror stories about boom breaking in accidental broach with a mid-boom preventer. However, with suitable tension (maybe a bit flexible line?) your system should give way before the boom bends.

BR,

Tommi
s/y Anniina

[Yngmar]

I'd call this a boom brake, not a preventer. If fully loaded, it will bend the boom, as it attaches to a single point in the middle, unlike the main sheet which has the load spread out over multiple points. If used as a brake it shouldn't be fully loaded though and probably slow a gybe down to safe speeds.

We've rigged twin preventers via two low friction rings attached with soft shackles to the bow fitting (I've added a large folding eye there for them). Under the boom hangs a single Dyneema preventer strop, which is parked on a plastic cleat at the point where the kicker attaches to the boom. Into that, the preventers are clipped and led through the bow and aft on each side via the midships cleats (which on our boat are polished stainless and ideal for the job). From there to the small aft winches. This has worked well and since they go to the end fitting of the boom (the one labeled "preventer only"), they can carry the full load of a backed main - yes, we've had that happen once or twice and were very glad to have them in place!