Lm30 preventer lines / downwind

[Paul123]

Hello I'd be interested to know from anyone who's fitted these lines to their boom . Photos if poss
I attached a line from the back of the boom to the front's cleats and then back in board to by the main winch . The only problem is that dependent on how far the boom was out I needed to re rig as when underload the line was pulling on the safety wires and stanchions . I also tried the cleats in the middle on both sides but this was of no benefit.

[Sula]

If you rig the preventer from somewhere around the middle of the boom, then it will stay inboard of the lifelines and stanchions, I would have thought.

And I invite you to register as a Forum member, as it's obviously of interest to you.

[jdp]

I rigged a preventer for the first time this week on my LM 30 Lone Star this wee while on a downwind leg from the Thames to the Blackwater .

I just used a block on the bow and tied the end j on f the sheet to the topping lift shackle st the end of the boom It seemed to work ok but probably needs a bit more thought as to the route for the sheet to avoid snagging
I’ll try a few options and post the results

John

[pete]

John has the right idea. I would caution against attaching a preventer to the middle of the boom, in heavy weather (when you really need the preventer), an accidental gybe could break it. In my racing days, alas long gone, I saw a few breakages with mid boom preventers.

Cheers,

Pete.

[Sula]

People must do what they see fit, but an LM doesn't carry the amount of sail, and in conditions, that a racing boat does. Many boats (including some LMs) have mainsheets from mid-boom as standard, and proprietary preventers are typically mid-boom.

An end of boom attachment doesn't necessarily protect from breakages, just make for different ones. I had my LM mainsheet track and mainsheet block destroyed in an accidental gybe (a result of no preventer being in place).

The aim of a preventer system is to avoid shock loadings. A mid-boom preventer should be able to cope with the force on the sail just as well as a mid-boom mainsheet does, in my view.

[paulsailing]

I have a preventer on my lm27. Shackled to the outer end of the boom and held in place by an elastic. When required it is easy to connect a spare spinnaker line to the free end via the front centre cleat and back to the cockpit. Seems to work well in testing - hope it does the same when we really need it. (Booms designed to have sheets in the middle are strengthened to take that specific load - mine is not)

[Sula]

Jul 4, 2023 9:53:26 GMT paulsailing said:

Booms designed to have sheets in the middle are strengthened to take that specific load - mine is not 

Are you sure about that first claim?

Is your boom strengthened to take the load of the kicking strap/vang?  How does it cope with that?

How does the boom cope when your mainsail is fully reefed and the mainsheet, at the aft end of the boom, is nowhere near the force from the sail?

Note also that the force from the sail is
(a) concentrated towards the forward end of the boom (because you have much more sail there), and
(b) unless you have a loose-footed mainsail that force is spread along the length of the boom, not concentrated solely at its ends.

I'm glad, though, that you have a system that works for you.

[chrismunson]

I rigged a preventer from the former main sheet anchor point on the cabin top. The anchor point was abandoned when I installed a hauling traveler for the main sheet across the cabin top.