Hi all,
looking for for some advice re boom brakes.
I had a recent trip with lots of down wind travel, in light conditions with choppy seas. There was enough wind to set the main, most of the time. During periods of low wind the main bangs back and forwards with the swell, made for very uncomfortable travel. To settle the main I rigged a temporary rope from the boom, forward to the toe rail, with some tension on the rope to hold the boom "out". This worked fine and I am looking to set up a more peremnant system.
I am wondering though if I should just fit a boom brake, but am uncertain if they would work in the above situation?
I also recall seeing a reference to using to using rock climbing gear, some sort of friction drag, for this purpose. It was way cheaper that the sailing boom brakes. Is this a reasonable alternative?
Thoughts please?
I use a preventer line from the boom sheeting point forward to the bow cleat I never can seem to get my head ar boom brakes? People don't like going on deck? I jibed it only a couple of times and just altered back without any damage.
there has been a lot of discussion on this , try a search ,and there is a post with even earlier links
www.seabreeze.com.au/forums/Sailing/General/Where-to-mount-preventer-comparo-with-Boom-Brakes-2/ www.seabreeze.com.au/forums/Sailing/General/Value-of-Boom-Brakes/
oh !!!! we have the technology !!!! 
Select to expand quoteSandS said..
www.seabreeze.com.au/forums/Sailing/General/Where-to-mount-preventer-comparo-with-Boom-Brakes-2/ www.seabreeze.com.au/forums/Sailing/General/Value-of-Boom-Brakes/
oh !!!! we have the technology !!!!
SandS,
thanks, and apologies for not looking harder.
For what its worth:
In March I joined a sailing charter to Cape Horn on board Skip Novak's sloop Pelagic Australis. He has rigged preventer-vangs as shown below. The boom must be close to 30 ft long and reputedly weighed 1.5 tonnes. This yacht does 2 trips to each of Cape Horn, Sth Georgia & Antarctic Peninsula each year. The running rigging took a while to learn! We also had runners to remember. This photo was sailing north from Cape Horn, across Bahia Nassau in 30-45 kts (third reef in main and storm jib). His rigging is based on "nothing must flap - nothing must break". I learnt a lot from this trip!!!
Select to expand quotesaintpeter said..
For what its worth:
In March I joined a sailing charter to Cape Horn on board Skip Novak's sloop Pelagic Australis. He has rigged preventer-vangs as shown below. The boom must be close to 30 ft long and reputedly weighed 1.5 tonnes. This yacht does 2 trips to each of Cape Horn, Sth Georgia & Antarctic Peninsula each year. The running rigging took a while to learn! We also had runners to remember. This photo was sailing north from Cape Horn, across Bahia Nassau in 30-45 kts (third reef in main and storm jib). His rigging is based on "nothing must flap - nothing must break". I learnt a lot from this trip!!!
What an amazing experience that would have been. Would love to do the same!
The use of twin head sails when cruising is an old and today overlooked trick of the passage maker.
No banging of the main, as one drops it while twins are in use. Day on end in cases. Need a second pole thou.
Untamed preventers are good until one stronger gust brakes the boom.
In my experience, the preventer - if one must have one - should be attched to the boom in two places on each side. This is to prevent the boom from receiving the load in one point if only one attachment on each side of the boom is used. It does matter little, whether it is attched at the end or the middle of the boom. Hoever, if the preventer is attached in two spots, end and middle, and a slip ring or sheave is transfering the pull to the sheet going forward to the turning block, the forces are halved and so, brakage prevented. The rope betwen the two points on the boom could be made of very strong surgical rubber.
An other trick is to use industrial strength ocky straps or surgical rubber at the end of each sheet to take up the forces.
Similar surgical or industrial rubber what one might use rigging a sail to steer ones boat.
You sound like a common sense guy.
I hope you drink BEER not the reconstituted horsepiss called american Budweiser!? 
Select to expand quotesirgallivant said..
You sound like a common sense guy.
I hope you drink BEER not the reconstituted horsepiss called american Budweiser!?
That's cordial You should get a bottle of stove fuel home brew off Bubbles777 you can use it in the stove or drink it .
Im saving it for Fraser Island Ill row to shore and stay the night on the sand 
Sorry, this last post of mine got hijacked from it's intended place which was for '2Ton great white' !
My apologies!
Select to expand quotesaintpeter said..
For what its worth:
In March I joined a sailing charter to Cape Horn on board Skip Novak's sloop Pelagic Australis. He has rigged preventer-vangs as shown below. The boom must be close to 30 ft long and reputedly weighed 1.5 tonnes. This yacht does 2 trips to each of Cape Horn, Sth Georgia & Antarctic Peninsula each year. The running rigging took a while to learn! We also had runners to remember. This photo was sailing north from Cape Horn, across Bahia Nassau in 30-45 kts (third reef in main and storm jib). His rigging is based on "nothing must flap - nothing must break". I learnt a lot from this trip!!!
i love his videos.
^^^ that looks like a serious chunk of metal to have flying around if something breaks ^^^
All,
thanks for the information. It sounds like all the options need a bit of trial and error to set up, and even then may well not work.
I will try the figure of 8 decenender, but think that the geometry must be critical. If you set the ropes directly across the boat, then as the boom swings the required rope length gets shorter ( it becomes clear if you set up some string) If the required rope length gets shorter, then friction between decender and rope will be lost and the boom swings free.
I suppose that you may be able to maintain friction by angling the ropes forward, so I will try and see. To much angle would put some unusual loads into the goosneck and mast.
My initial question was about stopping the boom swinging around in light winds, and can see advantages in the decender in achieving that aim, so will have a try.
PS Aus005, is that a photo of the Cavalier, and does it work? Lots of wraps, so would minimise the effect of tension changes as the boom swings.
Select to expand quoteLMY said..
All,
thanks for the information. It sounds like all the options need a bit of trial and error to set up, and even then may well not work.
I will try the figure of 8 decenender, but think that the geometry must be critical. If you set the ropes directly across the boat, then as the boom swings the required rope length gets shorter ( it becomes clear if you set up some string) If the required rope length gets shorter, then friction between decender and rope will be lost and the boom swings free.
I suppose that you may be able to maintain friction by angling the ropes forward, so I will try and see. To much angle would put some unusual loads into the goosneck and mast.
My initial question was about stopping the boom swinging around in light winds, and can see advantages in the decender in achieving that aim, so will have a try.
PS Aus005, is that a photo of the Cavalier, and does it work? Lots of wraps, so would minimise the effect of tension changes as the boom swings.
I think you have hit the nail on the head. The geometry is such that the only solution that does not load up the goose neck or toe rail attachments is to have a check rope that will work when the windward rope is slack, something like a grooved sheave with a friction brake. But then the amount of friction needed to make that system effective would make it difficult to sheet the main. Brakes that have enough friction to effectively check the boom act as a de facto main sheet and so need some thought as to how they should be attached to the boom to minimize the chance of breakage.
I have not had happy times with a preventer trying to stop the boom slapping about in light conditions with a swell running. I tore out a stanchion that was through bolted with a backing plate on a cat but admittedly cats have a lousy motion in that kind of sea, and the boom had a bit of weight.
hi lmy yep on the cav i am told works very well but i have no experience of it yet myself
