Boom brake

[wheels 543]

It's the Chinese gybe the Preventer stops happening. Whent eh main fly's over and comes to goes bang on the other side, all the mass of air wants to keep going and that is what rips the sail. That was my very first crash gybe I eperienced and I watched the main break darn near every plastic sail slug along the boom like a Zipper.

[Fish 0]

Having done a little mountaineering previously, the problem with using a figure 8 descender as a boom brake would be that they are very sensitive to the 'tail' rope tension. So if you have any amount of slack in the system I expect the boom would still move over very quickly.

 

I used to use a different style of belay device called an 'ATC' - air traffic controller, kind of like a nut that runs the rope through and chokes it on a caribener. The good thing with this is the speed limiting function is the thickness of rope in relation to the belay device. So even if you have a slack tail, the device limits the speed to something that should be suitable. A 12mm rope in one of these devices should be good I reckon.

 

Similar examples are these two tings from Petzl, the Verso, or reverso 3 on this link:

http://www.petzl.com/en/outdoor/belay-d ... descenders

 

The equivalent devices will be availbe from most NZ outdoor shops such as Bivouac. You poke a loop of rope through one side (slot) of the device, and hook a caribener through that loop. The normal procedure is to stick the caribener onto your harness then leap of a bloody big cliff... In this case you would subsitute the boom for your harness and clip the caribener to that. The device chokes the rope around the 'bener, causing friction and slows the rope, of course it also produces a bit of heat...

 

I'll try it out first opportunity I get (could be a while at the mo, a few pressing maintenance issues...)

[Fish 0]

Here is a slightly better photo of the general set up

http://www.supertopo.com/photos/1/18/133350_7174_XL.jpg

[Fish 0]

Basically I think using a belay device as a boom break is a brilliant idea. What I meant to say is that a figure 8 is a fairly low tech belay device and there are other options of belay device that give better control / smoother action / better speed control than a figure 8.

 

I could see this being very handy gybing two up

[NevP 0]

It's also a legitimate use of a figure-8 device (even when climbing) to end for end it to increase friction for smaller diameter rope.

What I mean is shackle/carabiner thru the large hole (instead of small) and rope thru the small hole (instead of large) but otherwise threaded in the same manner as the original pic posted by BM.

Will be interesting to see how your ATC trial goes Fish. Do you have a figure-8 to try out as well, so you can compare the two?

I wonder which would be more robust with extended use? My gut reaction would be the figure-8.

[Fish 0]

Hi NevP,

Yes that could work as well, turning the figure 8 around. Yes I have a figure 8. The main issue with increasing the friction, either by using an ATC, or the small end of the figure 8, is that more heat is produced. This wouldn't be a problem in this application, but in absailing you do need to watch your speed. With a nylon rope you can melt it, worst case melting through it but more likely cust melting the sheaf. The only real risk for usign this set up as a boom break would be stuffing the rope that you use. Personally I'm going to use an old stuffed sheet anyway, not dynema. Climbing ropes are super stretchy so some stuffed old yatch braid should do nicely. Strechy rope will also reduce the shock loading on the fittings.

[NevP 0]

Yeah, I know what you mean about the heat generated, but as you said, it shouldn't be an issue with use as a boom brake.

I wonder if a piece of 'retired' climbing rope would actually work well as the line for this. The extra stretch in the line might make the friction on the brake more adjustable.

[Guest]

The sheet to use should be braided sheet and not a spectra covered core as the friction thru the fitting will tear the covering or crimp as it passes thru it!

[SloopJohnB 322]

From the Commodores Cup

 

Can someone let the preventer go.

[B00B00 310]

having a preventer on in that situation would be pretty nasty, the boat would be pinned over untill something broke.

I would only ever use one in a sloppy sea and lightish airs to stop the boom floping around.

[Guest]

I was thinking the same Booboo.

Would it drive the bow under as well while the boom hung up in the air?

[Guest]

I found bog std 3 strand works best, polyester over nylon given the choice.

 

Never had or seen heat issues and are struggling to see how you would short of gybing every 3 seconds for a few minutes.

 

You don't need a preventer to get in the shite like that while racing. What do you think they invented 'the dumbarse on the runners'?

[Fish 0]

I don't think the guys that want to use a preventer are the same guys that go out with a full race crew and end up Chinese-ing it... horses for courses. There is a difference here though, a preventer is a preventer, it will end in pain. A boom break will (should) let the boom go across but in a controlled manner.

 

Heat wont be an issue on a boat, but it can be in the alpine environment when doing long absails or when someone has a screamer (falls off) - a bit like when someone mixes up the kite halyard clutch with aarrgghhhh