Preventers

[Joseph]

I am toying with the idea of installing accidental-gybe preventers. The main problem with classic preventers (i.e. lines linking the boom to the toerail in the foredeck) is the fact that they need to be "tacked" before every gybe, which usually requires hands on deck, something to be avoided given the risk of an accidental gybe, particularly if single-handed. A simple option could be to attach two blocks forward on both sides near the toerail, and run a line from the boom up to the blocks on each side and then back to cleats in the cockpit.  Then all one would need is to do is to release the preventer in the leeward side *from the cockpit* before the gybe, pull in the mainsheet, gybe ho, and then tension the preventer also from the cockpit on the new leeward side. However, I am sure that these two additional lines running along and across the deck may also pose some risks of snagging, etc.

I have also found several suggestions for "friction preventers":

http://www.landfallnavigation.com/wichardgybeasy.html
http://www.walderweb.com/walder_en.htm
http://www.dutchmanboombrake.com/Product.htm

Has anyone considered or installed any of the above or similar devices?

J.

[Tom Ray]

I would only use one in light air to prevent the boom from bouncing around and moving out of position in lulls.

If it is really blowing, the helmsman is your preventer. If he fails, let the darn sail go where it wants! The stresses imposed and poor trim caused by a preventer actually doing its job in strong winds are to be avoided, IMO.

[capt_nemo]

I agree with Tom that the helmsman is really the FIRST Preventer, especially when sailing downwind "By the lee" or close thereto in moderate to heavy air. That said, I still believe that a tackle should be used
as a Preventer when sailing downwind, especially in heavy air. Think of it as an insurance policy for that UNEXPECTED unfavorable change in wind which results in the beginnings of an uncontrolled gybe despite
the attentiveness of a good helmsman. The stresses on the rig and Preventer anchor points at the onset of an otherwise uncontrolled gybe, which are checked by a Preventer, are indeed significant. However,
they are far less IMO than the ultimate force exerted on the rig when the boom and full powered up sail careening across the centerline over to the other side are brought to an abrupt halt by the extended
mainsheet or, God forbid, the shroud! The anchor points for the Preventer should be chosen or made as strong as possibe to handle those initial stresses of an unexpected gybe. To avoid the possibility of an
unexpected or "accidental" gybe in moderate to heavy air, I have sometimes intentionally "tacked" downwind from one broad reach to the other using the mainsheet to control the boom in "controlled gybe"
fashion. Your idea of trying two tackles, one attached on each side of the boom, to avoid the hassle of releasing and reattaching the Vang/Preventer is a good one. I would recommend taking some spare
blocks and line and try gybing your boat in light air to see if the technique suits both you and the boat before committing to the more expensive parts of the system.

[Tim Gardner]

This is the system I have adapted to my 19.

http://www.wwpotterowners.com/JohnTurpin1.html

I use blocks attached to the stanchion bases and a set of cleats that are on my gunwales forward of the winches to control it.  Because of the angle when sailing down wind, it can also help control the sail shape.

TG

[gray]

Tim, that looks to be a nice safeguard. I wonder how well it would work with the larger boom of a Suncat. Anyone out there tried this or something similar?

[Tim Gardner]

An extra wrap around the neck will provide a lot of holding power.  FWIW I've used the same device to lower myself (240#s)from a tree very safely.

TG