proper use of vang

[capt lar]

one of the guys that taught me to sail larger boats (35') would, on a broad reach or run in light air, use his boom vang as a preventer by moving it off the base of the mast to a stanchion base. it gave a better angle and kept the boom from riding up and dumping air. it also kept the boom outboard to prevent unintentional jibe caused by roll. i always expected the stanchion base to launch, but he got away with it for years. opinions ?
capt. lar

[Alan Wheeler]

Not sure I would use the staunchion base. The use of the vang for the preventer task is common. However, I don't. It can also be a dangerouse way of doing the task. It puts a lot of strain on the mid point of the boom. If you happen to dip the end of the boom in the water, you will most likely bend or even break the boom. It is much safer to take a preventer to the end, or at least 3/4 the way out toward the end of the boom. I have a sheet attached to the end of the boom that is out of the way when sailing normally, but can be easily acessed when I need a preventer. As our wind here is greatly influenced by surround landscape, winds can come at all sorts of strange angles and a preventer is a must. I did a lot of damage a year ago with downwind sailing and no preventer.

[Vasco]

I've used a Walder boom brake for years as I've always chosen to have a solid vang. Actually I feel that a vang is too substantial to be used as a preventer, I've always been told that a preventer should be light enough to part if a heavy load is put on it , rather than holding and bending the boom.

[capt lar]

thanks wheels - that makes good sense. i look forward to more info on the incident.

hey vasco - "a preventer should be light enough to part if a heavy" is logical, but hard to gauge. with my old teacher/captain's method i guess he would know when the load was too heavy because the stanchion would come over and kill him.
i just spent 1k on parts for rigging and haven't ordered the cqr. the boat is in the paint shed at the yard and those boys are putting a serious hurt on me so no solid vang or boom break for me this year. i'd call it fiscal restraint, but who's kidding who

can you explain how the brake functions ? requires more lines run to cockpit ?

capt. lar

[Vasco]

The boom brake is just a friction device. It is essentially a worm screw and a line with a few wraps around it. I attach it to the underside of the boom about 3/4 ways down. There is one single line with (of course) two ends. I lead the lines to small blocks on the toe rail by the shrouds and then back aft where they're made fast. If on star tack tighten the port line first then take the slack out of the star line. If an accidental gybe happens the boom will s- l- o- w- l- y swing across due to the friction on the worm screw. If you want to gybe ease the lines and the boom will swing over a bit faster.

[capt lar]

thanks vasco - very cool. the one in the west catalog uses a friction brake (looks like probably a disc by photo). i like yours better. i did not understand that it worked separately from vang. seems simple and could help in a number of situations.

capt. lar

[BC Mike]

I leave the boom vang where it belongs. I use a clip on preventer from the mid boom to a stanchion base. Some time soon I will put a backing plate under the bolts. My boom does not hit the water. If it did on a regular basis I would use a line forward.
If the boom vang is used, the boom will rise up when jibing on a windy day and make the jibing more difficult than it should be. A batten could catch behind a shroud if the boom goes up, so it will only work in moderate winds, and I think our sytems should work when we need them the most. In light air with the wind too far behind I have someone lean on the boom.
I have a Coopers Hawk looking at me through the window. He visits about this time of the year. He better not mess with my pet duck.
Michael

[Alan Wheeler]

Yeah I suppose a bit could be learned from my wee incident, so I will share it. We have difficulty sailing in the sounds. Damn frustrating at times. The wind will come in different directions to what you expect. No joke, but I have been on a boat in a harbour race, where we had a wind direction indcator at the top of the mast and one at the bottom and both were pointing 180 degrees to one another. As a rsult, we seldom lift sails in the inner sound, it is just too hard and tiring to tack every few minutes on a big boat like ours.
So anyway's, we were sailing down a large reach of the sound and the wind was going from a good 20knts to nothing, then back to a good breeze. We had a wind coming from behind and I had the Genoa out to one side and the boom of the main to other winging it. We had just had a good set of speed and then the wind dropped off and we waited. A big wind shadow was coming up from behind us and I figured it just a case of waiting till it hit. The interesting thing was, the wind shadow was really ruffling the water surface as if it was a good blow, but the entire area of pressure took a long time to travel any distance. What I wasn't expecting was the change of actual direction when it did hit. The main being swung fully out to one side was hit from such an angle and wind strength, that it was swung hard across with such force that it bent shackles on blocks, ripped all the sail slugs clean out of the foot like a zipper, bent and damaged the mainsheet traveler control blocks and gave us all one heck of a fright as we Chinese gybed. I was stunned that the wind could come from one direction, yet have an almost 180 degree difference in it's affect on us. I reckon it must have been swirling like a giant whirlwind than just a straight blow. So ever since I have used a preventer.

[Jon D]

I too am a big preventer fan. We have a rigid vang which I use for sail shape but whenever the main is out really far and the wind aft of 150 degrees the preventer is clipped to the toe rail. We have a slotted toe rail so attachment is easy and the preventer is a 4 part block and tackle mid boom or so. Given the height of the boom off the water not too worried but it was in really big seas would also rig one from the end to allow it to raise. Has not even been close to the water yet but biggest we've been out in with this boat is about 20ft or so.

[capt lar]

i don't know wheels. your last 8 day cruise was beautiful landscape, but the waters were hairy, and now i learn the wind comes from 2 directions at the same time. don't you have any easy sailing down there ?

capt. lar

[ssullivan]

I was thinking the same thing, Capt Lar. Wheels, you must be a better sailor than all of us with those conditions.

I've been spoiled lately sailing in near-lake conditions of the Long Island Sound. No rough stuff in here, other than wakes from a 60 ft Carver 40 feet off the bow.

On the subject of preventers... although I've seen them used frequently by the best sailors, I have never felt I'd need one doing coastal cruising. I use my vang as a vang, and that's it. I might be a hack, but when the wind shifts, I just change my course momentarily and/or re-adjust sail trim after doing so if the change is permanent. I've never even come close to an accidental jybe. On the other hand... in conditions like Wheels faces, it would seem to be a must!

[Vasco]

Sean,

Going downwind with winds above 20 kts. with lumpy seas or a moderate swell, a preventer gives great peace of mind. Nothing grates as much as the boom nearly hitting the shrouds on the opposite side. Or just that little wait to see if the traveller is still holding. Just thinking about it give me the willies. If you really want an experience in gybing try it in a Nonsuch.

[delmarrey]

Yeah! Those Walder boom brakes are a neat trick but they are not available in the US yet. And I wonder what the load rating is?

Boom brake

When before the wind and cresting waves the sails like to puff which will work the rigging really bad and jerk the hell out of the shrouds/stays.

So preventers are a must on my rig. I already parted a set of traveler lines (actually, it was the first mate) by an accidental jibe.

I have a set of padeyes installed P/S about half way of my "J" dimention forward. With a line (to cockpit) and block with snapshackles for hooking up to a second boom bail back by the outhaul assembly.................................._/)

[BC Mike]

If you do not think you need a jibe preventer, put the spinnaker up on a windy and gusty day with minimul crew.
After a banana split or two, and the odd Chinese fire drill, you will start using a preventer.
If that does not work you need more wind.
Michael

[Alan Wheeler]

It's no different for me, than anyone else in any area of the world that sails with hills and narrow water ways all around them. And not ALL of NZ is like that, just my area. And as I also said, we like to get out of the Sounds to have some good sailing fun.
The way the wind acts is very common for any land/seascape like this. Essentially, it is called a Catabatic wind. Only, a True Catabatic wind is usually coming off ice or snow, having been generated by a vast amount of air cooling and falling down a slope due to it getting heavier as it cools. We don't have the massive ice or snow feilds up on the hills, but the wind acts in a similar way as it "fall's" down the valleys and hills. The wind will "roll" literaly down a hillside and out onto the water. It is still rolling when it crosses the water. Depending on other factors, it may roll in many different ways. When moored at night, you can here them coming. They sound like freight trains and they can be so loud you would swear it's about to flatten you. Sometimes they hit, sometimes they miss you completely and the water around you remains calm and as smooth as glass, while just yards away it is beign wipped into a white frenzy. When the wind pressure hit's the water, you can sometimes see the pattern of what the wind is doing. It can roll headover itself, it can roll feet out from under itself and it can swirl verticaly around. We call those things, Williwars'(spell??)
When you are out sailing and further from the hillsides, you get larger area's of wind pressure. But these area's may still be swirling and it becomes very frustrating when you may have just had some pressure beam on at 20knts and then the next gust afew seconds later hits you head on. So unless you have a little easily tacked boat, you just don't muck around with it and head out to the open sea and have some fun.
The only thing that I could say that my sailign could possibly be different for many others and that includes Auckland maybe, is our wind strengths are much higher here. A good sea breeze is about 15-20knts. If you don't want to sail in 20knts, then 90% of the time you are going to be tied up in the marina. You have to be happy and comfortable to sail in air pressures of upto 30knts, cause that will be the norm in this area. However, 25-30knts bring very large seas due to the tidal forces around here. I have been in 4m(18ft) after the wind has been 35knts and at the time had dropped to 20-25knts. The biggest was 40ft with 50knts, but I am happy to say it was not my boat and the boat was really big, so it was actually fun.