Gybing Techniques / Associated Boom Gear

[Martin King]

Re: Rudder re-design

Originally posted by cajmills
I plan on going offshore and consider the rudder modification as a priority.

An excellent top priority! The 37 was designed by my dad
for the 1 ton cup and we owned hull #1 for a while and
campaigned her heavily. She would not be my first choice
for a round the world cruise but that's just my opinion. The
37, 39, and 46 all have similar underbodies and rather
smallish rudders. After discussing this issue with my
dad, I lengthened the rudder on my old 39 about 8 inches
while maintaining the same profile. This was easily accomplished
because the Foss company still has the OEM rudder mold. I
don't know if the 37 mold still exists but you might check with
them. If you are really serious about this mod, email me
off list and I would be happy to go over the details with you.

Martin

 

[Lawdog]

rudder modificaitons

I currently drive a 1983 E 38, and had a wild ride from Oxnard to Newport in the feeder race for the Newport/Ensenada Race last year. I had purchased the boat in Oxnard (I live in Maine) and outfitted her in Oxnard. My maiden voyage on the 38 was with one other friend in this feeder race. We left Oxnard Channel with about 20 knts at 1 pm start time, and figured that since we were heading pretty much on a broad reach, no problem for 20 kts. Of course, after about a hour and 1/2, the wind was gusting to over 30, and we were broaching fairly frequently, and the waves had picked up to 10 to 12 feet. Steering this boat was a monster job, so I rolled the jib in to the second reef mark, and reefed the main to the first reef. Still broaching, but less often, I rolled the jib in the rest of the way and put a second reef in the mainsail. This finally made the 38 somewhat controllable, although we still hit 10.5 kts surfing on a regular basis, and I remember hitting 11.4 kts at one point. We crossed the finish line in Newport Harbor just before midnight. The 38 remianed a bear to drive, requiring lots of muscle in anthing over 20, so I went underneath the steering station and found that the bearings for the sheaves were junk. I have since replaced them and can say that she handles much easier, but not great. Any extension on the rudder would cause the rudder to hit the bottom before the keel (6'6") and I dont want to risk that kind of damage. I will be adding an adjustable backstay, and full battened main next year, both of which will help in stronger winds. I talked to Bruce King about this, and he said the single most significant and costs effective improvement is to invest in a full battened main. I have also talked with several people who own 38's about modifying the keel by adding a bulb, and everyone who has done that, swears by it.
I did have a 1976 E 29, which broached in anything over 20, and added onto the rudder with fantastic results, but the rudder on the 29 is like a shark fin, and gets smaller as it gets deeper, so everytime you heel, you lose control.
Neal

 

[NateHanson]

Personally, I'd never permit a gybe "all-standing". The pressures on the rig, and particularly on a boom that has mid-boom sheet attachment, is huge, and the probability of failure is probably higher than any other maneuver we might do. I can't imagine putting that much stress on my rig on purpose.

In all but light air (when I simply guide the bundle of mainsheet across the cockpit by hand, using my weight to gybe the roach across) I quickly sheet the boom in to midships, gybe it over and immediately ease it out while remaining as close as possible to ddw (to prevent a broach). If you don't have the crew to do this properly I would suggest tacking around instead of gybing.

Regardless of whether I have sufficient crew, I don't gybe in greater than 25 knot winds or in a large swell (which makes it difficult to hold the boat downwind and rolls the boat, both making a broach more likely).

But even in any wind conditions I never allow the boom to gybe freely across. I think such a practice is inviting disaster, and contributes to premature wear of components.

Nate

 

[u079721]

Come about?

Well, it probably isn't very seamanlike or pretty, but the few times I was singlehanding down wind and needed to jibe I decided to just come up into the wind and then tack. It shoots the hell out of your boat speed, but it is a way to get the boom on the other side of the boat downwind without an uncontrolled jibe.

 

[Loren Beach]

Doing a tack clear around in order to gybe the boom is the time-honored way to avoid damage when in bigger winds. I used to know a racer that called this a "chicken gybe"... and he used it too!
Loren

 

[NateHanson]

"chicken gybe". I like that.

 

[evm]

For gybing I've always sheeted in a bit and then grasped the sheet in the middle between the blocks and pulled with a good tug. This brings the boom to centerline and the roach will then move over pulling the rest of the sail over.

As the sheet comes "loose" pull the rest in you as you can and then as the wind fills the sail let the sheet go back into the blocks as slowly as you can.

Holding the sheet acts as a shock asorber and with the mechanical advantage of the blocks allows a smooth gybe.

Of course in strong winds there are a lot of forces but you do reef down of course.

 

[Roger Ware]

Chicken gybes ROCK!

If you've had experience gybing a racing dinghy in strong winds, it may help with gybing a big boat. On my 505 I would always reverse the helm hard as the boom came over, and keep praying hard. As far as single handed gybing goes, what about steering to ddw, put the boat on AP, crank the boom half way in, dial in another 20 degrees on the AP, crank the sail in the rest of the way as the boat steers through the gybe.

Assuming you have an autopilot, that is.

Cheers, Roger in Kingston, ON

 

[Seth]

Yeah, but

Nice idea, Roger, but in the conditions where you are nervous enough about gybing to do this, the boat will be much too squirrely ddw for the autopilot to steer with that much precision. If you are alone, and it is that hairy, I would tack around!

Yes, I owe you some paperwork-it is coming!

Cheers,
S

 

[Roger Ware]

OK this was a theoretical AP gybe

I intended to add that I hadnt tried my AP gybe, and I am sure that Seth is right, although my 8001 system seems to steer better than I do most of the time. Of course, reading Seth's earlier post again, I realize that after setting the AP to "GYBE" you should be sheeting out, not in, at that point. And I defintely wasnt intending the undermine the merits of the Chicken Gybe.

Cheers, Roger

 

[Geoff Johnson]

One thing that hasn't been factored in is the preventer that should be used for downwind sailing. On my boat I use the soft vang attached to the outboard track, but ideally one should have lines run forward and back to the cockpit.

 

[Seth]

No worries

Roger,

I know you were not making any such implication-this is a good discussion for sure, and is how we all learn!

Geoff,

Preventers do have a place on most sailboats, but for me, the only useful and safe way to use them is in light-moderate air, when the boom is moving in an out from LACK of pressure keeping it out, or if sailing deep (but never in big air when a gybe is at all dicey) but having the same issue (wind pressure will not keep it out there). For me, this is the ONLY safe way to use them.

If you cannot, for whetever reason, keep the boat under control downwind so that there is no fear of accidental gybes, you must either head up or gybe, but DO NOT sail a course like that in these conditions. If you gybe accidentally WITH a preventer, you will either pin the boat under the main, or break something when the preventer lets go (or hurt someone).

The idea of being laid over in an accidental gybe, and then "easing" the preventer line, is not a good or sfae one-certainly nothing I would allow on any boat I sail offshore on.

When the breeze gets up, the preventer goes below. Period.

My apologies if this was understood already, Geoff-I would thing you already knew this, but I did want to make the point since I often hear of sailors using these things to "prevent" accidental gybes-which they certainly do not do.

Light air broad reaching and running-sure-go for it! In fact, the 35-2 and 39's almost need this-as the conventional vang sometimes does not do the trick with the standard layout....

Another tuppence for the day

 

[Geoff Johnson]

Seth,

I don't have your sailing experience, but the experience/instruction I have received indicates that a preventer should be used. A few years ago I crewed a 42' Swan from Newport to Bermuda. Part of the trip was down wind in Force 9 and 10 conditions flying only a triple reefed main. The skipper failed to rig a preventer and we were not able to prevent uncontroled gybes in the 20 to 30 foot following seas. At 2 am, on my watch, the boom broke about a foot from the goose neck. We were lucky it did not bring down the rig. (As you can imagine getting the boom back on board and the tattered sail down was a nightmare. Those waves were like freight trains coming out of the night.) All the other boats in the flotilla had rigged preventers and came through with booms intact.

I can see your point about what can happen with the preventer attached in a broach, but in those conditions, running was the only option. I suppose we could have taken down the main and rigged a small jib, but an attempt to turn the boat into the wind to accomplish it could have been catastrophic.

I have also spent a couple of weeks on a 65 boat. The skipper (currently the skipper of one of the boats in the Clipper Round the World Race) had an ironclad rule that the preventer was to be rigged whenever the boat was not going to weather.

This SailNet article by John Rousmaniere seems to confirm this approach:

http://www.sailnet.com/collections/articles/index.cfm?articleid=rousma0049

Here's a photo of the mess after the storm blew through:

 

[NateHanson]

Again I don't have the extent of offshore experience as is sounds like some of you do, but my understanding has been that an offshore preventer (one run to the BOW rail, not let straight down to the rail) is used in heavy conditions because it will prevent a gybe if the boat is pushed slightly to the lee. It won't prevent dissaster in the case of a major mis-steer, but it won't allow the boom to be thrown over violently when the boat is ddw, and gets rolled to weather by a large wave. While I agree with Seth that I'd never want to have my boat pinned under a backwinded main, held up by a preventer after a gybe, I'd much rather keep the boom intact, and I think allowing an all-standing gybe greatly runs that risk, as Geoff's experience illustrates.

In the case of a broach, it's very important to run the preventer to the bow (and lead the control end back to a cockpit winch) rather than use a vang, or tie a preventer straight down to the rail, because if the boom were to drag in the water in a broach under heavy conditions, the boom would be in danger of breaking.

On the same subject, did anyone here see the video footage about 4 years ago from the Volvo Ocean Race, when an Open 50 did a death roll under spinnaker at 20 knots before arriving in Sydney? Incredible video tape! The boat was completely laid over to windward, with the boom held up by a preventer and the spinnaker shredding itself. The bulb keel was parallel to the water surface, and it took about a minute for the boat to get back on it's feet (spin cut away, and preventer eased). Crew were tucked between the windward lifelines on the rail, and were held underwater for that time, until the boat righted! :eek:

 

[Geoff Johnson]

Booms in the water are bad. A member of my club crewed on the Albatross (the boat in the movie "White Squall") and was on the boat when it went down. He claims the problem was not particularly severe weather or shifting ballast, but the sail plan. It had a fore and aft sail with a very long boom off the stern that became buried in the water. Normally, the boat would round up, but because of its square sails on the fore mast, it was prevented from doing so and so it was held on its beam ends until it filled.


I agree with Nate about not using the vang. I do use one instead of a preventer, but only in light airs where there is no chance of burying the boom.

 

[boatboy]

Boom Control

Two words: Boom Brake. As far as I can tell, this device gives you all of the advantages of a preventer, but none of the dangerous disadvantages. I have not yet installed one on our E-39, but I had a Dutchman on my previous boat and liked it very much. In light air it acts exactly like a preventer, but if you accidentally gybe in heavy air it will allow the boom to come across slowly.

 

[Geoff Johnson]

The Boom Brake is mentioned in the Rousmaniere article.

 

[NateHanson]

I've been interested in the boom brake too, but it seems that it would get awfully annoying to climb over it every time you go forward (I believe it stays permanently rigged). Also it could be a liability for the boom in heavy weather because it holds the boom down, and if the boom hits the water it could snap.

 

[boatboy]

Boom Brake

The boom brake does not hold the boom down any more than the vang does. Both vang and brake control lines can be led to cleats which can easily be released if necessary.

 

[ted_reshetiloff]

Can we strip this thread out of the rudder modification one and create its own in another forum like crusing and racing? There is very valuable discussion going on here and it would be easier to locate at a later date if it was its own thread. Moderator?