Features June 27, 2018

Controlling Jibes With Boom Brakes

Sea trials with the economy Heinson , new Dutchman, and the long-standing French-made Walder boom brakes.

Ten years ago, you may recall having seen the Walder boom brake demonstrated at sailboat shows. There wasn't anything quite like it. The device caught on for a time with single-handed racers, who liked the way it slowly eased the boom across during jibes. (Philippe Jeantot had one on Credit Agricole when he won the first BOC Challenge.) When your hands are full with jib sheets and the wheel or tiller, there's too often the tendency not to pull in the mainsheet to minimize the shock load on the gooseneck when the boom slams across to the new tack.

The Walder is essentially a large sheave hung from a bail on the boom, about where a vang would attach. A line is wrapped around it, taking about three turns on the sheave; one end of the line is then tied to the deck to one side - at a stanchion, padeye, or whatev­er strong attachment point can be found. The other end may be run through a block and led aft to a cockpit winch for tensioning (or you can use a multiple-purchase block and tackle with cam). The friction of the line on the sheave is what slows the boom.

The Boom Brakes Tested

The Walder Boom Brake is available in three sizes for boats from about 20 to 60 feet. We used the middle-size, Model 203, with 5/16" line, on our C&C 33 test boat. The entire unit is anodized aluminum. It sells for $350 plus $47 shipping (the 103 sells for $245, the 303 for $465; larger custom sizes are available).

From West Marine (Defender Industries and BOAT/U.S. also sell it) we bought a Heinson, the smaller of two available sizes, which sell at discount for $149 (boats to 39') and $165 (boats to 50'). The drum and cheeks are hardcoat anodized aluminum. Instead of having fairleads on arms, like the Walder, the plastic leads are bolted to the cheeks. The instructions say to take four turns around the drum. The line is not included.

Martin Van Breems, who makes the popular Dutchman Sail Flaking System, sent us a prototype model of a unit he manufactures, which he calls the Dutchman Boom Brake. Van Breems imported the Walder from France for several years until recently when Walder felt not enough units were being sold. So he designed his own, feeling he could improve on the Walder's already pretty good perfor­mance. His unit has three compara­tively narrow aluminum sheaves­ - two side by side at the top, the third at the bottom - sandwiched between anodized aluminum cheeks. The top two are fixed, while the bottom turns, though it can be tightened by a large handle to provide additional friction and a means of fine tuning.

Two rigging methods are provided for, the first as described above with a single control line led aft through a turning block; the other with a block and tackle led to the base of the mast and the control line led aft along the cabin top. The difference is basically where you want your control line to come from, the mast or deck. Also, the mast base method with block and tackle builds in a means of tensioning the brake, theoretically obviating the need for a winch. But in our tests, in heavy air all of the brakes are easier to properly tension with the added power of a winch.

On a blustery October day, we sailed out into Rhode Island Sound, furled the jib, then rigged the three brakes. We executed a half-dozen or more jibes with each one, adjusting line tension each time in an effort to find the right amount of friction for the prevailing conditions. We repeat­ed these trials on another boat on an even windier day, when it was gust­ing more than 20. These devices re­quire some fiddling time to obtain the correct amount of friction for the prevailing winds. And every time wind speed changes, you need to retension the brake. If you can't get the tension you need with the winch, you may need to change line size (larger diameter line increases friction), and/or the number of wraps on the sheave (in the cases of the Walder and Heinson only).

Observations

Walder and Heinson promote the vanging qualities of their boom brakes, stating that you no longer need a vang. The Dutchman instructions, however, clearly state that the brake will work better with a separate vang. In the brochure, Van Breems explains his reasoning: "The Brake can function as the vang, as it will pull the boom down when tensioned. However, if the Brake is also the vang, when running off the wind and you release the tension on the Brake, the boom will rise. The tension on the Brake will not decrease much, which will make it harder to jibe. If the Brake and vang are separate, releasing the tension off the Brake will allow the Brake line to become more slack, for easier jibing." Van Breems told us that all three of the brakes will per­form better in conjunction with a vang, and we're inclined to agree, though the dif­ferences may be apparent only at higher wind speeds.

After determining the correct amount of tension, each of these devices theoretically could be left alone to permit smooth jibing. In practice, however, we found ourselves having to overtension the line prior to initiating the jibe, then easing tension as the mainsail backed. Once you find the correct tension, it's hands-off - until the wind speed changes.

But finding the right tension isn't easy. Too much tension makes the brake act like a preventer, keeping the boom from moving at all. Too little tension and the boom slams across as if there were no brake at all. On most attempts, we found the brake at first would prevent a jibe, and as eased it would allow the boom to jibe too quickly - not as hard as a flying jibe, but harder than you should be able to achieve.

If and when you get it right, a brake works beautifully. And even if you don't, it does eliminate having to haul the mainsheet in. It's a very clever, useful piece of hardware that takes the fear out of jibing. The safety advantages are obvious.

There are two ways to look at boom brakes: For the average sailor, a brake might be viewed as just another piece of gear to clutter the deck. To the sailor who enjoys downwind sailing, wing-and-wing or with a spinnaker, a boom brake could be a valuable piece of sail-handling gear to control jibes, act as a preventer (not as ideal as an end-boom preventer), and for the odd job when holding the boom outboard to bring in a man-overboard or dinghy.

All three models work on the same principle, differing in the design of the drum or sheaves. We obtained the best results with the Walder and Dutchman, followed by the Heinson. The Dutchman, by virtue of its two tensioning mechanisms, probably works in a somewhat wider variety of wind conditions. And at nearly half the price of the mid-size Walder, we think it's the best choice.

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