Even in moderate winds on smaller boats, the force of the boom when jibing can be deadly, let alone the potential for rig damage. Although inexperienced crew or guests are especially at risk, knowledgeable sailors have also been killed or injured in jibing accidents. If you want to sail downwind without worrying or having to set up a preventer, the Dutchman Boom Brake is for you.

Our boom brake uses the same principle as a line wrapped around a winch to control side-to-side boom movements. Under tension, the boom brake works like a preventer. Ease the tension, and the boom swings at a slow, controlled rate. With the tension off, there is no effect on the boom's movement, and tacking upwind is not affected. No more near misses, or worse, because the boom never has a chance to speed up to dangerous velocities.

 

The "Dutchman" works with conventional or full-batten sails, and can be easily retrofitted to an existing main. were basically a drum that the line wrapped around. Models with grooved drums tend not to override and jam, but are expensive. Models with flat drums can jam. They also allow the line to flatten under load, increasing the contact area and amount of friction which makes them hard to control. To quote the Practical Sailor (January 1, 1994), "The Heinson, the least expensive of the three, was the most difficult to obtain the correct amount of friction."

 

A clear-sided cover in place of an aluminum side allows you to see the two upper fixed sheaves, and the lower rotatable sheave controlled by a tension knob.

With any drum-type brake, the only way to adjust the maximum amount of friction is to take off or add a wrap of line around the drum. Naturally, this is inconvenient to do this, since it means unfastening and re-running the break line.

Our boom brake uses three sheaves, which the line wraps around in a serpentine fashion. The upper sheaves are fixed. The lower sheave can rotate between friction plates. By adjusting the knob, more or less friction can be applied as needed. In light air, the lower sheave should rotate so the boom can come across on its own. In more wind, the knob should be tightened, locking the lower sheave.

While underway, the friction is regulated by adjusting the tension on the brake line. To hold the boom in place, tighten the brake line. To allow a jibe, just ease off on the brake line. In time, you will get a good feel for how much tension is required.

You must be able to adjust the tension on the brake from the cockpit. Either run the brake line along the toerail back to a cockpit winch, or pull the brake up towards the boom using a wire pennant attached to a block and tackle. The tail of the block and tackle is run back to the cockpit from the base of the mast. In either case, it helps to have a separate vang to prevent the boom from rising when the brake is released. The brake is normally installed aft of a rigid vang.

 

The brake can also be tensioned by a wire pennant attached to a block and tackle, if it's easier to run a line back to the cockpit from the base of the mast. Note the separate vang attached to the becket on the wire block.

The boom brake attaches directly to the boom. The line runs down to a turning block close to the chain plates, then aft to the cockpit along the toe rail. Note the separate vang forward of the brake.