Boom adjustment

[Grumpy]

Y'all did so well with last thread, I thought I would throw aut another question.

What is the reason for the height adjustment for the boom on the mast?

 

[Ed Schenck]

Did not know that you had one. My H37C has a fixed gooseneck. I owned a Catalina 22 that did have an adjustable boom. It is just another way to provide control of the mainsail luff with the cunningham(downhaul). Pull the boom down to tighten the luff and depower(moves the draft forward) the main.

 

[sandpiper10471]

Hoist the main as high as you want it. Then reef down on the boom using a four part tackle. Tensions the luff and you don't need a haliard winch.
When I had my 33 I took that track off and installed a custom ss gooseneck. Probably stronger than the track.

 

[Blaise]

A sliding gooseneck allows you to control the draft of the main with a downhaul instead of a cunningham. If you race your boat, you can't hoist the head of the main past the black band at the top of the mast. A sliding gooseneck allows you to alter the draft without the associated wrinkles that eminate from the tack. Much better looking sail. It is not practical on boats much over 30 feet because of the side loading on the track, which makes it hard to adjust under load.

 

[SamLust]

Among other things it allows you to position the whole sail upor down on the mast. As I understand the thinking, higher gets it up into stronger cleaner air but at the expense of greater heel. Lower is less heel, more head banging. The Cunningham is a cringle silghtly up from the tack of the sail. Invented by Briggs Cunningham of 1950's sports car racing and Americas cup fame. In racing your sails are limited to a certain set of dimensions which, if your mast has them, are marked by black bands. To change the draft without exceeding the size limit you haul down on the Cunningham.

On my 1983 H 33 with Kenyon mast I settled on a position for the boom, locked it in place with the pin on the gooseneck slider car, and cut off the excess track above that point. This allows the sail slugs to drop down further during reefing.

 

[DianaOfBurlington]

I LOVE the sliding gooseneck! With a little bit of friction this is not the 'danger' or problem most people think it is. Leaving the spare main halyard attached to the gooseneck can help as well.

The best advantage is when slab-reefing; rather than pulling UP on the halyard when you've taken in the sail you haul DOWN on the boom. This lowers center of effort and reduces heel.

Unfortunately most people like the sliding gooseneck because they can fit a bimini top. We see far too many boats with recut mains to be shorter/higher and to enable 'standing headroom' under the canvas. This has all the worst drawbacks of a sliding gooseneck, raised center of effort, higher heeling moment, shortened sail area AND lack of upward visibility due to the canvas hood. But for serious sailing at sea, shorthanded, the sliding thing is the way to go.