Backstays

[sailingforever]

How exactly do they work? I haven't ever been on a boat that uses them.
Why doesn't it stop the boom?

[PBzeer]

A backstay is part of the standing rigging of a boat. You have a forestay, 2 to 3 shrouds on each side, and a backstay. These not only hold the mast upright, but in alignment as well. The boom doesn't go all the way back to the backstay.

That's the short story, I'm sure someone will add the long story.

[sailingdog]

Some boats don't have a backstay. Most marconi/bermudan rigged sloops and cutters do. It is the cable that goes from the top of the mast down to the back of the boat. On most boats with a backstay, there is either a hydraulic adjuster or a block-and-tackle to adjust the tension on the backstay, which helps control the sail shape. A few of the trimaran designs, like the Farrier-designed Corsairs do not have a backstay IIRC.

Most smaller keelboats, like J/24s, Solings, Sonars, etc. have a backstay. I don't know what you've sailed on, so I can't say whether what you've sailed on has one or not, and you've just not recognized it.

A lot of small dinghies do not have a backstay, and many don't have most of the standing rigging as the mast is often free-standing.

[nolatom]

Your smaller, more old-fashioned sloops with booms that overhang the stern, won't have a backstay. They will, however, have sidestays that lead down to a couple of feet aft of the mast step. These will act like a backstay, and keep the mast from collapsing forward on a windy run.

[Jeff_H]

Actually most "old-fashioned sloops with booms that overhang the stern" had running backstays (one on either side of the boom) which were eased and tensioned after each tack.

Jeff

[sailingforever]

if you visit this link http://flickr.com/photos/runningwind/192651140/
does this friendship sloop have a running backstay? Is that the line that goes across the sail towards the stern?

[Jeff_H]

That diagonal line appears to be part of the lazy-jacks or a topping lift. I am glad that I said "most" because the friendship sloops in the photos appear to be an exception. I am surprised at that since the Friendship sloop that I have sailed did have runners.

Jeff

[SteveCox]

Jeff,
I have a Mariner 32 ketch and the original rigging plan for the Mariners called for running backs on the mizzen. On mine, and most pictures that I can find of others there is a inner shroud (from the spreaders down) that goes to a chainplate 12" aft of the mizzen step. This seems to have taken the place of the running backstays and I have not heard of any problems with this setup.

[pluscard]

A J/24 is a fractional rig - that is the forestay doesn't reach the top of the mast, but rather connects about 3/4 of the way up. That means when you put on some backstay, the top of the mast bends backward, with the middle of the mast arching forward - tensioning the mainsail across the middle.

The flatter main is better for higher winds. Took me awhile to grasp the above concept - hope I've explained it plainly.

Mike

[nolatom]

[quote=Jeff_H]Actually most "old-fashioned sloops with booms that overhang the stern" had running backstays (one on either side of the boom) which were eased and tensioned after each tack.

Jeff[/quot

Okay, well maybe not *that* old-fashioned. Growing up in the late '50s, mid-60's, the Turnabouts, M'head Town Class, Herreshoff 12s, etc, whereon I cut my teeth, just had fixed "lowers", nary a running backstay in sight on most of the one-design classes I remember. The latter were a recipe for disaster if you forgot to tension one in time.

I'm just not old enough.