Swept back Spreaders and Pre-Bend

[Ian McColgin]

Just as an aside, many rigs allow for considerable flex in the direction normal to the stay, whether this is spreaders or a dolphin striker.

The spreader needs to bisect the angle that it creates in the stay to avoid slipping up or down, but under tension it will automaticly find the fore and aft angle that allows for the shortest distance. If you've a flexable joint (such as I always install on the striker for a bobstay since without the flex, the joint will sooner or later fail due to anchor or mooring rode side stresses) you can see this for yourself by just pushing on the spreader and feeling the resistance.

Or set up a line between two trees and push it out of straight with a stick from the ground. You'll see how this 'spreader' will find its angle and will be stabile then so long as the end away from the stay is past a line between the two ends of the stay. Simple force geometry.

In the swept rig, you absolutely must have some room for the spreader to swing aft as you increase stay tension and bend the mast.

On many traditional rigs, spreaders that are rigid in the fore and aft will fail at the joint due to flexing stresses that happen as the unloaded lee stay takes a strain when tacking.

G'luck.