horizontal loads on base of deck stepped mast

[elias]

Hi,
I was wondering what kind of stress i can safely put on the base of a deck stepped mast, i.e spring lines while docked or a tether to a safety harness.
Should i treat a deck stepped mast any differently than a keel stepped mast in this regard?

Thanks - Elias

[Ian McColgin]

Ahoy,

It depends upon the boat. In general the step has some sort of plate to spread the compression load and a compression post or bulkhead or very strong beam under. There are usually bolts connecting it all, likely more bolts and spread further into stouter structures than any cleat you have.

So, for the most part, a line around the mast close to deck level is about as strong a point as the boat has. That's why a line around the mast is preferred for a storm mooring or a longish tow.

But look first. There are boats, mostly light open boats but also some day sailors, where the mast, the step, or both are not up to much loading.

G'luck

[Brion Toss]

Hi all,
In addition to lightly-built masts, you might also see some where internal corrosion has eaten away at the tenon structure inside the mast, or where it was never strong enough, owing to poor construction. Either case would leave a deck-stepped mast vulnerable to shear loads. And even the best-made, best-condition deck-stepped mast won't be as strong, in this application, as a keel-stepped mast, where nearly all the shear load will be applied to the partners, not the step.
Fair leads,
Brion Toss