Whisker Stay Loads?

[Jak Mang]

How does one calculate whisker stay loads? Bob stay loads?

Thanks,
Jak

[Ian McColgin]

For bobstay loads, take the known headstay loading (which should include an abundant safety factor) and apply the parallelogram of force. The loading is shockingly high, which may help you decide to not use chain.

Whisker stays, on the other hand, are usually quite lightly loaded but I am not sure how to calculate it. On small boats, a plank bow sprit with no whiskers is often quite enough.

[Brion Toss]

Hi,
The jibstay's lateral load component is what the bowsprit shrouds (you almost certainly do not have whisker stays) deal with. Assume about 20% of the jibstay's load going lateral, when on the wind. From there you can work out the bowsprit shroud loads, based on the angle to the centerline. They are typically the lightest-loaded wires in the boat.
You'll find the diagram for bobstay loads in the "Apprentice."
Fair leads,
Brion Toss

[Ian McColgin]

Thank you Brion for both the clear engineering model and the terminological correction. I've been calling them whiskers for years despite their not really being like all the stuff on nosegear that involves jib booms and martingales and all that. I ask myself, will I change? I don't know. But I do like the systematic elegance of 'bowsprit shrouds.'

[benz]

I haven't much difficulty with "bowsprit shrouds", but I do wish there were a shorter term for the bowsprit shroud chainplates. Something crunchy and foreign sounding like "gammon" or "cranse". Perhaps it's time to coin a new word?

[Brion Toss]

Hi again,
My friend Tony Latimer had a similar reaction. He has a pinky schooner, salty enough to rust your eyeballs, but no spreaders on the bowsprit shrouds, so no "whiskers," but "bowsprit shrouds" just seemed too prosaic a term. So he came up with "spritsherds", and refuses to call them anything else.
Fair leads,
Brion

[Ian McColgin]

Ah, so the spreaders turn a bowsprit shroud into a whisker stay. Then Granuaile (Marco Polo with a bowsprit) had whiskers while Goblin (Alden 43) had bowsprit shrouds.
Hmmmm. Makes sense. Very logical and cartisian and all that. Could even be metric.
Just does not feel right.

[benz]

Oh, Ian: if it makes sense and sounds good, how could it possibly be metric? But I like "spritsherds". And from now on, 'Spritsherd Chainplates' they shall be on my boat. Thanks Brion.

[Ian McColgin]

Just teasing Brion with his bit about tenths v. twelvths.