chainplate calculations for a jordan drogue

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Hi, Brion,

This is helpful - thank you!

From the drogue design notes, the peak load would be:

Peak line load for both chainplates: 10,000 lbs (displacement) * 80% = 8,000 lbs
Peak load per chainplate would be 8,000 lbs * 70% = 5,600 lbs (that's a breaking wave load on the quarter)
Working load limit in a severe storm = 8,000 lbs * 10% = 800 lbs.

The breaking load on the 1/2" pin 209a Crosby shackle according to the specs should be at least 3xWLL, so the shackle should break around the same load as the 1.5"x0.25"x12" chainplate =~ 18,000 lbs.

Now that I'm looking at these numbers, keeping in mind your note about yield vs ultimate strength, it may be that I don't need dedicated chainplates on the topsides and the cleat and eye pad may be able to handle all but the most severe conditions.



What do you think?

Thank you!
Gleb