bilboes

The bilboes were iron bars fixed to the deck a little abaft the main-mast.

From On the Spanish Main Or, Some English forays on the Isthmus of Darien. by John Masefield

Shakspeare mentions Hamlet thinking of a kind of fighting, "That would not let me sleep: methought, I lay Worse than the mutines in the bilboes."

From The Sailor's Word-Book An Alphabetical Digest of Nautical Terms, including Some More Especially Military and Scientific, but Useful to Seamen; as well as Archaisms of Early Voyagers, etc. by Sir Edward Belcher

Two weeks later his trial was had, and he was ordered "to be set into the bilboes," and afterwards sent prisoner to England.

From England in America, 1580-1652 by Lyon Gardiner Tyler

The old-fashioned arrangement of iron bars called the "bilboes" was fastened to the bulkhead at the bow end of the alleyway.

From The Black Buccaneer by Stephen W. (Stephen Warren) Meader

Then, if we do not obey their foolish rules, they nab us when we come into port again, and fine us—perhaps put us in the bilboes.

From Dulcibel A Tale of Old Salem by Howard Pyle