The hulks

old or dismasted ships, formerly used as prisons.
- Dickens.

See also: Hulk

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in classic literature ?
People are put in the Hulks because they murder, and because they rob, and forge, and do all sorts of bad; and they always begin by asking questions.
Joe's thimble having played the tambourine upon it, to accompany her last words - I felt fearfully sensible of the great convenience that the Hulks were handy for me.
If I slept at all that night, it was only to imagine myself drifting down the river on a strong spring-tide, to the Hulks; a ghostly pirate calling out to me through a speaking-trumpet, as I passed the gibbet-station, that I had better come ashore and be hanged there at once, and not put it off.
It was there Wilmore had first met him and fought against him; and in that war Zaccone had been taken prisoner, sent to England, and consigned to the hulks, whence he had escaped by swimming.
We went back to the hulk and re- shipped our cargo.
It rained all the time we were taking it back from the hulk, and now with this long passage it got heated, and there was another case of spontaneous combustion.
Here in thy loneliness the eglantine Weaves her sweet tapestries above thy head, While blow across thy bed, Moist with the dew of heaven, the breezes chill: Fire-fly, will-o'-the-wisp, and wandering star Glow in thy gloom, and naught is heard but the far Chanting of woodman and shepherd from the hill, Naught but the startled bird is seen Soaring away in the moonland sheen, Or the hulk of the scampering beast that fears Their plaintive lays as, to and fro, The pallid singers go.
"They took the hulks and quenched them, and that released a whole lot of ash," says Burlingame.