I've been looking for information about how bilge pumps worked before there was such a thing as steam or deisel power. Unfortunately, bilge pumps are still very much in use and more modern results have stymied my researches. I'm thinking the age of the great sailing ships (16-1700s?) but I'd be interested in other kinds of ships as well.
I'm mostly interested in practicalities, including diagrams if I can get them. Water obviously came in everywhere, but a pump can't be everywhere. Were there low points in the hull for the water to congregate and the pumps to sit in?
There are references to "elm tree" and "bucket chain" pumps, but I haven't found any illustrations. How were the pipes that carried water made to be watertight and yet still survive the shifting and stress of vessel being acted upon by water and wind? I've also come across some references to valves. It sort of sounded like they were check-valves, (to prevent blowback from the waves) but that can't be right, I don't think? Brass works weren't sophisticated enough for checkvalves, were they?
Thanks for all your help!
I would especially like to see a diagram of the cross-section of a hull to get a feel for how the system was organized, if any such thing exists.
I have a book at home which has diagrams, if nobody's posted any by the time I get home I'll get you some pictures. But for now, this is the best I can find (Source: http://www.history.navy.mil/ussconstitution/)
Elm tree pumps, also known as chain pumps, were one sort of bilge pump used. You can see one in HMS Victory in Portsmouth. Two elm tree trunks, which are long and straight, were bored out to form long tubes. These tubes were placed vertically, side-by-side, running from the lowest point of the bilge to the deck. Then, a long loop of chain was run down one tube, around pulleys at top and bottom, and back up the other tube. At regular intervals on this chain were attached metal discs with rubber edges, which sealed against the inside of the elm trunk tubes. The pulley at the top was turned by manpower with a windlass, causing the metal and rubber discs to pull water up one of the tubes. As each disc reached the top, the water would spill over the top of the elm trunk, and into channels that directed it overboard.
There were other types of bilge pumps involving a pair of one-way valves and a similar wooden tube, pumped by a handle in a similar way to land-based hand water pumps of the time, but they were less efficient than the elm tree chain pump.
I hope that is clear.
Edit: This thread has some more information and pictures.
Edit: Source is The Arming and Fitting of English Ships of War, 1600-1815, Brian Lavery
