The Collaborative International Dictionary
Chain pump \Chain" pump`\ A pump consisting of an endless chain, running over a drum or wheel by which it is moved, and dipping below the water to be raised. The chain has at intervals disks or lifts which fit the tube through which the ascending part passes and carry the water to the point of discharge.
Wiktionary
n. A water pump consisting of a series of buckets on a chain, wheel or drum
Wikipedia
Caution, the definition does not correspond to the given examples; either the definition, or the examples are inaccurate.
The chain pump is type of a water pump in which several circular discs are positioned on an endless chain. One part of the chain dips into the water, and the chain runs through a tube, slightly bigger than the diameter of the discs. As the chain is drawn up the tube, water becomes trapped between the discs and is lifted to and discharged at the top. Chain pumps were used for centuries in the ancient Middle East, Europe, China, and ancient Egypt.
Usage examples of "chain pump".
And you can be sure the Calypso will bilge herself on the only rocks along a mile of sand and spring some planks, so all we'll hear for the next couple of days will be the clanking of the chain pump and the creak of our own muscles.
Anyway the chain pump leathers wanted wetting daily if they were not to dry and crack.
The Calypso's pump dale was also on the lee side, a wooden trough which carried the bilge water over the side from the great chain pump.