Roman Chain Pump

[Marcus Minucius Audens]

This pump description refers to yesterday’s double picture of said pump. My apologies for the double view of the device. The great advantage of this style of pump is that the head height to which the pump can lift water is not dependent on a wheel diameter. It is dependent only by the available amount of power used in relation to the quantity of water required to be raised. Vitruvius comments on this style of pump (Book X, Chap. 4) without giving it a name:

“But if a supply is required at a still greater height, a double iron chain is made to revolve on the axle of the same wheel and let down to a lower level, with bronze buckets suspended to the chain, each holding three quarts. Thus the turning of the wheel makes the chain revolve around the axl and carries the buckets to the top. These are carried over the axle; they are made to turn over and pour into the conduit the water they have raised.”

Hero mentions this pump in a passing reference, and from that we get the name (halysis) or “chain’. The pump was powered by a treadmill on the horizntal axle and the chain was suspended from the axle over which it turned. The size of the bucket was a standard design called a “congius” (about 5 3/4 pints or 3.3 l). The arrangement can be constructed to be more efficient than the bucket-wheel since the buckets do not begin to tip until they actually each the wheel, and then they turn over rapidly and decisively because of the smaller diameter of the wheel. Spillage waste is greatly reduced to a negligable minimum.

References:

On extraction of water from mines, see
>> R.J. Forbes, “Studies In Ancient Technology,” (E.J. Brill, Leiden, 1963), Vol. VIII, Chap. 3;
>> R.E. Palmer, Notes On Some Ancient Mine Equipment and Systems, in “Transactions of the Institute of Mining and Metallurgy,” XXXVI, (1926/7), 299-310;
>> J. G. Landels, “Engineering In the Ancient World,” (Univ. of Calif. Press, Berkley, 1981;

On written resources, particularly Hero, see
>> A.G. Drachmann, “The Mechanical Technology of Greeks and Roman Antiquity,” (Copenhagan and Wisconsin, 1963);
>> J.J. Coulton, Lifting In Early Greek Architecture, "Journal of Hellenic Studies," vol. XCIV (1974), 1-19.

Respectfully Submitted;
Marcus Audens