Siege Thread

[Archimedes]

The capstan winch was used to pull entire California redwood / sequoia trunks up mountainsides by early loggers in California, so pulling enormous wooden loads by this method is not just a naval technique. Of course, the winch itself was often steam-powered, but the basic principle remains the same...

Archimedes

[Eleatic Guest]

Very nice and knowledgable discussion. I am searching, however, still for my belt drive in antiquity. Was the belt drive really only a modern invention?

Capstans btw were used both in antiquity and Renaissance to erect columns and obelisks. I know WP is totally reliable and waterproof here because I happen to insert these passages.

It is assumed that Roman engineers accomplished lifting these extraordinary weights by two measures: First, as suggested by Heron, a lifting tower was set up, whose four masts were arranged in the shape of a quadrangle with parallel sides, not unlike a siege tower, but with the column in the middle of the structure (Mechanica 3.5).[6] Second, a multitude of capstans were placed on the ground around the tower, for, although having a lower leverage ratio than treadwheels, capstans could be set up in higher numbers and run by more men (and, moreover, by draught animals).[7] This use of multiple capstans is also described by Ammianus Marcellinus (17.4.15) in connection with the lifting of the Lateranense obelisk in the Circus Maximus (ca. 357 AD). The maximum lifting capability of a single capstan can be established by the number of lewis iron holes bored into the monolith. In case of the Baalbek architrave blocks, which weigh between 55 and 60 tons, eight extant holes suggest an allowance of 7.5 ton per lewis iron, that is per capstan.[8] Lifting such heavy weights in a concerted action required a great amount of coordination between the work groups applying the force to the capstans.

http://en.wikipedia.org/wiki/Crane_%28machine%29

[D B Campbell]

I am searching, however, still for my belt drive in antiquity. Was the belt drive really only a modern invention?

Medieval, probably. It's the basic technology of the spinning wheel.