Steam powered donkeys were commonly found on large metal-hulled multi-masted cargo vessels in the later decades of the Age of Sail on through the Age of Steam, particularly heavily-sailed skeleton-crewed windjammers.
A donkey used in forestry, also known as a logging engine, was often attached to a yarder for hauling logs from where trees were felled to a central processing area. The operator of a donkey was known as a donkeyman.
- 1 Name
- 2 History
- 3 Design
- 4 Use
- 5 Preserved examples
- 6 See also
- 7 References
- 8 Further reading
- 9 External links
Steam donkeys acquired their name from their origin in sailing ships, where the "donkey" engine was typically a small secondary engine used to load and unload cargo and raise the larger sails with small crews, or to power pumps. They were classified by their cylinder type – simplex (single-acting cylinder) or duplex (a compound engine); by their connection to the winches (or "drums") – triple-drum, double-drum, etc.; and by their different uses.
A good deal of the cable-logging terminology derived from 19th-century merchant sailing, as much of the early technology originated in that industry. Common logging terms include high-lead yarder, ground-lead yarder, loader, snubber, and incline hoist.
In loggingSteam donkey on display at Disney California Adventure Park theme park
John Dolbeer, a founding partner of the Dolbeer and Carson Lumber Company in Eureka, California, invented the logging engine in that city in August 1881. The patent (number: 256553) was issued April 18, 1882. On Dolbeer's first model, a 150-foot, 4+1⁄2-inch manila rope was wrapped several times around a gypsy head (vertically mounted spool) and attached at the other end to a log....read more