Collections Online

Twin tandem triple expansion fan engine in operation at Navigation Colliery until 1967.

This engine once drove ventilation fan of a comparable size. Built by Walker Brothers of Wigan in 1912, it represents the ultimate stage in the development of the steam engine in terms of reliability and economy. It could run continuously for a year or more without stopping. Because of the possibility of explosion, caused by the accumulation of gas, a reliable ventilation system was imperative underground. Economy was also an important factor as the engines ran continuously. In the triple-expansion type the steam expands three times between high and low pressure in cylinders fitted in this example with Corliss valve gear. Unlike the engines which wound the miners’ cages up and down the shaft, fan engines ran at a constant speed and the fan engine driver, thus, had little to do, apart from checking the oil lubricators. A number of ropes were used to drive the fan. If one of them broke, the remaining ones would continue to drive the fan until it was convenient to stop the engine for repairs. The colliery’s fan engine room was usually kept immaculately clean. The engine was in operation at Navigation Colliery until 1967. (Source: Welsh Industrial & Maritime Museum Guidebook, 1984).

Uses steam more efficiently by passing it first through the small, high-pressure cylinder, then through the larger intermediate-pressure cylinder, and finally dividing the flow through the two large low-pressure cylinders. Used to drive a ventilation fan 24 feet in diameter, 8 feet wide, and capable of circulating 300,000 cubic feet of air per minute.

This extremely important exhibit is one of the very few mine ventilating fan engines to survive, and is the only one of the once numerous Walker engines to be preserved.

Serial number '14099' No'39'. Engine: 4 cylinder : 15" x 3'3" fitted with Corliss : 23½ x 3'3". Valve gear : 26" x 3'3" : 26" x 3'3". Output : 500hp. Efficiency : 20% Flywheel : 16' diameter, weighing 15 tons.