When Coal Was King
Industry, People and Challenges
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Air Locomotive

Air locomotives were common to most underground coal mines on both sides of the Crowsnest Pass years ago but very few have been spared the trip to the scrap heap. Today, there are only 4 or 5 of these air tanks on wheels left in Western Canada. You will find one on the interpretive walk around Bankhead Minesite in Banff National Park, one at Fort Steele with an Elk River Collieries label on it, the piggy bank engine at Coleman and a small one at the junction of Highways 93 and 3 just west of Elko, British Columbia.

The whole concept of air driven engines is a good one, having many advantages over other types of locomotion back then. Unlike other modes of transportation, there was little chance of setting fire to timbers or of setting off explosive gases by sparks. Also, they were easy to keep and cheap to repair because of their basic design. You could shut them down and draw power from them only when needed.

The basic concept of an air locomotive's operation is simple. The air stored at high pressure in its main tank is bled into an auxiliary tank before it is allowed to enter the locomotive cylinders. The auxiliary tank holds the air at a reduced pressure and is used directly in the cylinders. That way the pressure in the auxiliary tank can be adjusted by reducing valves to the requirements of the engine. Usually there was a steam driven air compressor outside that pumped high-pressure air into the mine via a cast iron pipeline to recharging stations or a storage tank. Storage tanks underground generally held air at a somewhat higher pressure and were of a larger capacity than the engine so that recharging could occur quickly.

Engine types were referred to as simple or compound, a compound having a setup where it used air at high pressure and then again at a lower pressure thereby giving you more "chugs" to the inch so to speak. Engines came in all sizes, designed to work in different mining conditions. There were even engines that had their own tender, that is to say an auxiliary tank towed behind in reserve. Probably the most unique engine design I've come across is an engine built to work in the very thin seams in Scranton, Pennsylvania. It had nine separate tanks, nine inches in diameter and was 10 feet long. It stood only 2 feet 11 inches high and the operator's cab was incredibly small.

This article was submitted  by John Kinnear. The Heritage Community Foundation and the Year of the Coal Miner Consortium would like to thank John Kinnear for permission to reprint this material


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