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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