Steam trains and long tunnels are a dangerous combination, especially when not enough attention has been paid to ventilation, and when safe breathing apparatus hasn’t been provided to the train crew. Poisonous gases from the combustion of the coal can overcome crew members and the train can go out of control.
This is what happened in the tunnel through the Great Dividing Range in NSW, on the line between Muswellbrook and Quirindi, on July 9, 1926. A 44-car goods train, hauled by a 53-class locomotive, stalled on the steep grade and the engine crew was overcome by the fumes. The train was carrying about 485 tons of goods from Newcastle to Narrabri.
As was reported in the press at the time, “during the passage of the tunnel the actual summit is reached and a train slowly climbing up the mountain at once gains speed after passing that point”.
On the fatal day, the train ran away with an unconscious crew, tearing down the hill past the little station at Ardglen, north of Aberdeen, where the horrified stationmaster watched the train roar past at high speed instead of stopping as expected. Between Ardglen and the siding at Kankool the train ran off the rails, killing the fireman, John Heffernan, injuring the driver, Claude Holt and guard, William Peachey, and causing extensive damage to the line.
Later, the fireman stated that the first he knew of a problem was when his knees gave way. The tunnel was already notorious among train crews and among passengers who used the line, with many describing the noxious choking fumes, followed by the severe downhill grade, as an especially unpleasant experience. Many instances of passengers and crew fainting had been reported.
Following the accident respirators for crew members were introduced.
