Markham Colliery disaster

Following a thorough investigation, it was found that metal fatigue failure occurred in the braking mechanism used to slow down the cage as it descended.

Force is transmitted from the spring nest to main lever through a 2 in (51 mm) diameter steel rod 8 feet 11.875 inches (2.740 m) long.

It also consists of a servospring mechanism which uses the compressed air to counteract the spring force to move the brake shoes away.

For the sake of safety there is an automatic controller which cuts off the power supply to winder motor and applies mechanical brake.

A chemical analysis proved that the material of the brake rod (carbon steel with the designation En8, conforming to British Standard 970:1947)[2] was within the specification demanded at the time of manufacture.

Four strain gauges were attached at a distance of 21 inches (533 mm) from the lower end, located 90 degrees apart around the circumference of the rod.

The magnitude of stresses varied to such an extent that for the one farthest from the drum there was a change from tension to compression as the brake was released.

[3] [4] [5] The National Coal Board carried out a programme to examine the braking and safety systems on all of its mine winders and modified them in accordance with the recommendations of the reports.

The walking trail of steel figures is a memorial to the 106 miners who died in mining disasters at the colliery in 1937, 1938 and 1973.