The NSW Department of Primary Industries (DPI) has released a safety alert urging all mines to be vigilant when using tyre inserts after a RAM car operator was forced to evacuate his vehicle when a white smoke-like substance billowed from the rear of the car.
While operating the rubber-tyred mobile plant in an underground coal mine, the driver heard a bang and noticed a distinctive smell and white smoke-like substance coming from the rear of the machine.
A brown smoke-like substance followed. Miners at the face of the same heading smelt the substance in the ventilation current, put on their self-rescuers and walked out of the heading.
A few miners became nauseous, complained of headaches and were later sent to hospital.
An Investigation by the NSW DPI into the incident revealed both rear tyres had overheated internally with the RL inserts failing from the thermal degradation.
The internal heating created internal pressures which subsequently burst the side wall of the tyre and allowed products of combustion gases to escape.
Further investigation also revealed that the original tyres supplied by the mobile plant manufacturer (20.5R25) were replaced with a tyre of lower capacity (17.5R25).
Hungry boards were also fitted to the machine to increase volumetric capacity.
Following the incident, the NSW DPI recommended tyres, RL inserts and urethane fills on mobile plant only be operated within their maximum permissible duty cycle and tyre pressure rating (tonnes kilometres per hour – TKPH).
Mine Safety Operations Branch