The main issue of firedamp was from an accumulation in large cavities in the waste behind the longwall face and that it was forced out during a roof weight.

The firedamp accumulated because cavities were left when the roof in the waste failed to cave satisfactorily, and as the face was retreating and had solid sides, there was not the ventilating pressure difference across the waste which, with leakage through the packs into the return, leads to the gradual drainage of firedamp from the waste of an advancing face.

In the existing conditions adequate caving was unlikely to occur in the early stages of a face opening from a narrow heading and strip packs should have been built until the roof was caving satisfactorily.

Due consideration was not given to the risk of firedamp accumulation and of roof weight when deciding on the method of work.

Whilst the explosion was of firedamp up to the point at which it blew through into the intakes at the connections with the First West Materials and Belt Roads, it was thereafter continued by coal dust.

The coal dust was mainly derived from the conveyor belt and structures, from the vicinity of the transfer points and from the stentons.

There were defects in the system of dust sampling and in the measures taken to prevent, suppress and treat coal dust.

Insufficient consideration had been given to the system of ventilation, particularly in regard to the use of the auxiliary fans.

As a result of weaknesses in the organisation, there was a lack of effective supervision and control.