This district comprised a double unit face with a left side, 41 yards long, which was being gradually cut off by a seven feet down-throw fault and a right side, 127 yards long (see Plan 1). The gradient on the face was one in 28 dipping to the right. Three roadways communicated with the face; the left side gate branched off the middle loading gate and formed the main intake, with the right side gate as return. The loading gate was a leakage intake having two regulator doors a few yards inbye from the junction where the left side gate turned away. The roadways were formed some 12 feet by 14 feet by taking a roof ripping at the face and using the ripping material to build six yards wide gateside packs. Roadway supports consist of wood " cockers ", set about four feet apart to the strong roof and sides. Shots were fired in the front rippings and in the main gate back rippings as required using Ajax sheathed explosive, and in the coal using Viking sheathed explosives. On the coal filling shifts the shots were fired by shot firers and on the ripping shifts by the deputies.

The face worked on a 24-hour cycle as follows :—

Day Shift	6 a.m. to 1.30 p.m.	Coal getting.
Split Shift	12 noon to 7.30 p.m.	Boring shot holes in coal, conveyor turning, main gate back ripping.
Afternoon Shift	2 p.m. to 9.30 p.m.	Building waste packs, drawing off wastes, extending main gate conveyor.
Night Shift	10 p.m. to 5.30 a.m.	Coal cutting and main rippings.

The face normally yielded about 430 tons per shift. Roof conditions at the face were good, the roof being unbroken, the convergence slight and supports setting of a fair standard. A three feet thick bed of roof stone fell in the wastes, providing a plentiful supply of packing material but leaving the wastes open.

The district was ventilated by a separate split from the main intake, the air travelling along the main belt gate for about 200 yards then splitting at a junction, the greater part going into the left side tailgate. About 7,000 cubic feet per minute travelled the left side gate and 4,000 along the main gate after passing through two regulators placed a few yards inbye the junction. As a safeguard against firedamp accumulating at the face ripping lips a brattice cloth hurdle was maintained at each. According to the results of monthly air samples taken by the management, from the beginning of the year the methane content of the air current ten yards from the face in the return gate varied from 0.2 to 0.6 per cent., the June figure being 0.5 per cent. The corresponding figures in the intakes were nil to 0.05 per cent.

An examination of the deputies' reports showed that firedamp had not been reported to be found at any place in the district during the last three months. An inspection by the Safety Board Inspector, accompanied by Mr. T. Burke, local Workmen's Inspector, made on 19th June, 1956, revealed an explosive mixture in a cavity in the roof on the left side, main intake gate. This was followed up by one of my staff and after a second inspection on 28th September he reported the position as satisfactory. An inspection under Section 123 of the Mines and Quarries Act, 1954, was made by H. Swift and T. Burke on behalf of the workmen on 20th May, 1957, and they reported the ventilation to be in order.

Alternating current at 3,300 volts was taken inbye to North West No. 1 District Sub-station where it was transformed down to 550 volts for use in the district. The 150 KVA transformer was fitted with a 3,300-volt off-load isolator and 550-volt oil circuit breaker to form a transportable sub-station, or transwitch unit. The oil circuit breaker had two overcurrent trips with time lags and an under-voltage release trip. Attached externally to the casing of the circuit breaker was a control box housing a star connected impedance and sensitive earth leakage relay arranged to interrupt the circuit of the under-voltage release coil and cut off the supply from the 550-volt system in the event of an earth fault.

The main gate feeder cable was mostly 0.06 sq. in. 3 core, 33 KV grade, paper insulated, lead covered, double wire armoured; but the 50 yards length in the vicinity of the first back rip, whilst of similar general construction, had 0.12 sq. in. conductors and was 660-volt grade. For the major portion of the roadway the cable was slung from the roof supports, but in the vicinity of the several back rippings it was on the floor and buried in places. The feeder cable supplied a bank of five gate-end boxes, two of which were spare. The other three were arranged for the control of a coal cutter and two face conveyors, but there is no evidence that any of this equipment was in use at the time of the explosion.

The deputy in charge of the North West 1 District on this shift was Robert Ashton, the regular deputy, who is the holder of a Second-Class Certificate of Competency. The pre-shift inspection had been made by J. Triffitt, a spare deputy holding a First-Class Certificate of Competency, who was on duty during the absence of the regular deputy on that day. Triffitt, who was well acquainted with the district and indeed had been in charge on many occasions, reported everything to be satisfactory except that the telephone near the face was out of order. Both deputies are men of wide experience in the seam.

Coal filling had been completed about mid-day and when the conveyor turners arrived at the face at 12.30 p.m., they were able to uncouple the belts and begin moving them over into the new track in readiness for the waste side men to start their work when they arrived at 2.30 p.m. The men who formed the split shift were admitted by the day shift deputy, J. Triffitt, and were as follows :—

6 back rippers

3 conveyor turners

1 steel checker

2 gate belt extenders

In addition, two surveyor's assistants, J. Charlesworth and B. Silcock, were near the face extending the roadway centre lines. Charlesworth was the only man in the district with a flame safety lamp.

The main gate conveyor belt appears to have been stopped before 1.0 p.m. and two outbye sets of back rippers were engaged in setting wood cockers. On the back rip nearest the face and 82 yards from it, J. Hill and B. Holliday bored three shot holes by compressed air machine in the 2½-feet thick ripping lip.

On the main afternoon shift the following men entered the district at 2.0 p.m. :—

10 men for waste packing and support withdrawal;

2 men for main belt conveyor maintenance some 500 yards from the face.

At the time of the explosion work was proceeding normally at the face and no electric power was being used. The approximate positions of the men after the explosion are shown on Plan 1.