About the Pit
HULTON No. 3. Pretoria Pit. Atherton, Lancashire. 21st. December, 1910
The Hulton colliery was owned by the Hulton Colliery Company and was close to Atherton about 11 miles to the west of Manchester and comprised four different and distinct collieries. There were seven coal drawing shafts and prior to the accident about 2,400 tons of coal a day were raised. The colliery employed 2,400 people above and below ground.
The pit was commonly called the Pretoria and was one of a group of shafts.
The Nos. 3 and 4 shafts were sunk in 1900 and 1901 and were 18 feet in diameter and about 75 yards apart.
The No.4 was the downcast and No.3 the upcast shaft.
Both shafts were sunk to the Arley Mine which lay 434 yards from the surface. There were five seams worked from the two shafts the Trencherbone at 146 Year which was 3 feet 6 inches thick, the Plodder at 274 yards which was 2 feet thick, the Yard at 306 yards with intervening parting of about 18 inches was 3 feet 11 inches thick, the Three- Quarter at 361 yards which was 1 foot 5 inches to 1 foot 6 inches thick and the Arley at 434 yards which was 2 feet 11 inches thick.
The general dip of the seams was to the south at an average inclination of 1 in 5.5.
A large fault cut through the minerals worked from the Nos 3 and 4 (Bank Pit) shafts, east and west and another almost at right angles to the same made it necessary for an arrangement of cross-measure drifts and coal roads which allowed the three seams to be worked from one level in the No.3 shaft. These three seams were the Plodder, Three-Quarters and the Yard seams. It was on this level that the explosion occurred. The workings at this level were divided into five which were known as:-
- The North Plodder
- The Three-Quarters
- The Top Yard (or Up Brow)
- The bottom Yard (or Down Brow)
- The South Plodder.
These were further divide into the:-
- North Plodder No.1 and 2 faces.
- The North Plodder old workings were not worked
- The Three Quarters
- The Top Yard,
- The South Plodder, with the South Plodder old workings not being worked
- The Bottom Yard, East Jig District and the Down Brow District.
The most extensive workings were the Top and Bottom Yard and the other districts were workings in smaller seams below the Yard and connected to it by drifts.
Of these smaller districts, there were two rise workings, the North and South Plodder Districts. The Three-Quarters was a small dip district which employed a few men but the North Plodder, the highest district in the No.3 Pit employed 70 men.
The coal in all these districts was worked on the longwall system and the total number of persons working in the No.3 Pit on the day of the explosion was 344 and 545 in the No.4 pit. Of those in the No.3 Pit 230 were in the yard Mine, 90 in the Plodder mine and 24 in the Three-Quarter mine. In the No.4 District there were 109 in the Trencherbone Mine, 306 in the Arley mine and 130 in the Three-Quarters Mines.
The coal from the larger area of the There-Quarter mine was brought to the Arley Mine level and was drawn to the surface at the No.4 shaft from a mouthing in the No.3 shaft at the Yard Mine level, the coal from the Yard, Plodder and the small area of the Three-Quarter was raised. The Trencherbone coal was raised from a mouthing in that seam in the No.4 shaft.
There was a large Sirocco fan, 8 feet 2 inches in diameter, with a double inlet capable of exhausting 300,000 cubic feet of air per minute at 3 inch water gauge, was fixed at the surface of the upcast shaft. This fan was electrically driven and was used as a standby and was worked at the weekends when the underground fans were being overhauled or when there was something wrong with these underground fans. The speed of the fan could be varied only by changing the pulley on the motor which drove it which was an induction motor which ran at a fixed speed.
The mines were under the general control of Mr. Tonge who was also the agent and lived at the colliery and acted as manager but he did not go underground everyday. Under him there was an undermanager for each mine. Mr. Rushton who was killed in the explosion, was the undermanager for the Nos.3 and 4 Pits and held a first class certificate. He went down the mine every day at 6.45 a.m and came up for his breakfast at 10.30 a.m. which he had in the pit office and went down again between 11 and 11.15 a.m. He finally came to the surface about 3.15 p.m. under Mr. Rushton. The general manager saw his undermanagers but he did not see them every day.
Of the 11 firemen in the Yard seam where the explosion occurred, six were in the day shift, four in the night shift and one in the afternoon shift. There were 344 in the pit at one time and six firemen.
- Statue Tribute -
As the mine was a 'single shaft pit' as regards coal getting and winding, the coal getting shift started to descend at 6.45 a.m. and began to be wound up at 2.45 p.m. The repairing and mechanical coal cutting shift which carried out work in the North Plodder only, was from 10.30 to 6 30 a.m. and comprised about 150 persons. When the present manager, Mr. Alfred Joseph Tonge, came to the colliery it was ventilated by two furnaces and steam jets and shortly after his appointment, the change to the fans was made. Mr. Tonge said in evidence-
"Our seams are generally speaking, very thin, and we required a fairly high water gauge. The fan that we put in first was put in to work between four and five inches of water gauge to give us the required amount of air. We found after starting it up that we were only getting one half of the air underground that we were getting through the fan."
This pointed to a great deal of leakage underground. This was detailed in evidence that at the Deep Arley pit and the actual amount of air that was coursing through the workings was about half that produced at the fan and at the Chequerbent Pits the amount was reduced to twenty five percent.
The ventilation of the workings in the Nos. 3 and 4 pits was done by four electrically driven Sirocco fan underground, three were exhausting and one was a forcing fan. These fans were placed in the Arley mine, the Three-Quarters, the Yard Mine and the fourth in the Trencherbone. The forcing fan was used in the No.3 Pit workings and this means of ventilation was used due to the fact that the coal was brought up the shaft at the Yard seam level and wound up the upcast shaft. If an exhausting fan had been used it would have placed an obstruction in the mouthing and impeded with the drawing of the coal. The fan was placed close to the downcast shaft and sucked the air from there and forced it round the workings.
The air crossings in the No.3 Pit were built of brick with wooden tops laid on girders, the main road stoppings were substantially constricted of stone packing and faced with brick and the regulators were properly constructed with sliding wooden doors. The ventilation measurements wee made every calendar month and recorded in the official book but the place where they were taken were not recorded.
The type of lamp that was used in the mine was the Wolf Safety Lamp and not other lamps except the electric lamps at the bottom of the shaft were used. They burned naphtha, a mineral oil with a low flash point and were locked magnetically.
The coal was hauled by endless rope haulage which was powered by an electric motor. Where the coal was worked to the rise, it was jigged down from the face to the cross roads or main roads. No horses or ponies were employed in the mine. All the main haulage roads of the No.3 mine, with the exception of the Down Brow Yards seam were in the return airways. This was an important factor in the explosion and was dealt with at the inquiry.
There was mechanical coal cutting in the Nos. 1 and 2 faces of the North plodder.
The cutters were of the bar type and electrically driven. all the cutting was carried out on the night shift and the breaking down and filling of the coal was done during the morning shift when the conveyor which was also electrically driven was used. The conveyor at the face of No.2 North Plodder was a bogey which was hauled along the face by hand.
The Gibb type conveyor was on the No.1 face and was electrically driven.
There was a large electric power plant between Nos. 3 and 4 shafts which served all the mines in the group. It generated three phase current at 2,500 volts and the exhaust steam from the winding engine was used to drive the turbines which drove the generator. The current at the No.3 and 4 pits was taken down the shaft at a voltage of 465. There were two separate cables down the No.4 shaft and two cables down the No.3 shaft to the Yard Seam. There were other cables in the shaft which carried current to the Trencherbone and the Arley seams.
Electricity was used in the Yard seam level at the shaft siding near the downcast shaft and in two of the five main districts. The Bottom Yard had two electric pumps and the North Plodder had haulage and cutters as well as conveyors. There was also a motor in the course of erection in the South Plodder section. It had not worked up to the explosion and the cable to it was not live. After the explosion it was found the several motors had been running at the time and the bulk of the coal had been cut during the night but the conveyor was working when the coal getting shift was at work.
For several years the coal had been got without shot firing. Where great force was required to get the coal down, a hydraulic wedge was used and the only blasting in the mine had been for ripping and tunnelling. The ripping shots were fired in the metal above and below the seams and the tunnelling shots fired in rock, not coal. The blasting was done in the afternoon when the coal getting shift had gone. Fireman were the only one authorised to fire shots and three firemen came down in the morning on the coal getting shift and three hours later fired the shots two hours after the coal getting shift had gone out. A record of shots fired was kept and the explosive used was ammonite which was detonated electrically.
There was no regular system of reporting from the undermanagers to the manager.
The day shift fireman went down with the morning shift but did not make the statutory examination under General Rule 4. This was done by the night shift firemen. All the seams at the colliery gave off firedamp. The Yard seam particularly in the area known as the Top Yard was particularly gassy specially when it approached the fault the traversed the mine from east to west and gas was not uncommon in the Plodder seam.