Re opening of Norton Colliery 1912

Researched by John Lumsdon

This is an extract from the Institute of Mining Engineers. “The reopening of Norton colliery with self contained breathing apparatus after an explosion”.

By J.R.L. Allott

Introduction; As the reopening of this colliery after the recent explosion presented problems of an unusual character and difficulties not frequently met with after an occurrence of this nature, and as the whole of this work was affected by the use of mine-rescue apparatus, the writer has been asked to place the facts on record, in the hope that there may be of interest to the members of the Institution. Before dealing, however, with the actual work of reopening, a brief description of the colliery will be useful, to enable those who are not familiar with the mine, to follow the course of operations?

Description of the colliery; the colliery is situated on the eastern side of the North Staffordshire coal-field and has been working since 1863. The present winding-shaft is 386 yards deep and 14 feet in diameter and was sunk in the year 1889. Four seams of coal have been worked from this shaft, namely, the Coxhead (or Eight-Feet Banbury), seven and a half feet thick; the Froggery (or Seven-Feet Banbury), three and a half feet to 4 feet thick; the Hard-mine, four and a half feet thick; and the Holly-Lane Seam, three and a half feet thick.

The dip of the seam is 13 degrees. At the time of the explosion the Froggery seam was not being worked. The Coxhead and Hard Mine workings were to the deep sides of the shafts, and the Holly Lane workings were on the right side of the shafts. The method of working was principally longwall, advancing to the rise, although there was some pillar-work in the Coxhead Seam. The mine was ventilated by a Guibal fan, running at 56 revolutions per minute, with a 17-inch water gauge. A new fan sixteen and a half feet in diameter had been erected capable of producing 250.000 feet of air per minute with a 2.5 inch water gauge. It was connected, but not in use, at the time of the explosion.

There are two upcast-shafts, each 8 feet in diameter and 386 yards deep. The return air from the Coxhead Seam passed up the head-side shaft, and the return air from the Seven Feet, Hardmine and Holly Lane Seams passed up the deep side shaft. Endless haulage was used both along the main Crut or stone-drift and in the Coxhead engine-dip and was driven by steam-engines placed underground, the steam being taken down a 10 inch range in the head side upcast shaft. The pumping was effected by means of a Cornish beam-engine from the 220 yard level, the water from the pit-bottom being raised to this level by means of a horizontal steam-pump placed near the shaft-bottom, and fitted with a surface-condenser. The pumping shaft is 9 feet in diameter and 220 yards deep to a point a little below the Hardmine seam. Safety lamps of the Detector type, with magnetic locks, were used throughout the mine. No naked lights were used underground, except in the down-cast shaft pit-bottom. The workings in the Coxhead Seam were more extensive than in other seam; these workings were very dry and dusty.

The explosion occurred at 3.30 pm On Saturday, February 24th 1912. The colliery had been working as usual that day, with 500 men underground winding until 1 o’ clock. The reports of the underground officials were all satisfactory and normal, with the exception of a small accumulation of gas was reported in the working place at the bottom of No. 6 Dip, No. 2 South-Coxhead levels.

Instructions had been given by the under-manager to a fireman and 2 others for this gas to e removed in the afternoon when all the men were out of the pit. At 1.30 pm two brattice sheets were fixed in the thirling or cross-cut A, and one at B in the top heading was removed to carry the air past the end of the affected place, for the purpose of gradually clearing the lower portion during the afternoon, and properly clearing the whole of the gas during the weekend.

After fixing the brattice sheets, the fireman and the 2 other men returned along the main level towards the engine dip. They made a test for gas but found no indication. They then went up the engine-dip and through the separation-doors above No.1 level into the back-dip, here another test was made for gas and finding none, the three men rode up the back-dip to the pit-bottom, and together with a pump-man left the pit at 2 pm. They extinguished the lights about the pit-bottom before leaving.

When they reached the surface, the speed of the fan was reduced so as to enable three shaft-men to pack an expansion joint in the steam-range in the head-side upcast shaft. One of these men was left at the Ten-Feet inset, 100 yards from the surface, to signal for the others who were to work on the cage 100 yards lower down. They were about to commence their work when the explosion occurred at 3.30 pm.

The man in the inset stated that a cloud of dust and smoke rushed up the pit and knocked him down against the separation doors between the up-cast and the pumping shafts; when he recovered, he found that his light was dying out. He then went through the separation-doors to the pumping shaft and signalled for the skip, so he could go up. Whilst waiting, he tried to get back to the up-cast shaft, but the smoke was so dense that he had to return. He then went to the surface, and was informed that his mates had been drawn out. The underground pump-man, who happened to be standing on the bank at the time of the explosion, had told the engineman to draw the cage up, and both men lay unconscious upon the cage top. One of them, whose head was lying over the cage, met with severe injuries, from which he died, but the other man soon recovered upon artificial respiration being applied.

Inspection by Rescue-brigades. A telephone message was sent to the rescue-station at Stoke-on-Trent, and six sets of apparatus (of the Proto type) reached the colliery at 4.20 pm A number of local men who had been trained in the use of the apparatus had by this time arrived at the colliery. Six of them put on the apparatus and after it had been ascertained that safety- lamps were not extinguished and a canary was unaffected by the atmosphere of the mine, they descended the deep-side upcast shaft at 5.55 pm. and returned at 6.20 pm.

They reported that in passing through the separation doors at the bottom marked C. And D, on the plan, they found that C. Opened satisfactory, but it was difficult to open D. Owing to material lying against it. Both doors indicated that the force of the explosion had travelled towards the shaft. After passing through these doors, they found that a few tubs of dirt had fallen from the deep side of the stable-level at the point E. They looked into the stables, but did not go in.

Proceeding along the stable-level towards the down-cast pit they noticed that the separation doors F. And G. Between the level and the Hardmine back Crut; they found some loaded tubs had been overturned into the empty tub-road at the point H. And that the air-crossing I. over which the Coxhead return air passes to the head-side up-cast shaft had, had blown down.

Then passing through the small roadway J. Leading to the top of the Coxhead main dip, they found a large fall, which prevented them reaching the separation doors K. And L in order to examine the Coxhead back dip. Being unable to get to the bottom of the down-cast pit through the empty “empty-tub” side of the air-way M, they passed through the new archway N, and found the pit-bottom that a number of tubs had been blown into the inset and sump, and that two of the conductors were broken. Proceeding into the Coxhead engine-room, they found things generally in order; but in the new sub-station between the Coxhead and Hardmine engine-rooms they found the switch-gear and stands had been blown over. This sub-station was in course of construction and was not in use. Returning from the Coxhead engine-room, they proceeded to the air-crossing I, which it was impossible for them to cross over; they then retuned to the up-cast shaft bottom and examined the stables, and found that all the horses were dead, after which they returned to the surface at 6.20 pm.

At 6.55 pm the second team descended the deep-side up-cast shaft. At the bottom they found a lamp hanging on the frame of the first separation-door C, about 2 feet from the top. Both doors were closed, but had been bent inwards towards the shaft by the force of the explosion. Proceeding into the pump-room to the right of the up-cast shaft-bottom, they found that two cable-drums had been turned over. Everything else appeared to bein order, but there was a very thick coating of dust everywhere.

Proceeding into the stables, they found that the explosion had passed through them, upsetting the corn bins and water-tubs, but that a regulator fixed at the far end was not damaged. Returning from the stables, the proceeded along the level towards the down-cast pit-bottom, and noticed that the separating doors O and P between the level and the Coxhead top heading had been blown inwards and the separation doors F and G between the level and the Hardmine back-Crut were badly damaged and blown towards the up-cast shaft. Proceeding towards the Coxhead engine-dip, they found a very large fall at the top. They returned to the Hardmine main Crut, and went in-bye, climbing over a fall at point Q. The haulage wheels were blown down, and a safety lamp which they were carrying was extinguished.

Beyond the fall they proceeded into the Seven Feet Bambury level under the Hardmine air-crossing R, which was broken, and the separation doors S and T were blown towards the up-cast. Returning by the back Crut the found several settings of timber blown down, and indications that the explosion had passed along the Crut to the deep-side upcast shaft. Here the canary was affected, but it revived at the pit-bottom. They ascended the shaft at 7.55 pm having been underground for exactly an hour.

After hearing the reports of these two brigades, it was decided to stop the fan evasee, as another explosion was feared. The sealing of the shafts at the surface was affected by means of timber, brattice, and heaped sand, and completed at midnight. The writer was away from home when the explosion occurred, and did not arrive at the colliery until midnight, when the sealing of the shaft was just being completed.

A water gauge at the down-cast shaft showed a negative pressure of three quarter inch when the sealing was complete.

At 10 am on Sunday morning the sealing’s at the top of the shafts were examined and made good in several places. The water-gauge at the down-cast shaft had decreased to half an inch and the air in the fan drifts was becoming very foul. Air samples were taken at 5 pm on Monday 26th February 1912 and analysis presented, a blood test was made at the same time which confirmed the presence of carbon monoxide.

Further samples were taken on Tuesday February 27th from an iron pipe passing through the sand stopping at the top head-side upcast shaft showed a fall in the presence of carbon monoxide. More samples were taken on Wednesday 28th and 29th of February. Little change had taken place in the intervals, the carbon monoxide, however, had disappeared from the air. A mouse was allowed to remain in the gas for 20 minutes. The blood test showed traces of carbon monoxide, but too little to be expressed in figures. On March 1st a sample was taken on 5.15 pm 226 yards down the headside upcast shaft, by means of a glass tube filled with water, which was emptied in the shaft by means of a second wire. This sample was taken just below the Hardmine inset, and as the same air would circulate through this inset down the down-cast and round to the up-cast, it would indicate better the state of the air at the bottom of the down-cast and pit bottom. A mouse was allowed to remain in the fan drift and on examination was found to be quite healthy, the blood showing a slight trace of carbon monoxide.

Consideration of the Possible Causes of the Explosion; In order to decide upon the safest plan of reopening the mine, much consideration was given to the possible causes of the explosion, the following being carefully discussed;

1.  The possibility of an old Gob-fire having revived:

2.  The heating of a Jig-wheel or haulage pulley:

3.  Shot firing:

4.  A box of matches hidden or otherwise left in the pit:

5.  A fire caused by the steam-pipes in the vicinity of the pit bottom:

6.  A spark from the signalling apparatus in the Coxhead back-dip

7.  A light in the upcast shaft, and:

8.  Electricity.

Cause No. 1. The possibility of an old Gob-fire having revived. On May 9th 1907 (nearly 5 years previously) a Gob-fire was detected in No.2 South Coxhead District in a dip which passed through an overlap fault where the coal was very friable and of twice the ordinary thickness. The actual seat of the heating could not be reached, but pungent smoke was seen. Work had finished in this Dipabout a fortnight before the stink was detected, and considerable falls had taken place about the area of the broken ground. The district was sealed off by means of six stoppings, numbered one to six respectively on the plan, one in the top return air-way from No.1 South District, two at the No.1 south levels, one in the top return air-way ofNo.2 south levels and two at the No.2.south levels. Each of these stoppings consisted of two, four foot brick walls with 6 to 8 feet of sand between them. The effected area remained sealed off for a period of 13 months. It was re-opened on June 20th 1908, by removing the middle portions of the stoppings No’s 5 and 6 in the No. 2 levels, but they were maintained as precautionary stoppings for again sealing off the district in case of an emergency. Stoppings 4 feet thick were built in the Dips above the top heading of No. 2 level, in order that there should be no leakage into or from the workings above, and to allow resumption of development work further south.