Opening day celebrations of The Minnie Pit of the Podmore Colliery, Halmerend. The pit was named after Minnie Craig, the daughter-in-law of one of the owners. (The owner had 13 children of whom six were girls. John Craig, one of his sons, married Minnie Craig of 17 Christchurch Rd., Folkestone, London in 1882, aged 24. It is mentioned in the Indenture June 19th 1890 held at Stafford Record Office.)
The shaft was 1,200 feet deep.
The pit is shown here during the celebration of opening day in 1883. The first sod was cut in 1871.
The sinking of the Minnie Pit commenced three hundred yards from the North Staffordshire Railway Company Station at Halmerend in April 1883, to a depth of about 1,200 feet.In sinking the shaft there was trouble with quicksand and water. This persisted for a depth of 38 feet. The final diameter of 16 feet 3 inches for the shaft was less than originally intended owing to the lining that had to be fitted to combat the sand and water. The headgear over the shaft was of strong pitch pine timber and its main legs were 50 feet long.
Minni Pit Explosion Card 1915
An explosion occurred on Sunday 6th February 1898 without loss of life, although numbers of pit ponies were killed. Then on 17th January 1915, when only twenty-seven men were at work, tragedy struck with an explosion killing nine men with others severely injured. A third of the work force died that day. Had it been a weekday it would have been a calamity.
Safety measures in today's mines are more stringently applied than may have been the case in days gone by, when the coal barons of the day were more interested in production and profit than in safe working conditions of their workforce. Even so, in today's relatively good conditions, working many hundreds of yards under ground can hardly be described as an ideal environment in which to earn a living.
What then of the working conditions in the Minnie pit in the days prior to the third explosion in 1918?
A modern colliery will probably have coalfaces up to 200 or 300 yards in length with an intake airway and a return airway at the other end, so that an uninterrupted flow of air is carried through the entire workings. In such conditions it would be more difficult for noxious gases to accumulate. In contrasted the Minnie pit had many steeply inclined and honeycombed workings. The air entering these districts became warm as it progressed through the working places and the temperature increased as heat was picked up from the coal, the bodies of men, pit ponies, lamps and shot firing. By the time the air reached the outer limits of the district, the temperature would have risen substantially. This warm air, being lighter, would concentrate, along with any methane gas present in the higher parts and roof cavities of the workings.
Because of a weakened airflow in these areas, highly dangerous pockets of inflammable gas would tend to accumulate.
A modern colliery will have a system of piping off this methane gas for commercial use, but in the old days they were happy enough to be able to disperse the dangerous accumulations by directing airflow over the higher parts of the workings. This task was made so much more difficult by the fact that many of the working areas were off shoots from the main dips. The air circulation became more and more sluggish as it found its way into these isolated pockets. In some cases metal pipes were bolted together in an attempt to introduce a better airflow into the more inaccessible places, but it must be realised that noxious gases could not be removed from the areas where men were working, in a totally satisfactory manner.
Another method of combating these dangerous conditions was the use of brattice cloth, a thick Hessian type of material. If a test for gas proved positive, the brattice cloth would be erected in such a manner that it would re-direct the gas/air mixture into places where dilution would occur, thus making a potentially dangerous mixture relatively harmless.
A gob is the void left after the coal has been extracted, and because of the old pillars of coal and props previously supporting that area that area have been weakened, a certain amount of caving in of the roof has taken place. These old areas invariably had a certain amount of coal left in them, and gave rise to spontaneous combustion, resulting in a gob stink, a sulphurous gas. A gob fire could follow, and the only way to combat this situation would be to completely seal off the area, as these gob fires were impossible to extinguish by conventional methods. Of course, a gob fire is one of the means of igniting the methane gas and causing an explosion.
Explosions are traditionally regarded as the most serious of hazards faced by the miners in the course of their daily work. Traditionally firedamp is blamed for colliery explosions, but in fact, with rare exceptions, violent explosions have been caused by the combustion of coal dust. So it is worthwhile to look at some of the historical facts on coal dust explosions.