Tower, Hirwaun, Glamorganshire. 12th April, 1962
On the night shift immediately prior to the disaster, coal had been filled normally for the first half of the shift but was interrupted by a mechanical breakdown of the MC3 loader. The fault could not be rectified quickly and it was decided to complete the shift by shortening the scraper chain conveyor and lengthening the belt conveyor. The work had not been completed at the end of the shift and was carried on during the morning shift when the normal work force of seven in the heading was added to by two persons from other districts, as well as two fitters who were working on the CC3 loader and the ventilation official, who was later joined by three electricians. Two representatives of the workmen were approaching the heading along the return roadway on inspection duties.
The movement of the conveyors made it necessary to move forward the two coupled gate end switches which controlled the scraper chain conveyor and the MC3 loader required the addition of a new length of cable. Electricians, N. Lewis, (Class I), T. Davies (Class II) and an apprentice, M.A. Pearce were instructed by the electrician, in charge of the mine, to move the switches and extend the cable. Some difficulty had occurred with a pump in another part of the mine and Lewis had first to attend to that. He made sure that Davies knew how the work should be done in the MC3 heading and told Davies and Pearce to go to the heading and make a start.
Davies arrived at the ‘G’ panel at about 8 a.m. and found the undermanager, C.J. Bell, in the ‘Miner’ heading. After some discussion, Davies cut off the power at the section switch in the substation for both the ‘Miner’ heading and the MC3 heading, removed the connecting pins in the box near the top of the ‘Miner’ heading and restored the power at the section switch. This cut off all power to the MC3 heading without interfering with the supply to the ‘Miner’ heading which was able to carry on working. This was at about 9 a.m.
Davies and Pearce then proceeded to disconnect the gate end switch in the MC3 heading and had almost completed the work when Lewis arrived back. He left Pearce to complete the work and Lewis and Davies made a test on a length of cable to be installed, which, at the time was lying alongside the main conveyor in the return roadway. They found the cable to be satisfactory and Lewis secured a chain to the end of the cable which was then dragged by a horse for a distance of about 100 yards up the MC3 heading to it’s new position. This was a few minutes after 10 a.m.
The underground manager, Mr. Bell, arrived in the heading at this time and was told by the deputy in charge,
K. Strong, that the auxiliary fan had been stopped for 15 minutes. The Inspector, M.r C. Leigh commented:-
“This statement was hard to believe since the power had been cut off at 9 a.m.”
Five or six yards back from the face Bell found a concentration of gas near the roof which he estimated at two percent. He instructed the deputy to send everyone except the electricians back to have their food at the bottom of the heading while he remained with the electricians until they completed the connecting of the switch. This was done and he came out of the Heading with the electricians.
Lewis and Davies, having first cut off the power at the section switch in the substation, restored the connecting pins at the box at the top of the ‘Miner’ heading and went back to the section switch to restore the power to the whole of the ‘G’ panel. They had not made any tests of the re-erected apparatus.
Davies was the first to reach the section and stated that he tried to close the switch but failed because he ‘was too quick’. Lewis closed the switch. He stated that he was watching the ammeter expecting to see the indication of the load of the auxiliary fan starting up when the explosion occurred. At this point he put the switch out. This was at 10.30 a.m.
The undermanager was in the intake level and went back to the scene with the overman who had been in the ‘Miner’ heading throughout the shift. He telephoned the manger to inform him and then went some distance up the MC3 heading so as to be sure that there was no one there. He found the heading too full of dust to be sure that there was no one there. He saw no sign of flame or burning of any description and the normal ventilation was only interrupted for a moment. The manager immediately went to the scene with other officials and workmen gave first aid treatment to the injured and arranged for them to be taken to the surface.
The Dinas Permanent Rescue Station was informed and the brigade arrived without delay and made an inspection of the heading. Later other brigades assisted in re-establishing the ventilation in the heading and for this a separate auxiliary fan was installed and supplied with current from a separate circuit.
Those Killed Were:-
|E. Bond aged 47 years, labourer
|L. Davies aged 37 years, fitter
|Daniel Jones - Died of injuries, 25th April
|T. Jones aged 57 years, collier
|William John Maull, aged 61 years, collier
|D.J. Price aged 51 years, collier,
|L.R. Price aged 27 years, collier,
|W. Smith aged 39 years, deputy,
|K. Strong aged 32 years, deputy and Kay Strong’s father
|D. Williams aged 37 years, fitter.
10 died, not 9?
L.W. Boulton aged 52 years, collier,
E. Davies aged 58 years, transfer point attendant.,
J. Jones aged 52 years transfer point attendant,
A. Lewis aged 52 years ventilation official,
A. Lewis aged 47 years roadsman,
T. Lewis aged 56 years transfer point attendant.,
R. Morgan aged 26 years, repairer,
M.A. Pearce aged 20 years, apprentice electrician and
W. Strong aged 55 years, chargeman.
The inquest into the deaths of the men was held by M.r T Alwyn John, H.M. Coroner for North Glamorgan on 11th. May 1962. The jury returned the following verdict:-
“All nine had died as result on multiple injuries accidentally received in an explosion in the MC3 road at Tower Colliery.”
The Report into the causes of and the circumstances attending the explosion at the colliery was conducted by C. Leigh, H.M. Divisional Inspector of Mines and Quarries and presented to The Right Honourable Richard Wood. M.P., Minister of Power in November, 1962.
The explosion area was carefully examined after the disaster by all interested parties and the effects of the explosion were found to have been confined to the MC3 heading and a short length of the return level outbye of the junction with the heading. There was little evidence of flame and violence was apparent only at the junction with the return level and immediately outbye of that junction. The explosion was of gas only and coal dust played no part.
Little gas had been found in the mine prior to the explosion but on the day before the explosion tests showed that there had been an increase. The heading had been unventilated for about 90 minutes when the power had been cut off and the auxiliary fan stopped and gas could have built up. This was confirmed by tests a few days after the explosion.
At the time of the explosion there were no persons in the heading and no operations going on while the power was being restored. The means of ignition was from a severe short circuit which had blown a hole through the cable, a loop formed by a bend in the cable. Further investigations discounted any other means of ignition.
The Inspector, Mr. C. Leigh concluded:-
“I conclude that the explosion resulted from the ignition of inflammable gas in MC3 heading. The igniting source was arching resulting from a short circuit to earth in a newly inserted length of cable serving the electrical equipment in the heading, and occurred on the inside of a loop in the cable where it had been bent back on itself in order to connect it up to the switch in the heading. I think it highly likely that the short circuit was directly due to the insulation of the cable having been weakened as a result of the acute bending to which it had been subjected in making the connection to the switch.”
At the conclusion of the inquiry, the Inspector recommended that:-
“1). In any system of working requiring the use of an auxiliary fan provision shall be made so that the power supply to the fan may be maintained while any or all of the other plant in that working is shut down.
2). In any system of working requiring the use of an auxiliary fan arrangements should be made whereby the supply of electricity is automatically cut off from all electrical apparatus in that working place whenever the auxiliary fan is stopped.
3). In rapidly advancing headings where short lengths of cable have to be inserted frequently, pliable wire armoured cable or P.V.C. insulated cable should be used. Cable should always be transported in such a manner as to ensure that it is not damaged.”