By J. BLUNT, C.Eng. F.I.Min.E.
General Manager of Rescue Stations, NCB
Reprinted from 'Colliery Guardian Annual Review', August 1975
(a) Construction of Stoppings
The building of stoppings or fire seals has become one of the Rescue Services important functions and one to which a good deal of thought has been given in recent years. Stoppings often have to be built in emergency situations where the atmosphere is lethal and visibility due to smoke is poor and where there is considerable heat and humidity.
In mines where there is a possibility of a build up of explosive gases behind the stoppings, and this apertains in the majority of cases in this country, it is essential to maintain ventilation around the affected area until the final sealing takes place. In order to achieve this, it is common practice to build into stoppings ventilation tubes or tunnels, which will allow sufficient ventilation to circulate over the fire to dilute inflammable gases to safe percentages.
To enable quick sealing, explosion-proof doors are fitted at the inbye ends of the tunnels. These doors can be closed and fastened simultaneously and there is no necessity to fill in the tunnels. To prevent access into the tunnels end plates are bolted onto the tubes at the outbye ends. These tunnels have the added advantage of enabling re-entry into sealed areas for examination and subsequent re-opening at a later date if conditions in the sealed areas allow. Modern methods of monitoring the atmosphere behind the stoppings have greatly facilitated the possibility of re-entry and there are many examples on record where this has been successfully carried out.
The Rescue Service has developed, or assisted in developing several types of tubes and doors varying from round tubes of 2 ft. 3 in. diameter to square tubes of 3 ft. or 1 metre in section, The tubes are designed in various sectional forms to meet different conditions and are capable of withstanding an explosive force of 50 lb. per sq. in.
Hand built stopping drawn by Ray Havill.
Click on image to enlarge
During the last 15 years, there has been a gradual changeover from the traditional type of sandbag stopping, which was very time-consuming to build, to the use of monolithic stoppings built with gypsum based products.
All rescue stations now have the necessary equipment for pumping on stoppings remotely in a relatively short time. The pumps will deliver in excess of three tons of material per hour over a distance of 500 metres, thus allowing the pumps to be sited in fresh air. There is a programme at all rescue stations for the training of part-time men in the use of this technique.
Photo Shows Explosion Proof Stopping Tube
Emergency Winders - Click Here
(c) Rescue by Barehole
Following experiences abroad where men had been trapped underground and eventually rescued by boring large-diameter holes, the NCB purchased a drilling rig and associated equipment for rescue purposes, although it was realised that the possibilities of using this method successfully in British coal mines might be remote, except in the shallower mines. In all workings less than 1,200 ft. in depth, emergency plans are prepared should it be necessary to use this method of rescue. When not in use, the complete equipment is kept at the works of Messrs. Foraky Ltd. at Nottingham, which firm is under contract to operate the rig in an emergency. The drill has been used on a number of occasions to bore holes for useful purposes, usually for pumping, and also in emergency situations at Lynemouth Colliery in 1966, at Winsford Salt Mine in 1968 and at the Lofthouse Colliery disaster in 1973.
At Lofthouse, when seven men lost their lives due to an inrush from old workings, the rig was used to bore a small-diameter hole to connect with the return airway from the affected district with a view to establishing contact with any survivors. The intention was to use the borehole to supply food and drink, if contact was made, and to consider the possibility of boring a larger diameter hole for rescue purposes if other means failed. In the event, after drilling 676 ft., the affected area was penetrated from an underground roadway and drilling was stopped some few feet short of the roadway, but nevertheless, valuable experience had been gained.
(d) Non-Mining Activities
The Mines Rescue Service has always given assistance to the civil and military authorities when requested and there are numerous cases on record where trained men helped to rescue persons, sometimes children, who were trapped or lost in old mine workings, shafts, potholes, caves, and in buildings following fires or accidents from other causes. In 1939, a team of trained men attached to the Hednesford Rescue Station recovered the bodies of 116 men who were drowned in the sinking of the submarine Thetis after it had been beached off Anglesey. In 1944, teams from Ashby and Ilkeston assisted in recovery work following a very serious explosion in an underground bomb store in an old gypsum mine at Fauld where there was a large loss of life. Several rescue workers were decorated for the gallant work which they carried out. More recently, following the tragic disaster at the Nypro Works at Flixborough, when 28 men were killed, rescue workers from Doncaster rescue station and two local pits played a large part in the recovery of the bodies in most difficult and unpleasant circumstances.