Collapse of tunnel casts doubt over pit safety: Standards may have been breached in drive for productivity

ACCIDENT investigators will today scrutinise the technique used to secure the tunnel that collapsed at Bilsthorpe Colliery, trapping six men.

Roof bolting, in which holes are drilled into the rock above the coal seam and bolts, like giant Rawlplugs, are driven in and 'glued' into place, is relatively new in Britain. It is considered cheap and flexible and has become widely used in deep mining.

Although some have condemned the technique as more risky than traditional hydraulic support systems, it has been authorised by the Mines Inspectorate and Bilsthorpe men had considerable experience using the method.

Last night, Gerard McCloskey, editor of International Coal Report, said roof bolting was widely regarded as 'the way forward' in deep mining.

There were also suspicions that safety standards might have been breached in an effort to improve productivity at the threatened pit. Bilsthorpe is one of 11 pits under threat of closure because British Coal cannot find a market for their output. Twelve pits were 'reprieved' following the Government's recent review of the coal industry but their future depends on the generators, National Power and PowerGen, agreeing to buy extra coal. One of the 12 has already ceased production.

There are no extra sales in prospect and the 11 remaining reprieved mines are churning out up to a million tons of unwanted coal a month - adding to British Coal's existing stockpile of about 14 million tons.

The accident comes at a time when the number of deaths in Britain's mines has fallen to a record low, with only three men killed last year.

For the second year running there were no deaths at the coalface. However, British Coal figures show, there were 326 major accident casualties and 1,711 'other' casualties - where miners were off work for more than three days. The overall accident rate stood at 17.52 per 100,000 manshifts, down 17 per cent on 1991.

Last year's figures confirm the historic trend of a reduction in death and injury towards a lower risk of death or injury as new safety procedures have been introduced. In 1950, 476 miners died in coalface, underground roadway or pit-head accidents, a rate of 0.28 per 100,000 manshifts.

Ten years later the figure had fallen to 316, 0.22 per 100,000 shifts. By 1975 fatalities stood at 59, a rate of 0.11, and in 1984, at the start of the miners' strike, the total was 27, a rate of 0.06.

Despite the accident rate, coal mining compares favour ably with the construction industry, farming, and oil and gas exploration. From 1986 to 1990, 70 coal workers died compared with 403 in the building trade and 187 in the oil business.

The question that will still be asked, however, is whether British Coal's safety record can be maintained as the Government prepares the company for privatisation - a goal ministers would like to achieve within the lifetime of the next Parliament.

National Power and PowerGen have about 35 million tonnes of stockpiled coal and want to run those stocks down rather than buy more. What little extra they might take will be put out to competitive tender and will not necessarily come from British Coal.