TREMENDOUS BLAST

Wanganui Chronicle, Volume 73, Issue 449, 15 December 1930, Page 11

TREMENDOUS BLAST

LIFTING LIMESTONE CLIFF ABOUT 30,000 TONS MOVED CHANGING OF NATURE’S FACE The bones of a number of ancient Britons which have lain peacefully for many centuries in a “barrow” on the crest of Bricrlow Hill, near Buxton, Derbyshire, got a rude shaking on October 15 when some 30,000 tons of limestone rock were dislodged in their near vicinity. The blasting operation, which was the largest of its kind undertaken for some time, was arranged in the normal course of their work by the Beswick Lime Works Company. A distinguished company had been invited to view the blasting, including the Mayor and Mayoress of Buxton, and several aidermen, justices, and councillors of the county. About 200 people in all, including scattered groups of workmen, were gathered, says a correspondent of the Manchester Guardian, on a stretch of rising ground a little to the left of the rough face of the rock, which at this point rises sheer to a height of nearly 100 ft. Into this cliff a small army of tunnellers had been at work for weeks driving galleries and constructing special chambers in the rock where the high explosive might be laid.

There was a sudden hush as the hoarse siren from the works ceased its five-minute warning; a tiny figure with a macintosh flapping round its legs raced away from the original cutting in the rock—known technically as a “heading” or “drift” —a passing ’bus halted to watch on the road far below; now only the birds continued to wheel and circle near the rock face. At a point on the top of the cliff three pigmy figures were still to be seen—these were the engineers in charge—one of them dropped a handkerchief; then they, too, disappeared. A moment afterward there was a

low rumbling which burst into a roar. The bottom of the cliff blew out to a distance of twenty or thirty yards, and the top like Jill, came tumbling after. There was a mighty crash as the huge pieces of rock fell away from the body of the cliff, then a grinding as they dropped on to the original surface and slowly settled there; a mighty cloud of fine and very white dust flew up and covered the feet and clothes of a party of watchers, who were standing a quarter of a mile away. Then it was all over, and the spectators trooped across to get a nearer view. Thus, in an instant, can the whole face of the countryside be altered. A philosophical workman turned to thel writer: “Sometimes,” he said, “I thinks we’s gotten a cheek!” Afterward, at lunch’, the writer talked with one of the engineers. He said that the explosive which is used nowadays for blasting operations such as these is a new and a “high” one, which is much safer than the old low explosive, “black powder,” as it was called. There were less than 20001 b of “Ammonal Grain” in the three chambers dug in the rock for that day’s operation, and yet they wore the equivalent to nearly four tons of black powder. Another improvement which has recently been effected in blasting work is the confinement of the actual task of exploding to a few experts. In the old days almost every workman was entrusted with explosives, and habitually carried some cartridges, and even a detonator, in his pocket. Now that this haphazard system has been done away with the number of serious accidents has been cut down to a minimum.

Tlje work is still hazardous, however, for sometimes after a big shot there will still be huge lumps of rock overhanging, only one lump of which may'weigh 100 tons, and the workmen have to get at these from above, by ladder or swinging crane.