Shaft sinking from 1940 to 1970: The Golden Age
The period between 1940 and 1970 can really be called the golden age of shaft sinking. It was during this period of time that the shaft sinking records, which still stand today, were in a number of countries around the world. Listed below are the shafts which were sunk at record-breaking speeds:
January 1960: President Steyn #3 shaft (South Africa) — 1,020 feet (311 metres)
March 1962: Buffelsfontein shaft (South Africa) — 1,251 feet (381 metres)
September 1964: Staric main shaft (Czechoslovakia) — 1,053 feet (321 metres)
April 1964: Proletarskaya (USSR) — 1,280 feet (390 metres)
May 1969: 17–17 Bis mine (Ukraine) — 1,316 feet (401 metres)
Shaft sinkers from the Republic of South Africa generally claim to hold the shaft sinking record for their sinking project at the Buffelsfontein mine in 1962; however, as can be seen from the list above, both the Russians and the Ukrainians were faster.
The South Africans used much larger sinking crews than Europe or North America. Table 1 compares statistics on some of the shafts sunk during this period. Note the number of persons employed on the Buffelsfontein project.
Details on the Proletarskaya and the 17–17 Biz shafts are not available; however, the equipment and manpower utilized are probably similar to those of the New Boutoff shaft sinking a few years earlier.
Although the sinking rates of North American shaft sinkers do not compare with those achieved in South Africa and Eastern Europe, they are worth noting as they are faster than those currently being achieved. Some of the more notable sinking rates achieved by North American shaft sinkers in the 1950s and 1960s are as follows:
November 1958: Shattuck Denn, Bardon Shaft — 392 feet (120 metres)
January 1965: Alwinsal Potash (A.M.C. Harrison) — 570 feet (174 metres)
September 1966: Noranda Potash (A.M.C. Harrison) — 620 feet (189 metres)
November 1966: PCS Cory (Cementation) — 640 feet (195 metres)
There were a number of inventions during this period that contributed to the increase in sinking advance rates — the mechanical mucking machine contributed the most to faster rates.
Perhaps the first mechanical mucking machine for the underground mining industry was the EIMCO rocker shovel loader, introduced in the United States in 1938. This particular model was not suitable for shaft sinking because it ran in rail. EIMCO, however, soon followed up the 12B model with the 630 model, which was crawler-mounted and therefore suitable for shaft sinking.
The EIMCO 630 was not favoured by Canadian shaft sinkers, probably because it was not particularly suited to the benching method of blasting. In other countries, where the full face shaft sinking round was used, it has been utilized effectively up until the present day. It has been particularly popular in both the United States and the Republic of South Africa.
In 1943, the Riddell mucking machine was introduced in Canada and was immediately used with good success in the rectangular timbered shafts that were popular in Canada at that time. The Riddell worked much better than the EIMCO 630 for timber shafts, where the benching system of blasting was invariably used.
The Cryderman mucker was introduced in the late 1940s to Canadian shaft sinkers but did not find any real popularity until the early 1950s. Since that time, however, the Cryderman has been the mucking machine of choice for most Canadian shaft sinkers.
Certainly the clamshell or cactus grab type of shaft loader has been the most popular and commonly used shaft mucking machine, although not in North America. It was developed and used in both Eastern and Western Europe as well as South Africa, all at about the same time.
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