II. Modernization of the coal mine and labour conditions

The increases in production levels at the mine produced an intensification of labour activity; the modernization and mechanization was motivated by the strong rivalry with the oil industry. Because of the mechanization of the mining and product transportation methods, labourers suffered from ever-increasing hardships. The mechanization of the coal mine in the post-war era started in 1948 when a flat-bed-type belt conveyor was imported from the Federal Republic of Germany. If the speed of mining operations was too slow, the belt would not function properly, and this increased pressure on the labourers to speed up their extraction efforts.

In 1956, a coal planer was introduced from the Federal Republic of Germany. This equipment, which cut the bottom of the coal seam with its very sharp edges, made much deeper cuts than the equipment the miners had been using previously. Thus the coal wall, after being cut out by this new machine' would fall immediately on the conveyor belt and be carried away at once. The belt conveyor was forced up against the coal seam through the action of water pressure; then the belt conveyor with the coal planer was brought forward to the coal wall for cutting and immediate extraction. With the old method, dynamite was used to blow out the coal-seam wall, but the new system eliminated most of the intermediate mining processes.

Because of the introduction of this system, the speed at which mining took place was increased by a factor of two. The pillars that supported the ceiling of the mine had to be moved faster - water pressure was used to provide the locomotion necessary to move these supports. Also, with the use of pressurized water, the coal-seam cutter speed was increased by a factor of four. Because of this great increase in productivity all efforts had to be increased, from the coal-cutting processes to the coal-transportation systems.

With this came an increase in the activity of the miners as the pressures for increased productivity were brought ever more forcefully to the workplace. There was no room in the production schedules for the maintenance of safety or reduction of hazards. Mechanization meant that workers were forced to attend to one machine after the other in a very difficult subterranean environment. Under these circumstances, crisis conditions increased as mechanization progressed.

The working conditions in coal mines are so bad that any comparison with the worst conditions in surface factories provides no adequate understanding of the difficulties involved. The pressure on workers underground is such that they are under continual stress. When the pillars that support the roof begin to weaken, rocks fall and much injury results. There is also the risk of a sudden injection of underground water or problems produced by pockets of methane gas. Fire is the main hazard in both surface and underground mines, while rocks and water are also major sources of danger. Any crisis is magnified by the enclosed spaces that are an inherent aspect of underground operations. The transportation systems for taking out the coal and bringing in tools spread throughout the underground maze like a great spider's web, and hold the potential for even greater crises. Rocks fall on the workers, and the coal and rock dust produces any number of lung ailments. Increased productivity is bought at the cost of workers" health and safety. It was inevitable that the mechanization of the coal mine should result in a vast increase in the number of crisis situations.

Table 5.3. On-the-job Injury Rates for Different Industrial Sectors

a. Injury rate = (Deaths and injuries)/(Man-hours x 1,000,000)

Source: Rodo tokei yoran (Labour Statistics).

During 1959, the labour union at the Miike coal mine was very active in the safety movement. Among the 11,711 persons in the union, there was one death, 1,190 serious injuries, and 1,753 slight injuries: thus injury and death were at a 25 per cent level. After the dispute between the union and the company in 1961, there were 10,946 union members and the injury and death rate went up to 38 per cent of the membership, or 4,230 persons.

The death and injury rate was higher for coal and other mineral mining than for any other industry, as is clearly seen from table 5.3.

The most dangerous hazard in any type of mining is that of coal-dust explosions. At the end of the nineteenth and into the beginning of the twentieth century, in confluence with the rapid worldwide growth of the mining sector, mine explosions occurred with ever-increasing frequency and scale in Europe, the United States of America, and Japan. In 1906, the Curie mine in France experienced a massive explosion which killed 1,000 people. From that time on, the mechanisms of mine explosions were clarified and their number decreased. However, in Japan alone there was no reduction in coal-mine explosions. The lessons learned by the international community on this score were not applied in Japan.

As was indicated earlier, safety personnel at the Miike mine had been greatly reduced in number in order that more people could be placed on the production lines. In a word, the mine was being operated with almost no attention to safety and explosion prevention. On 9 November 1963, an explosion occurred in the Mikawa area of the Miike mine, as a result of which 458 persons were killed and 839 suffered from carbon monoxide poisoning. It is clear that this tragedy occurred as a result of the neglect of mining safety.