神岡鉱山における坑道掘進の急速化について

抄録

Since 1959, we began to develop our plan including several long tunnels (nearly 3, 000m each, sectional area 6-7m₂) and blind raises (200m respectively). Our rocks, Gneiss and Mokuji (green skarn), reject easy advance, the former hard to drill, the latter tough in blasting. Under these circumstances, we have been managing to speed up the development through the following technical items:
1. Self-made Conveyer Loaders designed from our original ideas.
2. Short-gauge drilling using expansible cartridged explosines.
3. Re-arrangement of crew system adding shift basses.
There improvements shortened mucking time to 30 minutes, yet arose drilling-speed 1.40 times faster and brought drifting cycle-time within only 2 hours.
From Oct. 1962 to Jan. 1963, we advanced 1, 096m including 324.3m in Nov. Other records over 300m are 301.4m in June, 356. 3m in Nov. both in 1964. Also a 200m raise attained within 2 months (formerly, 6 months needed)
The auther believes this rapid drifting can be applied universally and economically everywhere, because it seems just fit for any small sectional, single track drifting.