Registered: December 2004
No. 330 —38.0 x 53.9 cm. Watercolour and Ink.
What the text says:
“Oga”, “Pick”, “Keiben”, “Sura"
From the Taisho period (1912-1926) onwards [ed comment: into the Showa period (1926-1989)]
Nittetsu Inatsuki Pit had introduced “O-ganomi” (a small sized electric drill with a chisel head) in 1936. In 1937, the electric drill with a replaceable screw head, using “O-mu neji” (Screw) to hew out coal, appeared in the coal mine. However, miners used rock drills to mine faults of the coal seam.
“Pick”, a compressed air machines to mine coal [a jack-hammer], was used from the same period
of the time to break up big lump of coal into small pieces. The length of the chisel in the jackhammer is about 30 cm long with a sharpened tip. When the tip is pressed on the ground with the switch on, the machine started to work. The jack-hammers were suitable in any place where
pickaxes could not be used.
“Keibensura” (better designed coal skip) was introduced at some small & middle sized pits during World War II and became more popular after the war. It was particularly used in a small pit with the pillar mining method and was much more efficient than a normal skip. Behind the
“Keibensura”’, a wooden board was hooked to the bottom of the skip, and the miner stood on the
board to brake and make the skip slow down in descending steeply sloping drives (Bangayari).
The diameter of the wheels of the skip was 10 cm, the axle was 30 mm; the rail gauge was 20
cm, and the track was extended to coal face. The skip box was detachable from the wheel chassis
for loading and it carried over 200 kg of coal.