Page 72 - Safety and health in construction
P. 72
Safety and health in construction
10.3.9. Where practicable, in addition to a suitable man lock and a material lock,
tunnels should have an emergency lock capable of holding an entire heading shift.
10.3.10. A suitable medical lock should be provided when work in compressed
air is carried on in tunnels at pressures exceeding 1 bar.
10.3.11. In all tunnels 5 m or over in diameter or height a well-guarded overhead
gangway should be provided from the working surface to the nearest airlock with an
overhead clearance of at least 1.80 m.
10.3.12. Every tunnel should be provided with a water line extending into the
working chamber to within 30 m of the working face, sufficient hose connections at
suitable places, and sufficient hose.
10.3.13. When blasting work is being done in compressed air in tunnels:
(a) no worker other than the blaster and his assistants should be in a working chamber
while boreholes are being loaded;
(b) no worker should re-enter a working chamber after a blast until the fumes have
cleared.
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