Page 69 - Safety and health in construction
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Cofferdams and caissons and work in compressed air
10.2.2. Before being taken into use, shafts should undergo an appropriate
hydrostatic test.
10.2.3. Every caisson and shaft containing flammable material should be provided
with a water line, sufficient hose connections and sufficient hose or appropriate
extinguishers.
10.2.4. Every caisson, shaft, working chamber, medical lock and man lock should
have a minimum internal height of 1.8 m.
Working chambers
10.2.5. Every working chamber should be provided with a wet-bulb thermometer.
10.2.6. Work under pressure when the wet-bulb temperature exceeds 28 C should
be restricted unless it is absolutely necessary.
10.2.7. While any person is in a working chamber, the door between the chamber
and a man lock leading to a lower pressure should as far as practicable be kept open if
the lock is not in use.
Medical locks
10.2.8. Where the pressure in a working chamber ordinarily exceeds 1 bar, a
suitable medical lock conveniently situated should be provided solely for the treatment
of workers employed in compressed air.
10.2.9. The medical lock should have two compartments so that it can be entered
under pressure.
10.2.10. While any person is employed in compressed air a medical lock should
be in the charge of a suitably qualified person.
Man locks
10.2.11. Every man lock should be of adequate internal dimensions and equipped
with:
(a) pressure gauges that indicate to the man-lock attendant the pressure in the lock and
in each working chamber to which it affords direct or indirect access and indicate
to the persons in the lock the pressure in it;
(b) a clock or clocks so placed that the lock attendant and the persons in the lock can
readily ascertain the time;
(c) efficient means of verbal communication between the lock attendant, the lock and
the working chamber or chambers;
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