Page 51 - Safety and health in construction

Plant, machinery, equipment and hand tools

7.8.4. On silos, notices should be conspicuously displayed:

(a) containing details of the requirements for entry;
(b) calling attention to the danger of sinking in fine materials.

7.8.5. If the material in the silo is liable to cause a blockage, agitators,
compressed air or other mechanical devices should be preferably provided. To clear
blockages, equipment such as poles, long-handled tools, rammers or scraper chains
should also be available for emergency use.

7.8.6. Silos for material liable to spontaneous combustion should be provided
with fire-extinguishing equipment.

7.8.7. In silos in which explosive mixtures of gases or dusts are liable to form:
(a) all electrical equipment including hand lamps should be flameproof;

(b) only non-sparking tools should be used;
(c) explosion vents should be provided in the walls.

7.8.8. Entrances of silos should be kept closed and locked.

7.8.9. Workers should not enter a silo unless:
(a) the discharge opening is closed and secured against opening and filling is stopped;

(b) they are duly authorised to do so;
(c) they wear safety harnesses with lifelines securely attached to a fixed object;

(d) another authorised person provides constant surveillance and is in attendance with
suitable rescue equipment.

7.9. Concrete work equipment

7.9.1. Concrete mixers should be protected by side railings to prevent workers
from passing under the skip while it is raised.

7.9.2. Hoppers into which a person could fall, and revolving blades of trough or
batch-type mixers, should be adequately guarded by grating.

7.9.3. In addition to the operating brake, skips of concrete mixers should be
provided with a device or devices by which they can be securely blocked when raised.

7.9.4. While the drum of a concrete mixer is being cleaned, adequate precautions
should be taken to protect the workers inside by locking switches open, removing fuses
or otherwise cutting off the power.

7.9.5. Concrete buckets for use with cranes and aerial cableways should be free
as far as practicable from projections from which accumulations of concrete could fall.

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