Lifting appliances and loose gear

Pages:113-171
 
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4. Lifting appliances and loose gear
4.1. Basic requirements
4.1.1. General requirements
1. Every lifting appliance and item of loose gear should
be:
of good design and construction, of adequate strength
for its intended use and free from any patent defect;
made to a recognized international or national standard;
tested, thoroughly examined, marked and inspected in
accordance with section 4.2;
maintained in good working order.
2. Occupational safety is affected not only by the de-
sign of lifting appliances but also by that of their accessories
and other loose gear used with them. The proper design and
maintenance of all of them are essential, since breakage of
any of them may cause serious accidents. Deterioration may
be visible, as when it starts from the surface, or concealed in-
ternally; in either case, the mechanical strength of the ma-
terial is reduced.
3. Documentation (as appropriate) relating to lifting
appliances should include:
a driver’s instruction manual;
an erection manual;
a maintenance manual;
a spare parts manual;
the manufacturer’s certification of fitness for use;
a certificate of test and thorough examination after
initial erection;
Safety and health in ports
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the manufacturer’s certificates for wire ropes installed
on cranes;
examination and maintenance records.
4.1.2. Brakes
1. Every power-operated lifting appliance should be
provided with an efficient brake or brakes capable of stop-
ping a load while it is being lowered.
2. The brakes should normally be applied automati-
cally when:
the motion control lever is returned to its neutral position;
any emergency stop is operated;
there is any power supply failure;
in the case of electrically operated brakes, there is a
failure of one phase or a significant drop in voltage or
frequency of the power supply.
3. Band brakes generally act in a preferential direction
and are sometimes jerky. They should only be used for
emergency braking. Brakes with symmetrical jaws and two
pairs of pivots have a gradual action.
4. A slewing brake should be capable of holding the jib
stationary with the maximum safe working load suspended
at its maximum radius when the maximum in-service wind
acts in the most adverse direction. Sudden application of the
brake should not damage the jib.
5. The brake lining or pads should remain adequately
secured during their working life. Unless the brake is self-
adjusting, appropriate means should be provided to permit
brake adjustment to be readily carried out in safety.
Lifting appliances and loose gear
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6. The design of electrically operated brakes should en-
sure that the operating solenoid cannot be accidentally
energized by the back electromotive force of any motor
driven by the crane, by a stray or rogue current or by break-
down of any insulation.
4.1.3. Electrical supply
1. Self-reeling flexible cables should not allow long
lengths of cable to drag on the ground where they can be ex-
posed to damage. Outlets should generally be not more than
50 m apart. The use of motorized reels is preferable to
springs or counterweights. Reels on quay cranes should be
placed on the waterside, preferably on the outside of the
gantry legs.
2. Trolley systems should be fed by overhead conduc-
tors or conductors in channels.
3. Overhead conductors should be sufficiently high to
prevent contact by a vehicle or its load. Supports should be
protected by suitable barriers where necessary.
4. Channels for conductors should be properly drained
and designed to prevent entry of any object likely to cause
danger.
4.1.4. Safe working load (SWL)
1. The safe working load (SWL) of all lifting appliances
and items of loose gear should be based on the factors of
safety set out in Appendix E.
2. Every lifting appliance and item of loose gear should
be marked with its safe working load. The markings
should be in kilograms if the safe working load is 1 tonne or
less, or in tonnes if it is more than 1 tonne.

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