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Safe operation of Lifting appliances and gears on board cargo ships
Guideline for Lifting Operations on board
Every lifting operation must be -
(a) properly planned;
(b) appropriately supervised; and
(c) carried out in a safe manner.
No lifting operation should be begun using equipment which is
mobile or can be dismantled unless the employer is satisfied that the lifting
equipment will remain stable during use under all foreseeable conditions
taking into account the nature of the surface on which it stands.
All lifting operations must be properly planned, appropriately
supervised and carried out to protect the safety of workers. Whilst this
applies to all vessels, it is particularly important where cranes are being used
on work boats and other small vessels as overloading of the crane, or
attempting to lift at the wrong angle could, in some circumstances, result in
the vessel sinking.
No person should be lifted except where the equipment is
designed or specially adapted and equipped for the purpose or for rescue
or in emergencies.
Contact with bare ropes and warps with moving parts of the
equipment should be minimised by the installation of appropriate protective
devices.
Weather conditions can play a significant part in the carrying out
of lifting operations whether in the open air or within the vessel. In the
former case high winds or wave action can for example cause suspended
loads to swing dangerously or cause mobile equipment to topple.
Movement of the ship due to wind or wave action can also have a similar
effect in relation to lifting operations inside the ship. Consideration should
be given to the effects of weather conditions on all lifting operations
whether inside the ship or outside on deck, and such operations should be
suspended before conditions deteriorate to the extent that lifting becomes
dangerous.
Loads should if possible not be lifted over a person or any access
way, and personnel should avoid passing under a load which is being lifted.
All loads should be properly slung and properly attached to lifting
gear, and all gear properly attached to appliances.
The use of lifting appliances to drag heavy loads with the fall at an
angle to the vertical is inadvisable because of the friction and other factors
involved and should only take place in exceptional circumstances where the
angle is small, there is ample margin between the loads handled and the safe
working load of the appliance, and particular care is taken. In all other cases
winches should be used instead. Derricks should never be used in union
purchase for such work.
Any lifts by two or more appliances simultaneously can create
hazardous situations and should only be carried out where unavoidable.
They should be properly conducted under the close supervision of a
responsible person, after thorough planning of the operation.
Lifting appliances should not be used in a manner likely to
subject them to excessive over-turning moments.
Ropes, chains and slings should not be knotted.
A thimble or loop splice in any wire rope should have at least
three tucks with a whole strand of rope and two tucks with one half of the
wires cut out of each strand. The strands in all cases should be tucked
against the lay of the rope. Any other form of splice which can be shown as
efficient as the above can also be used.
Lifting gear should not be passed around edges liable to cause
damage without appropriate packing.
Where a particular type of load is normally lifted by special gear,
such as plate clamps, other arrangements should only be substituted if they
are equally safe.
The manner of use of natural and man-made fibre ropes,
magnetic and vacuum lifting devices and other gear should take proper
account of the particular limitations of the gear and the nature of the load
to be lifted.
Wire ropes should be regularly inspected and treated with
suitable lubricants. These should be thoroughly applied so as to prevent
internal corrosion as well as corrosion on the outside. The ropes should
never be allowed to dry out.
Cargo handling equipment that is lifted onto or off ships by
crane or derrick should be provided with suitable points for the attachment
of lifting gear, so designed as to be safe in use. The equipment should also be
marked with its own gross weight and safe working load.
Before any attempt is made to free equipment that has
become jammed under load, every effort should first be made to take off
the load safely. Precautions should be taken to guard against sudden or
unexpected freeing. Others not directly engaged in the operation should
keep in safe or protected positions.
When machinery and, in particular, pistons are to be lifted by
means of screw-in eye bolts, the eye-bolts should be checked to ensure
that they have collars, that the threads are in good condition and that the
bolts are screwed hard down on to their collars. Screw holds for lifting bolts
in piston heads should be cleaned and the threads checked to see that they
are not wasted before the bolts are inserted.
Safe Working Load (SWL)
A load greater than the safe working load should not be lifted
unless:
(i) a test is required by regulation; and
(ii) the weight of the load is known and is the appropriate proof load; and
(iii) the lift is a straight lift by a single appliance; and
(iv) the lift is supervised by the competent person who would normally
supervise a test and carry out a thorough inspection; and
(v) the competent person specifies in writing that the lift is appropriate in
weight and other respects to act as a test of the plant, and agrees to
the detailed plan of the lift; and
(vi) no person is exposed to danger thereby.
Any grab fitted to a lifting appliance should be of an appropriate
size, taking into account the safe working load of the appliance, the
additional stresses on the appliance likely to result from the operation, and
the material being lifted.
In the case of a single sheave block used in double purchase the
working load applied to the wire should be assumed to equal half the load
suspended from the block.
The safe working load of a lift truck means its actual lifting capacity,
which relates the load which can be lifted to, in the case of a fork lift truck,
the distance from the centre of gravity of the load from the heels of the
forks. It may also specify lower capacities in certain situations, eg for lifts
beyond a certain height.
More on general cargo ship :
- Rope handling safe procedure
Ropes are made of short fibres that are spun into yarns,
which are then made into flat or twisted strands.
And the strands are spun or braided to make the finished
rope .
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-
Synthetic man-made ropes and hawsers
Although natural fibre ropes are still widely used throughout the marine industry, they have been superseded by synthetic fibres for a great many
purposes. Not only do the majority of synthetic ropes have greater strength
than their natural fibre counterparts, but they are more easily obtainable
and at present considerably cheaper.
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-
Natural fibre rope
All natural fibre rope is manufactured from manilla, sisal, hemp, coir, cotton
or flax fibres.The process of manufacture consists of twisting the fibres
into yarns and turning the yarns in an opposite direction to establish the
strands.
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-
Lay of Ropes and hawsers - Small Stuff descriptions
The lay of rope is a term used to describe the nature of the twist that produces the complete rope .The most common form of rope at sea is known as ‘hawser laid rope’ comprising three strands laid up right- or lefthanded.
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- Stresses in ship structures and how to mitigate
Heavy weights tend to cause a downward deflection of the deck area supporting the load .This subsequently produces stresses, with
consequent inward and outward deflections of supporting bulkheads,
depending on the position of initial loading .
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- Anchoring safe practice
Prior approaching an area for anchoring ships master should investigate fully a suitable anchoring position and conduct a planned approach including speed reduction in ample time and orienting the ships head prior anchoring to same as similar sized vessels around or stem the tide or wind whichever is stronger . Final decision to be made on method of anchoring to be used , the number of shackles , the depth of water, expected weather and holding ground. .
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- MacGregor single-pull weather-deck hatch cover
Hatch covers are used to close off the hatch opening and make it
watertight. Wooden hatch covers, consisting of beams and boards over
the opening and covered with tarpaulins, were once used but are no
longer fitted. Steel hatch covers, comprising a number of linked steel
covers, are now fitted universally. Various designs exist for particular
applications, but most offer simple and quick opening and closing,
which speed up the cargo handling operation..
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- Cargo holds access arrangement
The access shall be separate from the hatchway opening, and shall be by a stairway if possible. A fixed ladder, or a line of fixed rungs, shall have no point where they fill a reverse slope
.
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- Prepare cargo holds prior loading
Washing is always carried out after the compartment has been swept. Drying time for washed compartments must be allowed for, before loading the next cargo; this time will vary with the climate, but two to three days must be expected.
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- Strength and stability of the Lifting appliances
The vessel's structure, crane, derrick or other lifting device and the supporting structure should be of sufficient strength to withstand the loads
that will be imposed when operating at its maximum load moment .
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- Lifting appliances - Maintenance, testing, controls & safety measures
When there is any suspicion that any appliance or item of
equipment may have been subjected to excessive loads, exceeding the Safe
Working Load (SWL), or subjected to treatment likely to cause damage, it
should be taken out of service until it can be subjected to a thorough
examination by a competent person.
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- Safe operation of Lifting appliances and gears
All lifting operations must be properly planned, appropriately
supervised and carried out to protect the safety of workers.
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- Derricks for lifting cargo on board
Derricks for lifting cargo on board is required to be of adequate strength and stability for each load, having regard in particular to the stress induced at its mounting or fixing points , securely anchored, adequately ballasted or counterbalanced and supported by outriggers
as necessary to ensure its stability when lifting.
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- Deck cranes
Deck cranes have a number of advantages, the rigging
time being negligible, and the crane is able to pick up and land permitted
loads anywhere within its working radius. The safe working loads of cranes
is generally of the order of 10 to 15 tonnes and larger cranes are available
capable of lifts from 30 to 40 tonnes..
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- Characteristics of Marine paints
Paint consists of pigment dispersed in a liquid referred to as the ‘vehicle’.
When spread out thinly the vehicle changes in time to an adherent dry film.
The drying may take place through one of the following processes..
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- Protection by Means of Paints
It is often assumed that all paint coatings prevent attack on the metal
covered simply by excluding the corrosive agency, whether air or water. This
is often the main and sometimes the only form of protection; however there
are many paints which afford protection even though they present a porous
surface or contain various discontinuities. .
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- Role classification societies maintaining seaworthiness of vessels
classification societies publish rules and regulations which are principally concerned with the strength of the ship, the provision of adequate equipment, and the reliability of the machinery .
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- Periodic survey requirement by classification societies
To maintain the assigned class all steel ships are required to be surveyed and examined by the Society’s
surveyors at regular periods.
The major hull items to be examined at these surveys only are discussed
here..
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