GENERAL SPECIFICATION G4--Lifting Equipment
Keyword:Lifting Equipment Time:2020-10-19 21:13:00
CHANGI WATER RECLAMATION PLANT PHASE 2
CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
GENERAL SPECIFICATION G4
Lifting Equipment
CONTENTS
G4.3 Lifting Equipment ........................................................................................................................ 1
G4.3.1 General ............................................................................................................................. 1
G4.3.2 Reference Standards ........................................................................................................ 2
G4.3.3 Submittals ........................................................................................................................ 3
G4.3.4 Quality Assurance ............................................................................................................ 4
G4.3.5 Electric overhead travelling cranes .................................................................................. 4
G4.3.6 Manually operated overhead cranes ............................................................................. 10
G4.3.7 Jib Crane ......................................................................................................................... 11
G4.3.8 Monorail Hoists Block and chain block .......................................................................... 12
G4.3.9 Crane Access .................................................................................................................. 13
G4.3.10 Trolley ............................................................................................................................ 13
G4.3.11 Testing ............................................................................................................................ 13
CHANGI WATER RECLAMATION PLANT PHASE 2
CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
G4.3‐1 Lifting Equipment
G4.3 LIFTING EQUIPMENT
G4.3.1 General
(a) All lifting equipment shall be provided complete with drive units, access platforms,
ladders, runway beam, supports, plinths, painting, labelling, field control panel,
emergency stop button, cabling, etc., with all necessary instruments required to
control the operation of system/ equipment and all other necessary accessories and
ancillaries required to form a completer and functional system.
(b) All lifting equipment shall be registered with the Factory Inspectorate under the
Ministry of Manpower (MOM), Singapore and copies of registration certificate (from
MOM) for the crane/lifting equipment, copies of which must be handed to the S.O..
(c) The Contractor shall be responsible for maintaining the lifting equipment
registration with MOM, including all fees to be paid until the end of defect liability
period (DLP).
(d) All lifting equipment provided shall bear a permanent inscription on each side
legible from ground floor level stating the safe working load and the registration
number assigned by the Factory Inspectorate.
(e) The Contractor shall provide the test loads, any instrumentation required and the
level of supervision as required by the concerned authorities. The test load shall be
removed from site by the Contractor after successful tests have been carried out.
(f) The Contractor shall make his own assessment, by calculation or approved load
testing equipment, of the weight of main components to be lifted and, prior to
lifting, shall satisfy the S.O. that the safe working loads (SWL) of lifting equipment
are not exceeded.
(g) All relevant drawings and calculations of the lifting equipment endorsed by P.E and
submitted to the S.O for approval before any fabrication and installation is carried
out.
(h) Lifting gear shall be designed to allow a straight lift to be achieved.
(i) The “Safe Working Load” shall be marked conspicuously and clearly on all lifting
equipment.
(j) The Contractor shall engage a Professional Engineer (P.E) to design the crane system
and its associated equipment including any structural design. Contractor shall be
responsible for any necessary authority submission and obtain approval. The
Contractor shall submit application to MOM and engage an MOM approved person
to test the lifting equipment and certify it is safe for use. The PE certification and
registration with MOM shall valid until the end of the defects liability period (DLP)
for the Works.
(k) Laboratories accredited by the Singapore Accreditation Council (SAC) under the
SINGLAS scheme shall carry out all mechanical and non‐destructive testing for all
lifting equipment, as required by the Chief Inspector of Factories, Ministry of
Manpower. Only test reports issued by SAC‐SINGLAS accredited laboratories shall
be recognised.
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CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
Lifting Equipment G4.3‐2
G4.3.2 Reference Standards
(a) The following is a list of standards referenced but not limited to, in this Section:
(i) American National Standards Institute (ANSI):
1) B30.2, Overhead and Gantry Cranes (Top Running, Single or Multiple
Girder).
2) B30.10, Hooks.
3) B30.11, Monorails and Underhung Cranes.
4) B30.16, Overhead Hoists (Underhung).
5) B30.17, Overhead and Gantry Cranes (Top Running, Single Girder).
6) HST 1M, Performance Standard for Electric Chain Hoists.
7) HST 2M, Performance Standard for Hand Chain Manually Operated
Chain Hoists.
8) HST 4M, Performance Standard for Overhead Electric Wire Rope Hoists.
9) MH27.1, Underhung Cranes and Monorail Systems.
(ii) British Standards Institute (BSI):
1) BS EN 13001, Cranes. General design. General principles and
requirements.
2) BS EN 15011, Cranes, Bridge, and Gantry Cranes.
3) BS EN 12385‐1:2002+A1:2008, Steel wire ropes. Safety. General
requirements.
4) BS EN 3506, Mechanical properties of corrosion‐resistant stainlesssteel
fasteners. Bolts, screws and studs.
5) ISO 11660 Cranes. Access, guards, and restraints. Jib cranes.
6) BS EN 14985 Cranes slewing jib cranes.
(iii) Crane Manufacturer’s Association of America (CMAA):
1) 70, Electric Overhead Travelling Cranes.
2) 74, Top Running & Under Running Single Girder. Electric Overhead
Travelling Cranes.
(iv) Factories Act (Chapter 104), Singapore.
(v) International Electro technical Commission (IEC): 60529, Degrees of
Protection Provided by Enclosures (IP Code).
(vi) National Electrical Manufacturer’s Association (NEMA): MG 1, Motors and
Generators.
(vii) Singapore Productivity and Standards Board (PSB):
1) CP 5, Electrical Installations.
2) CP 16, Earthing.
3) CP 27, Factory Layout Safety, Health, and Welfare Considerations.
4) SS 497, Electric Overhead Travelling Cranes.
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CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
G4.3‐3 Lifting Equipment
G4.3.3 Submittals
(a) Contractor shall submitted the following as minimum:
(i) Make, model and weight of each equipment assembly.
(ii) Complete catalogue information, descriptive literature, materials of
construction, and specifications on hoist, wheels, gears and bearing, hoist
motor and assemblies, hook, brakes and accessories.
(iii) Structural design calculations for Crane and associated structure, Jib crane
mast, boom, support system, connection to main structure, and calculations
of deflection and loads on building. Designs and all calculations shall be
endorsed by the Contractor’s Professional Engineer (P.E) registered in a
relevant discipline.
(iv) Detail Shop Drawings of carne system, jib crane mast, boom and their
attachments to building concrete.
(v) Factory finish system.
(vi) Operation and Maintenance Manuals
(vii) Registration Certificate with Chief Inspector of Factories.
(b) Refer to electrical Specifications for motor submittals.
(c) The Contractor shall also submitted the following documents as minimum
requirement for the Quality Control Submittals:
(i) Factory Functional Test Report.
(ii) Factory and field test procedures.
(iii) Manufacturer’s Certification of Compliance that the factory finish system is
identical to the requirements specified herein.
(iv) Special shipping, storage and protection and handling instructions.
(v) Manufacturer’s printed installation instructions.
(vi) Manufacturer’s Certificate of Proper Installation, including Site Functional
Test Report.
(vii) Statement from Manufacturer confirming 5 years of experience with similar
equipment required on the works.
(viii) Reference list of installations of similar equipment that has been in operation
for the past five years.
(d) Suggested spare parts list to maintain the equipment in service for a period of 1 to
5 years. Include a list of special tools required for checking, testing, parts
replacement, and maintenance with current price information.
(e) List special tools and materials supplied with equipment for use prior to and during
commissioning and for future maintenance.
(f) Provide warranty with the Employer named as beneficiary for complete equipment
including accessories and control system as specified under this contract
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CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
Lifting Equipment G4.3‐4
G4.3.4 Quality Assurance
(a) Qualifications:
(i) Manufacturer shall have a minimum of 5 years’ experience manufacturing,
providing, installing and commissioning similar equipment as required for
these Works.
(ii) Reference list of installations of similar equipment that has been in
operation for the past 5 years.
G4.3.5 Electric overhead travelling cranes
(a) General
(i) Cranes shall be designed in accordance with BS EN 13001 and BS EN
15011:2011+A1:2014.
(ii) The term crane shall be deemed to include gantry rails, platform with hand
rails for maintenance purposes, access ladder, down shop conductors, end
stops, holding down bolts and all other items required for complete
installation.
(iii) The longitudinal station travel, the transverse and the hoist shall be
electrically operated. The hoist by travel and traverse must be capable of
reaching every part of the area served and must be able to handle all the
corresponding installed equipment.
(iv) Operation shall be from ground floor level by bridge‐mounted pendant pushbutton
controls or remote control as specified.
(v) All the movements of the crane shall be geared so that one man of average
stature and strength can move and control the fully laden crane with
accuracy.
(vi) Controls shall be mechanically and electrically interlocked to prevent
inadvertent operation of opposing motions. The pendant control voltage shall
not exceed 50 V AC.
(vii) The pendant shall be supported independently of the electric cable and shall
be arranged for extending when necessary.
(viii) The crane shall be fitted with limit switches to prevent excess travel, overhoisting
and over‐lowering of the crane hook.
(ix) Electro‐mechanical fail safe brakes shall be incorporated on all poweroperated
motions.
(x) The crane shall be fitted with a load‐limiting device to stop the lifting
operation when the load exceeds the pre‐set limit.
(xi) The load sensor shall be of the strain gauge bridge transducer type calibrated
at the factory.
(xii) Crane hooks shall be fitted with safety catches and the hook block shall
incorporate fully guarded rope sheaves.
(xiii) Down shop conductors shall be of the fully insulated shrouded bus bar type.
The current collectors shall have renewable contact pieces. Festoon cables
may be used for the cross travel.
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G4.3‐5 Lifting Equipment
(xiv) A crane power supply isolating switch, lockable in the off position and
incorporating a supply on indicator light, shall be provided at the bottom of
the access ladder.
(xv) A second isolating switch shall be provided at the control cubicle located on
the crane platform.
(xvi) All motors shall be of the quick reversing type.
(xvii) All movements shall be electrically operated and shall function with the hook
loaded. Facilities shall be provided for the accurate location of the hook by
means of "inching" the cross travel and down shop travel motions.
(xviii) All the motions shall be suitable for the dismantling and accurate re‐assembly
of the equipment parts. The range of speeds shall be designed to give ease
of handling and maintenance of equipment without danger to the people,
staff or pumping station, installation etc.
(xix) Sufficient slings, ropes, shackles, and lifting beams shall be supplied to handle
all items of plant served by the crane. They shall be labelled or marked with
the Safe Working Load (SWL) and the purpose for which they are intended.
(xx) All necessary contactors, control cubicles and protection equipment
necessary to operate the crane and provide adequate electrical protection
against overload, phase and earth fault and fail safe protection in the event
of an interruption in the power supplies shall be provided.
(xxi) All electrical equipment shall be fully tropicalized where necessary. Motors
and switchgear shall be provided with anti‐condensation heaters which shall
be energised when the crane is at rest and suitable warning labels shall be
fitted.
(b) Crane accessories
(i) Hoisting Unit
1) The hoisting unit shall be of an electric driven wire rope type. It shall be
capable of safe operation with optimum acceleration characteristics.
Importance shall be given to minimum maintenance.
2) The design shall incorporate a normal hoisting speed and a much
slower creeping speed. Adequate interlocking and control shall be
provided to prevent over travel both upwards and downwards.
3) The crane hoist shall be capable of lifting and traversing in two
directions and to hoist a maximum load as specified.
4) The crane hoist shall be capable of lifting and traversing in two
directions and to hoist a maximum load as specified
(i) Cross travel unit
1) The above unit, namely the hoist trolley, shall have an electric drive.
Safe operation and optimum acceleration characteristics of the cross
travel unit shall be ensured through the use of individual drive units
incorporating self‐braking motors. Hoist trolley shall operate through
the entire distance along the crane girder
2) Importance shall be given to the presence of features allowing for
minimum maintenance.
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Lifting Equipment G4.3‐6
(i) Long travel
1) The long travel unit shall have an electric drive. Safe operation and
optimum acceleration characteristics of the long travel unit shall be
ensured through the use of individual drive units incorporating selfbraking
motors.
2) Importance shall be given to the presence of features allowing for
minimum maintenance.
3) The drive shall be of the direct torque transmission type. Transmission
to the travel wheel shall be by splines through reduction gears and with
the gear wheels running in oil‐bath and with all shafts on anti‐friction
bearings.
4) The long travelling wheels shall be of double flange special spheroidalgraphite
cast iron type.
(ii) Hoisting rope
1) The rope shall be of the best plough steel, of twist‐free type and shall
comply with BS EN 12385‐1:2002+A1:2008.
2) Its breaking strength shall be not less than six times the safe working
load (SWL). Sufficient length of this rope shall be provided.
(iii) Rope drum
1) The rope drum shall be rolled, welded and precision machined from
high grade steel and shall be flanged at both ends. It shall be driven
through an internal gear rim and supported by large diameter bearings.
The drum shall have specially machined grooves.
2) The size of the drum grooves shall be such as to accommodate within
1 layer the length of rope required for the specified lift. Furthermore,
it should have no fewer than 3 dosed turns at each anchored and a
spare groove at the other end.
(iv) Rope guide: The rope guide shall consist of a pressure ring and a threaded
ring smoothly guiding the rope off the drum and operating the limit switch in
the event of hook over travel.
(v) Hook Block: The hook block shall be of the fully‐enclosed type conforming to
BS EN 1677 Part 5. The material of the hook shall be forged steel. The hook
shall be fully swivelling and shall be mounted on a ball or roller bearing. A
protective skirt shall be provided to enclose the bearing. A safety catch shall
also be provided. The block must be arranged for lowering down to the floor
level. The shape of the block shall be designed to avoid the catching of the block
when lifting through floors and openings.
(vi) Hoist rope pulleys: The above pulleys are to be of cast steel fitted with roller
bearings and arranged for grease lubrication.
(vii) Brakes
1) All motors shall be equipped with conical rotor electric mechanical
brakes. The springs for the brakes shall be of the compressive type and
shall not be stressed in excess of 80% of the torsional elastic limit of the
material.
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CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
G4.3‐7 Lifting Equipment
2) All brake linings shall be effectively and permanently secured.
Provisions shall be made for simple and easily accessible means of
adjustment due to wearing of the lining.
3) All brakes shall be protected from oil, grease, dust and any other
adverse effects.
4) The brake for the hoisting unit shall be the automatic type. When the
circuit is cut‐off or fails, it shall be able to arrest the motion and hold at
rest any load up to and including the test load at any position of the lift.
It shall be able to control with safety the lowering of any up to and
including the test load. The brake torque shall not be less than 250% of
the rated motor torque.
5) The brakes for the traversing and travelling units shall be able to bring
the crane safely to rest at any load up to and including the test load and
shall be of the automatic type.
(viii) Gears, bearings and lubrication
1) All gears are to be mounted on anti‐friction bearings and totally
enclosed within an oil tight housing. They are to be of high quality gear
steel and are to possess accurately machined teeth. The gear teeth are
in addition required to be hardened and highly resistant to wear and
fracture.
2) The bearings are to be of the anti‐friction type and required to be
permanently lubricated. The bearings shall be designed for a minimum
service life of 5 years.
3) Re‐lubrication, if necessary, shall be made possible through easily
accessible grease nipples. The latter shall be of uniform type and
readily accessible. Special attention is to be given to the lubricating of
points not readily accessible.
(ix) Crane runway rails
1) Contractor shall design, supply and install the crane runway rails. Rails
shall be constructed from the steel universal I‐beam.
2) The sizing of the steel universal I‐beam shall take into account of the
total load of the overhead travelling crane and the rated working load
with the appropriate safety factor for an efficient operation of the
overhead travelling crane.
3) The rails for the portal cranes shall be constructed of square bar of steel
suitable for the portal crane application. The rails shall be welded to
the levelling plates which extend throughout the whole length of the
rails.
(x) Transverse crane beam
1) Transverse Crane Bridge shall be a single box girder mounted on the
top of double channel end carriages for crane with a safe working load
of less than 10 tons.
2) Transverse Crane Bridge shall be a double box girder of double rail crab
for crane with a safe working load of 10 tons and above.
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CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
Lifting Equipment G4.3‐8
3) The box section shall comprise two rolled steel joints with the flanges
butting and continuously welded to provide a horizontally stiff girder.
(xi) Crane rail Support Joints
1) The rolled steel support members to which the crane rails are to be
fixed shall be provided. The joints are to be of approved dimensions
and type capable of adequately supporting the fully loaded crane at all
points and during travel without significant deflection.
2) The members are to be securely fixed to the supporting corbels from
reinforced concrete columns provided by the main contractors, by
purpose made shoes and deep stainless anchor bolts. The fixings shall
be of an approved design such that the members are simply supported
on the columns and impart no fixing moments.
3) End stops shall be installed to arrest the crane
(xii) Crane Rails
1) The crane rails complete with fish plates, holding down bolts and stops
etc. are to be supplied and fixed complete. The rails and fittings are to
be of heavy gauge flat bottom type.
(xiii) Bolts, Nuts and Washers
1) Bolts, nuts and washers shall be of stainless steel and shall conform to
BS EN 3506 ‐ Specification for corrosion‐resistant stainless steel
fasteners.
(c) Control of crane
(i) General
1) The complete electrical isolation of the crane shall be controlled from
the main electrical control panel and such isolation shall have the effect
of stopping all hoist movements
2) The crane shall be controlled by low voltage operation via reversing
magnetic contactors from a pendant push‐button station if specified.
The control voltage, preferably 42V, shall be supplied by a transformer,
the primary and secondary windings of which are to be protected by
special fuse links.
3) Adequate control will be levied through the use of suitably placed limit
switches and brake mechanisms. Sufficient interlocking will also be
provided to ensure a fail‐safe unit.
(ii) Pendant push‐button system
1) If the crane control specified controlled from a push‐button station, it
shall be modern, practical and handy design and suitable for floor
operation.
2) The push‐button station shall be suspended from the Crane Bridge and
mobile along one side of the bridge through the use of trailing cables
supported by ball bearings trolleys or sliders running smoothly on a
rigid light aluminium track adjacent to the bridge.
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CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
G4.3‐9 Lifting Equipment
3) The control pendant shall be lockable to prevent misuse and shall be
provided with a special flexible hose to protect the control cable
against tensile stresses and possible mechanical damage.
4) The weight of the control pendant shall be supported independently of
the electric cable. If the control pendant is of metal, it shall be
effectively earthed.
5) The push‐buttons shall be housed in a sturdy, dust‐proof box of
approved material so designed as to give the required mechanical or
electrical protection to all operating parts.
6) The control pendant shall be capable of withstanding damage.
7) Each crane motor will be operated by two (2) push‐buttons, one for
each direction of motion. Each push‐button is to be of the double
pressure type for dual speed operation. All the buttons being resetting
and leaving the hoist ready for subsequent operation by any other
control button.
8) The push‐button station for the portal crane shall be of weatherproof
construction with a protection of IP 65.
9) The pendant control shall be positioned 1.3m above the operation and
control floor level or as per specified.
10) The pendant and cable shall be supported by a flexible non‐ferrous or
galvanised steel wire rope secured by splices and shackles.
(iii) Limit switches
1) Long travel and cross travel limit switches with over‐riding facilities
shall be incorporated and suitably arranged in the crane unit.
2) Limit switches required to cut‐off the raising and lowering motions
when the hook block reaches its top and bottom maximum limits shall
be provided.
3) Position limited switch shall be provided where more than one trolley
is operated on the same bridge to prevent the overshoot of the
crane and collision.
(iv) Load Limiting Device
1) Each crane shall be equipped with a load limiting device which can
measure the mechanical load being hoisted and can cease lifting
operation (and maintain the load in place) when the load exceeds the
pre‐set limit. The load sensor shall be of the strain gauge bridge
transducer type calibrated at the factory.
(d) Electrical works
(i) General
1) Contractor shall supply and install all the electrical works necessary for
the proper functioning of the electric overhead and portal crane
systems.
2) All the electrical works shall comply with the specifications of the
distribution system in General Specification ‐ Electrical Works.
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CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
Lifting Equipment G4.3‐10
(ii) MCC
1) MCC shall be complete with the following components:‐
Motor starters
MCCBs/ MCBs
Main isolator
Name plate
(iii) Power supply and Crane wiring
The crane shall operate on a 3 phase, 415 Volts, 50 Hz supply. Supply
shall be 60 volts fed from a transformer with an earthed centre tap
secondary.
1) Generally, the power supply to the cranes shall be through totally
enclosed copper bus‐ducts suitable for safe mobile power feeding to
the cranes except the portal crane.
2) The supply across the gantry beams shall be made by means of heavy
duty type multi core PVC cable running along a collector channel and
loading onto a spring loaded drum. The supply along the length of the
station must be completely insulated in a PVC housing and protected
against any accidental contact. The wiring collector and pick‐up gear
must be arranged for ease of maintenance from the crane gantry.
3) A red warning lamp shall be provided at each end of the track and shall
be illuminated when the power is on.
4) The controller shall be fixed to the crane and arrange for easy
maintenance.
(iv) Motors
1) The motors shall be squirrel cage induction motors with adequate
surface ventilation for intermittent duty and complies with General
Specification Electrical works.
2) The motor ratings shall conform to the relevant FEM design rules. Duty
times shall be assumed to be at least 25%. Insulation shall be fully
tropicalized and be preferably categorised in Class F.
3) The type of enclosure for the motor shall be dust and damp proof and
fitted with anti‐condensation heater as minim. And shall be conformity
with the appropriate IEC rules and the requirements as specified in
General Specification – Electrical works.
(v) Earthing
1) The crane structure, motor frames and metal cases of all electrical
equipment including metal conduit or cables guards shall be effectively
earthed.
G4.3.6 Manually operated overhead cranes
(a) Cranes shall be designed in accordance with BS EN 13001 and BS EN 15011.
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CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
G4.3‐11 Lifting Equipment
(b) The term crane shall be deemed to include gantry rails, end stops, holding down
bolts and all other items required for complete installation. All access ladders and
platforms necessary to carry out maintenance and repairs shall also be provided.
(c) Sufficient slings, ropes, shackles, and lifting beams shall be supplied to handle all
items of Plant served by the crane. They shall be labelled or marked with their safe
working load and with the purpose for which they are intended.
(d) The Contractor shall supply the test load. The test load shall be removed from site
by the Contractor after successful tests have been carried out.
G4.3.7 Jib Crane
(a) The jib cranes lifting capacity shall be according to the Particular Specifications and
contractor shall verify the loading capacity for the selected plant and equipment and
submitted the loading schedule for S.O. approval.
(b) Each unit shall complete with the base plate, mast, boom, hoist, anchor bolts,
provision for manually moving the hoist, lifting the load and rotating the boom as
required to make it as a complete functional system.
(c) All the jib cranes are manually operated.
(d) All materials shall be properly selected for the stresses to which they will be
subjected. Jib crane assembly shall be fabricated in accordance with latest standard
and regulations
(e) The Jib crane mast, boom, trolley, hoist and other components shall be fabricated
using established procedures and welding shall be carried out by qualified welders.
(f) Lifting Lugs shall be provide for equipment and components weighing 40kg.
(g) All Anchor Bolts shall be Type 316 stainless steel, sized by equipment manufacturer,
(h) Free‐standing Jib crane
(i) Crane mast shall be base plate mounted. The crane will have full web gusset
plates, welded to the mast and base plate for stability and reinforcement.
Insert or sleeve mounted cranes shall not be accepted.
(ii) The crane mast shall be of adequate section size for the specified loading
conditions.
(iii) The mast height should be selected to have enough head room to facilitate
lifting of the equipment as indicated in the data sheets at the end of this
section.
(iv) The material of construction shall be carbon steel or any other suitable
material of manufacturers’ standard.
(v) The top end of the mast should be finished to attach the crane boom.
(vi) The boom will consist of a standard I‐beam or wide flange, and may be
reinforced with a cap channel for lateral stability.
(vii) Trolley stops will be utilised to prevent the hoist trolley from falling off the
boom or contacting any obstruction.
(viii) The boom will be level and horizontal, and will permit a hoist and trolley to
ride upon its flat flange track.
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CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
Lifting Equipment G4.3‐12
(ix) The crane’s deflection at the end of the boom should not exceed 1/150 of the
crane’s span.
(x) One end of the boom should be attached to the mast and should be able to
rotate about this connection point.
(xi) Bearings shall be heavy‐duty roller type, prelubricated and sealed. The
bearing shall have a L‐10 life of 50,000 hours as minimum.
(xii) All apparatus supplied under this Section shall be constructed with due regard
to safety of operation, accessibility, interchangeability and durability of parts.
G4.3.8 Monorail Hoists Block and chain block
(a) Monorail hoist shall comprise an electric hoist and a rolled steel joist.
(b) Load chain wheel driven through gear reductions, a hand chain wheel, load blocks,
sheaves, chain, hook, and hoist braking.
(c) Chain shall be Non‐jamming alloy type suitable for one man manual operate it with
reasonable ease from floor level. n. Hand wheel shall have a guard that prevents
chain slipping or jumping. Chain hoists shall have chain storage adequate for storing
full lift length of chain and shall be designed and located to avoid interference while
hoisting.
(d) The hook shall be constructed with sufficient ductility to open noticeably before
hook failure, equipped with safety latch, free to rotate 360 degrees with rated load,
and positively held in place with locknuts, collars or other devices
(e) The brakes shall be accordance with ANSI HST 1M and 2M, adjustable to
compensate for wear. Positive action, Weston type mechanical load brake, with
uniform composition lining and forged steel alloy latch pawl.
(f) The chain block shall be provided with geared hand travel four wheel trolley suitable
for running from a rolled steel joist.
(g) The lifting chain shall be set quality corrosion resistant steel alloy, of such length to
allow a lift to be made from the ground level to loading level without re‐slinging.
(h) Electric hoist
(i) The lifting wire rope of the electric hoists shall be of best plough and of such
length to allow a lift to be made at ground floor level without re‐slinging. The
hoist mechanism shall be controlled from a hold on push button pendant.
(ii) Hoists shall be fitted with load limited devices for overhead travelling cranes,
unless otherwise specified.
(iii) The pendant shall be suspended independently of the electric cable 1300mm
above ground floor level. A stainless steel pendant holder shall be installed
on site. Control supply shall be not more than 60V fed from a two winding
transformer with an earthed centre‐tap.
(iv) Cables feeding the electric hoist unit and down shop cables shall be flexible
cables suspended from carriers sliding on taut wires.
(v) The electric drive motors shall be fitted with electro‐magnetic brakes to
prevent over travel on release of the control button.
CHANGI WATER RECLAMATION PLANT PHASE 2
CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
G4.3‐13 Lifting Equipment
(vi) Limit switches shall be installed to prevent over travel, over lowering and over
coiling of the lift rope. End stops and limit switches shall be provided to arrest
the hoist block.
(i) The lifting equipment shall include a triple leg chain sling with hooks; a suitable wire
rope sling; a nylon rope sling. The slings shall be of suitable length and strength to
enable a safe lift to be made of all items of equipment intended as indicated in the
drawings.
G4.3.9 Crane Access
(a) Fixed aluminium ladders and catwalks complete with toe boards etc. as required for
the full and proper access to the crane and appurtenant equipment for maintenance
purposes shall be provided.
(b) An aluminium alloy catwalk shall be provided on the crane, complete with handrails
and toe boards to enable ease of maintenance of the crane unless otherwise stated.
G4.3.10 Trolley
(i) Frame: Welded steel, cast steel, or ductile iron construction, or a combination
thereof. Construct to control deflection of trolley assembly while transmitting
the carrying load to running surface.
(ii) Drive shall consist of chain sprocket mounted on shaft. Furnish chain to within
5 feet of operating floor level. Drive shaft shall drive the trolley wheels
through a gear and pinion or spur gear arrangement.
(iii) Furnish roller assembly stabilizers on single‐girder trolley units to prevent
tipping during load pickup.
(iv) Wheels: Rolled or forged steel, accurately machined and ground to receive
inner bearing races. Furnish alloy steel axles. Rotating axles with wheels
mounted press fit and keys, or with keys alone. Minimum tread hardness 210
Brinell.
(v) Drive Gears: Helical, spur or herringbone type, rolled or cast steel, with
machine cut teeth.
(vi) Bearings: Combination radial and thrust type, double row, angular contact
ball bearings or single‐row tapered roller bearings. Bearings prelubricated
and sealed, or fitted for pressure lubrication. Locate pressure lubrication
fittings for accessibility during maintenance.
(vii) Brakes: Suitable for service class and rated torque capacities as specified in
ANSI B30.11.
G4.3.11 Testing
(a) The crane shall be tested in the presence of the S.O to demonstrate the safe
condition of the crane.
(b) Full Load tests in compliance with OSHA, ANSI and BS standards and Factories Act
by an approved person registered with the Chief Inspector of Factories. The load
test plan shall be submitted to S.O. for approval.
(c) Registration with Chief Inspector of Factories: The Contractor shall register the
equipment with the Chief Inspector of Factories, Ministry of Manpower.
CHANGI WATER RECLAMATION PLANT PHASE 2
CONTRACT C22B‐CIVIL & STRUCTURAL, MECHANICAL & ELECTRICAL WORKS FOR TRAIN 5
Lifting Equipment G4.3‐14
(d) In the event the power supply is not available when the crane been installed,
temporary power supply or a hand operated hoist shall be arranged temporarily.
(e) After all the equipment have been installed the entire crane assembly included the
hoist chain shall be completely tested for all functions in the presence of the S.O
and a licensed tester. The contractor will be responsible for obtaining a certified test
certificate for the crane, a copy of which must be handed to the SO.
(f) Test complete assemblies for proper alignment and connection, and quiet
operation.
(g) In additional to the latest standard and regulation required, the full load test to be
conducted shall require that weights equalling the maximum capacity of the bridge
cranes and hoists be carried by the units as minimum, while the cranes and hoists
are operated as follows:
(i) Hoists operated through the entire lifting height for each of the units at
various positions of the crane and trolley for each crane, as directed by the
S.O.
(ii) Cranes operate through the entire length of the crane rails.
(iii) Hoist trolleys operate through the entire distance along the crane girder.
(iv) If the equipment fails the test all necessary changes shall be made and the
equipment shall be re‐tested. If the equipment again fails to meet the test
requirements to the satisfaction of the S.O, it shall be removed and replaced
with satisfactory equipment.
END OF SECTION