4-1.1. Main Hoist Drive
(1) The main hoist drive reduction gearbox shall be totally enclosed, oil bath lubricated type.
(2) Two AC servo operated disc brakes shall be fitted on the high speed pinion shaft.
Each brake shall be rated at 150% full load motor torque and shall be capable of stopping and holding the maximum rated load from full rated speed. Final adjustment of brake torque shall be carried out during commissioning using appropriate calibration equipment.
(3) Overspeed switches shall be fitted to the main hoist drums to shut down the drive and set the brakes if the load exceeds 115% of rated speed. Geared limit switch unit for the main hoist shall be electromagnetic type.
(4) Pulse generator encoders shall be installed on the main hoist drums.
(5) Acceleration from zero speed to a maximum speed or deceleration to zero speed shall be smooth and steeples for any load under spreader. (See 2-7. 1 (8) for speed/time requirements.).
(6) There shall be two stages of the upper main hoist slow down to cater for an empty spreader and a loaded container in order to enhance performance of container handling. In the condition of empty spreader the hoist shall incorporate a lower slow down whilst the loaded spreader condition shall incorporate a higher slow down. Under each condition the emergency limit position shall not be tripped. The Contractor shall propose a method statement with calculations for the Purchaser’s review.
(7) Frequent inching operation and plugging operation shall be catered for in the design.
(8) The main hoist motor and brakes shall be fitted inside weather-proof enclosure. The enclosure shall be designed to provide for ease of motor and brake maintenance with suitable removable doors. Thermal cycling due to hot and cold climatic changes shall also be considered within the design of the enclosure.
(9) The enclosure shall be equipped with an exhaust fan. Cool air may be drawn from any opening beneath the main hoist motor housing; however water shall not be drawn into the enclosure under any circumstances.
(10) The main hoist wire ropes to the headblock shall not interfere with the stacked containers when the Crane is working on a single slot between two - five high stacks.
Outside wire ropes shall be stationary during hoisting and lowering motion.
(11) The main hoist reeving arrangement shall be such that these are no imbalance in the horizontal components of the resultant forces in the main hoist ropes, at the head-block-sheave level.
(12) Load cells shall be provided for sensing the weight of the container suspended under the spreader. Display of the weight of the container shall be installed inside the operator’s cabin. The accuracy of the load cell reading shall be within +/-2%.
4-1.2. (Refer to 2-7. 1. (10))
(1) The Anti-sway/yaw device or sway/yaw damping system shall work effectively for a short distance travel as well as for a stop after full deceleration. The operation of the system shall not alter the elevation of the spreader with or without load at any height.
(2) A simple mechanical anti-sway system which is a proven design and which preferably shall be based on a main hoist eight (8) single fall rope reeving system.
Hydraulic type anti-sway system is not acceptable.
(3) Details of the construction and performance of the mechanical anti-sway system shall be submitted with the tender document.
4-1.3. Skew Control
(1) The Spreader skew motion to be controllable up to its maximum angle of ±5 degrees.
Speed ½degree/sec.
(2) One push button switch on the control console shall automatically correct the spreader position to a ‘Zero skew’ position.
(2) “Zero skew” position shall be indicated with a lamp on the panel in cab.
(4) Screw jack mechanism shall be adopted for the skew control.
(5) Limit Switch shall be installed to prevent over travel of the ball screw-jacks.
4-2. Trolley, Trolley Drive 4-2.1. Trolley Frame
(1) The trolley frame shall be fitted with the main hoist machinery, trolley drive machinery, anti-sway device, skewing device, operator’s cab, and buffers for forward motion and backward motion collision impact. The buffers shall be capable of absorbing and dissipating the impact of collision at full speed with rated load (refer to 5-1.13).
(2) The trolley frame shall be fitted with safety lugs which shall support the trolley in case of wheel shaft failure.
(3) The trolley frame shall have adequate jacking points for trolley wheel replacement work.
(4) The trolley frame shall provide an emergency access from the operator’s cab to the walkways of the girder at any point of trolley travel range.
(5) The trolley drive system, and wheel, shaft and bearing system shall be designed to facilitate fast replacement of components at any point on the girder.
(6) The trolley frame shall be provided within safe maintenance platform and access to all of its components and machineries for maintenance.
(7) The trolley frame shall be equipped with drop-pin type storm/gale stowage pin device. The stowage pin device shall allow a one-man operation to engage / disengage pins on both sides of the trolley from the girder. The stowage pin device shall allow approx. ±100mm trolley positioning allowance. The girder shall be marked for the operator to spot the storm/gale stowage position. The dropping of the stowage pin shall prohibit the trolley motion.
(8) A mirror of non-breakable material construction shall be provided to assist viewing the far side of lifted container in a slot underside of the trolley frame.
(9) Four pairs of heavy duty side guide rollers shall be fitted on both sides of the trolley frame at fore and aft to guide the trolley movement on the rail without running of misaligned trolley wheel due to uneven track way. The roller bearing of the rail side guide shall be heavy duty and design to carry calculated and imposed forces without damage.
4-2.2. Trolley Drive
(1) Trolley shall be driven by conventional “driven-wheel” system.
(2) The gearbox input shaft shall be fitted with an AC servo operated disc brake rated at 150% full load motor torque. The installation of the brakes shall allow all round access for maintenance.
(3) The reduction gears shall be totally enclosed, oil bath lubricated type.
(4) Geared limit switch drive shall be by a proper gear reducer and a flexible coupling.
Chain drive is not allowed.
(5) Frequent inching operation and plugging operation shall be catered for in the design.
(6) The trolley drive system design shall take into account effects of ±2% cross grades of the runway, and additional grades caused by deflection of the tyre due to moving loads. For the acceleration and deceleration time requirements refer to 2-7.1. (8).
4-2.3. Sway and Position Control
(1) The sway control shall bring the spreader to a stop following full deceleration of the trolley from full speed with any operational load to within +/- 50mm at any lifting height as measured at the bottom corners of the 40’ container or the twist lock of an empty spreader. It shall be capable of bringing the spreader to a stop to within 2 cycles of sway.
4-2.4. Power Feeder (Power Chain System)
(1) An approved low noise weatherproof, heavy duty energy chain system design for rated speed of the trolley shall be proved from the junction boxes at the end of the fixed trolley girder to a similar junction boxes mounted on the moving trolley.
(2) The energy chain shall have extra slots for extra cables (in addition to the specified spare wires) and shall be designed so replacement and cable replacement can be accomplished without dismantling or taking down the carrier assembly.
(3) The chain design shall afford complete segregation of cables for power, control and data transmission. Cables shall be suitably rated, extra flexible round or flat form adequately sized (minimum wire diameter of 1.5mm square). The installation shall not generate mechanical damage to cables and be such that bend radius specified by the cable manufacturer is not exceeded.
The installation, including junction box(es) terminations shall be EMC compliant.
The required quantity of each size and type of conductor shall be provided plus with the exception of AC Motor power cables, 25% of each as spares.
The supplier of the Energy Chain shall also supply the cables and cable glands.
(4) Access to the energy chain system shall be by a permanent walkway and platform.
Manufacturer’s recommendations shall be adhered to strictly for installation detail and tolerances. A platform on the trolley can be used for access to the energy chain providing it provides safe access and hand rails are fitted.
(5) The system design shall not generate water traps internally, between cables and chain material or externally between chain material or crane structure.
(6) Two (2) spare fiber optical cables (62.5/ 125 multimode) shall be provided and installed from Driver’s cabin to the Electrical House.
4-3. Gantry Drive 4-3.1. Gantry Drive
(1) Eight (8) - rubber tyred wheels shall be provided for gantry drive. All the tyres shall be tubeless rubber tyres, minimum 40 ply.
(2) Four (4) gantry motors shall be used for the gantry travel system. It is preferred that each gantry motor is driven by individual drive. The drives and motors shall be sized to meet the operational requirements for future possible installation of the AGSS.
(3) The gantry drive, motors and brake system shall provide sufficient thermal capacity, torque and traction for all operating condition.
(4) The gantry motor and brake shall be rated to be able to safely operate the unladen crane on a slope of ±3% with rated speed. The brake capacity to be sufficient to stop the Crane whilst not sustaining damages in the event that an emergency stop button is pressed during full-speed gantry travelling with 25 m/s tail wind.
(5) Wheel yoke and equalizer beams shall be designed to allow simple removal of any wheel. Easily identifiable jacking points shall be provided on the wheel yoke. The
Jacking load and position shall be reviewed by the Purchaser to prevent overloading of crane runways.
(6) Wheels, dual chains and gears shall be fitted with safety guards. The guards or covers shall have greasing windows.
(7) Robust tyre guards shall be provided on all wheels.
(8) A sleeve shall be fitted between the gantry equalizer beam and the yoke wheel assembly enclosing the vertical yoke shaft. This sleeve shall be designed and fitted to all yoke shafts to allow for the bending movement of the gantry motion to be transmitted from the yoke shaft to the sleeve to eliminate shaft breakage.
(9) All vertical gantry motor disc brake assemblies shall be fitted with a sealed steel cover fixed permanently by bolts in order to prevent water ingress.
4-3.2. Steering
(1) Proper manual control steering system for running on crane runways (both longitudinal and cross travel directions) shall be provided.
(2) The drive and steering system shall be designed taking into account effects of ±1%
cross grades with a rated load at any trolley position. Steering guide bars pointing at the inner edge of pathway of 1,500 mm wide shall be fitted on each wheel close to the ground level. These guide bars must be clearly visible by the operator.
4-3.3. Right Angle & Pivot Turn
(1) Each wheel shall be able to be turned 90 degrees for cross travel, or an intermediate angle to allow spin turn of the Crane for shifting the crane to another lane. The turning of the wheels shall be controlled by the operator in the cab. Positive locks to keep the wheel in position parallel, at an intermediate angle, or at 90 degrees to the sill beams shall be provided. An audible signal shall be given in the cab when all wheels have fully rotated and locked in the designated position. The maximum time to turn the wheels through 90 degrees shall be 70 seconds. Proximity switches shall be used for installation of the wheel turn and locking mechanism.
(2) The limit switches for the hydraulic wheel jack system shall be “external type”.
4-3.4. Gantry Skew Control
To enable better gantry skew control, each gantry motor shall be driven by individual drive for the gantry travel system.
4-4. NOT USED
4-5. Electrical House, Control Panel, Regenerative E.M.F. Absorbing Resistors 4-5.1. General Construction
(1) The electrical control panels shall be housed in a walk-in type dust and weather proof panel house which is installed on top of cab end sill beam.
(2) Special consideration shall be given for corrosion protection of the panel house and weather protection of resistor banks.
4-5.2. E-House Temperature Control
The inside temperature of the panel house shall be maintained below 240C. Air intakes to the house or panels shall be filtered by non-corrosion washable mechanical filters.
Over/under temperature protection with control interlock shall be provided.
4-5.3. Emergency Lights and Fire Control
(1) The panel house shall be equipped with ample lightings for maintenance work, and also battery operated emergency lights with door switch for unexpected shut off. The emergency lights should be last for at least 1.5 hours.
(2) One (1) - 5 Kg portable C02 fire extinguishers shall be provided outside the panel house in a wall mounted cabinet.
4-5.4. Back Power Absorbing Resistors
Regenerated back E.M.F. absorbing resistors shall be installed outside the panel house to avoid affecting the inside temperature of the panel house.
4-5.5. Provision for Future Installation NOT USED.
4-5.6. Control Panel (in the Electrical house)
(1) The control panels shall be of steel construction hinged door lockable type with full access from the front. Each panel shall be equipped with lights to facilitate maintenance work.
(2) The panels with electronic control units shall be designed to maintain the inside air temperature below 40 0C at all times. Any air inlet for cooling air shall be equipped with air filters.
(3) Each motion control panel shall be fitted with motor frequency meter, motor RPM meter, ampere meter and volt meters which indicate operating frequency, motor revolution, motor current, reference voltage and motor voltage.
4-6. Operator’s Cab, Checker’s Cab 4-6.1. Construction General
(1) The cabs shall be constructed of zinc plated mild steel, double bottom, double ceiling and double wall, fire proof, fully air conditioned and heated. The cab shall be water tight as operated in the conditions as specified in previous clauses.
(2) The cab shall be fitted with a drain hole on the floor to drain out water due to rain ingress or cleaner’s hose water. A handy plug shall be fitted into the drain hole to avoid dropping of small materials and it shall be almost flush on surface of the floor.
(3) The design of the cab to allow the operator to clean outside of all the glasses safely.
(4) The cab connection to the trolley shall include anti-vibration mounts to reduce impact and vibration to the operator.
(5) Shields shall be fitted above the windscreen to prevent wire rope lubricants from splashing onto the glass.
(6) The operator’s cab shall be bolt mounted to the trolley and fitted with safety drop-stop lugs, which shall prevent the cab from dropping off the trolley in case of supporting failure.
(7) Sun visor shall be installed on all the window. The type of sun visor shall be approved by the Purchaser.
4-6.2. Cab Access
Cab access shall be from a hinged door on one side of the cab. The door shall be self closing, with a latch to keep the door in open position. Electrical and mechanical interlock shall be provided to prohibit the trolley movement when the function is triggered. The access gates shall also be locked (closed) when the trolley is not at the trolley access platform.
4-6.3. Window Visibility
Cab windows to provide as much views as possible including lower rear view. The rear side of the cab shall have a full height window. It shall protect the operator from the glare of the sun with fine screen type roll up sun shade on upper front, side and rear windows which have characteristics to allow vision through it. Window glass shall be non-glare and scratch resistant that meets the requirements of BS 857 safety glass with their both surfaces being flat, parallel and fine polished, giving clear undistorted vision. Full direct vision of a ground slot between two - 6 high stacks immediately below the front bottom window shall be ensured without supplemental devices, from the normal seating position of the operator.
The front and bottom window shall be laid out symmetrical about the Crane centreline in left and right direction. The design of operator’s cab shall allow replacement of window glass to be carried out inside the cab. Protection shall be installed to prevent the window glass from falling off or out.
4-6.4. Cab Dimension
Minimum inside floor width of the cab shall to be 2,500mm and length (fore and aft) 2,000mm excluding bottom glass frame.
4-6.5. Cab Fittings
The operator’s cab shall be fitted with the following fittings and shall not in any way obstruct operator’s view required for Crane Operation.
(1) One right-hand and one left-hand control consoles. The consoles together with the chair shall be ergonomically laid out to minimize fatigue of the operator. For detailed requirements refer to 5-4.6.
(2) One upholstered operator’s chair. The chair height and position forward and backward shall be adjustable to best suit each operator (oriental size). The operator’s console and chair shall be fixed (non-rotatable) and mounted on the same base. The access to the seat shall be via outside and front of control console.
(3) Spreader ‘Landing’ (Amber) and ‘Lock’ (Red), ‘Unlock’ (Green) indicating lamps in a box fitted at lower (middle) front part of the cab.
(4) Window wipers and washers
Wipers and washers to ensure the view angle required for operation. Wipers and washers shall be fitted to front and side windows.
(5) Communication equipment (refer to 5-6).
(6) Split type air conditioning unit.
Minimum 12,000 BTU Hr. Capacity.
(7) Service outlet (two 13 amp, 220V, 50Hz with NFB).
(8) Lights and light switches.
(9) A foot rests for the operator (position to be adjustable for each operator).
(10) D. C. outlet for radio communication equipment
See Section 5-3.2 (6), (7) for details of this power supply complete with a battery relay to cut off battery supply after 300 - 500 seconds.
(11) 3 KW capacity heater (flat type) with manual heat level adjuster (independent of air conditioning unit).
(12) Safety bars wherever necessary to prevent accidental fall of the operator or maintenance staff.
(13) Siren foot switch (or call for emergency warning sound). For details see 6-5.1(2) for full description on the common amplifier.
(14) One (1) - 2 kg CO2 fire extinguisher at outside near the door.
(15) 2 Spare MCB’s 220V, 1-phase, 13 Amp capacity.
(16) Coat hook.
(17) A foldable chair embedded into the wall at suitable level for use by operator trainer or a second operator inside the cab. The foldable chair shall be able to swing back to the wall with a latch when not in use and shall mount flush on the wall surface.
(18) Spreader height indicator.
(19) Container load indicator.
(20) Demisters to lower front and floor windows shall be installed to cover full glass area.
4-6.6. Checker’s Cab NOT USED 4-7. Personnel Lift
NOT USED.
4-8. Headblock 4-8.1. Headblock
The Contractor shall propose a direct reeve-in type spreader, which does not have a separate headblock frame. (See 4-9.2 below). The headblock shall be designed fully adaptable to the existing spreaders (Bromma YSX40E) using for operation.
(1) Fittings
The ma jor fittings on the spreader are as listed below. All components on the headblock shall be laid out to maximise operator’s front view. The dimensions, sizes for all bolts, nuts, couplings etc shall be SI units (metric).
i) Main hoist sheave blocks. Arrangement to minimize the spreader rocking
i) Main hoist sheave blocks. Arrangement to minimize the spreader rocking