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Technical Description of Dam Gate Gantry Hoist


2×125kN two-way gate hoist (hereinafter referred to as gantry crane) is installed on the pier top of the spillway of PUAH dam, with a rail surface elevation of 299.50m.

Mainly undertake the following tasks:The main hook of the gantry crane is used for maintenance of gate, opening & closing and hoisting the cover plate of the spillway of PUAH dam. The auxiliary hook is used to open and close the bulkhead gate and its door magazine cover plate. The auxiliary hook is used to open and close the bulkhead gate and its door cover plate.

Working Limit and Service Load: Maximum load of the gantry crane: 2×125kN in span, upstream limit 2 × 125kN; The maximum static wheel pressure is 235kn and the maximum dynamic wheel pressure is 210kN.


Composition of Gantry Crane

PUAH2 ×125kN gantry crane is a double lifting point hoist with a track gauge of 5m and a base distance of 11m. The gantry crane is composed of trolley, crane traveling mechanism, gantry, cab, anemometer, lightning protection and grounding device, protection device and electrical equipment, and is equipped with main and auxiliary hooks. The trolley is equipped with a machine room.


The trolley is composed of lifting mechanism, trolley running mechanism, trolley cover, trolley frame, electrical control equipment and other devices.

The trolley cover adopts combined steel structure frame, the height of the trolley cover is not less than 2.2.m, and the external wall and roof adopt composite sandwich heat insulation board.

Main, Deputy Hoisting Mechanism

The main hoisting mechanism mainly includes motor, brake, reducer, open gear device, drum device, movable pulley device, fixed pulley device, steel wire rope, bearing seat, coupling, height controller, load limiter, etc.

The main hoisting mechanism adopts the layout scheme of double lifting points and double drum drive. The magnification of pulley block is 2. Each reducer is driven by a motor. The reducer drives the drum device through a pair of open gears at the low-speed shaft.

The auxiliary lifting mechanism adopts MD 12-6D electric hoist.

Two brakes are set on the high-speed shaft of each reducer of the main lifting mechanism.

The height indicator is equipped with an encoder, and the sensor is installed at the end of the drum shaft to control the upper and lower limit positions. Preset a small opening stroke to meet the opening and closing requirements of the gate.

The load limiter has the functions of weighing display, overload control, etc.


Long Traveling Mechanism

The crane traveling mechanism is composed of three in one reducer, bench frame, wheel group, electric drive and control equipment, etc.

The travel switch and anchor plate are installed on the traveling mechanism of the crane, one at both ends. When the gate hoist runs to the end of the track, the travel switch will automatically cut off the power supply.


The gantry has a gauge of 5m and a base distance of 11m without cantilever. The main stressed components of the portal frame adopt box structure. The portal frame is composed of main beam, end beam, outrigger, lower beam, trolley track, ladder, railing platform, etc. Trolley track, anti-collision frame and travel switch are set on the main beam of gantry. Ladders and railings. The gantry frame is divided into main beam, end beam, outrigger and lower cross beam. The main beam of the gantry frame is connected with high-strength bolts during installation. The gantry is fabricated by welding and the main material is Q235B.

Electric Drive and Control Equipment

In addition to the above electric drive and control equipment included in each mechanism, the electric drive and control equipment also includes crane power supply device, trolley power supply device (the trolley is powered by festoon cable), operation control system, signal detection system, lighting, grounding, air conditioner, communication and other equipment. The whole equipment realizes frequency conversion speed regulation and PLC control of main lifting mechanism, auxiliary lifting mechanism, long and cross traveling mechanism. Centralized display and control shall be realized on the linkage console in the cab.

Auxiliary Equipment

Auxiliary equipment includes: automatic rail clamping device for trolley, automatic rail clamping device for trolley, audible and visual alarm for crane running, anemometer device, lightning protection grounding device, buffer device, cab and communication equipment.


The gantry crane track model is qu70 and the length is 88m. Anti collision frame and travel limit switch are set at both ends of the track. The gantry crane is equipped with 2 sets of crane anchoring devices, which are usually anchored on the installation

The trolley track is installed on the main beam of the platform on the gantry, and the clamp is fixed by welding.

Automatic Hanging off Beam (self-provided)

Protection equipment

The hoisting mechanism is equipped with a composite load limiter,. Equipped with local display device, the comprehensive error of the sensor is no more than 5%, and the misoperation caused by dynamic load can be avoided.

Height indicator

The main hoisting mechanism is equipped with digital display instrument type height indicator and local display device.

Travel limiter

The main and auxiliary hoisting mechanisms are equipped with independent upper and lower limit position limiters.

Travel limiter shall be installed for long and cross traveling mechanisms.

Wind rail clamping devices are installed on the crane and trolley.

The rail clamp is linked with the anemometer. When the wind speed reaches 20m / s, it will send out shutdown alarm and prompt clamping; When the wind speed reaches 36m / s, it will send out alarm signal and stop automatically, and then clamp the rail support.

The rail clamp is interlocked with the drag system. Before operation, loosen the rail clamp first and then start the machine; Before shutdown, the electronic control system controls the rail clamp to tighten.

An anchoring device shall be installed at a suitable position in the operation section of the crane and trolley. Before operation, the power supply can be connected only after the gantry crane is de anchored.


The long and cross traveling mechanisms of shall be equipped with buffer, and measures shall be taken to make the height of the buffer center from the rail surface no more than 300mm.


An anemometer shall be installed at the upper part of the gantry crane where there is no wind. When the wind speed is greater than the working limit wind speed, it will send out audible and visual alarm signals to stop operation, and can display the instantaneous wind speed.

The emergency stop button shall be set at the appropriate position of the rack and machine room to ensure the safety of equipment and personnel.

Cabin, Electrical Room and Machine Room

The cab shall be arranged to avoid collision with the spreader and gate, and the distance between the spreader and gate and the cab glass window shall be greater than 400mm.

The cab is set on the downstream lower beam, and all mechanisms can be operated in the cab. The cab is convenient to operate the main lifting mechanism and the auxiliary lifting mechanism.

The cab is equipped with air conditioner, and the windows are made of tempered glass.

The bottom surface of the electrical room shall be inlaid with non-metallic thermal insulation materials, and the floor surface shall be paved with non-conductive and non slip gaskets. The electrical room is equipped with ventilating fan, and is rain proof and heat insulation.

The electrical room of gantry crane shall be equipped with sufficient fire-fighting facilities.

The gantry crane trolley is equipped with a machine room with a height no less than 2.2m. The machine room is equipped with an ventilating fan and is rain proof and heat insulation. There is a proper slope on the top of the machine room to prevent ponding.

The cab, electrical room and machine room shall be provided with appropriate lighting.

Electrical Equipment and Control

Basic requirement

The electrical control part adopts advanced programmable control technology (PLC) and 1:10 variable frequency speed control technology, which has the advantages of strong function, advanced technology, safety and reliability, flexible control and convenient operation.

Electrical equipment is composed of power supply system, main and auxiliary lifting mechanisms, main and auxiliary trolley traveling mechanisms, crane traveling mechanisms, electrical transmission and control system, gantry crane operating system and lighting power supply system.

The electrical system can realize the operation and control of the gantry crane and the exchange of flashlight; It can monitor the operation status of the gantry crane and make judgment or alarm; It can realize the collection, display and processing of data and operation signals of various mechanisms.

Power supply: AC three-phase, four wire 415V, 50Hz.

Power supply mode: four core flexible trailing cable for power supply. Set at downstream side.

Protection function: it is equipped with short-circuit protection, over-current protection, interlocking protection, voltage loss protection, phase loss protection, zero protection, overload and under-load protection, limit protection and other functions, and has audible and visual alarm function

The lifting and traveling electric control cabinets of the main and auxiliary trolleys are placed in their respective trolleys, and no additional electrical room is set.

The long traveling electric control cabinet and the main power cabinet are set on the lower beam at the downstream side of the gantry.

Travel switch setting: limit travel switches are respectively set on the long traveling bogie and trolley frame, and collision frames matching with the travel limit switches are set at both ends of the crane and trolley tracks. When the travel limit switch contacts the collision frame, it will automatically cut off the power and stop the machine.

Control and Configuration

The power incoming line of the gantry crane is 400V four phase AC power supply, which is led from the power supply box of the power station through the cable drum connector of the gantry crane to the main power control panel (A1) in the electrical room of the gantry crane.

The core of the control system of the gantry crane is the programmable controller PLC, which adopts Siemens S7-300 series PLC, with host and remote I / O. The main hoist, crane and trolley are controlled by PLC frequency converter.

The man-machine interface in the cab adopts LCD touch screen plus a small amount of signal lights and instruments. PLC host communicates with remote I / O and LCD through fieldbus.

Before the operation of the gantry crane, all power supply switches, main power supply contactors and control power switches shall be closed. Adjust each limit switch and travel switch in place, and adjust the zero position of the lifting height sensor and the zero position of the load limiting instrument. The program of PLC is correct and the picture of LCD is complete, which meets the requirements of operation and display.

Power Operation

Manually close the power supply circuit breaker, electrical circuit breaker or switch of each mechanism and control circuit switch. The connection or disconnection of the main contactor shall be operated on the operation console in the cab. If the phase sequence of the power supply changes, phase loss or phase failure, and the corresponding control relay acts, the main contactor cannot be connected.

Before the operation of each mechanism of variable frequency speed regulation control, the position of each mechanism shall be confirmed to ensure that there are no potential safety hazards, and then the operating lever on the linkage console can be operated. When the frequency converter fails, the "frequency conversion fault light" is on, and the "frequency converter reset" button can be pressed to remove the frequency converter fault. If the fault occurs again, professional personnel are required to check the cause and eliminate the fault before operation again.

Long Traveling Operation

Launch the long traveling signal display screen on LCD.

Operate the crane mechanism master controller on the linkage console in the cab. Turn left, the crane mechanism moves left, turn right, and the crane mechanism moves right. Before operation, loosen the crane rail clamp first and operate it when the rail clamp indicator is off. When the crane is operated, the audible and visual alarm for crane traveling sounds.

When the crane is operated, other mechanisms cannot be operated.

Trolley Hoisting Operation

Launch the cross traveling signal display screen on LCD.

Operate the master controller of the trolley mechanism on the linkage console in the cab. Move forward, the trolley mechanism moves forward, move backward, and the trolley mechanism moves backward. Before operation, loosen the trolley rail clamp first and operate it when the indicator light of the rail clamp is off.

When the trolley travels, other mechanisms can not be operated.

Lifting Operation

When action is required, the main lifting lever is turned to the corresponding first step, the frequency converter outputs torque (to prevent hook slipping), then the PLC makes the brake energized and released, the lifting mechanism is started, and then turn to step 2 ~ 4 in turn, and the motor accelerates to the corresponding rated speed.

In the process of running at the rated speed, if it is necessary to reduce the running speed, the operating lever can slow down from high gear to low gear.

When shutdown is required, turn the operating lever back to "0" position, and PLC will stop the lifting mechanism.

Limit automatic shutdown is that PLC receives the opening and closing height signal transmitted by the sensor in real time. When it reaches the setting value (on-site setting during commissioning), the lifting mechanism will stop automatically.

Protection shutdown refers to the automatic shutdown of the lifting mechanism after PLC receives the protection action signal.

Interlock and protection


During the main lifting operation, PLC interlock makes the crane, automatic beam grabbing, trolley and other operations invalid


When the main hook rises, the overload protection is set at 110% of the rated load.

During the operation of the main hoist, if the variable frequency speed regulating device of the main hoist fails, the upper and lower limit protection, motor over-current protection, motor over-speed protection and main circuit short circuit protection act, the PLC acts on the shutdown and drives the fault signal lamp on the LCD to light up. (disappears after the fault is removed).

Installation of Gantry Crane

The installation of the gantry crane shall comply with the relevant provisions of the Code for Manufacture, Installation and Acceptance of Gate Hoists in Water Resources and Hydropower Projects (DL / t5019-94), and shall be based on the attached drawings and this manual.


Before installation, the gantry crane shall be fully inspected.

Check whether there is damage, corrosion and missing parts caused by packaging and transportation.

Check whether the assembly quality of all parts of the gantry crane meets the requirements.

Carefully remove the dust, oil, iron filings and other sundries of the machine parts.

Check whether the quality of infrastructure works is stable and safe.

Carefully study the drawings and eliminate errors and defects caused by improper transportation or storage according to technical requirements. Especially for metal structure, it needs to be corrected before installation.

Mechanical Equipment Installation

All ordinary bolts shall be fastened with standard wrench, and high-strength bolts shall be fastened with ac28-76 torque wrench. The construction method shall be in accordance with the construction specification for high strength bolt connection of steel structure.

The gantry shall be installed and hoisted according to the sequence of lower support - gate leg - upper structure - trolley, and finally all parts of the lifting mechanism shall be hoisted on the trolley. The technical requirements shall be in accordance with the provisions of the drawing.

When unfastening the steel wire rope wrapped in a disc, the rope shall be rolled by grasping the rope loop or put the rope loop on a rotatable stand to unfasten the rope. The rope shall not be unfastened at will when the rope loop does not rotate. Otherwise, it is easy to cause tight, loose and twisted rope.

The machine room and the base are in place as a whole, and the base is welded to the trolley by fillet weld.

Handrails, ladders and platforms shall be welded on site according to the drawing requirements.

When installing the cab, first weld the base plate on the middle cross beam, and then connect it firmly with bolts.

Installation of Electric Control Equipment

The main power supply, main hoist and its automatic grabbing beam, trolley, crane, crane rail clamp, cable drum electric control equipment, PLC host, etc. are installed in the cab; PLC Remote I / O is installed in the machine room; 1 set of PLC Remote I / O, operation linkage console, operation display LCD, etc. are installed in the cab.

During installation, the following methods shall be followed for installation:

Installation method of lights

The ceiling lamps in the cab and machine room are installed on the ceiling, and the rack lamp and searchlight are fixed at the corresponding positions of the turning table and middle beam according to the construction drawing.

Lubrication System

Scattered lubrication

Regularly check whether the bearing lubrication of the reducer is good, and fill in the lubricating oil in time.

Regularly check the oil level and sealing of the reducer, eliminate oil leakage and supplement new oil in time.

The first oil change shall be carried out after the reducer of the lifting mechanism operates for 300-600 hours. After that, change the oil every other year, the TA reducers of crane and trolley traveling mechanisms have been filled with oil before leaving the factory, and the oil shall be changed after one year’s operation

Add lubricating grease to the bearing regularly, once every half a year, and clean it every other year to one and a half years.

The steel wire rope shall be lubricated regularly, once every 3 ~ 6 months in the initial stage, and once every half a year ~one year after 1 year.

Centralized Lubrication

The working time of the electric pump of the centralized lubrication system is 10min / 2h. After working for 100 hours, the lubrication time can be appropriately increased or reduced according to the lubrication situation.

The centralized lubrication system adopts progressive distributor, and the following matters shall be paid attention to during use:

Joints and pipelines shall be firmly connected without leakage.

When installing the distributor, the plunger must be in a horizontal position. After installation, the distributor must act accurately and flexibly without leakage.

Ensure that the grease used is qualified.

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