Position: Home > Blog

Gantry Crane Operation Manual--Part Ⅱ Erection,Test and Maintenance

DATE: Mar 3rd, 2023
1. Gantry crane erection

1.1 Gantry crane erection preparations
First of all, the workers, engineers and manager should have a meeting, discuss and make plan. The safety department should review the election plan, and the installation persons should respect safety department's opinion which is related to safety operation.
The gantry erection plan should accord with technical requirement of the technical documents, dead weight of the lifted load, site conditions.  The detailed operation condition for example the capacity of the lifting equipment should seek for all installation persons' opinion to make sure the coincidence of practice and understanding.
Before erection, check every piece of equipment and site condition. If there is any object which may kinder erection on the installation site for example wire or variety pipe etc. , if necessary we should dismantle them, or take other temporary measure to ensure other department's routine work. To see if the winch used for lifting work runs smoothly or not, especially check whether the brake work reliably or not, winch fixed safe or not. In the progress of lifting, avoid the winch drag under impact of weight. Check the upper and lower pulley used for lifting, the strength of the wire rope used for binding trolley, and the binding situation. The lifting wire rope should have more than 5 safety factor, without break, kinking and other damage. Except brake part, all rotate part for erection should fill enough grease.

1.2 Gantry crane general safety technical requirements
The following safety rules must be obeyed.
①Before erection, the supervisor should introduce the lifting method, lifting steps, command signal, notice items and each personnel's responsibility.
②The person should hold signal flag (usually red or red green two colors) , stand in obvious place. All persons can see and hear the command. If it is necessary, assign special person responsible for contact and install loud speaker and telescope, to observe main parts banding, connecting and work.
③If there is no sufficient lighting equipment, night erection work is forbidden.
④It is strictly forbidden to lift or lower the person with the wire rope or trolley.
⑤If it is not necessary, the lifting attachment and lifting tools are forbidden to repair under the condition of suspending in the air.
⑥In erection area, ensure the bare wire doesn't contact with personnel.
⑦During erection process, stay and pass under the crane is strictly forbidden. Unauthorized personnel is not allowed to enter the erection area.
⑧In case of power failure, ensure to effectively stop the lifting crane. If erecting at night, the lighting equipment which may not get influenced by power will be prepared to avoid power failure. During power failure time, assign someone to guide the parts. Stay under the suspension crane is strictly forbidden.
⑨In order to check whether the erection work is good or not, lift the crane up to 100~200mm above floor for a while, check all lifting equipment and tools, binding condition, lifting wire rope hanging condition in the pulley, guide wheel fasten situation, crane correct gravity center, if it is easy for drag wire rope, mast base condition. After make sure everything is no problem, and then begin the regular erection work.
⑩The winch shall run stably, try to avoid abnormal situations such as urgent vibration and shake.

1.3 Gantry crane erecting requirements
The erection of the crane should need professional persons to fulfill according to installation plan requirement.

2. Gantry crane operational test
For the newly erected crane, the commissioning and test must be carried out. It can also be done as a regular test.

2.1 Gantry crane erection preparation and inspection
In order to operate the crane safely and smoothly, careful inspection must be done before the test, making full preparation for the test.
①Cut off all the power for crane, check fastening of all connections.
②Check if all the traveling mechanism is precise and flexible, if there is any deformation of the steel structure, and if the winding of steel ropes in wheels and drum is all right.
③Check the insulated resistance of circuits and electrics equipment with ohmmeter. Make sure that they are eligible.
④Cut off the power-check the operating circuit and whether all the transmission parts are flexible and reliable.
⑤ Add grease to the all lubricating points (finish it before delivery), add grease to reducer as required.
⑥Ensure electric equipment works reliably, therein especially pay attention to electromagnet, limit switch, safety switch and emergency switch. Check the connecting wire phases sequence of separate driven motor, make sure two motors run synchronously.
⑦Clean everything which may influence the testing on crane track, crane and test area.
⑧Other persons that are not related with the erection should leave the crane test site, and take measures to prevent the participating person from electric shock.
⑨Preparing the loading test weights such as steel ingot, billet, bar steel, pig iron or mass rough cast. Weigh them carefully and pack them safely.
⑩Check test condition (for example site, wind speed etc.) to see if they accord with requirement or not.

2.2 Gantry crane unload test
①Turn the braking wheel of each system manually, make wheel shaft and drum shaft turn one circle to see if they can move flexibly.
②Turn on the mechanism separately. The operating direction should be same as mechanism travelling direction. Operate each mechanism at slow speed first as a trial, then a treated speed, the system should be travelling smoothly without any abnormal, such as strike, vibration and noise.
③Operate the crane to make it travel along the rail for three times, check each traveling mechanism. The driving wheels of trolley for double girder crane should contact with the rail all the way along.
④Moving speed of cable should coordinate with the travelling mechanism.
⑤Test every limit such as limit switch, door switch etc.  check if everything is in good condition.
⑥While the hook is at the lowest position the safety circle of wire rope on drum should be less than 2 wraps.

2.3. Gantry crane load test
After the test without load is over and all right test with load is allowed to be carried on. The test divides into two steps static load test first and dynamic load test second.

2.3.1 Static load test
The purpose of the static load test is checking the capacity of crane and all parts. Static test for each lifting mechanism should be carried out separately. For double trolley crane when total lifting weight is the sum of two trolley capacity the test should be carded out at the same for the two main hooks in order to test capacity of the bridge. When lifting weight is one of the trolley carry on the test separately with the trolleys.

Firstly operate the crane to hoist small load 0. 5-0. 75 of rated load for several times then hoist rated load run the trolley along the girder back and forth several times. Then stop it on the
middle of the girder get the benchmark.

Secondly increase the load up to 1. 25 rated load lift 100-200mm from the ground hold for 10 min. Then unload it check the deflection to the benchmark suspend a plumb from the middle of the bridge or the structure of the roof and correspondingly set up a measuring pole on the ground or the main girder. Repeat this test for three times after that the girder should not have any permanent distortion move the trolley to the leg zero point the actual camber should be no less than 0. 7S/1000 upward degree of effective jib shall be no less than 0. 7L1( or L2) /350.
Finally, stop the trolley in the middle of the bridge, lift the rated load to 100mm from the ground, measure the lower deflection of the main girder. For grade Al~A5, ≤S/700, grade A6, ≤S/800, grade A7~A8, ≤S/1000 (see appendix C for foundry crane). The test is qualified if there is no cracks, no permanent distortion, no peeled paint or any other damage like these which may affect safety.

2.3.2 Dynamic load test
The purpose of the dynamic load test is to validate the function of every system and brakes of the crane Lift 1. 1 times of the rated load for dynamic load test, run each system (or start 2 of them at the same time ) , repeat each movement and function, control as per working procedure, work duty and operating instruction, the test last for one hour.

After the test, there should be no crack, no permanent deformation or paint peeling off, or damage that will affect performance and safety of crane, no damage or loose for connection, than the test is qualified.

3 Gantry Crane Maintenance and Lubrication
In order to make crane works well and prolong its working life or the working life of its components and elements, regular check and adjustment must be done.

3.1. Gantry crane inspection of metal structure
Check the steel structure 1 or 2 times each year, see if there is any looseness, cast, distortion, craze or cauterization. The check content and standard for the steel structure are as shown in Table 5.
Table 5 Check content and standard for steel structure
Item Contents Standard
Gantry Main girder distortion Check the deflection of the main girder with rated load located in the mid-span
deflection < S/700on the basis of level line
Check the level sideway bending and other distortion of the main girder when hoisting rating load Sideway bending and other distortion value should be in accordance with standard
structure Check if there is any crack,rust, abnormal distortion,twist as a whole for the structure and local instability All these trouble cannot exist
Check if there is any looseness, break off, crack, erosion in connection parts All these trouble cannot exist.
Others Check the surface protection of the metal structure No bubble, peeled off paint or obvious rust
Trolley frame structure Check if there is any crackdistortion or crack No crack,distortion or craze
Check surface protection of steel structure. No bubble,peeled off about paint or clear rust
Check if there is any looseness and fall off in connection parts No looseness or fall off
Connection of Cab and main girder Check if there is any crack in main material and welding area No crack
Check if the bolts are tight and reliable Each one should be tight and reliable

3.2  Gantry crane component inspections and maintenance 
3.2.1 Check hoisting mechanism:
Check content and standard for hoisting mechanism is shown in table 6-2 examination for the same parts in lifting and traveling mechanisms, such as motor, couplings, reducer, shaft and bearing, etc, can refer to the relevant contents and standards in Table 6.

Table 6 Check content and standard for hoisting mechanism
Item contents standard
Drum assembly Drum group Check if there is crack distortion or abrasion,any abnormality No crack,obvious distortion or abrasion
Check if there is any abnormality for the fastening of steel rope No looseness
Check if there is any trace of steel rope missing from the grooves fastening of the drum fixed. No trace of steel rope missing from the groovesdrum is fixed well.
Shaft and bearing Check if there is crack,distortion or abrasion No crack, obvious distortion or abrasion.
Check if there is any distortion or looseness on baffle in the shaft end No distortion or looseness
Check if there is any abnormal noise,heat or vibrations from bearing No abnormal noise vibration or heat
Pulley group Pulley Check if there is any crack flaw,damage or abrasion No crack,flaw,damage or abrasion
Check if there is any abnormality of rope groove No abnormality of rope groove
Check if there is any trace of steel rope missing from the grooves No trace of steel rope missing from the grooves
Check if there is any looseness of clamp or orientation pin No looseness
Rope baffle for shaft and bearing balance pulleys, etc. Check if there is any crack or abrasion No crackobvious abrasion
check the lubrication Lubrication is good
Check if there is any abnormal noise or eccentricity for turning pulley No abnormal noise or eccentricity.
Check if there is any rope missing from grooves,any break off distortion or crack. No rope missing from grooves,break off,distortion or crack
Wire rope Structure of the rope Check if the structure and diameter of the wire rope conform to design when wire rope is changed. Completely in accordance with drawing attached
Check the safe circles of wire rope on drum when the spreader is at the lower limit position. There must be at least 2 circles of wire rope on the drum for the sake of safety
Structure of the rope Check the safe circles of wire rope on drum when the spreader is at the lower limit position. There must be at least 2 circles of wire rope on the drum for the sake of safety
Check if there is any broken thread, broken strand,exposed core,twist,erosion looseness,abrasion There must not be 10broken thread in 1 length of lay. Diameter of the rope is not allowed to be less than 93 of that ratedno obvious defect
Rope condition Check if there is any broken thread,broken strand,exposed core,twist,erosion looseness,abrasion There must not be 10broken thread in 1 length of lay. Diameter of the rope is not allowed to be less than 93 of that ratedno obvious defect
Check if the structure of the wire rope applied in high temperature environment is correct The structure should accord with the purpose of application
Check if the processing of the end and the fastening is correct There should not be any defects fastening should be reliable
Check if there is any rope missing from grooves No rope missing from grooves
Check if there is any dust sand,impurity or moisture attached on the rope No dustsand,impurity or moisture attached to the rope
Installation and application of the wire rope Check if the wire rope crash against structure parts There should not be any collision
Check the contacting condition with each pulley. No obvious abrasion. There should not be any pressed deflection or loose
spreader Hook Check the hook and see if there is crack distortion or abrasion No crack,obvious distortion or abrasion
Rotate Hook and see if there is any abnormal noise for bearing and thread part. Rotate smoothly and no abnormal noiseno abnormal distortion
Check if there is any abnormal distortion at the hook mouth; check lubrication of the bearing Lubrication is good and oil mass is right
Connecting Plateconnecting piece Check the fastening of connecting plate and connecting piecesit shall has no falling Reliable fasteningsafeno loose
Pin,shaft ,side plate have no deformation No distortion
Check if anti-off device of wire rope function well Normal function and no distortion
Check the lubrication of bearing No crack,abrasion and distortion
Check the lubrication of bearing No crack,abrasion and distortion

3.2.2 Inspection and maintenance travel mechanism of gantry crane
Check item, content and standard of crane and trolley travel mechanism see table-7

Table 7 Check item, content and standard of crane and trolley travel mechanism
Item Contents Standard
Motor Base Checks if there is crack on the baseloose connection or fall off. No crackloose or fall off.
coupling key and key slot Check if there is key loose out of the slot or deformation. No looseout of slot or evident deformation
Check if there is crack or deformation of key slot. No crack and evident deformaion
Transmission shaft Rotate coupling to check if there is run-out and end face run-out No evident radial run- out and end face swing
Rubber elastic ring Check the condition of deformation and wear Don’t exceed scrap limit
Gear coupling Check the lubrication and see if there is leakage. Proper lubrication and no leakage
Bolts and nuts Check if there is abnormal noise No abnormal noise
Brake Brake Check the working condition of brake Normal,effective,no eccentric wear
foot-pedal-op erated brake Check if they’re normal for pedal gap and clearance between pedal and bottom plate when treading. Gap and clearance should be appropriate
Check if there is loose or mis alignment for lever system. No loose or mis-alignment
Hydraulic brake Check the fluid level and if there is an oil leak Oil proper,no leakage
Check the function of cylinde damage and leak Work well,no damage and leaks
Check if there are bendingdeformationoil and leakage for push rod No obvious bending,appropriate oil and no leakage
Electrical magnetic disk brake Check the work condition of electromagnet Stable movementno abnormal noise and disgusting smell
Brake wheel and brake shoe Check if there is any loose for brake installationand if it is any peel offdamage and eccentric wear for friction shim. No loose,no peel off,damage and eccentric wear.
Check if it is ageing for spring No aging
Check if there is any crack wear down and damage for brake wheel No crack and damage,normal wear.
Check if it is appropriate for brake clearance. Brake clearance meets requirements.
Regulating mechanism for stroke and brake torque Check if there are any abnormal for regulating mechanism such as stroke, brake torque Suitable regulator, stable movement
Check if they are any crack bend and wear for pull rodsaxis pinslevers and bolts. No crack, distortion and obvious wear.
Installation of bolts and pin shaft Check if bolts and nut shave any loose from axis pin No loose.
Reducer Gearbox casing Check if there is any crack deformation and damage. No crack,obvious deformation and damage
Check if there is any loose or fall off for installation connection No loose and fall off.
Check oil massoil product and oil quality. Appropriate oil mass, no pollution
Check if there is leakage No leakage
Gear wheel Check if there is any abnormal noisefever and shaking No abnormal noise, fever and shaking.
Check if there are any abrasion and damage on tooth surface No obvious abrasion or damage
Check if there is any crack deformation or damage for wheel hubwheel disc and gearwheel No crack,deformation and damage
Check if there is any loosedrop from groove or deformation of key No loose,drop from groove and obvious deformation
Check if there is any crack or deformation on key groove No crack and deformation
Check if they are abnormal for gear tooth contact and engagement Good contact,suitable contact depth
Check the lubricate condition Good lubrication
Gear box cover Check if there are any crack deformation or damage. No crack,obvious deformation and damage
Check if there is any loose for connection and installation No loose
Shaft Rotation shaft. Arbor transmission shaft Check any deformation and abrasion. No deformation,damage,good lubrication.
Check if there is vibration for drive shaft No abnormal vibration,noise or obvious heating.
Check if there are any loose deformation or crack for key and key groove No loose and crack
Bearing Rolling bearing Check if there is any crack and damage. No crack and damage.
Check the lubrication conditions Good lubrication
Check if there is any abnormal vibrationlever and noise in idling and load situation No abnormal vibration,noise or obvious heating
Sliding bearing Check if there is wear for bearing. No obvious wear
Check if there is burning loss or heating in no load and loaded condition No burned or obviously rise in temperature.
wheels flange Check if there is any crack lossdeformationwear No obvious deformation and abrasion
Wheel tread Check if there is any abrasion for tread No obvious abrasion
Check the diameter deviation of driving wheel and driven wheel Error value of wheel diameter should conform to the related standards.
Check the crack,deformation and peeling off of tread surface No crack,deformation and peeling off.
Bearing in the wheel hub Check the lubrication condition of the sliding bearings Normal
Check if there is abnormal vibration, noise,rising in temperature in no load and loaded condition. Normal
Check the lubrication condition shaking,noise, and rising in temperature of rolling bearing. Normal
Gap between hub for vehicle wheel and end carriage side plate Check if there is any friction and wear No friction and wear
Check the installation accuracy Good installation

3.2.3 check of the rails
Check crane and trolley rails for 2-4 times one year. Track is the base of crane and trolley smooth running. The impaction and vibration generated by crane travel may lead to track looseness, connecting parts fall off, distortion and crack, and precision index out of tolerance, all these defect will affect the normal operation of crane and trolley.

Check and adjustment can ensure all the structure work well. The rail check item and content are as shown in Table-8
Table 8 cheek content and standard for rail
Item Contents Standard
Rail Rail Check if there is crack,head of rail sag,distortionor any damaged on side face No crackevidence cave indistortion or seriously wear
Rail fastening bolts Check if connecting bolts have any loose or fall off No loose or fall off
Connecting plate and pads Check if Check if  bolits have any loose or fall off No loose or fall off
Connecting plate and pads Check if there is displacement,fault or fall off for connecting plate and pads No displacementfaults or fall off
Buffers, end stoppers Check if there is any damage or dislocationany loose or fall off for installation. No damage or dislocationNo loose or fall off.
Rail joint Check if rail joint have any dislocation and gap change No obvious dislocation and gap change
rail welding and install Check if there is crack and gap for welding line No crack or craze
Geometry dimension error Check deviation of gaugecenter line and top elevation of rail Don’t exceed the specified value

3.3  Gantry crane maintenance of control system and electrical equipment
3.3.1 check-up of power supply system, electrical components and control system.
Refer check item for power supply unit, drive device, electrical components, and control system in Table 9.

Table 9 check items, contents and standards for electric and control system
 Item   Contents   Standard 
 Motor   Resistor   Check if insulated resistance has any heating   No abnormal heating within the prescribed scope 
 Bearing   Check the lubrication conditionany abnormal noise   Good lubrication and no abnormal noise 
 Sliding ring   Check whether there’s any change in color any crackany loose connection   No obvious change in colorcrack or loose connection 
 Brush and conductor   Check whether there’s any wear and loose   No obvious wear or loose 
 Brush and conductor   Pressure   Proper pressure 
 Toner adhesion check if there is carbon powder   No carbon powder absorbed 
 Check whether there’s loose for rotating the motor shaft   No loose 
 Current Collecting device   Sliding wirecurrent collecting rail   Check if there is any deformationabrasion or damage   No obvious deformation abrasion or damage 
 Check whether it is normal for tension device   tensile force is normal 
 Check the contact condition of sliding wire and sliding block   Good contact 
 Check if there is any loose for insulator supports   No loose 
 enclosurecover   Check whether there’s enough damage or deformation   No damage or obvious deformation 
 Insulated collector   Check if it is normal for anti-electric shock device   There’s enough distance from sliding wire 
 Insulator   Check if the wiring of for insulated collector has any abormality   Reliable connection among cable corejoint and enclosure. 
 Mechanical part   Check if there is any fall off, loose,crack,or dirty   No fall off,loose,crack,dirty 
 Check whether there’s any damage or wear   No obvious damage or wear 
 Spring   check whether lubrication is good   Good lubrication 
 Wiring and insulation   Check if there’s any deformation erosion and fatigue damage   No deformation,obvious erosion, and fatigue damage 
 joint bolt   Check any break of wireany dirt or damage of isolator   No broken line or damagedirty 
 insulating layer   Check if there’s any loose or fall off for fastening parts   No loose or fall off 
 joint   Check if there’s any damage   No damage 
 Cable and direction guider   Check if there’s any loose or fall off for fastening parts   No loose or fall off 
 Electric parts and the control system   Switch contact part and protector   Check if stretching part of cable has any bendingdistortionor damage   No bending,distortion or damage 
 Movement condition of cable and guiding device   Smooth movement 
 Check whether the switch motion is abnormaland there is any appearance damage.   normal motion and no damage 
 contactor   Check whether pressure of the hinge and clip of contact part is appropriate   contacting pressure is appropriate 
 spring   Check whether installation and capacity of protector is appropriate   Installed correctly and capacity is appropriate 
 movable iron core   Check the contacting pressure of contactor and the damage of contact surface.   No gap between contacting surfaces and disconnect completely when disconnecting 
 Check if there’s any deformationdamageerosion and fatigue aging.   No deformationand fatigue aging. 
 Check whether there is any adhesive material on the suction surface of iron core   No attachments 
 check whether there’s abnormal sound or any broken line for shielded coil   no abnormal sound or broken line 
 arc-suppression coil   check if there’s any damage or wear on limited block   no damage or wear 
 arc chute   check whether there is any gap when open circuit   no gap 
 Check if there’s any loose for fastening parts   no loose 
 fastening parts   Check whether it’s in the original position   should be in the original position 
 spring   check whetherit’s over-burning   no obvious over-burning 
 time relay   check if there’s any loose   no loose 
 damp delayer   check whether there’s fatigue damage   no bucklingdeformationerosionfatigue damage 
 check the time-limited   time limit is correct 
 operation of contact pieces   Check whether the oil drum falls offleak oil   No oil leakage or falls off 
  oil quantity and quality oil quantity and quality are normal
Check whether contact surface has any damage and wear No obvious damage and wear
Mechanism and operation test Hand operated,check movement conditions movement should be normal
Mechanism and operation test Check the connection of connect terminal No loose or fall off
Internal wiring check whether wiring and insulation have damage degradation no damage,pollution and degradation
check whether conduit inlet have any abnormality no damage or obvious degradation
check if there’s any loose no loose
connection of fastening parts Check if there’s any abnormal for electric shock protection device no damage,fall off,deformation or degradation
electric shock protection device check if movement is normal smooth movement
movement condition check whether movement of zero limiter and pendant are normal. position of limiter and pendant is reliable
check contact pressure
Fastener with no looseness
contact completely or disconnect completely when separated.
Clutch disc and clutch roller ubricating condition of clutch roller no looseoil feed is normal
Check if there is any breakagedeformationcorrosion and fatigue damage No breakagedeformationcorrosion and fatigue damage
return spring check lubricating condition oil feed is appropriatelubrication
bearing and gear check whether contact surface has damage or wear no obvious damage or wear
contact chip and terminal contact depth of contact chip contact completely
check whether there’s crackdefacement no crackor obvious defacement
insulating rod check whether there’s damage or pollution Display clearlyno obvious defacement
Lines and communication display board of movement direction check whether conduit inlet  have any abnormality no damage or obvious change
wire inlet check movement condition normal movement
Switch if there’s any damagepollution no damage or pollution
check if any abnormality for enclosure cover gravity protection device no damage
Check if fastners have any looseness no loose
terminal whether there is any crack damage no crack or damage
resistor disc check whether there is any contact between resistor discs no contact
check whether there’s any loose no loose
check whether wiring and insulation near terminal is overheating or burning no over-burning
check whether there is any dust on the insulator no dust accumulation is allowed
check if there’s any loose for tightening part no loose
connection of fastening parts check if there’s any damage on protection layerand there is too tight twistedand loose wire clamp no damageshall not be too tighttwisted or loose
open wire check whether illuminating is appropriate brightness Ensure sufficient brightness for operation and instrument
lighting and signal light any loose joint no loose
check whether fastners have any looseness. no loose
check whether there is any damage for bulk and protection device no damage
check whether insulation resistance of each branch circuit of distribution circuit is abnormal. Insulation resistance value should be within the prescribed scope

3.3.2 Maintenance of electricity equipment
Establish maintenance system of electrical equipment, all maintenance cycles are regulated according to work duty and environmental condition of the crane, all the following regulations apply for the common condition.

Daily maintenance should be done by crane drivers when handing over to the next shift, the scope of maintenance is as follows:
Remove attachments such as dust, sludge and oil outside the electrical equipment, check heating condition of motor, electromagnet, controller contact, resistor and so on by hand, check whether bearing is leaking oil, wire joint of main equipment is tight, dust, iron filings and so on shall be prevented when open the hand hole cover or enclosure, write down all observed special conditions.

Ten-day (or bi-weekly check ) maintenance should be done by electrician and crane driver, the scope of maintenance is as follows:

Clean the dust, dirt and oil inside the electrical equipment, check the wear of brush carrier and slip ring of carbon brush of motor, any abnormal noise from motor, electromagnet, relay and electromagnetic head, check and repair controller and contact switch.

Annual maintenance or overhaul should be done by electrician, content is as follows:
Disassemble electrical equipment and clean them, overhaul supporting frame of each equipment, clean the rolling bearing of motor and change grease, survey the gap between rotor and stator, replace the rolling bearing if found it uneven. Survey insulation resistance, dry it when necessary, repair all problems during annual repairing, replace parts beyond repairing, each item of equipment actual attrition and the obsolete degree. the scope of annual maintenance and overhaul are determined by actual wear and obsolescence degree of equipment.

Only dry fire extinguisher is allowed to be used on crane.  The most commonly used is carbon tetrachloride fire extinguisher, does not allow to use foam fire extinguisher, the sand can only be used to put out the fire of conductor, but can not be used to put out the fire of motor.
When the fire breaks out, first power supply shall be cut off, then cut off power by emergent switch or knife switch on the protecting panel.When the conductor in front of protecting panel catches fire, cut off the knife switch.

Check and clean the crane that has burnt, dry and inspect all electrical equipment and wiring, which can't be used until it's repaired and qualified.

3.4 Gantry crane lubrication
The lubrication will affect the running of crane, all the axes, holes and grinding part should be lubricated regularly. so the operator and maintenance man should check the lubrication points and add grease on time. According to requirements of customers, the lubrication has Sub—point lubrication and centralized lubrication.
3.4.1 Lubrication points distribution of lifting equipment
①two ends of pulley shaft of hook and thrust bearing under hook nut.
②fixed pulley shaft (on trolley frame )
③wire rope
⑤gear coupling
⑥each bearing base (including wheel block, bearing case and drum base )
⑦motor bearing
⑧each hinge point of brake
⑨ bearing of pulley

3.4.2 lubrication condition and material
Crane equipment has to use appropriate lubrication grease, apply lubricants regularity、lubricating devices and lubrication point must be kept clean. General regulations of the lubricating time of main components and lubricating materials recommended are shown in Table 10.
Table 10 The lubricating material and cycle for typical parts  
  Name of parts     Lubricating cycle     Lubricating condition     Lubricating material  
  Wire Rope     Commonly once every 15-30day,or according to actual conditions     1.Heat the lubricating to 50-100℃ then apply.2.Apply without heating     core wire rope (SH/T0388 19992);Calcium-based graphite grease(SH/T0369-1992)  
  reducer     At change beginning oil once a season, later change oil once half or one year according to actual condition      Industrial closed gear oil L-CKC(GB5903-1995)
open gear Clean once every half month, season or half year Extreme pressure lithium base grease (GB/T7323-1994)
gear coupling once a month 1.temperature ranges from -20℃ to 50℃
2.working temperature higher than 50℃
3.working temperature lower than -20℃
1.calcium lubricating grease(GB/T491-1987)
2.General Purpose Lithium Lubricating Grease(GB/T5671-1995)
3.use no.1 and no.2 special lubricating grease(Q/SY1110-70)
rolling bearing once every 36 months
sliding bearing according to actual situation
gear disk inside drum add oil when over haul
motor annual repair or overhaul 1. normal motor
2.with H insulating grad,and used 
1. General Purpose Lithium(GB/T5671-1995)
2.complex aluminium base grease(SH/T0378-2003)
hinge point of brake once every month industrial lithium lubricating grease

3.4.3 Notices of lubrication
① Keep lubrication material clean
②Do not mix r and use lubrication grease of different brands.
③ Check sealing condition of lubricating system regularly.
④ For lubrication work, choose suitable lubrication material and add it grease regularly.
⑤ It's better to adopt pressure grease (oil gun or pump ) , Try to avoid smearing grease.For the grease does not easily get into the friction surface, try to push the grease to the friction surface if necessary.
⑥ Lubrication work is only allowed when crane completely power off.
⑦ Make sure that the pipeline doesn't get crushed, pressed and impacted.
⑧ When disassembling the pipeline, take care of the pipe ends or joints. for fear of damage or mechanical impurities. When re-installing, carefully clean the joints to make sure the oil way is clean enough.
⑨ Sodium grease is not applicable for humid area, as it's absorbent and easily void.
⑩ For the rotate parts without grease points add thin oil to the gaps of all rotate parts regularly to reduce abrasion and prevent rust.

Note the fat body with a rotating point location should regularly point dilute oil injection site in the rotation slot to reduce engine wear corrosion prevention.
When lubricating points adopt appropriate rotation to make the grease distributed uniformly.
Various lubricants materials without the required replacement interval have been found contaminated or metamorphic and should be replaced immediately.  
If various lubricating materials which doesn't reach the replace interval are found contaminated or metamorphic replace them immediately.

4 Gantry Crane Common Faults and Handling Methods
During the using of crane mechanical parts electrical control and hydraulic system would inevitably have abrasion or damage Reasons that cause same damage may not one-to one correspond carefully analyze the fault find out the real reasons and take corresponding measures to eliminate the fault Thus recover the technical performance of the fault point. The main faults and the methods are as follows:

4.1 Gantry crane common faults and handling method of metal structure table 11

Table 11 Malfunction of steel structure
Faults Causes Eliminating Method
Fatigue crack on main web plate or cover plate Overload for long time When crack is less than 0.1mm,use grinding wheel to grind it. For bigger crackdrill Ф8 holes at each side of the crack and open 60° on both sides of the groove,and weld.
Wave-like distortion on web plate of main girder Overload makes local part of web plate lose balance Rectify with flame,remove distortion,eliminate internal stress with Hammer,strictly prohibit overload operation.
side bending of main girder caused by overlaying of working stress,wrong transportation and storage Rectify with fireheating the protrude parts of main girder and use some tools.
Main girder sinking distortion. Main girder structure stress web plate wave-likes distortion effect wrong storage,transportation. Adopt pre-stressing force to rectify After flame-treatment,use channel steel to strengthen along lower cover plate of main girder.

4.2 Gantry crane problems and solutions of each structure (tablel 12, 13, 14 )
Table 12 Failure (failure of each part of hoisting mechanism ) and trouble-shooting of each mechanism
Name Failure and damage condition Reason and Result Trouble-shooting
Forged Hook fatigue crack on hook surface Overloadovertime use,flaw of material replace it if any crack found
wear of opening and dangerous section Lessen the rigidity, or it is easy to cause hook break and accident replace hook when the abrasion over 10 of dangerous section
Crack and wending parts have plastic deformation Long time overload and fatigue. Replace immediately
Laminated hook distortion of hook Long time overload,and it is easy to cause hook break replace
surface has fatigue crack overtime overload and hook damage replace
the abrasion of pinshaft is more than 3 -5 of nominal diameter Hook fall off replace
earring has crack or burr earring breakage replace
the abrasion of earring’s lining reaches 50 of original thickness bad forced condition replace
wire rope Breakage,knotting,abrasion Cause to breakage of rope Stop to use it when wire rope break and knot; replace according to standard when thread break,and replace the wire according to standard rope-when it have abrasion
pulley Uneven abrasion of block’s groove material asymmetry, bad installation and bad connection of rope and wheel replace it when abrasion of groove’s wall reaches 1/10 of previous thickness,and gauge ware reaches 1/5 of wire rope diameter
pulley can not rotate shaft and bearing damage replace the shaft and bearing and then lubricate and maintain them
pulley incline or loose keeper of shaft loose or wire rope hop out of groove Fasten the keeper and repair the wire rope’s hopping
crack of pulley or break of wheel flange pulley damage replace
drum Drum fatigue crack break of drum replace drum
abrasion of drum’s shaft and key break of shaft and cause the load fall off stop using and inspect the shaft key immediately
Groove abrasion and rope hopping.The abrasion reaches
15%~20 of the original thickness
The rigidity of drum becomes weaker and easy to break. And wire rope is twisted replace the drum
gear Gear teeth break abnormal noise during operation,if continue to use, it will damage the transmission mechanism replace the new gear
Abrasion of gear reaches the 15 ~20 of the original teeth thickness impact and vibration occured during working and then damage the transmission mechanism replace the new gear
Gearc rackgear key groove damaged by rolling of key Vibration and noise caused by overtime use and improper installationwhich make load fall off replace lifting mechanism,for traveling mechanism,repair or renew the key
Flack section reaches 30 of the working area. And the depth reaches 10of the teeth thicknessCarburized layer abrasion reaches 80 of teeth the thickness. Overtime use,Bad material, improper heat treatment cause the damage of shaft. replace:for the reducer with peripheral speed>8m/s, when there is some abrasion,replace pairs of high speed gear of reducer.
shaft crack Bad material improper heat treatment cause the damage of shaft. replace
Bending of shaft is more than 0.5mm/m cause damage of shaft and influence the transmission and cause vibration Replace or rectity
damage of key groove unable to transmit torsion for lifting mechanism,replace them,or traveling mechanism,repair them
wheel wheel tread and wheel flange have fatigue crack damage of whee replace
Uneven abrasion of drive wheel surface leads to rail gnawing,tilt of crane replace in pairs
Abrasion of tread reaches 15 of wheel flange thickness vibration when traveling;damage of wheel replace
Wheel flange abrasion reaches 50 of the previous thickness Due to the crane tilt and rail gnawing,and cause derailment replace
brake part Fatigue crack on lever brake fails to work replace
Fatigue crack on spring brake fails to work replace
The abrasion of mi nor shaft and mandrel reaches 3 5 of nominal diameter Fails to brake replace
the abrasion of brake wheel 40% 50 of the original wheel flange thickness load fall off or crane slide replace
Brake shoe friction shim wear 2mmor to 50 of primary thickness failure break replace friction shim
Coupling crack on coupling damage of coupling replace
loose in connection bolts Impact and vibration during braking starting will cause bolts breakage and falling of loads Tightened
Abrasion or breakage of coupling gear Lack of lubrication, heavy workload,start oppositely will lead to damage of coupling For the lifting mecha nism,when the abrasion of gear teeth reaches 15
the original thickness, replace it,and for the traveling mechanism,when the abrasion of gear teeth reaches 30
 the original thickness,replace it.
Press and deformation of key groove cannot transmit the moment of  torsion, key falls off for lifting mechanism, replace them,for other mechanisms,repair them
Abrasion in shaft, pin and rubber ring etc  Heavy impact and vibration when starting or braking Replace worn parts
rolling bearing Temperature is too high lubricating oil dirt clean dirt,replace bearing
Completely lack of oil add lubrication oil as per regulation
Too much oil check the quantity of lubrication oil
abnormal noiseContinue to dead sound dirty bearing clean dirty
metal grinding noise lack of oil add oil
topping or impact sound Pamage of coupling support, rolling body Replace bearing
sliding bearing over heating incline of bearing and press too tight Eliminate deflection,tighten reasonablely
improper clearance adjust clearance
lubrication shortage add lubrication
bad lubricants use good and qualified lubrication

table13 Fault and troubleshooting (lifting mechanism part )
Name cause Solutions
brake Fail to lock brake wheel
(load fall down)
Hinges of leverage is stuck Remove stuck and give lubrication
oil on the brake wheel and friction shim Clern oil dirt
lack of travel distance of magnet iron core adjust brake
brake wheel and friction shim have heavy abrasive wear replace friction shim
main spring loose or damage replace main spring and nut
Lock nut and lever loose Fasten lock nut
Hydraulic thruster impeller not work Check electrical part of thruster
Brake fails to release Magnetic wire burned Replace
Disconnection of wire to magnetic conductor Connect the wire
Shoe block on on braking wheel Clean with kerosene
Gemel stuck Eliminate the lock and lubricate it.
Main spring force is too large or configuration is too heavy Adjust the main spring force
Push bar inflectedcan not move the magneticiron(hydraulic push bar break) Straighten the mandril or change he mandril
Improper oil application Chang oil according to working condition
Impeller is locked Adjust push rod and check electrical part
85 lower than the rated load,magnetic force is not enough. Find out the reason of voltage reduction,eliminate the trouble.
Break heating, friction shim realease scorched smell and get worn soon. Shoe can’t fully disengage braking wheel friction when break looseso cause friction Adjust clearance
Asymmetrical distance from two brake shoes to braking wheel Adjust clearance
Supporting spring damage or bending Replace or repair the spring
Rough surface of break wheel Turning the surface of brake according to requirements
The brake is easy to deviate from the adjusted po sition. And the breaking torque is not steady Fasten nut is loose. Screw thread damage Fasten nutReplace it
Magnetic overheat or abnormal noise Main spring is over pressed Adjust to proper extent
Push bar is blocked Eliminate the block and make lubrication
Wrong position of iron core and mandrel leveling fitting surfaces
reducer phenomenon of periodic cyclical gear vibration, especially for the driven wheel Section distance error,gear side clearance beyond tolerance Repair,re-install
Severe metal friction sound, reducer shake, shell tinkers. Gear backlash is too small,gear
axes are not parallel
,gear has sharp edges
gear meshing,irregular rattle,
shell shake.
teeth surface is not flatteeth with flaws, gear contact surface are not completely clench,but contacton on one angle replace gear
shell heating,especially the place where bearing installed bearing damage replace bearing
bearing neck is stunk replace bearing
bearing wear replace gear
lack of lubrication oil Replace lubrication oil
oil lealcage of subdivision surfaces seal failure replace sealing parts
shell deformation check Subdivision surfaces, replace it when heavy damaged
Subdivision surfaces are not flat Subdivision surface levelled
Connection bolt is loose Clear the return chute,and fasten the nuts
reducer shake on base anchor bolt is loose adjust anchor bolt
shaft center lines are not match Diagonal line adjustment
base rigidity is not enough reinforce base and increase rigidity
Heating of reducer Too much oil Adjust oil level
Rope and pulley Wire rope abrasion and damage Diameter of pulley and drum are too small change wire rope with better flexibility,increase the diameter of pulley and drum
The wire rope diemension does notmatch with the groove of drum,it is too small Use thinner wire rope of same capacity,or change sheaves and drum
dirty and lack of oil Clean and lubricate
False installation of lifting baffte and cause rope abrasion frequently Adjust
Pulley groove and wheel edge are not smooth and have defects Adjust
some pulleys cannot rotate Bearing lacks of oildirt and corrosion in bearing lubricate,clean

table14 Failure and Trouble-shooting (crane/trolley travel mechanisms)
Name Reason Method
crane travel mechanism bridge travel tilt, rail gnawing two driving wheel diameter difference excessive measure, machin and replace wheel
driving wheels are not fully contact with rail balance rails and adjust wheel
wheel horizontal difference is too much Check and eliminate wheel lateral deviation exceeds to lerance  pnenomenon
Deformation of metal structure rectify
Gauge,side direction and 2 rail height differences deviation too much Adjust rail and make rail in stallation satisfy technical requirements
oil or ice on rail head remove oil dirt and ice
trolley travel mechanism Rail skid oil on rail head clean
wheel load is not even adjust wheel load
rail top height difference is too much at the same cross section adjust rail till it meets technical requirements
start or brake too violently change method of motor startchoose winding motor
trolley twists when starting 1.trolley wheel load not even or on Wheel suspend in air
2.Rail gnawing
1. Adjust the problems that only 3 wheels touch the rail               
 2. Solve rail gnaw

Table 15 electrical part malfunction and methods
AC motor Evenly overheat of the whole motor JC too big cause over load lower down working duty or change high JC motor
working at low voltage stop working when working voltage is 10 lower than rated voltage
motor selection is not right select right motor
Crane Parometers specs changed after checking Check and adjust to ensure specification
local overheat of stater silicon-steel plate is short circuited use insulation paint to the places where short circuit happened
local overheat of stator winding Uiring fault Check and eliminate the wrongly wiring
2 points on winding have short circuit with shell repair winding of phase
temperature of raise rotorheavy current impalt statormotor cannot get full speed at rated current End winding terminalsneutrality points and parallel winding get poor contact. check welds and eliminate defects
winding group and sliding loops have loose connection check connection condition
Electrical brushes have loose connection check and adjust brushes
Poor contact in rotator circuit Check loose and poor contact condition and rectify Check the resistance and change the brolken one.
motor vibration when working Motor and reducer axes are not at the same line Re-install
Bearing damage and wear replace bearing
Deformation of rotor check
abnormal noise when working phase of stator error check wiring and modify
stator iron core is not pressed check stator and repair
bearing wear replace bearing
wedge expands cut expanded part or replac wedge
After motor is loaded, its rotation specd slow down ends of rotat or short circuit or 2 locations of rotor winding earthing eliminate short circuit check each loop, repair the damaged and eliminate short circuit.
friction of stator and rotator when motor working end of bearing connection is short circuited replace damaged bearing and check the cover position,eliminate rag on stator and rotor
loop connection is not right, flux is not balanced make connection right and check if each phase is equalin stator
spark on brush or sliding ning is burned brush bad grinding nice grinding
brush is too loose when working just properly brush or grinding
brush or loop are dirty clean with alcohol
loop is not flatcause brush jumping machining and grinding loop
low pressure of brush (18~20KPa) adjust brush pressure
brush grade can not match replace
current distribution of brush is not even check power-feeding wire and brushcorret
sliding ning open circuit loop and brush dirty clean dirt
AC electri cmagnet overheat of loop Overload of Magnetic iron force Adjust the spring pulling force
Fixed part and stationary part of close circuit have gap eliminate clearance
Loop voltage and power voltage are not match replace loop or change connection method
too noisy when working Magnetic iron overload Adjust the spring
Dirt on magnetic flow circuit surface Clean dirty
Deflection of magnetic system Adjust mechanical part of brake and eliminate deflection
Unable to over-come the spring force Magnetic iron overload Adjust the main spring of break
spring force is too big Adjust the main spring of break
low voltage stop working 
AC contactor and relay overheat of loop loop overload reduce the pressure that the movable termincal acts on the fixed terminal.
Movable part of magnetic flow cannot contact with fixed part Eliminate deflection jamming,dirt or change loop
contact is too noisy loop overloaddirt on magnetic flow surface reducer contact pressure, clean dirty
Magnetic flow self adjust system jamming eliminate jam
contact overheat or burned contact lacks of pressure adjust pressure
contact is dirty clean or replace
main contact cannot get through Switch not closeEM switch not close close switch
upper door switch not close close switch
control stick is not at 0 position put stock to 0 position
control circuit fuse burned check or replace fuse
no power in circuit check if voltage is on
Break-off happens frequenly when crane is working contact pressure is not enough adjust contact pressure
contact is burned replace or grinde contact
contact is dirty clean
working overload, over current reduce current load
slide wire is not parallel, loose contact between current collector and slide wire adjust the rail or wire
contact too slow clearance of magnet pole surface is too large Shorten pole surface clearance
upper part of base plate is more protruding than lower part install parts vertically

Table 16 electrical part malfunction and methods
Name Reason Method
fuse in control circuit burned after knife switch closed This circuit phase earthing in control circuit check earthing part by ohmmeter and eliminate malfunction
after mechanism transmission over current relay still work setting value of over current relay cannot meet  requirements adjust relay as following formula Irated=2.252.5I rated
mechanical transmission part jammed led to motor overload check transmission part and eliminate jam
Motor cannot rotate after controller is closed first phase power cut and motor has noise find damage and re-wiring
wire breakage in rotor circuit find damage and re-wiring
loop has no voltage find damage and re-wiring
Contacts in controller cannot contact repair controller
current collector brush failure repair brush of collector
brake malfunction and cannot release repair brake
motor can only rotate to one direction after controller is closed reverse contact loose connection or malfunction with steering mechanism check controller and adjust contact terminal
distribution wire failure find malfunction by short method
working mechanism travel to limit and press limit switch Eliminate malfunction
limit switch malfunction check switch and eliminate malfunction
terminal limit switch is on,main contact not release short circuit of lerminal suitch circuit Checkeliminate short circuit
connect with controller cause disorder correct wrong wire distrimltion
controller jam and impact
when working
malfunction when positioning eliminate error
contact jam in curve chamber adjust contact position
controller cannot pull when working Positioning mechanism failure just pressure
contactors kurning and bonding clean contactor
generator cannot excitant Excitation loop wiring cut check excitation loop
reverse rotation of generator replace 2 phase wiring of driving motor
After disconnecting power (control circuitbreak)the contactor of protection box won't break off short circuit or earthing in control circuit find those places and solve problems
Weld contact terminal, give power supply to main circuit Cut burued contact terminal, to malce it function again.

5. Notice for gantry crane user

5.1. Gantry crane safety regulations
5.1.1 Technical rules for safety that must be abided in applying of the crane
1 ) Operate crane by professional worker.
2) The name plate shall be on one side of crane that contains, SWL, span, working duty, manufacturer.
3) No people standing on crane except in cabin.
4) Cut off power when check or maintaining.
5) When hook is no load, it shall be at least 2. 5m or more above the ground. (exceed the height of one man )
6) Loads are not allowed to cross head of people.
7) The lowest point of load shall be 0. 5 m higher than the highest point of obstacles
8) People transportation on hook is not allowed.
9) no tossing from crane.
10) Tools, spare parts, fasteners, varia should be in special cases, they are not allowed to be placed on crane, to avoid dropping object hurts or damages equipment.
11) When lifting expensive load or noxious liquid, no matter how heavy it is, only after check reliability on the position that above ground 150-200mm, can the crane keep lifting.
12) combustibles are not allowed to be positioned on crane, fire prevention should be considered.
13)Wind-force is more than class 6, stop using crane outdoor.
14) When outdoor use crane is out work, and wind-force is more than class 6, use raft clamp to fix crane to avoid accident
15) Give crane periodic [routine] inspection that includes dynamic and static load test, and results should be achieved.

5.1.2 Electrical components examine and repair regulations.
1) Electrical maintenance work shall be conducted only by qualified worker.
2) Use voltage no more than 36V portable searchlight when doing maintenance.
3) If working needs power is on,  rubber gloves and boots must be worn, use tools with insulated handles.Specially-assigned person that monitoring switch must cut power if emergency happens.All area that are near to conductor parts should be enclosed.

5.2. Gantry crane duty of drivers
5.2.1 Familiar with purpose, components, operation and maintenance of crane.
5.2.2 Strictly follow safety regulations
5.2.3 Before operation should do:
1) Know power supply, do not start crane when voltage is no more than 90% of rated voltage.
2) Check crane when the main power is cut off and check main connection parts, do adjustment if necessary
3) Check if there are tools or other things left on crane, to avoid dropping hurts worker or damages equipment when crane is working.
4) Give lubrication to every points according to regulation.
5) For crane working outdoor, make sure the wind-proof when it is out of work.
6) Driver reset all controller switch to 0 position, close doors before power is on.There is not allowed anyone standing on bridge or rail when crane is working.
7) Give alarm every time before crane start.(electrical bell )
8) Lifted load shall not more than rated load.
9) Driver should cooperate with worker on ground closely, keep step with closely.Handle loads on ground;driver should just follow workers who handle loads on hook.But no matter who gives the signal of“stop”, driver should stop immediately.
10) Lift load in its vertical condition, prohibit use crane and trolley to dray load.
11) Crane and trolley should use the lowest speed when they are near edge area, gradually close to limit position under the condition that they not dash collision-proof frame.
12) Crane controllers shall be on one gear by one gear, when mechanism is not totally stopped, push controllers from veer location to reverse position for braking crane is not allowed. But in case of accident EM condition, this can be used for emergency method, and only after check there is no damage for all mechanism shall the crane continue work after controller is on reverse position first gear.
13) Shall make sure to avoid cranes dash against each other.The only circumstance that allows one crane to push another one is that the former crane is breakdown, and when one crane push another, both of them shall have no load and use the lowest speed.

14) Cut main power and put all controllers to 0 positions if voltage drops violently or power is cut off.

15) Put all controllers to 0 positions and cut main power immediately if crane motors suddenly power off voltage drop violently.  Driver shall warn the worker signal.
16) Workers are not allowed to leave the cabin if there are still loads on hook.
17) Lift hook to higher position and put controller to the 0 position, cut off main power.
18) Cut off main power and cut off e-lock after work.
19) After shifts, clean crane and check it again, prepare for next shift.
20) When shifting work, worker on duty should hand over record book to the next worker, and tell him or department concerned if any problem found in his duty.
21) Crane should be stopped at designated position and be fixed when driver leave the crane.
Copyright © Kingda Mechanical&Electrical Equipment All Rights Reserved Technical
Support : coverweb