1.The special climatic conditions mainly include:
1)The beam is being erected in the wind which reaches level 4-6.
2)The beam is being erected in the rain or after the rain.
3)The beam is being erected in the course of a freezing season, influenced by the ice, snow as well as the low temperature.
2.If the wind level is more than 4, the operation of going through the holes before the bridge erecting crane is not allowed; if the wind level is more than 6, the beam is not allowed to erected; if the wind level is between 4-6, the detailed conditions including downwind, cross wind, regular or intermittent wind, the following matters should be considered:
1)Stability
To avoid the sudden attack of the heavy wind, the bridge erecting crane should be fixed by the cable after it is in the right place.
2)The shake of the beam
To avoid the fierce shake of the beam, the beam should be placed slowly through the chain.
3)Protection issues
If the beam is to be erected in the wind, the safety measures should be taken. The top surface of the pier should be protected with the fence or the safety net of facilities.
3.If the beam is to be erected in the wet season, necessary measures should be adopted to prevent the occurrence of accidents based on the quality of the roadbed, the rainy days, the total rainy volume, drawing etc.
4.In the frezzening seasons, the following requirements should be complied with.
1)The ice and snow on the supporting cushion stone must be cleared away.
2)The angle iron should be warmed in advance before the connecting board is being welded.

3.The erection of the uphill bridge
When the bridge erecting crane is erecting the uphill bridge, the height of the front and middle triggers should be adjusted according to the slope of the bridge with the bridge erecting crane well assembled. Before the machine travels longitudinally, the height of the front triggers should be lowered and the height of the back trigger be increased to make the longitudinal slope of the machine less than 0.5%. And the hoist should be hung on the front part of the machine to prevent the slip of the machine when it is traveling. With the nose girder in place, the front trigger should be traveled on the bent cap , after which the height of the front trigger should be adjusted based on the height of the middle trigger. With the machine ready, the erection can be started.
4.The erection of the downhill bridge
The erection of the downhill bridge just repeats the above steps. That’s to say, When the bridge erecting crane is erecting the downhill bridge, the height of the front and middle triggers should be adjusted according to the slope of the bridge with the bridge erecting crane well assembled. Before the machine travels longitudinally, the height of the front triggers should be lowered and the height of the back trigger be increased to make the longitudinal slope of the machine less than 0.5%. And the hoist should be hung on the front part of the machine to prevent the slip of the machine when it is traveling. With the nose girder in place, the front trigger should be traveled on the bent cap , after which the height of the front trigger should be adjusted based on the height of the middle trigger. With the machine ready, the erection can be started.
5.The erection of the curved bridge
When the machine is erecting the curved bridge, the included angle between the front and middle triggers should be adjusted according to the actual situation of the radius of the curve.
6.The erection of the skew bridge
When the machine is erecting the skew bridge, the front and middle triggers should be kept paralleled. The two sides of the front and middle triggers should be in the same direction with the main beam to meet the condition of the erection of the skew bridge.

The Function of the Special Girder Span(Ⅰ)
In the process of bridge erecting, there are usually special girder span including uphill girder, downhill girder, curing span etc. For this, our company develops the HZQ series bridge erecting cranes. Now take the HZQ40-140 walking type bridge girder launcher as an example.

The technical parameters of HZQ40-140 walking type bridge girder launcher.
Item Value
Rated span 40m
Rated lifting capacity 140T
slope ≤±3% for longitudinal slope，≤±2% for transverse slope
Skew bridge angle 0-45°
Longitudinal traveling speed 4.0m/min
Transverse traveling speed 2.75m/min
Trolley longitudinal traveling speed 0-4.24m/min
Trolley transverse traveling speed 1.3m/min
Lifting speed 0.9m/min
Operating method Walking type
The central distance between the two main beam 6.0m
Allowable wind level ≤6
Total power about120KW

1.The erection of the first supportbar
When the first supportbar is being erected, the middle trigger usually is on the bridge abutment and the basis of the transverse rail of the middle trigger must be solid to prevent the occurrence of accidents caused by the sink of the bridge erecting crane; before the longitudinal traveling of the front trigger, the height of the front trigger must be adjusted properly to make it in place successfully; before the bridge erecting crane travels longitudinally, everything should be checked to avoid any accidents.
The bridge erecting crane is just put into use when the first supportbar is being erected; therefore, the safe instead of speed concerns most.
2.The erection of the last support bar
When the machine erects the last support bar, the opposition of it is the bridge abutment and the front trigger must be travel on the bridge abutment; hence, the height must be decreased. The machine is equipped with chassis2 specially used for the front trigger, the middle part of which can be disassembled, and then the chassis2 and core plate are connected; finally, the chassis2 and traveling wheel box are connected.

The Bridge Process And Precautions of the Bridge Erecting Crane(Ⅱ)
3.Lift the beam
1)Before any operation of lifting the beam, at least one test should be went on. That is to say, withe the completion of binding the beam, the test of braking should be went on 2-3 times.Then, a few beams are lifted and whether the steel rope are quit and the iron tiles move or jump off should be checked. Only after all of this are checked, can the formal operation start.
2)Lifting the beam should be in the same step with the hoist,both of which bear even stress. The overload of the hoist and the fierce shake of the beam body should be avoid.
3)The beam should be kept balance when it is being lifted, moved and placed. If you find any tilt by your eyes, it should be corrected immediately. Sometimes, a little tilt is allowed but not too much.
4)The beam should be move on the high level.
5)When the beam is moved, the professional persons should inspect the moving state of the beam in the pier platform. Especially when the beam is to in place, the inspecting persons, commanders as well as drivers should be cautious and highly concentrated and corporate with each other.
6)The bridge erecting crane is not allowed to overload.

4.Place the beam
1)When the beam is being placed, responding measures should be taken to prevent the occurrence of accidents.
2)When the beam is being placed,the chain block should be in the front and some measures should be taken. And the chain block must be hung in the firmly.
3)When the beam is 200-300mm to the bearer, the beam can be placed continually after the bearer and shogging equipment are in place.
4)When the beam is to be in place, the two jacks in one end should be in the same step to prevent the accidents caused by the slaying beam.
5)When the bridge erecting crane is swaying, there should be professional persons to inspect the trolley.After the beam is in place, the trolley should be fixed with wheel stopper to prevent the trolley from sliding.

The Bridge Process And Precautions of the Bridge Erecting Crane(Ⅰ)

There are usually four processes to erect a piece of precast beam, namely feeding the beam, binding the beam, lifting the beam and placing the beam.
1.Feed the beam
1)Before the beam going into the bridge erecting crane, whether there are obstacles influencing the advancing of the beam in the whole machine and whether the beam capstone are too high influencing feeding the beam should be checked.
2)Before feeding the beam, the back support of the bridge erecting crane should be checked to avoid the big sinkage when the machine feed the beam.
3)When the beam is being transported, there should be personnel inspecting the bearer to prevent the collision with the whole machine. The girder transport should be run by professional persons.
4)When the beam is being transported,no person is allowed to go with the beam in the end of the beam or stand on the scaffold floor to avoid the wounding caused by the objects falling from the top of the beam.
5)When the beam is being transported,the girder transport should be pushed in slowly.And when the beam is being pushed, there should be professional persons to inspect it to prevent the body of the beam or the girder transport collide with the whole machine.

2.Bind the beam
1)When the beam is being bound, the iron tile should be fixed and symmetrical to make the steel rope in the middle. And whether the steel rope is knotted, torsional or connected with the rod should be checked.
2)The distance from the two lifting points to the points of the beam should be equal to prevent the occurrence of overload caused by the uneven stress born by the hoist.
3)The jack line used to bind the bear usually should be kept vertical.

On November 25 to 28, 2014, Bauma China is to be hold by Munich International Expo Group (MMI), an exhibition of China International Construction Machinery, Building Material Machines, Construction Vehicles and Equipment. Zhengzhou Huazhong Construction Machinery Co., Ltd will take part in Bauma China with its products.
Bauma China is an feast of professional construction machinery industry hold every two years in Asia.Since its first success in 2002, its stable development makes it an authoritative professional fair of construction machinery and building material machinery industry in Asian.It also enjoys the reputation of China”s first commercial exhibition.
Zhengzhou Huazhong Construction Machinery Co., Ltd is an professional manufacturer of construction machinery and lifting machinery. The corporation has professional and experienced technical team, in good relationship with Xi”an Jiaotong University, Dalian University of Technology and Shijiazhuang Railway Institute. It becomes the qualified manufacturer producing online casino Gantry Crane, Overhead Crane, Bridge Girder Launcher, Movable Support System, Shotcreting Machine, Concrete Batching Plant and Concrete Mixing Plant etc. Since it established for more than 20 years, it adheres to the the purpose “first-class products, qualified service and customer first”, striving to be the most professional manufacturer in China.

Our company sincerely invites you to visit our exhibition and communicate with us in Bauma China 2014.
 
Date: November 25 to 28, 2014
Place：Shanghai New International Expo Center
Booth Number：E2.115

The Test Run Steps of the Bridge Erecting Crane

Check whether each connecting part is firmly connected.
Check whether the electric connection is correct.
Check each part of the hydraulic system for leak.
Check whether there are card lag phenomenon in each mechanical and structural part.
Check the lubrication conditions of each rotating part.
Check the oil level in the tank meets the requirements and put the hydraulic system into a test run.

Through the oil inlet, No.32 hydraulic oil(the old No.20) are poured into the tank.
The hydraulic oil of different brands and types should not be mixed up to use and online casino should be filtered once each year.
The overflow valve should be fully loosed, the power switched on and the oil pump opened to work without load for 5 to 10 minutes to check whether the running direction of the oil pump is correct and whether there are noises during its running process.

Rotate (or push-pull) the manual reversing valve, and tighten the overflow valve appropriately to make the jack began to start, and then under the condition of full stroke, reciprocate and flex for 4 to 5 times to rule out the air from the system as much as possible.

When the manual reversing valve is working for changing the direction, the move should not be too fast and fierce. When it turns from the forward direction to the back direction, there should be a stop for one moment to avoid the hydraulic shock, which should be went on if there are load.

Maintenance of bridge erecting machine（Ⅱ）

1.The brake of the lifting mechanism should be checked every day and the brake of the operating mechanism every 2 or 3 days. When they are being checked, whether the movements of each brake system is flexible should be paid attention to.The segments should be fit on the brake wheel without physical damage. The brake of the lifting mechanism must ensure 1.25 times of the rated capacity and the damaged sunny canopy should be replaced timely.
The bearing for drive of the traveling box of the crane and the trolley should be pointed into albany grease every 2 years.

2.The maintenance of the electrical equipment
To ensure the safe operation of the crane, the reasons and solutions of various accidents of the bridge erecting machine should be familiar with.
The electrical equipment including the resistor, control panel and contactor etc., should be kept clear, and the dust as well as the dirt outside or inside the electrical equipment should be cleared away to prevent current leakage, breakdown, short circuit and so on.
Whether the motor rotor slip line and brush contact is in good order should be checked frequently.
Whether the sound produced by the motor, electromagnet, electromagnetic relay and switch is normal.
Whether the cam controller and contactor appear the sign of burning, if any, they should be replaced or reused after they are being polished with emery cloth.
When the outside conditions are bad, the motor, electric wire as well as the insulation resistance should be checked regularly.
The rust and dirt on the slide rail must be cleared away timely.
The inspection whether the installation of each electrical equipment is fixed and the movable parts move flexible should be made frequently to exclude the abnormal factors.

The right use, regular inspection and reasonable maintenance can ensure the safe operation of the bridge erecting machine and its service life.

1.The maintenance of the metal structure

The main girder is the main stress-bearing components. The performance,safety and the service life depend on whether the machine is well maintained.

1.1 The sharp start and brake must be avoided.

1.2 The welding seams among the girders should be checked, and if any one of them is found, the machine should be stopped to be welded again.

1.3 If the main girder is founded to be deformed and not stable, it should be stopped and handled properly.

1.4 All the metal structures should be painted twice every year. The oil stain, water and other things on the surface of the metal structure should be cleared away before the metal structure is being painted.

2.The maintenance of the main components

2.1 The open and closed gear painted monthly using a lubricating grease.

2.2 The wire rope should be  lubricated periodically and before that the pollutants should be cleared away.Whenever over 6 ropes are broken in the joints, they should be replaced instantly.

2.3 The bearings must keep lubricative and be lubricated regularly. If the temperature is too high and noise too big, they should be checked carefully and if there are any damage of them, they should be replaced timely.

2.4 When the thickness of wheel wear is over 15% of the original wheel, the wheels should be replaced.

2.5 The reducer should not be short of oil that must be replaced regularly. If there appear any abnormal state or noise, it should be checked.

ZZHZ launching gantry

concrete girder for high speed railway

The longitudinal and traverse rail of the bridge-erecting crane need to be adjusted with the condition that the longitudinal slope should not be more than 1.5%.

The traverse traveling rail needs to be placed solidly,and the two ones need to be paralleled. As for the whole rails,that the both ends are a little higher than the middle part is better.

When the bridge-erecting crane transports or erects the girder, the precast beam should be placed to the lowest place for the operation.

When the bridge-erecting crane travels longitudinal to pass through the hole, there should be professional staff before the traveling wheels to check whether there appear abnormal situations, especially the control of the distance size of the traveling rail to prevent the overturn. The operators must fully focus on the work with full ears to listen to the commander’s instruction to ensure the normal state of the operation.

As for the emergency signal, no matter who send it, the operator must stop the machine immediately.

Before the machine starts to work, all the braking mechanism of the machine should be inspected regularly to ensure that it can operate normally.

The two points fixed by the wire rope should be inspected regularly by certain people to ensure that they are not loose and hence there appears no potential danger.

The wire rope of the hoist should be checked frequently; when it meet the standard of rejection, it should be replaced timely.

Before each operation of the bridge-erecting machine, it should try lifting objects for many times,only which proves normal, the next step can go on.