1. Application range of THQ900t bridge girder launcher for tunnels

ZZHZ develops THQ900 bridge girder launcher for tunnels and THY900B girder transporter to solve construction technical problems below:
● high speed railway bridge and tunnels are connected frequently
● the bridge girder launcher and girder transporter need to smoothly pass the tunnel to install girders
THQ900 bridge girder launcher in tunnels and THY900B girder transporter can meet the demand to install double track whole span box girder32m, 24m, 20m for passenger special line, as well as meet the demand of span shift, tunnel entrance and exit 6m abutment and erecting curved bridge.

2. Main features and advantages of THQ900t bridge girder launcher for tunnels

● construct bridge connected with tunnel, reduce cost of dismounting many times
● four fixed points lifting precast girders with balanced lifting capacity ensure the safety of concrete box girder and lifting system structure. Slight longitudinal and lateral movement of lifting system can realize accurate positioning as installing box girder
● launching nose and bridge girder launcher do a cooperative work to cross piers longitudinally, featuring easy operation, safe and reliable
● can realize span shift installation and curved bridge erection, tyred girder transporter can directly carry the bridge girder launcher to transfer sites and pass the tunnels
● matched with the launching nose, lifting trolley and auxiliary overhead crane, the bridge girder launcher can install the first and last girders as well as girders for tunnel entrance and exit.

3. Main technical parameters of THQ900t bridge girder launcher for tunnels

Product Model	THQ900
Rated lifting capacity (max lifting capacity) (t)	900
Max size of the girder (m)	32.6×12.6×3.05
Moving speed of bridge girder launcher (m/min)	0-3
Trolley longitudinal moving speed (m/min)	0-3 (full load)/ 0-6 (empty load)
Trolley lifting speed (m/min)	0-0.5 (full load)/ 0-1(empty load)
Max lifting height (m)	7
Precast girder horizontal fine-tuning distance (mm)	±200
Precast girder fine-tuning speed (m/min)	0-1
Min radius of curved bridge (m)
Applicable gradient	L1500ongitudinal gradient 20‰, transverse gradient 40‰
Power (kw)	300
Out dimension (m)	61×15.3×14.6
Total weight (t)	585

4. The design basis of THQ900t bridge girder launcher for tunnels

The product design is in accordance with relevant provisions of new national codes and standards, it mainly has:
● 《crane design specifications》（GB/T 3811）
● 《construction equipment research technical conditions for Beijing-Shanghai passenger special line》
● 《general purpose gantry cranes》(GB/T14406)
● 《steel structure design codes》（GB 50017）
● 《steel structure construction and acceptance specifications》（GB 50205）
● 《wire rope with important purpose》(GB 8918)
● 《electrical device installation project construction and acceptance specifications》 (GB50256)
● 《hydraulic system general technical specification》(GB 3766)
● 《railway engineering construction safety technical procedures(Book One)》（TB10401.1）
● 《bolts, boults and double-screw bolts with fasteners mechanical character》（GB 3098.1）

5. Main design requirements of THQ900t bridge girder launcher for tunnels

● Lifting steel wire rope safety factor: n≥6
● Boom stretch stress safety factor: n≥6
● Structural strength calculation safety factor: n≥1.5
● Institutions transmission parts safety factor: n≥1.5
● Factor of safety against overturning n≥1.5
● Electrical equipment and wiring insulation class should be in accordance with that insulation class of construction ministry and related electrical equipment, protection level should  reach: electrical machinery IP54, other electrical equipment IP65 or above.
● Crane utilization grade: U0
● Crane utilization condition: Q3
● Crane working level: A3
● Crane institutions working level: M4
● Bottom deflection of main girder: S/700

6. Main mechanical manufacturing technology of THQ900t bridge girder launcher for tunnels

There are many mechanical manufacturing (machinery-building) technologies; the rules of management are following:    
● Firstly, the technology department reviews the drawing from manufacturability.    
● Drawing up the technology guide book and making  procedure qualification.   
● Making welding procedure card, mechanical manufacturing card, assembly process, camber drawing of box girder according to drawing , rules and criterion ; emphasizing the size of welding angle, geometry size and requirements of assembly etc.
● Designing the assembly technology clamp according to the requirements of drawing.     
● Making the finishing time of manufacture and patrolling card  according to the requirements of drawing; controlling the quality of manufacture strictly.

7. The quality control in THQ900t bridge girder launcher for tunnels manufacturing process

Technology file drawing and project are handed to production department which assorts with related department and quality department to process, manufacture, control, check and accept of product.       
The workshops do the following work according to drawing:
● blanking splicing（technology and requirements of blanking splicing）
● assembling welding（welding procedure card, welding technology qualification and welding record）
● mechanical manufacture（mechanical manufacturing card）
● finishing time of manufacture and patrolling card
● Assembly（assembly technology）
● checking descriptive chart（controlling the geometry size and key part）.

8. Tracing data and leaving factory data of THQ900t bridge girder launcher for tunnels

● The tracing data of product is made up of contract, review file, drawing , calculation book of design, specification, installation project, raw material quality certificate, product quality inspection record, welding inspection report and purchased certificate.
● leaving factory data is made up specification, installation project, certificate and receiving report etc.

9. The installation method and steps of THQ900t bridge girder launcher for tunnels

The bridge girder launcher (launching crane) is the heavy duty hoisting equipment which requires very high safety. A little negligence maybe causes serious accident, therefore, the installation of launching gantry must be directed or installed by professional works, and the steps are following:
● surveying positioning
● paving rails
● assemble two sides main girder symmetrically.
● installing front and rear connecting frame
● installing front, middle and rear legs
● installing lifting trolley and auxiliary trolley
● hydraulic system, electrical system, operating platform and plug in power
● test run and commissioning.

10. Checking methods after installation of THQ900t bridge girder launcher for tunnels

We should check geometry size, perpendicularity, degree level and deflection etc. after the structures are installed completely:
● Checking connecting parts connect firmly or not.    
● Checking the electric connection is correct and limit switch is reliable or not.  
● Checking  parts of hydraulic system leak oil or not and the lifting is good or not. 
● Checking mechanism and structure parts run successfully or not. 9.5、checking lubricating condition of rotating parts. 
● Checking the oil level meet the requirements or not ,and then making a trial run .
● After all of above checking and adjustments are finished, and making sure every part goes well, and then doing the trial run. 

11. Operating requirements and attention of THQ900t bridge girder launcher for tunnels

● Adjusting the height of transverse rails of front legs and middle legs  when erecting girder or moving from one pier to keep main girder’s longitudinal slope≤0.5%，transverse slope≤0.5%.   
● The normal working wind speed should less than 6 grade when bridge girder launcher works in the open air ; when the wind exceed 6 grade, the bridge girder launcher shouldn’t moving from one pier to next pier, and components should be locked; the machine can’t work in thunderstorm day and must cut off power.  
● check the steel rope is broken or not,  the circuitry leaks electricity or not, the brake is reliable or not, and after the reducers get enough lubricating oil and the oil lubricate the open gears, the machine start to work; the safe circle of steel rope on the drum shouldn’t less than 3;checking the surface and fixed parts after every shift of steel rope and making a specific check every 7～11 days;
● the brake system of winch is allowed to start again after it checked;
● the lifting ,longitudinal traveling and transverse traveling shouldn’t work together; the speed of lifting and translational velocity should be slowly to avoid leaning and side tumbling;
● the goods are prohibited to throw out from bridge girder launcher strictly; it is prohibited to lift goods to pass over head strictly；it is prohibited to lift workers by hook or goods strictly；the inflammable goods are prohibited to put on the launching crane strictly;
● After the legs move to their places, plug the safe pin to prevent the hydraulic cylinder from bearing force for a long time;
● When the tubes of components are fault, the operator should cut off power immediately, and it is checked and repaired by the professional technician; the operator shouldn’t disassemble privately; when checking and repairing the machine , the technician must cut off the power. 

12. The maintenance time and item of THQ900t bridge girder launcher for tunnels

● After construction are finished everyday, the workers must check the following content: if the level of main longitudinal girder meets the requirements or not; the connection of bolts and pins are firm or not; the electrical wires are broken and extruded; hydraulic system is regular or not; the track joints are plain and smooth or not;  the connection of position limiter of crane and trolley are firm or not; the rail clamping device is in the working position or not; bed timber is plain and stable and the size of gauge is right or not etc.     
● The welding lines are checked every month :：upper and down chords of main girder , web plate, vertical welding lines of legs  and the welding lines of connecting frame etc. The operators should stop working when the welding lines are broken or fatigue crack.  When the users find the crack by eyes, but they can’t make sure the dangerous degree, so they should use the welding inspection instrument to test and then adopt reasonable steps to deal with.
● About the painting of structure which should be painted again every two years. The users should clean the primary surface by steel brush and pay attention to the welding lines before the structure are painted.
● The lifting mechanism, traveling mechanism of crane and trolley, reducer of motor and steel rope of winch are lubricated and maintained according the rules of specification.

13. The disassembly and site-transferring steps of THQ900t bridge girder launcher for tunnels

The machine is disassembled according to the following steps after the erection construction is finished. 
● cylinder jacks up to make the whole machine go up 250—300mm。
● 2.0m sleepers are paved to nearby middle and rear legs respectively.
● take back the cylinder of legs and the put on the transporter.
● two lifting trolley are lifted and then put on the transporter by the special  gantry.
● disassembling front, middle and rear legs and front and rear connecting frame.    
● disassembling the coupling pin from back to front , each beam is carried in order and then the disassembly is finished.
● when disassembling and carrying the parts, brutal work and violent  collision are  prohibited, special hook and lifting tools are used for lifting. Connecting bolts and pins are put in order after they disassembled to avoid disordering and losing; the disassembly and assembly of connecting plates must be in order, and they must be marked clearly before they disassembled and assembled.

Contact Me: Amy

Email: zzhz114@gmail.com  

Tel: 0086-371-68000000

Mobile: 0086-13676949605

Website: http://zzhz.com