120T Counterweight Bridge Erecting Machine

Core Features

1. Adjustable Counterweight System

The machine features a rear-mounted counterweight system that balances the forward weight of the lifting trolley, girder, and front gantry. The counterweight can be adjusted by adding or removing weight blocks to optimize balance for different segment weights and reach distances, significantly minimizing the risk of tipping during critical launching phases.

2. High Lifting Capacity and Reach

The 120T rated capacity enables handling of heavy precast girders, making it suitable for large highway, railway, and extra-dosed bridges. The machine is ideally suited for erecting multiple spans of 30 to 60 meters efficiently in sequence.

3. Minimal Ground Disruption

The entire erection process operates from the bridge deck or piers, eliminating the need for ground-level cranes or scaffolding beneath the span. This is particularly advantageous for crossing protected ecosystems, water bodies, active highways, and live railway lines without interrupting traffic or causing ground disturbance.

4. Construction Efficiency and Speed

Once positioned, the machine operates in a fast, repetitive cycle: lift girder, move forward, place, and launch to the next position. This systemization speeds up project timelines and reduces weather dependency compared to methods requiring extensive ground support.

5. Precision Control System

Hydraulic systems allow for millimeter-precise positioning of heavy girders, which is critical for post-tensioned segmental bridges. The machine can handle Pre-stressed Concrete (PSC) I-girders, U-girders, and steel-concrete composite girders.

 

 

 

Parameter	Specification
Rated Lifting Capacity	120 tons
Adaptable Bridge Span	30–50 m (customizable)
Working Duty	A5–A7
Power Supply	3-phase AC 380V, 50Hz
Lifting Speed	0.8–1.5 m/min (frequency control)
Longitudinal Travel Speed	0–6 m/min
Lateral Travel Speed	0–3 m/min
Adaptable Longitudinal Slope	≤ 2–5%
Minimum Curve Radius	R ≥ 150–350 m
Skew Bridge Angle	0–15°

 

1. Main Girder Structure (Truss System)

Main Truss Girders - Triangular or trapezoidal truss twin-girder design fabricated from high-strength S355/Q345B steel; forms the primary load-bearing structure

Cross Beams - Connect the twin main girders; provide lateral rigidity and load distribution

Diagonal Bracing - Ensures structural stability and prevents deformation under eccentric loads

Pin Connections - Modular joints allowing on-site assembly and disassembly for transportation

Front Cantilever Section - Extends forward to guide the launching nose during span advancement

2. Counterweight System

Rear Counterweight Frame - Structural steel frame mounted at the rear of the main girder to house counterweight blocks

Counterweight Blocks - Adjustable concrete or steel blocks; total weight configurable to balance the forward lifting moment

Water Tank Counterweight (Optional) - Alternative water-filled tank for easy weight adjustment on site

Counterweight Adjustment Mechanism - Hydraulic or mechanical system for moving counterweight fore/aft to optimize balance

Counterweight Safety Lock - Prevents accidental displacement of counterweight blocks during operation

Load Monitoring Sensors - Detect counterweight position and load distribution in real time

3. Lifting Trolley System

Lifting Trolleys - Independent trolleys travel along the main girders; each equipped with hoisting winch and pulley blocks

Hoisting Winches - Frequency-controlled winches for smooth lifting and precise positioning of girders

Wire Rope & Pulley Blocks - Heavy-duty steel wire ropes with multi-fall pulley systems for 120T rated capacity

Lifting Hooks / Spreaders - Customized lifting beams and hooks designed to safely grip precast girders

Trolley Travel Drive - Motor-driven wheel assemblies enabling longitudinal movement along the main girder

Trolley Lateral Adjustment - Side-shift mechanism for precise girder alignment

4. Leg Assemblies (Support System)

Front Legs (Leading Legs) - Support the front end of the machine; equipped with articulation for curve negotiation

Rear Legs (Trailing Legs) - Support the rear end; include hydraulic adjustment for height variation

Middle Legs (Optional) - Additional support for long-span configurations

Leg Cross Frames - Horizontal bracing between leg columns for lateral stability

Telescopic / Adjustable Legs - Optional hydraulic or mechanical adjustment to accommodate varying pier heights

Leg Travel Bogies - Wheel or rail-mounted bogies at the base of each leg for longitudinal movement

5. Traveling & Steering Mechanism

Longitudinal Travel Bogies - Rail-mounted or trackless bogies that move the entire machine forward/backward

Lateral Travel Bogies - Enable side-to-side movement for precise girder alignment

Steering Cylinders - Hydraulic cylinders for adjusting machine direction on curves

Rail Clamps / Anchors - Secure the machine to the track or ground during lifting operations

Travel Drive Motors - Electric motors with gearboxes driving the bogie wheels

6. Hydraulic System

Hydraulic Power Unit - Central pump station supplying pressurized oil to all hydraulic actuators

Hydraulic Cylinders - Used for leg height adjustment, steering, leveling, and counterweight positioning

Control Valves - Directional, pressure, and flow control valves for precise operation

Oil Tank & Cooler - Reservoir and cooling system maintaining optimal hydraulic fluid temperature

Hydraulic Hoses & Fittings - High-pressure lines connecting the power unit to actuators

Hydraulic Accumulators - Store energy for emergency operations and smooth pressure fluctuations

7. Electrical & Control System

Main Control Cabinet - Houses PLC, contactors, relays, and power distribution components

PLC Control System - Programmable logic controller for automated sequence control and monitoring

Operator Cabin / Remote Control - Ergonomic cabin or wireless remote for machine operation

Variable Frequency Drives (VFDs) - Frequency converters for smooth speed control of winches and travel motors

Sensors & Encoders - Position, load, height, wind speed, and counterweight sensors for real-time feedback

Limit Switches - Prevent over-travel of trolleys, hooks, and legs

Cabling & Cable Reels - Power and signal cables with reeling systems for continuous movement

8. Safety Devices

Overload Limiter - Automatically stops lifting when load exceeds 120T rated capacity

Anti-Tipping Protection - Monitors counterweight balance and machine inclination; alarms or stops operation if stability limits are exceeded

Lifting Height Limiter - Prevents hook over-hoisting

Emergency Stop Buttons - Immediately halts all operations in case of emergency

Wind Speed Anemometer - Alarms and stops operation when wind exceeds safe limits

Anti-Collision System - Prevents collision between trolleys or with end stops

Voltage-Loss Protection - Safely holds load in position during power failure

Rail End Stops - Mechanical stops preventing machine derailment

9. Auxiliary Components

Access Platforms & Walkways - Safe access for maintenance and inspection

Handrails & Safety Gates - Fall protection for personnel

Lighting System - Work lights for night operations

Diesel Generator (Optional) - Standalone power source for remote sites

Tool Kits & Spare Parts - On-site maintenance and repair equipment

Launching Nose - Guide structure for advancing the machine to the next span

Temporary Support Brackets - Used during machine launching and positioning

 

 

 

 

1. Superior Lifting Capacity

120-ton rated capacity enables erection of heavier precast girders and larger bridge segments in a single lift

Suitable for long-span highway, railway, and extradosed bridge projects requiring high-capacity lifting

Reduces the number of lifting operations and minimizes risk associated with multiple-piece assembly

Handles Pre-stressed Concrete (PSC) I-girders, U-girders, and steel-concrete composite girders

2. Adjustable Counterweight System

Rear-mounted counterweight balances the forward weight of the lifting trolley, girder, and front gantry

Adjustable weight blocks allow optimization of balance for different segment weights and reach distances

Significantly minimizes tipping risk during critical launching and girder placement phases

Water tank option enables easy on-site weight adjustment without heavy equipment

Hydraulic fore/aft positioning of counterweight provides dynamic balance control during operation

3. Enhanced Stability & Safety

Counterweight system maintains machine stability even when lifting at maximum forward reach

Anti-tipping protection monitors balance and inclination; alarms or stops operation if stability limits are exceeded

Overload limiter automatically stops lifting when load exceeds 120T rated capacity

Wind speed anemometer alarms and halts operation when wind exceeds safe thresholds

Voltage-loss protection safely holds load in position during power failure

Complies with rigorous international safety standards for lifting equipment

4. Minimal Ground Disruption

Entire erection process operates from the bridge deck or piers, eliminating ground-level cranes or scaffolding

Ideal for crossing protected ecosystems, water bodies, active highways, and live railway lines

No interruption to traffic or ground disturbance beneath the span

Reduces environmental impact and permits obtained more easily for sensitive sites

Eliminates need for temporary ground support foundations

5. Excellent Structural Strength

High-strength S355/Q345B steel truss twin-girder design provides optimal strength-to-weight ratio

Triangular or trapezoidal truss configuration ensures excellent torsional rigidity

Modular pin-connected structure maintains structural integrity under eccentric and dynamic loads

Front cantilever section guides launching nose during span advancement

Designed for Working Duty A5–A7 for heavy-duty repetitive operations

6. Precision Control & Synchronization

Advanced PLC control system with real-time monitoring ensures accurate positioning

Dual-trolley synchronous control achieves millimeter-precise positioning, critical for post-tensioned segmental bridges

Variable Frequency Drives (VFDs) provide smooth acceleration, deceleration, and precise speed regulation

Hydraulic systems allow millimeter-precise positioning of heavy girders

Reduces impact loads on both machine and precast girders during lifting

7. Construction Efficiency & Speed

Fast, repetitive cycle: lift girder, move forward, place, and launch to next position

Self-launching capability advances to next span without auxiliary cranes

Systemization speeds up project timelines and reduces weather dependency

Eliminates repeated disassembly and reassembly between spans

Reduces dependence on ground-level crane equipment and site logistics

8. Flexible Adaptability

Adjustable span and height parameters accommodate varying bridge designs

Suitable for straight, curved, and skew bridge erection with skew angles up to 45°

Handles longitudinal slopes up to 5–7% for mountainous or hilly terrain

Adaptable to minimum curve radius of R ≥ 200–400 m

Suitable for balanced cantilever construction, span-by-span erection, and variable-span construction

9. Cost & Time Efficiency

Rapid assembly and disassembly due to modular design reduces mobilization time

Self-launching capability minimizes auxiliary equipment costs

High lifting and travel speeds accelerate project schedules

Reduces labor requirements and overall construction costs per span

Lower foundation and ground improvement costs due to deck-based operation

10. Ease of Operation & Maintenance

Ergonomic operator cabin or wireless remote control for convenient and safe operation

Real-time sensor feedback enables operators to monitor load, position, counterweight status, and machine condition

Access platforms, walkways, and handrails facilitate safe inspection and maintenance

Readily available spare parts and tool kits minimize downtime

Hydraulic accumulators enable emergency operations and smooth pressure fluctuations

11. Environmental & Site Adaptability

Optional diesel generator set enables operation at remote sites without grid power

Corrosion-resistant coating available for harsh environments (coastal, humid, or chemical exposure)

Trackless or rail-mounted options adapt to different site conditions

Low noise and emission configurations available for urban viaduct projects

Deck-based operation minimizes environmental disturbance to ground and water below

12. Wide Application Range

Highway bridge construction - precast box girders, T-beams, and segmental sections

Railway infrastructure - heavy girder erection for rail overpasses and viaducts

Urban viaduct projects - space-constrained urban environments

Balanced cantilever bridges - segmental erection with counterweight balance

Water crossing bridges - erection over rivers, canals, and coastal waters

Industrial and port infrastructure - heavy structural component installation

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1. Highway Bridge Construction

Precast Concrete Girder Erection - Lifting and positioning of precast box girders, T-beams, I-beams, and U-beams for highway overpasses and elevated expressways

Long-Span Highway Bridges - 120T capacity enables erection of heavier girders for long-span bridge projects

Multi-Span Bridge Projects - Self-launching capability enables efficient erection across long multi-span highway bridges

Segmental Bridge Construction - Suitable for erecting segmented precast concrete sections in balanced cantilever or span-by-span methods

Highway Interchange & Viaducts - Ideal for complex interchange structures requiring precise girder placement over existing roads

2. Railway Infrastructure

Railway Bridge Erection - Lifting heavy precast girders for railway overpasses, underpasses, and bridge crossings

High-Speed Rail Viaducts - Suitable for erecting precast box girders in high-speed rail elevated sections

Metro & Light Rail Projects - Used in urban rail transit elevated viaduct construction

Railway Station & Yard Bridges - Erection of girders over railway lines with minimal disruption to rail traffic

Electrified Railway Crossings - Deck-based operation avoids interference with overhead catenary systems

3. Urban Viaduct & Elevated Road Projects

Urban Expressway Viaducts - Space-constrained urban environments where ground-level cranes are impractical

City Ring Roads & Elevated Corridors - Efficient erection of precast girders over busy city streets

Pedestrian & Cycle Bridges - Suitable for erecting medium-span pedestrian overpasses and cycle bridges

Urban Rail Transit - Metro elevated lines and light rail viaduct construction

Night Construction in Cities - Lighting system supports around-the-clock erection with minimal traffic disruption

4. Balanced Cantilever & Segmental Bridges

Balanced Cantilever Construction - Counterweight system maintains stability during symmetrical segment erection

Span-by-Span Erection - Efficient repetitive cycle for multi-span segmental bridges

Post-Tensioned Segmental Bridges - Millimeter-precise positioning critical for segment alignment and tendon installation

Extradosed Bridges - Suitable for erecting heavy segments in extradosed bridge construction

Cable-Stayed Bridge Approaches - Erection of approach span girders for cable-stayed bridges

5. Water Crossing Bridges

River Crossing Bridges - Multi-span girder erection over rivers without ground support

Canal & Waterway Crossings - Deck-based operation avoids disturbance to water bodies

Coastal & Estuary Bridges - Suitable for bridge erection over coastal waters and estuaries

Reservoir & Lake Crossings - Erection over water bodies where ground-based cranes are impractical

Protected Ecosystem Crossings - Minimal ground disturbance for environmentally sensitive areas

6. Industrial & Port Infrastructure

Port & Harbor Bridges - Erection of heavy girders for port access bridges and cargo terminal viaducts

Industrial Plant Bridges - Pipe rack bridges, conveyor bridges, and heavy equipment access platforms

Mining & Energy Infrastructure - Bridge erection for mining haul roads, power plant access, and energy facility connections

Logistics & Freight Corridors - Heavy-duty bridge construction for freight rail and truck routes

7. Special Bridge Structures

Curved Bridges - Adaptable to minimum curve radius of R ≥ 200–400 m for curved viaduct erection

Skew Bridges - Handles skew angles up to 45° for non-perpendicular bridge crossings

Sloped Bridges - Operates on longitudinal slopes up to 5–7% for mountainous or hilly terrain

Variable-Span Bridges - Adjustable span parameters accommodate non-uniform bridge designs

First & Last Span Erection - Specialized capability for end-span girder placement

Widening & Retrofit Projects - Suitable for bridge widening and rehabilitation projects

 

1. Design & Engineering

Requirements Analysis - Define bridge type, span length, rated capacity (120T), counterweight requirements, and site conditions

Structural Design - Develop truss configuration, main girder dimensions, counterweight frame layout, and load-bearing calculations

Counterweight Balance Calculation - Determine optimal counterweight mass and travel range based on lifting moment and forward reach

Finite Element Analysis (FEA) - Perform stress analysis and structural verification for safety compliance, including stability analysis under counterweight loads

Detailed Drawings - Produce fabrication drawings with precise dimensions, welding specifications, and assembly tolerances

2. Material Preparation

Steel Selection - Procure high-strength structural steel (e.g., Q345B, S355) for main load-bearing components and counterweight frame

Incoming Inspection - Verify material certificates and conduct mechanical property tests

Cutting - Use CNC cutting machines or flame cutting to shape steel plates and sections according to drawings

Edge Preparation - Perform edge trimming, drilling, and beveling for weld joints

3. Fabrication & Welding

Surface Treatment - Remove rust, oil, and contaminants via sandblasting or grinding before welding

Welding Operations - Apply arc welding or gas welding for structural joints; ensure uniform, sound welds

Main Girder Fabrication - Weld truss modules including chords, diagonals, cross beams, and front cantilever section

Counterweight Frame Fabrication - Fabricate rear counterweight frame with mounting points and adjustment mechanism

Quality Control - Inspect weld quality through visual examination and non-destructive testing (NDT)

4. Machining & Component Manufacturing

Precision Machining - Machine pin holes, bolt holes, and connection interfaces for accurate fit

Leg Assembly Fabrication - Manufacture front, middle, and rear leg structures with mounting flanges

Trolley & Winch Assembly - Build lifting trolleys, hoisting winches, and pulley blocks

Bogie Manufacturing - Produce travel bogies with wheels, axles, and drive mechanisms

Counterweight Block Production - Cast or fabricate concrete/steel counterweight blocks with lifting points

Hydraulic Cylinder Manufacturing - Produce or procure hydraulic cylinders for leg adjustment and counterweight positioning

5. Surface Treatment & Painting

Shot Blasting - Clean steel surfaces to Sa2.5 standard for coating adhesion

Primer Application - Apply anti-corrosion primer to all structural components

Topcoat Painting - Apply finish coats with specified color and thickness

Corrosion Protection - Optional hot-dip galvanizing or specialized coatings for harsh environments

Counterweight Coating - Apply protective coating to counterweight blocks for durability

6. Factory Pre-Assembly & Testing

Trial Assembly - Partially assemble main components including counterweight frame to verify fit and dimensional accuracy

Counterweight Balance Test - Verify counterweight adjustment mechanism and balance characteristics

Mechanical Testing - Test winch operation, trolley travel, bogie rotation, and leg adjustment

Electrical System Check - Verify PLC, VFDs, sensors, and control cabinet wiring

Load Test (Factory) - Conduct rated load and overload tests to validate 120T lifting capacity

Stability Test - Verify anti-tipping protection and counterweight effectiveness under simulated load conditions

7. Disassembly & Shipping

Modular Disassembly - Break down into transportable modules with match-marking

Counterweight Handling - Prepare counterweight blocks for separate transport or on-site casting

Packaging - Protect components with wrapping, crating, and rust-preventive treatment

Shipping - Coordinate logistics for delivery to project site; counterweight may be shipped separately

Documentation - Prepare shipping list, assembly drawings, and operation manuals

8. On-Site Assembly

Site Preparation - Level and compact assembly area; ensure adequate space and access for counterweight installation

Component Inspection - Verify all parts received and inspect for shipping damage

Foundation & Support - Install temporary supports or assemble on pre-built track

Leg Assembly - Position front, middle, and rear legs with temporary bracing

Main Girder Erection - Lift and connect main truss girders using cranes; verify alignment and parallelism

Cross Beam Installation - Install cross beams and bracing to integrate main girders

Counterweight Frame Installation - Mount rear counterweight frame and adjustment mechanism

Counterweight Block Installation - Load counterweight blocks or fill water tank according to balance calculations

Trolley & Winch Installation - Mount lifting trolleys on main girder rails

Electrical & Hydraulic Connection - Connect control systems, sensors, and hydraulic lines

9. Commissioning & Load Testing

No-Load Trial Run - Test all motions: lifting, trolley travel, longitudinal/lateral movement, and counterweight adjustment

Counterweight Adjustment Verification - Test fore/aft movement and balance response under varying load positions

Safety Device Verification - Check overload limiter, anti-tipping protection, limit switches, emergency stop, and anemometer

Rated Load Test - Lift 120T test load to verify structural integrity and performance

Overload Test - Conduct 110-125% overload test as per safety standards

Stability Verification - Test machine stability with counterweight at minimum and maximum positions

Acceptance Inspection - Complete formal acceptance with client and regulatory authorities

10. Operation & Maintenance

Operator Training - Train operators on controls, safety procedures, counterweight adjustment, and emergency protocols

Documentation Handover - Provide operation manuals, maintenance schedules, and spare parts lists

Scheduled Maintenance - Regular inspection of wire ropes, brakes, hydraulic fluids, counterweight locks, and electrical systems

Counterweight Inspection - Periodic verification of counterweight integrity and adjustment mechanism

Ongoing Support - Provide technical support and spare parts availability throughout project duration

 

 

The company has installed an intelligent equipment management platform, and has installed 310 sets (sets) of handling and welding robots. After the completion of the plan, there will be more than 500 sets (sets), and the equipment networking rate will reach 95%. 32 welding lines have been put into use, 50 are planned to be installed, and the automation rate of the entire product line has reached 85%.

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