Formwork, Operations and Logistics in Formtraveller 

The efficiency of a Formtraveller depends heavily on how the formwork is designed and handled, and how site operations and logistics are planned. This includes panel dimensions, formwork surfaces, internal formwork launching, crew size, launching speed and workshop pre-assembly.

 

Internal and external formwork: configuration and handling

In typical applications, the external and internal formwork panels have a length of about 5.8 m, assuming a maximum segment length of 5 m in the concrete deck.

Internal and external panels are connected using threaded ties, such as Dywidag bars, passing through the deck webs. This creates a closed, stable formwork box that can carry fresh concrete and construction loads.

The internal formwork in Formtravellers is usually launched manually from one segment to the next:

• Chain tackles are commonly used to move the internal formwork along rails.
  
• Hydraulic cylinders can also be adopted, but the standard solution in many projects remains manual.
  
• The rails on which the internal formwork rests are launched together with the main structure of the Formtraveller.
  

As mentioned earlier, the position of internal diaphragms must allow the internal formwork to pass. If diaphragms are too close to the front of the segment, the internal formwork may need to be dismantled behind the diaphragm.

 

Formwork surfaces and materials

The most common formwork surface used in Formtraveller Systems is:

• Phenolic plywood, usually 21 mm thick.
  

Steel formwork surfaces are technically possible but rarely preferred:

• Rebuilding steel formwork for future projects is costly.
  
• For typical segment lengths and project sizes, plywood offers a better economic balance.
  

The usual arrangement is:

• Plywood sheets are screwed to timber sections.
  
• Timber sections are bolted to the steel ribs of the formwork structure.
  
• Parts of the internal and external web formwork are often made using wooden beams.
  

If the number of segments is very high, the phenolic plywood can be replaced during the life of the Formtraveller, while the underlying steel structure remains reusable.

 

Handling reinforcement: limits and special solutions

As a rule:

• Overhead Formtraveller do not normally allow the transport of pre-assembled reinforcement cages on the system itself.
  

However, in some specific projects where:

• The deck webs are vertical or nearly vertical, and
  
• Pre-assembled web rebar panels are desired,
  

it may be possible to develop special transport rails integrated into the Formtraveller. In such cases:

• A crane installs the pre-assembled web reinforcement panel.
  
• The load is then transferred from the crane to the special rails of the Formtraveller.
  

These are project-specific solutions, not the standard configuration.

 

Crew size, launching speed and construction cycle

To operate a Formtraveller– including:

• Opening the formwork
  
• Launching from one segment to the next
  
• Closing the formwork
  
• Introducing camber
  
• Preparing the formwork for reinforcement
  
• Concreting the segment
  

– a dedicated crew is required. 

The exact crew size depends on the segment weight, deck width and the target construction cycle, but in general:

• A team of 8 to 10 people per pair of Formtravellers is typical.
  

Regarding relocation speed:

• The normal launching speed of a Formtraveller is around 10 m per hour.
  
• Increasing the launching speed does not make practical sense, since the maximum segment length is only about 5 m. The marginal time savings are minimal, and the risks associated with higher movement speeds increase.
  

The typical construction cycle for a pair of segments using Formtravellers is approximately:

• 1 week per pair of segments,
  assuming standard times for reinforcement assembly, prestressing operations, concrete curing, and formwork operations.
  
  

Workshop pre-assembly, transport and on-site planning

During the original manufacture of a Formtraveller System:

• The steel structure is usually partially pre-assembled in the workshop.
  
• All components are marked with references, indicating their position in the final assembly.
  

For transport:

• Parts are designed to fit in 40-foot containers or on TIR truck platforms.
  

On site, careful planning of assembly and dismantling is essential:

• Correct definition of lifting points for sub-assemblies.
  
• Ensuring that the centre of gravity of each assembly stage remains within safe limits.
  
• Guaranteeing suitable access for cranes and transport equipment.
  

Accurate weights of all parts must be known:

• Typically derived from 3D models or detailed 2D drawings.
  
• If there is any uncertainty, scales can be used to confirm the component weights.
  
  

Design Criteria Document: selecting the right Formtraveller 

To evaluate whether a given Formtraveller is suitable for a specific bridge deck, it is essential to prepare a Design Criteria Document. This document must clearly define at least:

• Loads from the concrete segments and launching situation
  
• Safety factors
  
• Wind speeds:
  
  • During launching
    
  • During concreting
    
  • Under storm conditions
    
• Materials and steel grades
  
• Maximum span
  
• Live loads and other construction loads
  

The cost and site performance of a Formtraveller depend strongly on these definitions. A well-prepared Design Criteria Document is therefore the key technical basis for:

• Deciding whether an existing system can be reused or adapted, or
  
• Designing a new system optimised for the specific project.
  

In most successful cantilever projects, the Formtraveller is not an afterthought but an integral part of the initial design strategy for the bridge.

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Bridge construction has evolved dramatically over the past few decades. Among the most efficient technologies for cast-in-situ segmental bridge construction are Form Travellers (FTs) and Movable Scaffolding Systems (MSS).

Both systems enable builders to construct long-span bridges without extensive falsework or ground support. However, each has unique advantages, limitations, and ideal use cases. In this article, we’ll explore the key differences between Form Travellers and Movable Scaffolding Systems, helping you determine which is best suited for your next bridge project.

What Is a Form Traveller (FT)?

A Form Traveller is a specialized structural system used to cast bridge segments in place — typically in balanced cantilever construction. It allows engineers to build a bridge span segment by segment, extending out from a pier on both sides to maintain equilibrium.

Types of Form Travellers

There are two main types:

• Overhead Form Traveller: Supported from above the deck, ideal for deep valleys or bridges over water.
• Underslung Form Traveller: Suspended below the deck, used when there is sufficient space beneath the structure.

How It Works

The traveller is positioned at the end of the previously cast segment. After reinforcement, formwork, and concreting are completed, the new segment is cured and post-tensioned. The form traveller is then moved forward to the next position — repeating the cycle until the span is complete.

Advantages of Form Travellers

1. Minimal Ground Interference

Form travellers are entirely supported by the completed bridge structure itself, eliminating the need for ground-based falsework or scaffolding.

This makes them ideal for bridge construction over challenging terrains such as rivers, deep valleys, highways, and railways, where erecting temporary supports would be costly, dangerous, or even impossible.

By suspending operations above ground, contractors can work safely and continuously without disrupting the environment or traffic below.

2. High Precision and Geometric Control

Each segment constructed using a form traveller is aligned directly from the previous one, ensuring millimeter-level accuracy in deck geometry, slope, and alignment.

This precision is particularly important for long-span balanced cantilever bridges, where even small cumulative errors could result in significant misalignment.

Modern form traveller systems are equipped with hydraulic adjustment and monitoring systems, allowing engineers to maintain perfect geometry throughout construction.

3. Adaptability to Complex Bridge Designs

One of the strongest advantages of form travellers is their flexibility. They can easily adapt to variable spans, curved alignments, varying deck depths, and asymmetric cross-sections – features commonly found in modern architectural bridge designs.

Because the system is modular, it can be adjusted or modified for different segment lengths or shapes, making it suitable for architecturally complex or topographically challenging bridge projects.

4. Reduced Environmental Impact

Since form travellers do not require temporary supports or extensive site preparation, they significantly minimize ecological disturbance.

There is no need for foundation works in rivers or forests, which helps preserve wildlife habitats and natural landscapes.

This makes the method particularly favored in environmentally sensitive areas where traditional falsework would not be permitted.

5. Safety and Accessibility

Form travellers provide a stable and controlled working platform directly attached to the bridge, reducing risks associated with working at height or on unstable ground.

Engineers and workers can perform concreting, post-tensioning, and inspection operations in a secure environment with integrated walkways and access systems.

This contributes to improved safety performance and reduced downtime due to weather or ground conditions.

6. Long-Term Reusability

A well-designed form traveller can be reused across multiple spans or projects, which makes it a cost-efficient investment for companies specializing in segmental bridge construction.

The modular steel structure allows for quick assembly, disassembly, and transportation between job sites, enhancing operational efficiency over time.

Limitations of Form Travellers

1. Slower Construction Rate Compared to MSS

While form travellers offer exceptional flexibility, their cycle time per segment is typically longer than that of movable scaffolding systems (MSS).

Each segment must be individually set, reinforced, concreted, cured, and post-tensioned before the traveller can be advanced to the next position.

This makes the process less efficient for long, repetitive viaducts where uniform spans could be cast faster using span-by-span methods.

2. Higher Skill, Labor, and Equipment Requirements

Operating a form traveller demands specialized engineering expertise.

Precise alignment, load balancing, and structural monitoring are critical to ensure safety and quality.

Crews must be experienced in post-tensioning, segmental casting, and geometry control, which increases labor costs and training requirements.

Additionally, form travellers rely on advanced hydraulic and lifting equipment, adding to both capital and maintenance expenses.

3. Not Ideal for Low-Level or Easily Accessible Bridges

For bridges constructed close to the ground or in areas with easy site access, using form travellers is often unnecessary and uneconomical.

In such cases, conventional scaffolding or movable scaffolding systems (MSS) offer faster setup, simpler logistics, and lower overall costs.

Form travellers are most cost-effective when ground support is impractical or when the bridge spans are too long for traditional falsework methods.

4. Higher Initial Setup Time

The initial assembly, calibration, and load testing of a form traveller require considerable preparation.

Before casting begins, the system must be precisely aligned with the pier segment, balance loads must be verified, and safety systems must be tested.

While this setup ensures accuracy and safety, it also extends the pre-construction phase, which can affect project timelines.

5. Weight and Stability Constraints

Form travellers carry significant loads from both the fresh concrete and the equipment.

As a result, the pier and segment structure must be strong enough to support these loads during cantilevering.

For lighter or slender piers, additional temporary stabilization may be necessary — slightly reducing the overall efficiency advantage.

What Is a Movable Scaffolding System (MSS)?

A Movable Scaffolding System, often referred to as a Launching Girder, is an advanced construction method used for span-by-span cast-in-situ bridges. Instead of building segments one by one from a pier, the MSS supports the entire span during concreting.

Types of MSS

• Overhead MSS: The truss structure is positioned above the bridge deck.
• Underslung MSS: The truss structure is below the deck, used when overhead clearance is limited.

How It Works

The MSS is positioned between two piers. Once the formwork and reinforcement are ready, the entire span is cast in place. After curing and post-tensioning, the system is moved (or “launched”) to the next span. This method is ideal for repetitive spans of similar geometry.

Advantages of Movable Scaffolding Systems (MSS)

1. High Construction Speed

The Movable Scaffolding System (MSS) is designed for rapid, span-by-span construction.

Unlike form travellers that cast one short segment at a time, the MSS supports and casts an entire bridge span in a single cycle. Once the concrete has gained sufficient strength and post-tensioning is complete, the entire system is “launched” or moved forward to the next span.

This cyclical workflow significantly reduces construction time, making the MSS ideal for large-scale infrastructure projects such as expressways, metro viaducts, and high-speed rail bridges where many similar spans are required.

2. Efficiency for Repetitive and Standardized Designs

MSS technology is most efficient in projects that have repetitive span lengths and uniform geometry.

When bridge spans, pier heights, and deck shapes remain consistent, the system can operate in a steady rhythm that minimizes manual adjustments.

This efficiency not only saves time but also reduces material waste and formwork errors.

For long viaducts or elevated highways with repetitive spans, MSS is often the most cost-effective construction method available.

3. Excellent Safety and Working Platform

One of the major advantages of MSS is that it provides a secure and self-contained working platform.

Workers can complete all tasks such as formwork installation, reinforcement, concreting, and inspection safely within the structure itself.

Integrated walkways, railings, and working decks ensure excellent accessibility and safety, even when operating at significant heights.

This controlled working environment minimizes risks related to wind, unstable ground, or traffic underneath the bridge.

4. Reduced Crane Dependency

The MSS carries its own formwork, reinforcement, and concreting systems, which reduces the need for cranes during bridge construction.

Most operations are performed directly on the system, allowing continuous workflow even when crane access is limited or costly.

This feature is particularly valuable in urban environments or over busy roads, where lifting operations are restricted.

5. Consistent Quality and Alignment

Since each span is cast under identical conditions, the MSS ensures high geometric accuracy and surface quality across the entire structure.

Automated formwork adjustment systems maintain the correct deck profile and alignment, resulting in consistent appearance and performance.

This uniformity is especially important for transport infrastructure where smoothness and symmetry affect both aesthetics and durability.

6. Cost Efficiency for Large Projects

Although the initial investment in MSS equipment is significant, the cost per span decreases quickly when the number of spans is large.

For long viaducts with hundreds of spans, the amortized cost of the system makes it an economically efficient option, especially when combined with faster construction and reduced labor needs.

Limitations of Movable Scaffolding Systems (MSS)

1. Limited Flexibility for Variable or Curved Spans

MSS performs best on bridges with straight alignments and consistent span lengths.

If the spans vary in length or curvature, the system must be heavily modified, which reduces efficiency and increases setup time.

Bridges with complex geometry or asymmetrical designs often require custom adjustments that make the MSS less practical.

2. Heavy and Complex Setup

Movable scaffolding systems are large and mechanically complex.

They include heavy steel trusses, hydraulic lifting systems, and built-in formwork, all of which require specialized assembly and calibration.

Initial setup and testing for the first span can take several weeks, which makes MSS unsuitable for short bridges or one-time projects where the cost and time of assembly outweigh the benefits.

3. High Load Demands on Piers and Foundations

During concreting, the MSS together with fresh concrete applies very high temporary loads on the piers and foundations.

These loads can exceed the bridge’s service loads, meaning that the substructure must be designed to resist both permanent and construction-phase stresses.

This may increase pier size, reinforcement requirements, and overall construction cost.

4. High Initial Investment

The MSS requires a large upfront investment for design, fabrication, and installation.

It involves specialized hydraulic and launching systems as well as strong truss structures.

For small-scale or unique projects, this cost may not be justified.

However, for long linear projects such as highways and metro viaducts, the system becomes highly economical after repeated use.

5. Limited Suitability in Confined or Steep Terrain

The MSS requires ample space to move between spans.

In mountainous areas, curved alignments, or tight urban zones, it can be difficult to reposition or stabilize the system safely.

In such conditions, Form Travellers or precast methods are often more flexible and practical.

Form Traveller vs. Movable Scaffolding System: A Detailed Comparison

Feature	Form Traveller (FT)	Movable Scaffolding System (MSS)
Construction method	Segment-by-segment (balanced cantilever)	Span-by-span (continuous casting)
Span length	50–250 m	25–70 m
Speed	Slower but more flexible	Faster for repetitive spans
Flexibility	High — suitable for curves and variable spans	Limited — best for uniform spans
Ground clearance requirement	None (works over deep valleys or water)	Requires moderate clearance
Structural weight	Relatively light	Heavy steel structure
Typical applications	Cable-stayed bridges, high viaducts, crossings over obstacles	Elevated highways, metro viaducts, long repetitive bridges
Environmental impact	Minimal (no ground falsework)	Moderate (depends on site setup)
Initial investment	Lower	Higher, but faster payback on large projects

Choosing the Right System for Your Project

The choice between a Form Traveller and a Movable Scaffolding System depends on several key factors:

1. Bridge Geometry:
   • If your project involves curved alignments or variable spans, a Form Traveller is more practical.
   • For straight, repetitive spans, the MSS offers faster cycle times.
2. Site Conditions:
   • Form Travellers excel in areas with limited ground access (deep valleys, rivers, railways).
   • MSS requires space for movement and assembly, so it’s better suited for open terrain.
3. Budget and Timeline:
   • MSS involves higher upfront costs but pays off for large-scale projects with many spans.
   • Form Travellers are more cost-effective for shorter bridges or complex geometries.
4. Environmental Impact:
   • Form Travellers are ideal for sensitive ecological zones where minimizing ground disturbance is crucial.

Real-World Examples

• Form Traveller Use: on the link you can find many projects that we have completed during the years and used form travellers to construct various bridges.
• MSS Use: on the link you will find many bridges that we helped to build with MSS for repetitive spans, ensuring efficiency and uniformity.

Conclusion

Both Form Travellers and Movable Scaffolding Systems have revolutionized modern bridge construction. The Form Traveller stands out for its flexibility and precision in complex, high-altitude, or environmentally sensitive projects. Meanwhile, the Movable Scaffolding System shines in high-volume, repetitive-span infrastructure where speed and efficiency are paramount.

The best solution depends on your project’s geometry, environment, and timeline – not just the technology itself.

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The Strukturas Formtraveller system is a modern solution for cast in-place, prestressed concrete bridge and viaduct decks. As a type of pier-supported falsework, it enables bridge decks to be built without relying on ground-supported scaffolding. During construction, the Formtraveller carries the fresh concrete, reinforcement, workers, and formwork, safely transferring these loads into the completed portion of the structure.

As prestressed concrete technology advanced, the need arose for adaptable equipment capable of following the sophisticated geometry of slender, curved decks while still allowing long spans to be built efficiently. Over several decades Strukturas has refined its Formtraveller solutions, creating systems that adapt to many deck cross-sections, span lengths, longitudinal slopes, and plan radii.

We will explain all the types of form travelers and their differences, advantages here, for your deeper understanding, but you do not need to become an expert in this, because our team would choose the best solution for your individual needs.

Balanced Cantilever Construction with Formtravellers

In balanced cantilever construction, a pair of Formtravellers is mounted on top of a pier. Segments are cast outward from both sides in a symmetrical pattern to maintain balance. Each segment is cast in place, reaches the required strength, is prestressed, and becomes part of the permanent structure. After completion of a segment, the Formtraveller is released and launched to the next position.

Typical segment lengths are around five meters, though in special cases they may reach approximately ten meters. This construction method is ideal for viaducts over deep valleys, rivers, or busy infrastructure where ground-supported falsework is not feasible. The resulting prestressed concrete deck is structurally efficient, slender, and durable.

Form-traveller Systems for Span-by-Span Decks

Formtraveller Systems are used when the deck acts as a concrete beam supported directly on columns. Instead of building segments from the pier, each span is cast in one operation. Construction joints are placed near points of zero bending moment – often at roughly one-fifth of the span length – allowing the deck to behave as a continuous structure while keeping the sequence simple and repetitive.

Overhead Formtraveller

In an overhead Formtraveller the main steel structure sits above the deck, with the formwork suspended from it. This configuration is particularly effective when access below the deck is limited, such as over deep water or rough terrain. For the same segment weight and length, overhead systems are often lighter and more economical than underslung alternatives, making them a preferred option when site conditions support their use.

Underslung Formtraveller

In an underslung Formtraveller the main structure is located beneath the deck, supporting the formwork from below. This arrangement is chosen when access from below is easier, or when height restrictions exist above the deck. Underslung Formtravellers can be modified for decks with steep longitudinal slopes by keeping the traveller horizontal during casting and allowing it to follow the slope during launching. Braking systems ensure safe positioning on steep gradients.

Arch Formtraveller

The arch Formtraveller is a specialised system for casting concrete arch ribs segment by segment. It supports the fresh concrete and formwork for each new rib section and transfers loads into the previously completed part of the arch. By precisely controlling geometry and camber, it enables high-accuracy construction of concrete arch bridges even where traditional scaffolding is impractical.

Wing Formtraveller

The wing Formtraveller is used to cast deck wings in both composite decks (steel girders with a concrete slab) and full concrete decks with wide cantilever sections. Using a dedicated wing traveller allows the formwork to be optimised and reused from span to span, improving speed and surface quality while the main traveller handles the core of the deck.

Formwork, Segment Length and Deck Geometry

Formtraveller systems include internal and external formwork tailored to the deck geometry. Formwork panels are typically about 5.8 meters long, matching a segment length of around five meters and allowing for necessary overlaps. The internal formwork is advanced on rails integrated into the traveller structure. This is usually done manually using chain tackles, though hydraulic systems may be used when required.

Internal and external formwork panels are linked through the deck webs with threaded ties, forming a closed box that resists hydrostatic pressure and maintains geometry. A common facing material is 21 mm phenolic plywood mounted on a reusable steel frame. Plywood can be replaced as needed, while the steel substructure remains suitable for many projects. Timber beams are often used in web formwork for flexibility.

Efficient operation requires attention to deck design. Internal diaphragms must be placed toward the rear of each segment to allow internal formwork to pass forward. Maintaining constant spacing between deck webs simplifies the formwork layout and improves operational performance.

Launching, Deformation Limits and Construction Cycle

A Formtraveller is typically launched at a speed of around ten meters per hour. Because most segments are only five meters long, higher speeds are unnecessary; precision and safety take priority.

A standard two-segment construction cycle lasts approximately one week. This duration varies depending on reinforcement assembly, prestressing operations, concrete curing times, and formwork preparation. Formtravellers are designed to streamline operations such as opening and closing the formwork, applying camber adjustments, and preparing for installation of reinforcement.

Structural deformation limits ensure accurate deck geometry. A global deformation limit of L/400 (where L is the span of the traveller structure) is common, while local formwork elements typically follow a limit of L/250.

Supports, Anchorage and Interaction with the Bridge

Formtravellers attach to the concrete deck via threaded bar anchors passing through block-outs in the bottom and top slabs. These anchors safely transfer construction loads during casting and launching. Prior to construction, the equipment’s weight and reaction forces are submitted to the bridge designer to verify that piers and deck cantilevers can resist all construction-stage loads.

Design Codes, Machinery Directive and Safety Systems

Formtraveller structures are designed according to the relevant Eurocodes and manufactured under EN 1090. Since the Formtraveller includes mechanical and hydraulic systems and moves during use, it is classified as a machine under the Machinery Directive. This classification requires comprehensive risk analysis and the integration of safety systems.

Hydraulic cylinders used for launching include safety valves that prevent piston movement in case of hydraulic failure. On steep longitudinal slopes, braking systems secure the traveller to the rails during movement. Proper planning, procedures, and training ensure a safe environment for all site personnel.

Assembly, Transport and Reuse

During fabrication, Formtraveller components undergo partial pre-assembly to confirm fit and alignment. All parts are marked to ensure efficient and error-free assembly on site. Components are sized for transport in standard 40-foot containers or on truck platforms, and detailed weight information is provided to allow correct crane selection and safe lifting.

After dismantling, the same Formtraveller can be transported and rebuilt for future projects with minimal modifications. With proper care and maintenance, a Formtraveller can remain in service for more than fifty years, offering excellent lifecycle economy and sustainability.

Teams and Project Organisation

Operating a pair of Formtravellers typically requires a team of eight to ten skilled workers. Their tasks include opening and closing formwork, carrying out launches, adjusting camber, assembling reinforcement, and conducting concrete pours. Full-scale load testing is rarely practical; instead, safety is ensured through detailed engineering calculations, modelling, and strict inspection procedures.

Evaluating and Tailoring a Formtraveller Solution

Each project begins with the preparation of a Design Criteria Document, which defines segment weights, loads, safety factors, wind conditions, maximum spans, materials, and other technical requirements. The performance, safety, and cost-effectiveness of the Formtraveller depend heavily on this document, which is developed in close coordination with the bridge designer and contractor.

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As global infrastructure projects grow in scale and complexity, the construction industry continues to search for faster, safer, and more efficient methods. One of the most transformative innovations in recent decades is the Full Span Method (FSM), a technique that allows entire bridge spans to be installed in a single operation.

The Full Span Method has become the preferred choice for many large-scale projects such as high-speed railways, metro systems, and elevated highways. It combines speed, precision, and cost efficiency, making it a key technology in modern bridge construction.

What Is the Full Span Method?

The Full Span Method involves casting or precasting complete bridge spans and then lifting them into position using specialized equipment such as beam launchers or launching gantries. Instead of assembling multiple smaller segments on-site, the entire span—often ranging from 25 to 40 meters in length—is installed as a single unit.

These spans are typically precast in a dedicated casting yard near the construction site, where controlled conditions ensure high-quality production. Once ready, the spans are transported along the alignment and positioned directly onto the bridge piers using precision lifting systems.

This approach minimizes on-site labor and construction time while ensuring consistent quality and alignment across the entire structure.

Key Advantages of the Full Span Method

1. Unmatched Construction Speed

Because entire spans are installed in one go, the Full Span Method can shorten construction schedules dramatically. It eliminates the repetitive cycle of segment-by-segment erection and post-tensioning, enabling multiple spans to be completed in a matter of days instead of weeks.

2. Enhanced Quality Control

Precasting full spans in a controlled environment ensures uniform strength, surface finish, and durability. Each span undergoes strict testing before installation, which guarantees that only high-quality components are used in the final structure.

3. Improved Safety

By shifting most of the work to a casting yard and reducing on-site operations, the Full Span Method greatly improves safety. Workers are exposed to fewer high-risk activities such as lifting, welding, or post-tensioning at height. The reduced number of equipment movements also minimizes accident risk.

4. Minimal Disruption to Traffic and Environment

Since the Full Span Method requires little ground-level work, it is particularly effective in congested or sensitive areas such as cities, rivers, or highways. Spans can be installed during nighttime hours or limited closures, allowing normal activity to resume quickly.

5. Cost Efficiency

Although the method requires significant investment in specialized equipment such as beam launchers or transporters, it reduces the total project cost by saving time, labor, and materials. The long-term maintenance cost is also lower because of the consistent quality of precast spans.

6. Sustainability Benefits

The controlled production of spans in a casting yard minimizes material waste, energy consumption, and emissions. The ability to reuse equipment and molds across multiple spans contributes to a more sustainable construction process.

Applications of the Full Span Method

The Full Span Method is widely used in:

• High-speed railway projects
• Metro and elevated transit systems
• Expressways and viaducts
• Long-span overpasses and flyovers

Its efficiency and adaptability make it suitable for large infrastructure projects where rapid construction and high quality are top priorities.

Equipment Used in the Full Span Method

The Full Span Method relies on several key types of heavy equipment:

• Beam Launchers: Used to lift and place full spans directly onto piers with millimeter-level precision.
• Launching Gantries: Employed when spans need to be launched sequentially across long viaducts or areas with limited ground access.
• Transporters or Trolleys: Move precast spans from the casting yard to the installation site.
• Temporary Bearings and Support Frames: Ensure stability and correct alignment during placement.

Each component works together to make span installation safe, efficient, and highly accurate.

Strukturas: Expertise in Full Span Construction Equipment

Strukturas, a Norwegian company with over 30 years of experience in bridge construction systems, is a recognized global supplier of beam launchers, launching gantries, and form travellers for full span applications.

Strukturas designs equipment that complies with Eurocode 3 and EN-1090 standards, ensuring every structure meets strict safety and performance requirements. Using high-quality steel grades such as Q235 and Q345, their systems combine durability, strength, and ease of reuse across multiple projects.

The company provides complete engineering services, from design and customization to on-site assembly, operation, and technical supervision. This end-to-end support ensures optimal performance and safety throughout every phase of construction.

Why Contractors Choose Strukturas for Full Span Projects

• Comprehensive Equipment Range: Beam launchers, gantries, and form travellers designed for full span erection.
• Engineering Excellence: Compliance with international standards for quality and safety.
• Global Experience: Proven track record in major infrastructure projects across Europe and Asia.
• Sustainability Commitment: Reusable, modular systems designed to reduce waste and extend lifespan.
• Efficient Project Delivery: Shorter timelines, fewer disruptions, and reduced overall costs.

The Full Span Method represents a major step forward in bridge construction, combining high precision with remarkable speed and safety. By reducing on-site work and maximizing the benefits of prefabrication, it enables large-scale projects to be completed faster and more efficiently.

Strukturas continues to lead this innovation through reliable, high-performance equipment that helps engineers and contractors build bridges more sustainably and with superior quality. As infrastructure demands continue to rise, the Full Span Method remains one of the most effective and forward-looking techniques in modern bridge construction.

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Bridge construction has advanced rapidly over recent decades, driven by the need for faster, safer, and more cost-efficient infrastructure. Among the most important innovations transforming this field are launching gantries, specialized machines that lift and position large bridge segments with exceptional precision.

These systems have become essential in the construction of long-span and precast segmental bridges, where accuracy and speed are crucial. Launching gantries allow builders to assemble entire bridge decks in the air, eliminating the need for cranes or temporary scaffolding on the ground.

What Are Launching Gantries?

A launching gantry (also called a bridge launching girder) is a large truss system used to lift, transport, and position precast concrete bridge segments. Unlike cranes that depend on ground-level support, launching gantries move along the bridge alignment and place each segment directly above the piers.

They are usually made of high-strength steel and equipped with hydraulic jacks, winches, and trolleys that enable controlled vertical and horizontal movement. Depending on site conditions, launching gantries can be configured to operate above the bridge deck (overhead) or below it (underslung).

Their self-launching capability allows the equipment to shift from one span to the next without disassembly. This feature saves time, reduces setup effort, and increases productivity, especially in large-scale viaducts and elevated highway or railway projects.

Key Advantages of Launching Gantries

1. High Precision and Alignment

Launching gantries achieve millimeter-level accuracy when placing precast segments. This ensures perfect alignment of each piece, contributing to the strength, performance, and durability of the entire bridge.

2. Faster Construction with Reduced Downtime

By automating lifting and placement, launching gantries speed up the assembly process and reduce downtime between spans. Projects that previously took months using traditional methods can progress faster and more continuously, meeting demanding construction schedules.

3. Improved Safety

Because launching gantries operate directly above the piers, they reduce the need for workers to operate at height or near suspended loads. This greatly decreases accident risks and creates a safer working environment for construction teams.

4. Adaptability to Complex Bridge Designs

Modern launching gantries can handle curved alignments, variable slopes, and wide decks. Advanced articulations and hinge points make it possible to adapt to different geometries without compromising precision or load distribution.

5. Reduced Environmental Impact

Since launching gantries operate above the bridge structure, they require no temporary supports on the ground. This minimizes ecological disruption in rivers, valleys, or urban areas and helps maintain environmental integrity.

6. Cost and Labor Efficiency

A single gantry can perform the work of several cranes. This reduces labor requirements, simplifies logistics, and lowers overall construction costs. It also eliminates the need for heavy ground-based lifting equipment, which is often difficult to transport or operate in remote areas.

Applications of Launching Gantries

Launching gantries are used in a wide variety of bridge construction projects, including:

• Precast segmental bridges
• Metro and railway viaducts
• Elevated highways and flyovers
• River and valley crossings

They are especially efficient for projects with repetitive spans and high precision requirements, where ground access is limited or unsuitable for cranes.

Strukturas: A Global Authority in Launching Gantry Systems

Strukturas, a Norway-based company with more than 30 years of experience, is one of the world’s leading providers of bridge construction technology. Their launching gantries have been used in major projects throughout Europe, the Middle East, and Asia, recognized for their performance, safety, and long-term reliability.

Strukturas designs both overhead and underslung launching gantries, each customized to meet specific project needs such as span length, bridge curvature, and load capacity. All systems comply with Eurocode 3 and EN-1090 standards and are built from high-quality structural steel grades such as Q235 and Q345 for superior strength and fatigue resistance.

In addition to manufacturing, Strukturas offers complete project services, including design, assembly, testing, training, and on-site supervision. Their deep expertise ensures seamless integration of equipment into each construction process, even under challenging site conditions.

Innovations and Technical Excellence

Strukturas’ launching gantries feature advanced hydraulic systems that provide smooth segment handling, accurate load balancing, and precise positioning. Many of their models are modular, allowing them to be reused for different projects and adapted to changing structural requirements.

Systems such as the JP50/40 model are capable of handling spans of up to 40 meters while maintaining high stability and operational efficiency. These innovations reflect Strukturas’ commitment to combining engineering precision with practical on-site usability.

Why Choose Strukturas for Launching Gantries

• Tailored Engineering: Custom-built systems for specific bridge geometries and site conditions.
• Certified Quality: Designed and produced under Eurocode 3 and EN-1090 standards.
• Comprehensive Service: From design and fabrication to operation and dismantling.
• Proven Experience: Equipment successfully deployed in projects worldwide.
• Sustainability Focus: Modular systems designed for reuse and reduced environmental impact.

Launching gantries are among the most efficient tools available for modern bridge construction. Their ability to lift, move, and position heavy bridge segments with precision makes them essential for fast, safe, and sustainable infrastructure projects.

Strukturas continues to lead this field with state-of-the-art launching gantries that combine durability, safety, and performance. For contractors and engineers seeking reliable equipment and technical excellence, Strukturas remains a trusted partner for bridge construction worldwide.

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Introduction

Eurocode 3 (EN 1993) serves as the European standard for steel structure design, while EN-1090 governs manufacturing compliance, together forming the foundation of safe, reliable bridge construction across Europe. These standards are critical for ensuring structural integrity and safety in modern bridge projects, particularly when working with specialized bridge construction equipment like Movable Scaffolding Systems and Form Travellers.

Specialized bridge construction equipment such as Movable Scaffolding Systems (MSS) and Form Travellers represents the backbone of efficient, safe bridge assembly. These systems must handle heavy loads while maintaining structural integrity throughout complex construction phases, making compliance with the strictest design and manufacturing standards absolutely essential.

What This Guide Covers

This guide covers Eurocode 3 design principles for structural steel applications, EN-1090 manufacturing requirements for steel components, compliance essentials for specialized bridge equipment, and practical implementation strategies for construction projects.

Who This Is For

This guide is designed for bridge engineers, construction managers, steel fabricators, and project managers involved in European bridge construction projects. Whether you are designing suspension bridges or managing the fabrication of structural components, you will find actionable insights for ensuring compliance and project success.

Why This Matters

Understanding these standards directly impacts structural safety, regulatory compliance, and successful project delivery. Non-compliance can result in structural failures, legal issues, and significant financial losses, making mastery of these standards essential for professional success in the construction industry.

Understanding Eurocode 3 (EN 1993): The Foundation of Structural Steel Bridge Design

Eurocode 3 (EN 1993) is the European standard for the design of steel structures, encompassing bridges, building structures, and industrial applications using structural steel as the primary material. It ensures consistent design practices across Europe by providing engineers with reliable methods for calculating load-bearing capacity and ensuring structural integrity.

It includes design principles for various steel grades such as Q235 and Q345, describing their chemical composition, yield strength, tensile strength, and elongation properties. These steel grades are essential in balancing cost, weldability, and mechanical performance for modern infrastructure.

Eurocode 3 uses ultimate limit state and serviceability limit state principles to ensure structures remain safe under maximum and long-term loading conditions. It also includes fatigue assessment, vibration control, and corrosion resistance criteria.

Steel Properties and Characteristics in Modern Bridge Construction

Selecting the right structural steel is critical for bridge performance. The most common steels, Q235 and Q345, are chosen based on their mechanical and chemical properties.

Q235 Steel: Known for cost-effectiveness and weldability, with a tensile strength of 370–500 MPa and elongation around 26%. It is comparable to ASTM A36 (US) and S235JR (Europe).

Q345 Steel: Offers higher yield strength (around 345 MPa) and tensile strength (470–660 MPa). It contains low carbon (below 0.2%) and alloying elements like manganese and silicon, enhancing toughness and corrosion resistance. Q345 steel performs well in cold climates and under dynamic loads, making it ideal for arch bridges, suspension bridges, and heavy-duty structures.

Both steels can be galvanized or powder-coated to improve durability and reduce corrosion.

EN-1090: Manufacturing and Fabrication Standards for Steel Components

EN-1090 complements Eurocode 3 by defining manufacturing, fabrication, and welding standards for steel components. It ensures design intent translates into field reliability through strict control of materials, welding, heat treatment, and testing.

Execution Classes

EN-1090 defines four Execution Classes (EXC1–EXC4), which correspond to increasing levels of complexity and safety:

• EXC1: Simple structures
• EXC2: Standard buildings and bridges
• EXC3: Major structures
• EXC4: Critical infrastructure such as suspension or arch bridges

Each level adds stricter requirements for documentation, testing, and welder qualification.

Welding Standards and Quality Control

The standard ensures all welding and jointing processes maintain the mechanical properties defined in Eurocode 3. High-level projects (EXC3 and EXC4) require extensive non-destructive testing (NDT) and traceability documentation.

Specialized Bridge Construction Equipment: Movable Scaffolding Systems and Form Travellers

These temporary structures must meet the same quality standards as permanent ones because they support heavy loads and changing configurations during construction. Compliance with Eurocode 3 and EN-1090 ensures stability, safety, and durability.

Movable Scaffolding Systems (MSS)

MSS must meet design and manufacturing standards addressing variable load paths and stability during movement. EN-1090 compliance guarantees structural reliability through proper material selection, welding quality, and fatigue performance. Q345 steel, with high strength and toughness, is often used for MSS frames and joints.

Form Travellers

Form travellers are designed according to Eurocode 3 principles for cantilever loading and asymmetric conditions. They require tight fabrication tolerances, reliable welds, and heat treatment of steel elements to ensure safe load transfer during concrete casting.

Standard Components vs. Specialized Equipment

Feature	Standard Bridge Components	Specialized Equipment
Design Life	100+ years	20–30 years
Load Factors	Standard traffic and dead loads	Variable construction loads
Execution Class	Typically EXC3	Always EXC4
Testing Requirements	Standard NDT	Enhanced load verification

Strategic Advantages of Eurocode 3 and EN-1090 Compliance

Risk Mitigation and Safety Assurance

Compliance ensures steel components meet strict yield, tensile, and fatigue performance standards, reducing the risk of failure. It guarantees safety for both workers and future bridge users.

International Market Access and Project Qualification

Compliance with EN-1090 enables CE marking, granting market access across the European Union and globally recognized regions. It simplifies cross-border project collaboration and supplier integration.

Quality Assurance and Project Success

Adherence to standards ensures consistent material quality, reduces rework, and improves durability. Properly manufactured components result in lower maintenance costs and extended bridge life.

Strukturas: Specialist in Compliant Bridge Construction Equipment

Strukturas designs and manufactures Movable Scaffolding Systems and Form Travellers that fully comply with Eurocode 3 and EN-1090. Their expertise spans design, testing, and precision manufacturing to ensure every component meets structural and safety requirements.

Strukturas’s integrated engineering and production approach guarantees compliance while optimizing strength, durability, and efficiency. Their systems are used across Europe for high-standard infrastructure projects.

Frequently Asked Questions

What is the difference between Eurocode 3 and EN-1090?

Eurocode 3 covers the design of steel structures, while EN-1090 governs manufacturing, welding, and fabrication processes.

Why is compliance mandatory for bridge equipment?

It ensures that temporary and permanent structures can safely handle heavy loads while protecting workers and the public.

How do Execution Classes affect cost?

Higher classes require more documentation, testing, and quality control, increasing upfront cost but preventing expensive future failures.

What documentation is needed for EN-1090?

Material certificates, welding qualifications, inspection reports, and traceability documentation for all structural components.

Can non-European manufacturers be certified?

Yes. Certification is possible through approved notified bodies that verify factory control systems and quality processes.

Conclusion

Eurocode 3 and EN-1090 form the foundation of safe, modern bridge construction. They ensure structural components and equipment meet strict performance and quality standards, preventing failures and ensuring long-term reliability.

Whether constructing a permanent bridge or using specialized systems such as MSS and Form Travellers, compliance ensures durability, safety, and project success.

To begin:

1. Evaluate your current design and fabrication compliance.
2. Work with qualified engineers familiar with Eurocode 3.
3. Partner with certified EN-1090 manufacturers.