MOVABLE SCAFFOLDING SYSTEM - MSS

An advanced, cost-effective, reliable and economical solution for modern bridge construction.

The NRS Movable Scaffolding System (MSS) is one of the most popular and recognized system in the world at present for span-by-span in-situ construction of bridges. The system is renowned for its lightweight, easy to assemble, practical efficiency in operation, and innovative ideas.

The NRS MSS has the ability to adapt to different cross sections allowing the contractor to re-use the equipment for different projects.

The NRS MSS system consists of a support structure spanning between two piers from which formwork is either supported or suspended. The inner formworks (core form) is collapsible and can run on a rail system to allow easy relocation to the next span. The system is designed so that the outer formwork can be opened sufficiently and adequately to allow to pass around the bridge piers during the launching operation. After launching, the formwork is closed again and after setting to the designed alignment and level, placing of reinforcement can commence.

The NRS MSS system has been further developed over the years and the developments resulted in the reduction the high costs of construction manpower.

Today our widely proven MSS for construction of cast-in-situ bridges can many cost saving advantages to bridge construction through:

Optimized design
Ease of assembly
Efficient operation

One of the latest innovation enables the Underlane Type MSS to operate without the need for external cranes or lifting equipment. The system is most suitable for bridges over waterways, bridges with high piers as well as for site conditions where access for external cranes is difficult.

NRS is the first in the world to develop the Self-Launching MSS (SL-MSS). The difficulties in handling pier support brackets over water as well as on high piers prompted this development.

This system is able to transfer forward and mount the pier support brackets without any need of external lifting equipment or crane. The SL-MSS had been successfully used in the construction of several major bridge project worldwide and is widely sought after due to its low reasonable cost and operational efficiency.

SPECIFIC DETAILS

THE UNDERLANE MSS

A TYPICAL CONSTRUCTION CYCLE WITH THE UNDERLANE MSS

1. After concreting, curing and tensioning of cables, the Main Girders are lowered by the main jacks at the rear Suspension Gallow and on the front Pier Bracket.

2. The joints in the middle of the Transverse Beam system are released and the Main Girders are moved transversely into a position where the Transverse Beams can pass the piers.
3. The MSS is ready for launching. The launching operation to the next concreting position is to be carried out. The two Main Girders are moved independently to the next span.
4. During the launching operation, the Suspension Gallow is moved to its next position.
5. The two girders are moved transversely and joined in the middle of the Transverse Beam system.
6. The Main Girders are raised to the concreting position by the Main Jacks.
7. Adjusting the formwork by means of the screw jacks and the adjustable supports.
8. For box girder bridges: After placing the reinforcement and tendons of the bottom slab and webs, the Internal Formwork is moved to its next position.
9. When placing of reinforcement and tendons is finished, the MSS is ready for concreting of the next span of the superstructure.
10. During the concreting period, the rear pair of Pier Brackets are dismounted, moved to the next front pier and re-installed.

SPECIAL FEATURES

1. SF-UL-MSS - Launching.. — Launching of MSS with hydraulically folded bottom slab formwork (limited space for transverse movement)

2. SF-UL-MSS - Overhead... — Ovehead Carrier for lifting of reinforcement, prestressing ducts, forms and other miscellaneous lifting works.

3. SF-UL-MSS - Remote.. — Remote controlled Internal Formwork Rolling Wagon (folded position). Hydraulic cylinders fold the formwork, launching by hydr. motors

THE OVERHEAD MSS

A TYPICAL CONSTRUCTION CYCLE WITH THE OVERHEAD MSS

1. After concreting, curing and tensioning of cables, the Main Girder (or girders) is (are) lowered by the Main Jacks down to the Launching Wagon (located at the supports).

2. The bottom formwork (box section) or interior formwork (double T) is lowered by means of winches or hydraulic cylinders. The ext. part of the outer formwork will be lowered, too.
3. The MSS will be launched to its new position (next span). The rear support is connected to the Main girder(s) and will “automatically” be launched to its new position together with the MSS.
4. The formwork panels will be closed again (by means of either winches or hydr. cylinders).
5. The MSS will be lifted by the Main Jacks.
6. The formwork will be adjusted (if required) by adjusting the hanger bars.
7. When placing of reinforcement and tendons is finished, the MSS is ready for concreting of the next span of the superstructure.
8. For box girder bridges: After placing the reinforcement and tendons of the bottom slab and webs, the Internal Formwork is moved to its next position.
9. During concreting/curing, the now “rear” main support will be dismantled and re-installed at the next (3rd) pier.