Heavy Duty Modular Bracing System

A heavy duty hydraulic bracing system for large cofferdams up to 21.5m wide

Fifteen leg configurations for maximum flexibility
For sheet to sheet ranges of 3.8m to 21.5m
Pre-cambered beams maximise clear span
Temporary works design available
Supplied with fixed length extensions
Nationwide delivery

The Heavy Duty Modular Bracing System is our largest capacity hydraulic brace, capable of spanning up to 21.5m sheet-to-sheet. It is built for complex, large-scale groundwork where standard bracing simply will not reach.

Typical applications

Attenuation systems and storm water storage
Deep basements
Reinforced concrete structures
Culverts and large diameter pipework
Pump stations and wetwells
Large-scale cofferdams

How the system works

The heavy duty frame sits inside large excavations as a continuous ring of pre-cambered beams. Once lowered into the excavation and assembled, double-acting hydraulic rams are pumped out so the frame bears tightly against the sheet piles. This pre-loading ensures the frame is immediately active, holding back ground movement from the start.

Modular and adaptable

To span wide distances, the beams are built with an intentional inward curve, known as pre-camber. When the ground puts load onto the frame, these beams are designed to straighten rather than sag inwards, which allows for significantly wider clear spans without intermediate struts.

The system covers a massive range of sheet-to-sheet distances from 3.8m right up to 21.5m. It does this across 15 different leg configurations, built by combining the main hydraulic ram with fixed mechanical extensions in 1.25m, 3.0m, 7.0m, and 10.0m lengths, as well as a telescopic mechanical unit (MECH).

Design and support

Given the extreme loads of wide-span cofferdams, this equipment should always be installed according to a site-specific design. Our in-house engineers can provide full temporary works design to BS 5975, detailing the exact leg configurations, pre-load pressures and safe sequences for your project.

What is the Heavy Duty Modular Bracing System used for?

The Heavy Duty Modular Bracing System is a large-capacity hydraulic frame used to support sheet-piled cofferdams up to 21.5m wide. It holds back immense ground pressures to provide a clear, safe working area for constructing deep basements, attenuation tanks or major concrete structures.

What is the maximum span of the heavy duty bracing frame?

The heavy duty frame can span up to 21.5m sheet-to-sheet without needing central support legs or cross-struts, thanks to its high-capacity pre-cambered beams.

Why do the heavy duty beams have a pre-camber curve?

The pre-camber curve allows the beams to straighten under heavy loads instead of sagging. This structural behaviour is what enables the heavy duty system to maintain its line and achieve such wide clear spans safely.

What mechanical extensions are available?

The system uses fixed mechanical extensions in 1.25m, 3.0m, 7.0m, and 10.0m lengths. By combining these with the main double-acting hydraulic ram, you can build 15 different leg configurations to fit any excavation between 3.8m and 21.5m.

How is the bracing system installed and removed?

The components are lifted by crane or excavator, pinned together into a ring, and then the hydraulic rams are pumped to push the frame tightly against the sheet piles. For removal, the hydraulic pressure is safely released so the frame can be lifted out as the excavation is backfilled.

What if I need a smaller or lighter cofferdam bracing solution?

If you are working on a smaller scale, check out our Medium Duty Modular Bracing System. It uses the same pre-cambered beam principles but is lighter and designed for spans up to 13.5m.

Hire the Heavy Duty Modular Bracing System

For help specifying the right configuration, sorting out a temporary works design or for current hire rates, contact your nearest depot and we can put an engineer on it.

Leg configurations

Leg Type	Configuration	Sheet-to-Sheet Range	Clear Opening	Weight
LEG 1	RAM	3.8m – 5.1m	2.9m – 4.1m	2,240kg
LEG 2	RAM + 1.25	5.1m – 6.3m	4.2m – 5.4m	3,360kg
LEG 3	RAM + 1.25 + 1.25	6.3m – 7.5m	5.5m – 6.6m	4,480kg
LEG 4	RAM + 3.0	6.8m – 8.1m	5.9m – 7.1m	3,600kg
LEG 5	RAM + 3.0 + 1.25	8.1m – 9.3m	7.2m – 8.3m	4,720kg
LEG 6	RAM + MECH	8.4m – 11.5m	7.5m – 10.6m	4,240kg
LEG 7	RAM + 3.0 + 1.25 + 1.25	9.4m – 10.5m	8.5m – 9.5m	5,840kg
LEG 8	RAM + 1.25 + MECH	9.7m – 12.7m	8.8m – 11.8m	5,360kg
LEG 9	RAM + 3.0 + MECH	11.4m – 14.5m	10.5m – 13.6m	5,600kg
LEG 10	RAM + 1.25 + 3.0 + MECH	12.7m – 15.7m	11.8m – 14.8m	6,720kg
LEG 11	RAM + 1.25 + 1.25 + 3.0 + MECH	13.8m – 16.9m	12.9m – 16.0m	7,840kg
LEG 12	RAM + 3.0 + 3.0 + MECH	14.4m – 17.5m	13.5m – 16.6m	6,960kg
LEG 13	RAM + 7.0 + MECH	15.4m – 18.5m	14.5m – 17.6m	6,465kg
LEG 14	RAM + 1.25 + 7.0 + MECH	16.7m – 19.7m	15.8m – 18.8m	7,585kg
LEG 15	RAM + 10.0 + MECH	18.4m – 21.5m	17.5m – 20.6m	7,165kg

Beam width: 495mm. For clear internal distances, subtract beam width from the sheet-to-sheet measurement. This does not allow for deflection. 'MECH' denotes a telescopic mechanical unit.

System 80 Load Chart

The rest of our bracing range, from manhole frames to medium cofferdams

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