Leg Ref. External Working Range Leg Weight (kg) Beam Width (mm) Clear Opening (m)*
  Min Max     Min Max
A 2.0 3.0 260 180 1.64 2.64
B 3.0 4.0 305 180 2.64 3.64
C 4.0 5.0 390 180 3.64 4.64
D 5.0 6.0 445 180 4.64 5.64

* These ranges do not take into account the potential deflection of the waling beam, which will be dependent upon applied load and upon span. As such, the actual clear opening achieved is likely to be smaller than the values quoted above. 

These figures should be used as a rough guide and should not be relied upon to provide an accurate assessment of clear opening. 

    Legs are constructed from high yield steel sections and incorporate a double acting hydraulic ram. This means the legs can be both expanded and retracted hydraulically which aids the installation and removal process. In addition, some legs have a pinned rough adjustment which increases the operating range of the legs.

FAQs

What is Maxi Brace?

The Maxi Brace is a mid-range, heavy duty, hydraulically adjustable bracing system.


Why Choose a Groundforce Double Acting Manhole Brace?

The Maxi Brace range is often chosen due to its modular design which offers speed and simplicity of installation. 


What size excavations are suitable for Maxi Brace?

Maxi Brace is suitable for supporting clear span square or rectangular excavations ranging from 3m to 12m in size. Higher load capacity and/or longer spans can be achieved by incorporating either cross strutting or knee bracing.


How are the hydraulically adjustable legs connected?

The legs are connected using a single 60mm diameter corner pin.


How are the legs expanded or retracted?

The legs can to be both expanded and retracted hydraulically using either a Motorised Shoring pump or Manual Hand Pump.


How is the hydraulic connection made from the Shoring Pump to the legs / braces?

Two hydraulic hoses are connected from the pump to the hydraulic ram on the brace / leg (one to expand, one to retract). The connection is made using quick release hose connections.


Can the DA manhole Brace be locked in position once expanded?

Yes, the double acting legs incorporate a lock-off valve for greater security and allow the pump hoses to be easily released and reconnected without fluid loss.


What size excavations can DA Manhole Braces be used in?

These Manhole Braces can be used in conjunction with trench sheeting to support square or rectangular excavations from 2.0m up to 6.0m long.


Can more than one DA Manhole Brace be used in an excavation?

Depending on the depth of the excavation, multiple, pre-assembled frames can be added by lowering them through previously installed frames (in accordance with the design).


What other safety features are built into the design?

Restraining Chains are used to link the legs together to safeguard against depressurisation and subsequent movement of the frame(s).


Is there a video available that demonstrates DA Manhole Braces?

Yes, a video showing Double Acting Manhole Brace installation methodology is available to watch now on our YouTube channel.


Should any other safety equipment be used following completion of temporary works?

EdgeSafe and ladder access should be installed as soon as possible to provide a safe working environment in and around the trench. 


Do Groundforce offer training courses?

Groundforce Training Services offer industry leading accredited safety training primarily for those working in utilities, construction and civil engineering. From short duration health and safety awareness to more complex or specialist safety consultancy solutions.


What is the Instagrid GO?

The Instagrid GO is a portable 110V power supply designed to deliver grid-like performance for construction and industrial use. It’s lightweight, emission-free, and operates quietly, making it a perfect alternative to traditional generators.


Can Instagrid mobile power supply replace a generator on site?

Yes, the Instagrid GO provides a clean, silent alternative to petrol or diesel generators, and is suitable for powering tools, lighting, and charging stations, with no fuel, noise, or exhaust emissions.


How long does the battery last?

Battery life depends on the type of equipment being used. The battery capacity for the Instagrid GO portable power supply unit provides 2,074 Wh of battery capacity.


What types of equipment can the Instagrid GO power?

The Instagrid GO can power a wide range of construction power tools, including drills, saws, lighting, and charging stations. It’s also capable of powering the Groundforce 110V Electric Shoring Pump, making it versatile for various on-site tasks.


How long does it take to recharge the power supply?

The Instagrid GO portable power supply unit can be fully recharged in 1.5 hours using a standard power supply.


Is the Instagrid GO safe to use indoors?

Yes. The Instagrid Go produces zero exhaust emissions and minimal noise, making it safe to use indoors or in enclosed spaces where petrol or diesel generators would not be suitable.


Is there any maintenance required for the Instagrid GO?

No, the Instagrid GO requires no regular maintenance, oil changes, or fuel top-ups, making it a low-maintenance alternative to traditional generators.


Can the Instagrid GO unit be used while it’s charging?

No. The unit cannot power tools while charging, it must be fully charged before use.


Do Groundforce offer training courses?

Groundforce Training Services offer industry leading accredited safety training primarily for those working in utilities, construction and civil engineering. From short duration health and safety awareness to more complex or specialist safety consultancy solutions.


s a user guide available for the Instagrid GO?

Yes, a user guide will be provided with every hire and can be requested from Groundforce or can be downloaded from the Groundforce Shorco section of the Groundforce website. A user guide for the Instagrid GO Mobile Power Supply is also available below to download as a PDF.


Related Files

(656.90 KB)
GF Double Acting Manhole Brace Technical Literature

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