This video provides an overview of Vanguard’s 23/05 Modular Road Plate System — a composite plate solution designed to safely cover trenches while allowing traffic to continue flowing.

If you’d prefer to read instead of watch, here’s a clear summary of how the system works, where it’s used, and what to consider when using it.

What the 23/05 Modular Road Plate System is used for

The 23/05 modular road plate system is typically used when open trenching across a road, such as during the installation or repair of underground services.

By placing plates over the trench, contractors can:

• Keep traffic moving safely

• Maintain access to roads or driveways

• Reduce disruption while work is ongoing

These plates are especially useful during reactive or emergency works, such as burst water mains overnight. Instead of waiting for heavy steel plates and lifting equipment, crews can place these plates quickly with a two-person lift, temporarily securing the site until repairs can be completed.

Why composite road plates are used instead of steel

Composite plates offer several practical advantages compared to traditional steel trench plates.

No machinery required

The plates can be installed by two people, meaning there is no need for:

• Hiabs

• Diggers

• heavy lifting machinery

Faster installation

Because installation is manual and lightweight:

• Plates can be deployed quickly

• Temporary traffic management time can be reduced

• Repairs can proceed without waiting for lifting equipment

No asphalt ramping required

Steel plates often require asphalt ramping around the edges. Composite plates eliminate this step, saving additional time on-site.

How the modular system works

The 23/05 system is modular, meaning multiple plates can be joined together to cover wider trenches or roadways.

The system consists of three components:

• Centre modules

  • 2.3 metres long

  • 500mm wide

• Rounded end caps

  • 2.3 metres long

  • 700mm wide

• Lifting handles

  • Designed to make moving and positioning the plates easier

Because the modules connect together, crews can build the width needed to suit the trench they are covering.

Three-way securing system

One of the key safety features of the system is its three-way securing mechanism, which helps prevent plates from moving once installed.

1. Interlocking plates

Each plate uses a tongue-and-groove interlocking system. When plates are lowered into position at an angle, the connectors lock together and prevent the plates from separating.

2. Drop pins

Drop pins underneath the plate extend into the trench once the plate is in position. These pins press against the trench walls and help stop the plate from shifting out of place.

Because there are multiple drop pins, the system can adapt to different trench widths. Some pins may sit flat on the ground in narrower trenches while others engage against the trench walls.

3. Screw fixing points

Additional screw holes allow the plates to be fixed to the road surface if required, preventing them from lifting.

Construction and strength

Each plate consists of:

• A steel grid frame, which provides structural strength

• A heavy-duty composite plastic outer layer, moulded around the frame

The composite surface also includes anti-slip surfacing, which improves traction for vehicles passing over the plates.

Load capacity and span limits

The plates are tested and certified to handle:

• 44 tonnes distributed weight

• Across a 1200mm trench span

This equates to roughly 6.5 tonnes point load.

Important limitation

These plates are not designed for trenches wider than 1200mm. Exceeding this span increases the risk of cracking or failure.

To help prevent misuse, each plate has the 1200mm maximum span clearly marked on the surface so crews can quickly confirm they are operating within safe limits.

If trenches exceed this width, the typical options are:

• Using a larger steel plate, or

• Closing the road while works are completed.

Additional safety features

Raised profile

The slightly raised profile of the plates acts similarly to a speed hump, helping slow vehicles as they pass through the work zone.

Gas monitor access

Each module includes a gas monitoring point, allowing testing to be carried out without removing the plates when working over gas utilities.

High visibility

The plates are bright yellow, making them highly visible to drivers and improving worksite awareness.

Cost considerations

Composite plates typically have a higher upfront purchase price than steel plates.

However, when considering:

• Reduced machinery requirements

• Faster installations

• Lower traffic management time

• Improved handling safety

many contractors find the system pays for itself after only a few jobs.

As a general guide, a four-metre-wide set of road plates can cost approximately:

$12,000 – $16,000, depending on the configuration and whether it includes:

• End caps

• Lifting handles

• Storage stillages

Need help choosing the right plate system?

If you’re planning trench works and want to understand whether the 23/05 modular road plate system is suitable for your site, get in touch with out team.