How to Stay Safe Around Manholes and Trenches

NINJA GUARD Trench Safe - Trench Cover

Here is our Ninja Guard guide on how to stay safe around open trenches and manholes, integrating Health and Safety Executive (HSE) principles and the specifications for equipment from the Highway Authority and Utilities Committee (HAUC UK).

1. The Golden Rule: Hierarchy of Control

The HSE advocates a hierarchy of control. This means you must always first try to eliminate the risk entirely. If that's not possible, you must use the following controls in order of priority:

1. Elimination: Can the work be done without creating an excavation? (e.g., using no-dig technology).

2. Physical Controls: This is where trench covers and footway boards come in. They are a primary means of preventing falls into excavations.

3. Administrative Controls: Implementing safe systems of work (e.g., permits, signage, designated pathways).

4. Personal Protective Equipment (PPE): The last line of defence (e.g., high-visibility clothing, safety boots).

2. HSE Guidance: Key Principles for Safety

HSE's guidance (particularly HSG47 and HSG150) sets out fundamental requirements:

· Prevention of Falls: People and vehicles must be prevented from falling into the excavation.

· Stability of Excavations: The sides of the trench must be supported by battering, benching, or shoring to prevent collapse. Remember: Even shallow trenches can collapse and kill.

· Underground Services: Always assume services are present. Use service plans, CAT (Cable Avoidance Tool) and Genny (Signal Generator), and perform trial hole digging to prove service locations before mechanical excavation.

· Safe Access and Egress: Provide safe entry and exit points for workers, such as secured ladders or steps, placed within 7.5 metres of any worker.

· Inspection: A competent person must inspect the excavation:

  · At the start of each shift before work begins.

  · After any event likely to have affected its stability (e.g., a collapse, heavy rain, vibration).

  · After any accidental fall of any material.

  · The results must be recorded in a written report before the end of the shift.

3. Using HAUC UK Compliant Equipment: Footway Boards & Trench Covers

Using non-compliant, makeshift equipment (like old pallets or rusty, thin sheets of metal) is extremely dangerous and a direct violation of HSE guidelines.

What does "HAUC UK Compliant" mean?

HAUC UK brings together utility companies and highway authorities to agree on national standards for safety and equipment. Using compliant equipment ensures it has been designed and tested to withstand the required loads.

Specifications for Footway Boards & Trench Covers can be found on the HAUC (UK) Advice Note No. 2018/01 -

· Material: Typically made from high-density polyethylene (HDPE) or steel. HDPE is lightweight, robust, and non-conductive, making it safer around electrical services.

· Colour: Bright Yellow for high visibility.

· Load Rating: Equipment must be clearly marked with its working load rating. The standard classifications for Footway boards is 400kg and for Driveways boards 875kg

. Markings: they should be embossed with mandatory markings, including manufacturer details, trench width, working load, weight and not for road use all with a letter height between 25-40mm

. Slip resistance should also be tested to meet BS7976

4. Step-by-Step Safe Working Practice

Before the Excavation:

1. Plan: Complete a risk assessment and method statement (RAMS).

2. Locate Services: Use service plans and detection tools. Dig trial holes by hand to confirm locations.

3. Select Correct Equipment: Choose form the options available and ensure they are in good condition (no cracks, excessive warping, or damage).

During the Excavation:

1. Install Edge Protection: Erect strong barriers (e.g., Heras fencing with toe-boards and mid-rails) around the entire work area to keep the public and workers at a safe distance.

2. Use Boards Correctly:

   · Covers must extend a sufficient distance beyond the edge of the excavation

   · Ensure they are stable and cannot be easily displaced and mechanically fixed if possible

   · When covering a manhole, use a specifically designed manhole cover system or a large, stable cover that completely obscures the opening and is rated for the expected load.

3. Signage and Lighting:

   · Use high-visibility signs (e.g., "DANGER - EXCAVATION BELOW").

   · At night or in poor light, the site must be well-lit and demarcated with amber warning lamps.

At the End of the Shift or When Left Unattended:

1. Cover or Backfill: An open excavation must never be left unattended.

2. If it cannot be backfilled, it must be covered with HAUC-compliant temporary boards, rated for the location. The covering must be secure, level, and prevent any danger.

3. Barrier Off: The covered excavation must still be surrounded by physical barriers and warning lamps.

5.  Final Note:

This blog is designed as advice and you should always refer to the latest HSE publications (HSG47 "Avoiding danger from underground services", HSG150 "Health and safety in construction") and the HAUC UK specification documents for the most up-to-date information on how to work around open manholes and trenches.