1.0 Purpose & Scope

To ensure that excavation work is controlled and managed safely.

2.0 Definitions

Competent Person A person trained, experienced and duly authorized to carry out a particular function.

Excavation in earth including trenches bore holes and cofferdams

3.0 Responsibility

3.1 Site Manager/Manager

Ensure that arrangements are in place necessary to ensure:

Pre-Planning of excavation works

Obtaining records before the excavation work begins

3.2 Supervisors / Engineer

Before work commences, Supervisors must ensure that:

Any necessary surveys have been performed

Risks assessments have been prepared

Authorization from a Competent Person is obtained iv. A Permit to Work has been obtained

4.0 Process/Description

4.1 Preparations for Excavation Work

Prior to commencement of any excavation works the following must be done:

Survey

A survey must be undertaken to find out if there are any underground services in the area. The survey will include checking existing drawings, if doubt remains, hand digging pilot holes.

Risk Assessment

A risk assessment must be conducted. The assessment must take into account the likelihood of underground services (electrical cables, gas/water pipes etc.), hazardous substances, depth of the excavation, the possibility of water ingress, existence or previous excavations/foundations etc.

Permit to Work (Excavation)

• For excavation involving the following risks, a Permit to Work is required:
• Excavations within 5 meters of underground services
• Excavations deeper than 3 meters
• Excavations that may be deficient in oxygen or containing hazardous substances
• Other excavations of high risk, as determined by the Site HSE Representative and defined by the specific risk assessment

• Permits to Work must include the following, as a minimum:

Excavation location,

Nature and the time of works

The people involved

The risk assessment

Required inspections (before, during or at the end of works)

Emergency contacts

Authorization

A Competent Person must review all risk assessments, method statements and associate documentation, prepared for entry either by HSC or their Sub-Contractors, ensuring that all the requirements of this document and any local requirements have been met, prior to authorizing commencement of work in excavations.

4.2 Work in and Around Excavations

4.2.1 Collapse Prevention

• The sides of all excavations must be prevented from collapse by one of the methods listed below:
• Battering - sloping the sides to an angle not steeper than 1.5 to 1, i.e., for every 300mm of depth, the excavation must be tapered back 450mm.
• Benching – excavating one or a series of horizontal levels or steps (depending on the depth of the excavation) in the sides and ends of the excavation
• Shoring - supporting the sides and ends of the excavation using propriety trench supports, shuttering or piling.
• A Competent Engineer must prepare designs for all excavations deeper than 3 meters. The company undertaking the excavation must produce stability calculations indicating the safety factors to be taken i.e. slope angles, shoring etc. for review and acceptance by an HSC Competent Person, before the work can commence.

4.2.2 Access and Egress (in and around the excavation)

All excavations must be provided with safe access and egress located within 7 meters of all workers. Access and egress may be provided in the form of ladders, ramps or steps etc.

Note: Ladders must be secured and must extend at least 1 meter above the top of the excavation.

Bridges / crossing points must be erected over excavations where persons need to cross and must have guardrails strong enough to withstand approximately 100 kg horizontally.

4.2.3 Barriers

All excavations more than 1.2 meters deep must have rigid barriers and toe-boards around the outside to prevent persons and material from falling into the excavation.

Barriers must be strong enough to withstanding approximately 100 kg horizontally.

Excavations less than 1.2 meters in depth need not have a rigid barrier as long as they are highlighted with warning tape at a distance of at least 1.5 meters from all edges of the excavation.

4.2.4 Protection from Water Accumulation Hazards

Among the additional hazards stemming from water in an excavation are undermining the sides and making it more difficult to get out of the excavation. Employees are prohibited from working without adequate protection in excavations where water has accumulated or is accumulating. If water removal equipment is used to control or prevent water accumulation, a competent person shall monitor the equipment and its operation to ensure proper use. Diversion ditches, dikes, or other suitable means shall also be used to prevent surface water from entering an excavation and to provide adequate drainage of the adjacent area. A competent person shall inspect excavations subject to runoffs from heavy rains.

4.2.5 Inspections

Work must not be carried out in an excavation where any supports or battering and / or the excavation are more than 1.2 meters deep unless:

The excavation and any work equipment and materials which affect its safety, have been inspected by a Competent Person:

At the start of the shift in which the work is to be carried out

After any event likely to have affected the strength or stability of the excavation, and

After any material unintentionally falls or is dislodged; and

Inspection reports must contain the following:

Organization and person on whose behalf the inspection was carried out

Location of the place of work inspected.

Description of the place of work or part of that place inspected (including any work equipment and materials)

Date and time of the inspection

Details of any matter identified that could give rise to a risk to the health or safety of any person

Details of any corrective action taken and any further action considered necessary.

Name and position of the person making the report

4.2.6 General Precautions around Excavations

As a minimum requirement, material including spoil and backfill must not be stored within 1 meter of the edge of excavations. The actual distance necessary related to the particular excavation and must be calculated at site considering the depth of the excavation and the weight of the material.

Vehicles and construction plant must not be allowed to come within 2 meters of an excavation unless working in connection with the excavation.

Vehicle / plant working in connection with the excavation must have a person controlling the vehicles tipping material and their movement to prevent them from going so close to the edge that it shall cause damage to the excavation.

Persons are not allowed to work or stand under loads being loaded or unloaded.

All persons in excavations must wear safety helmets, safety boots and any other personal protective equipment as defined by the risk assessment.

Persons entering bore holes or similar restricted excavations must do so in a safety cage, the end of which must be attached to a winch or similar hoisting appliance at the top of the borehole with a Watcher on emergency standby

4.3 Training

All persons required to work in an excavation deeper than 1.2 meters must be given appropriate training. The level of training will depend on the complexity of the excavation but basic training must take account of the following:

Induction training for new persons

Details of the risk assessment

The dangers of working in excavations

The safety arrangements

Daily inspections

Who to contact in case of emergency

Fire protection

5.0 Records

Excavation Work Permit.