What is excavation safety?
Digging safely around buried AGL cables and services: finding them first, protecting the opening and the people in it, and reinstating the ground.
AGL cables and ducts are buried, and airfield lighting series circuits carry a lethal current at up to several thousand volts, so digging near them can be lethal if a cable is struck. Excavation therefore starts before the spade: drawings are checked, services are located with a detector and marked on the surface, and the dig is planned and permitted. Every cable is treated as live unless it has been isolated and proved dead under the site procedure.
The opening is then made safe. Edges are barriered, sides are sloped or supported, safe access is provided, and spoil is set back so it neither loads the edge nor becomes FOD. Near services the work is done by hand. If an unknown or damaged service is found, work stops and it is reported. At the end the cable condition is checked, the trench is backfilled in layers and compacted, the surface is reinstated and the area is cleared before it is reported clear.
Frequently Asked Questions
Q1What is excavation safety in AGL work?
The set of precautions used when digging near airfield lighting cables, ducts and other buried services. It covers finding services before digging, protecting the opening and the people working in it, digging carefully near services, and restoring the ground afterwards.
Q2Why is every buried AGL cable treated as live?
Airfield lighting series circuits carry a constant current at up to several thousand volts, so a damaged cable can be lethal. A cable is not assumed to be dead because it looks old or unmarked. It is treated as live unless it has been isolated and proved dead under the site’s procedure.
Q3Why locate and mark services before digging?
Cables and ducts are not always where the drawings show, and other services such as fuel, water, data and power may run nearby. Drawings are checked, services are located with a detector and marked on the surface, and the dig plan is agreed before the ground is opened. A detector may not pick up a cable that is switched off, so the survey is confirmed by hand-dug trial holes where the site rules require.
Q4How are trench collapse risks controlled?
Trench sides can collapse without warning. Depending on depth and ground, they are sloped back or supported with shoring, edges are barriered, safe access such as a ladder is provided, and nobody works in an unsupported trench. The site’s rules set what is required.
Q5Why keep spoil back from the trench edge?
Spoil piled at the edge adds load that can bring the side down, and loose soil and stone are FOD risks on airfield pavements. Spoil is set back, contained, and removed or reused as the work allows.
Q6What if an unknown cable or service is found or damaged?
Stop work and keep everyone clear. Do not touch or move the cable. Report it to the supervisor and, through the site procedure, to airport operations, and wait for it to be identified and made safe before work continues.
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