HOW TO DIG SAFELY

In conjunction with location devices and plans, trial holes by careful hand excavation are essential before beginning any excavation. Hand digging must continue until all of the cables have been found on the cable plan. If there is any doubt as to where the cables are located, stop work and consult with WEL.
 
WEL experts are available to indicate cable location using paint if required.  While this  provides a useful indication of the cable locations, those responsible for the excavation must also carry out all other precautions necessary to avoid injury and/or damage.
 
All cables should be considered as live and should not be used as hand or footholds by anyone climbing in or out of the trench, especially around cable joint positions. Special care should be taken when digging above or close to the assumed cable route.


HOW TO DIG AROUND CABLES

Best practice hand digging is to expose the cable using the spade parallel to the cable not at right angles. Hand-held power tools or excavators should not be used within 0.6 metres of any underground cable. When a cable has been exposed by pot holing, best practice is to then dig away from the exposed cable, not towards it with excavators.

  • Directional drilling or thrusting parallel to WEL’s 11kV or 33kV cables shall be at least 0.6 metres from the proven location of the cables.  The cables must be marked out by a competent cable location technician, and trial holes by careful hand excavation must be undertaken prior to the commencement of the work to prove the cable is parallel to the drill shot.
     
  • Underground cables are normally laid in trenches between 300 mm and 1.0 m deep, but these levels may change over time through the activities of roading or landscape works. Therefore, cables should be expected to be found at ANY DEPTH.
     
  • If buried cables have been found to be too shallow, or if the plans or other information have proved to be inaccurate, WEL should be informed, preferably before the excavation is back-filled, to allow the cables to be re-laid at the correct depth and/or the cable records to be amended accordingly.
     
  • Cables uncovered in an excavation may need to be supported or protected. WEL must be contacted as soon as this situation arises. Any cables lying in the bottom of an excavation should be protected by sandbags or appropriate nail free protection device. Precautions should be taken to prevent access to exposed cables by children or other unauthorised people.
     
  • Cables must not be moved under any circumstances. Moving live cables can cause them to fault and a fatality could result.  If a cable needs to be moved, the request should be made to WEL, who will arrange for the cable to be made safe prior to their relocation.

EMERGENCY DIGGING

In the case of emergency works, every effort should be made to locate buried underground cables, prior to undertaking machine civil work. It should always be assumed that buried cables are present and that excavation work should proceed with extreme caution by careful hand excavation.

(Where plans are not available in a situation, only excavation by hand should be carried out, until the location of any cable(s) has clearly been established.)


CABLE DAMAGE

If a buried underground cable suffers damage, however slight, WEL must be informed immediately.

Arrangements must be made to keep the public well clear of the area until the damaged cable has been repaired or otherwise made safe.


BACKFILLING

Back-filling of any excavation where cables have been exposed should only proceed following advice from WEL. Fill containing items likely to damage the cables, such as large pieces of rock and hard-core or other sharp objects, shall not be used.  Cables should be backfilled with fine material such as sand.

Hard or sharp material such as pieces of rock, large stones, hard-core or surplus concrete, should not be tipped into open cable trenches.  Advice on back-filling cable trenches should be obtained from WEL Networks.