Cable Strikes
Cable Strikes Increase During Lockdown
August 6th, 2021-
This article was written by Aaron Morby at Construction Enquirer
Cable Strikes
Power cable strikes have spiked since lockdown prompting the supply industry’s trade body to raise the alert in construction. Underground powerline strikes from July to September alarmingly jumped 20% to 475 incidents compared with the same time last year. The figures for Q3 are running 46% above the previous quarter (April – June 2020) total of 325.
It is not clear whether the surge has come from a rise in utility and roadworks or whether workers returning from furlough or shutdown are now neglecting basic safety procedures.
Research released today by the Energy Networks Association reveals 93% of construction workers believed they always dig safely, yet almost a third (31%) admitted to not always checking for underground electricity cables before beginning work.
Despite the threat to life, the main reasons workers did not check for underground electricity cables was because they felt it was not their responsibility (15%), or they would not dig deep enough to hit anything (24%).
Worryingly, almost one in six said if they uncovered an underground electricity cable encased in concrete, they would attempt to break them out, which could put them at immediate risk of life-threatening injuries.
To hammer the safety message home the ENA has released new emotive safety film, urging people to ‘Think Before You Dig’.
Peter Vujanic, Chair of ENA’s Public Safety Committee said: “It’s extremely concerning to hear that even though construction workers are one of the most-at-risk groups of injury involving underground electricity cables, more than one in four fail to check for cables before beginning work.
“With the proper education and support, these issues can be addressed and, ultimately, lives can be saved.”
ENA has also released life-saving safety guidelines under the slogan: Plan, Scan, Think Before You Dig.
- Plan ahead – Always be mindful of what services lie below ground when digging or excavating. Ask utility companies for plans in advance.
- Assess the risks – Identify the dangers and hazards associated with excavations and put controls in place to manage them.
- Scan and locate – Take care when digging, always locate underground cables before digging with the use of cable avoidance tools.
- First, use your hands – Before using any electric or mechanical excavation tool, you must consider hand-digging trial holes to expose the services
- Always assume – that underground cables are live even when damaged.
- Know who to call – In case of an emergency dial 999 and tell them electricity is involved. Call 105 if you have a safety concern related to the electricity network or if you spot damage to underground cables and substations that could put you, or someone else, in danger.
- Think Before You Dig!
Further Reading
- The Hidden Risks of Breaking Ground | Protecting Against Arc Flash
- Arc Workwear Saves Lives | Watch Mitchell’s Story
- Arc Flash Risks In The Rail Industry
- Arc Flash Survivor Story – Jason Brozen
Cable Strikes | Strike to Low Voltage Cable
May 18th, 2021
Cable Strikes
Utility Strike Avoidance Group
USAG have published a range of documents to assist industry understanding of the root cause and contributory factors behind specific incidents. The aim is to improve industry standards and reduce the number of cable strikes.
Cable damage is often caused by excavating machines – hand held tools such as pneumatic drills, crowbars, pins, picks and forks also expose workers to potential sources of danger when digging around underground cables.
The next in the series is a safety alert thanks to Highway England regarding a strike to a low voltage cable during a new build housing project.
Incident Overview
Cable strike to a low voltage distribution network damaged by a third party at Hamilton, Leicestershire resulted in a power outage to residents. This network was installed and owned by another company GTC and is a low voltage LV distribution network embedded within the wider network footprint of Western Power Distribution.
USAG recommends if you are working in a relatively new build area you should check plans for the presence of low voltage network where there should be. Below is a copy of the plan for this location and you can see missing low voltage schematics from the plan on the eastern edge where new homes are built and occupied. If you come across this situation you should check for further asset owners. The usual distribution network owner for the area should be able to help you identify the network owner if there are no above ground markings or signage on substations.
Strike to Low Voltage Cable
Protecting Cables Against Strikes & Restoring Power Post-Strike
Thorne & Derrick have been distributors for 3M Electrical since 1985 and can provide a range of reliable and easy to install Cable Repair Products – this includes Scotch Tapes, Scotchcast Joints and Cold Shrink Tubes to provide effective re-instatement of cable sheath jackets on all types of LV MV HV cables in onshore and offshore locations with safe or hazardous area workplace classifications.
Cable Repair Products
Our range of cable protection covers manufactured by Centriforce provide underground utility protection of LV MV HV cables including Tapetile (11kV) and Stokbord (33kV 66kV 132kV) – contact us to discuss Cable Damage Prevention Products including Dectamesh, the underground detectable warning tape for alerting excavators of the presence of buried cables and to prevent potentially lethal accidents during excavation.
Stokbord
Tapetile
Cable Strikes | Surface Cable Damage by Mower
May 18th, 2021
Cable Strikes
Utility Strike Avoidance Group
USAG have published a range of documents to assist industry understanding of the root cause and contributory factors behind specific incidents. The aim is to improve industry standards and reduce the number of cable strikes.
Cable damage is often caused by excavating machines – hand held tools such as pneumatic drills, crowbars, pins, picks and forks also expose workers to potential sources of danger when digging around underground cables.
The next in the series is a safety alert thanks to Highway England regarding surface damage to power cables during routine grass verge maintenance.
Surface cable Damage
Incident Overview
Electrical cable snagged by reform mower during grass cutting operation, 16 April 2020 at the Barley Mow junction A43/A421.
─ Electrical asset knockdown in same location on 28 June 2017 – made safe at that time (isolating and marking the location with a traffic cone)
─ Multiple grass cutting visits between June 2017 and April 2020 – no reported issues
─ A walkover on this occasion was undertaken and this is the same for all cuts – the cable was not observed, but sign frames were discovered and removed from site
Surface Cable Damage by Mower
| Cause Areas | Findings |
| Immediate Cause | Operators did not see any obstruction Cable was within the cut height of the mower |
| Underlying Causes | The cone used to mark the cable had been removed / damaged The passage of time between the knockdown and the incident may have permitted the cable to deviate from initial position, to be at a higher elevation |
| Root Causes | A cable was left on the surface where it could be compromised by grass cutting operations Standard operating practices at the time permitted an insecure method of highlighting the cable, albeit they did include the practice of electrically isolating the cable from the supply The grass cutting team were not advised of the potential of a cable No immediate permanent repair scheduled on the back of the temporary ‘make safe’ visit |
Cable Hangers | Cable Ducting | Cable Protection | Electrical Safety Equipment
The attending electrical crew isolated the cable at source, but left it ready for an imminent reinstatement – i.e. at the surface, marked with a traffic cone. This act prevented any later disturbance of the cable from causing any harm.
Grass cutting teams visually check the area, they located discarded sign frames, but missed the cable in the grass.
Working practice of the electrical teams has been enhanced by using more robust temporary bollards to highlight the hazard better. The bollard as shown may be placed provided with the directional arrow when replacing a permanent bollard, or plain yellow for a lighting column.
Protecting Cables Against Strikes & Restoring Power Post-Strike
Thorne & Derrick have been distributors for 3M Electrical since 1985 and can provide a range of reliable and easy to install Cable Repair Products – this includes Scotch Tapes, Scotchcast Joints and Cold Shrink Tubes to provide effective re-instatement of cable sheath jackets on all types of LV MV HV cables in onshore and offshore locations with safe or hazardous area workplace classifications.
Cable Repair Products
Our range of cable protection covers manufactured by Centriforce provide underground utility protection of LV MV HV cables including Tapetile (11kV) and Stokbord (33kV 66kV 132kV) – contact us to discuss Cable Damage Prevention Products including Dectamesh, the underground detectable warning tape for alerting excavators of the presence of buried cables and to prevent potentially lethal accidents during excavation.
Stokbord
Tapetile
Cable Strikes | Damage to Underground Service
May 18th, 2021
Cable Strikes
Utility Strike Avoidance Group
USAG have published a range of documents to assist industry understanding of the root cause and contributory factors behind specific incidents. The aim is to improve industry standards and reduce the number of cable strikes.
Cable damage is often caused by excavating machines – hand held tools such as pneumatic drills, crowbars, pins, picks and forks also expose workers to potential sources of danger when digging around underground cables.
The next in the series is a safety alert thanks to Highway England regarding damage to cable ducting and power cables during trial hole investigation works as part of London Power Tunnels project.
Incident Overview
Date of incident: 3rd June 2020
Time: 16:30
Location/Site: Hurst Site
Principal/Contractor: Hochtief Murphy Joint Venture
Damage to underground cables
What happened?
The Principal Contractor was undertaking trial hole investigation works as part of London Power Tunnels project to establish positions of existing services to allow a road widening to be installed. This activity was planned, had agreed RAMS and was being performed in accordance with HSG47 including the use of a Vacuum Excavator.
A Cat and Genny survey was performed prior to breaking ground with re-scanning every 150mm as the work progressed.
During these Vac Ex works a concrete block was uncovered and needed to be removed. This was discussed on site between ET operations, Capital Delivery and the Principal Contractor on 2nd June during a site walkover.
When lifting the concrete block, the watcher saw a clay duct stuck to the concrete, so they stopped the activity. The clay duct was embedded into the concrete. As the block was lifted the clay duct shattered, revealing the duct and its contents (5 cables).
To make the area safe the concrete block needed to continue to be moved. Once the block was safely removed it could be seen that there was damage to one of the cables (the outer sheath of a 15mm cable). The approximate position of the concrete block is shown by the red outline on the picture to the right. Immediate actions taken/Initial learning All excavation works where stopped immediately.
All relevant parties informed within timescales Drawings and CAT+Genny surveys are not a guarantee that all services have been identified. Additional actions are required to prove an area is sterile of buried services (e.g. perimeter slit trench using safe digging methods). Investigation underway to understand learning.
Categorisation of the incident: Medium
Protecting Cables Against Strikes & Restoring Power Post-Strike
Thorne & Derrick have been distributors for 3M Electrical since 1985 and can provide a range of reliable and easy to install Cable Repair Products – this includes Scotch Tapes, Scotchcast Joints and Cold Shrink Tubes to provide effective re-instatement of cable sheath jackets on all types of LV MV HV cables in onshore and offshore locations with safe or hazardous area workplace classifications.
Cable Repair Products
Our range of cable protection covers manufactured by Centriforce provide underground utility protection of LV MV HV cables including Tapetile (11kV) and Stokbord (33kV 66kV 132kV) – contact us to discuss Cable Damage Prevention Products including Dectamesh, the underground detectable warning tape for alerting excavators of the presence of buried cables and to prevent potentially lethal accidents during excavation.
Stokbord
Tapetile
Cable Strikes | Combined Gas and Electric Strike and Ignition
May 18th, 2021
Cable Strikes
Utility Strike Avoidance Group
USAG have published a range of documents to assist industry understanding of the root cause and contributory factors behind specific incidents. The aim is to improve industry standards and reduce the number of cable strikes.
Cable damage is often caused by excavating machines – hand held tools such as pneumatic drills, crowbars, pins, picks and forks also expose workers to potential sources of danger when digging around underground cables.
The next in the series is a safety alert thanks to Highway England regarding a strike on both Electric & Gas service connections to a property.
Incident Overview
Gas Pipe & Electric Cable Strike
What Happened?
Executive Summary – On Friday the 29th November at 14:30 CityFibre were informed of an incident in an FTTH City.
CityFibre’s Principal Contractor (PC) reported a combined gas and electric strike, resulting in ignition of the gas. SGN (Gas Network) and the emergency services were called to support in the incident. SGN and PC worked to make the area safe, no injuries were reported and the road was closed as a precaution whilst the repair was made.
The cables were lowered, trench backfilled and area made safe with full reinstatement undertaken the following morning.
The strike was on both Electric – 35mm & Gas – 25mm service connections to a property. The services had been laid in a combined utilities trench. There were no safety indicative markers such as tiles or tape present in the trench, nor was there any distinct separation or sand split between the two utilities.
Utilities were buried significantly shallower than specified with by NJUG (industry guidelines). The fire was extinguished by 17:00, with PC supporting SGN engineers by hand digging to expose the damaged plant and electricity cables. By 19:00 the electric supply was restored.
A temporary reinstatement was made of the excavation and the PC returned in the morning to permanently reinstate the works.
Key Learning
- Ensure all teams are briefed on the STREET WORKS UK GUIDANCE ON THE POSITIONING AND COLOUR CODING OF UNDERGROUND UTILITIES’ APPARATUS
- Ensure that Safe Dig Techniques are followed as per HSG47
- Ensure service drawings are in date and fully reviewed prior to any excavation work
- Use the CAT & Genny together (in avoidance mode). We recommend the use of the ECAT4+ and version 4 Genny so that Survey results can be recorded electronically. This will aid the identification of correct usage and level of usage. All operators of the equipment must be trained and competent to use.
- Safe systems of work such as risk assessments and method statements are in place and understood.
- All strikes must be reported to [email protected] as detailed in the contractors contract and/or construction phase plan.
Protecting Cables Against Strikes & Restoring Power Post-Strike
Thorne & Derrick have been distributors for 3M Electrical since 1985 and can provide a range of reliable and easy to install Cable Repair Products – this includes Scotch Tapes, Scotchcast Joints and Cold Shrink Tubes to provide effective re-instatement of cable sheath jackets on all types of LV MV HV cables in onshore and offshore locations with safe or hazardous area workplace classifications.
Cable Repair Products
Our range of cable protection covers manufactured by Centriforce provide underground utility protection of LV MV HV cables including Tapetile (11kV) and Stokbord (33kV 66kV 132kV) – contact us to discuss Cable Damage Prevention Products including Dectamesh, the underground detectable warning tape for alerting excavators of the presence of buried cables and to prevent potentially lethal accidents during excavation.
Stokbord
Tapetile
