Case Study - What would you do? - Utility Strike Avoidance Group

Case Study - What would you do?

5/5/2022

Event description:

Before excavation works, all existing utilities were sprayed and marked up as per safe dig drawings.

Independent 3rd Party specialist carries out initial marking. All teams have a hard copy of utility plans at work, including the Gas utility prints.

Utility plans showed a 3inch gas main running down the far side of the road in front of the houses; the plans do not show individual house services.

Surface marking on the road was in line with the gas inlet points as would be expected and in line with standard practice.

The excavation was carried out with an excavator and banksman. The team did not see any changes in ground conditions as they removed the surrounding ground. The banksman then noticed that a 22mm gas service PE pipe passed the trench at 45 degrees had been damaged as it was rising slightly at one end.

Gas service was over 3 metres away from the line of the gas tap on the footpath.

The asset owner registering the service pipes on the drawings would have been a real help. However, we would like to ask YOUR OPINION!

What would you have done to avoid this accident?

Click here & share with us your thoughts!

6 Comments

keith wigley

19/5/2022 01:41:32 pm

far too common in utilities , Yes owners shold mark service cables

Sean Crawford link

19/5/2022 02:20:51 pm

A couple of observations:
Yes offline services (not at 90*) should be recorded on as built. Other Network Operators include additional preventative measures of a marked up service drawing sticker within the meter box which allows a readily available, accurate representation of the location of the service. In my opinion all household utilities should adopt a similar model.
In this circumstance the only assumption to make make where there is an opposite side driveway as per the picture, services are generally offset to avoid digging driveways.

Vicky

19/5/2022 09:40:41 pm

It’s time that utility owners took control of their assets and ensured that services (including connections to premises) are adequately laid to the relevant guidance and specifications, and that their locations are marked on service prints (including indicative depths) so that those undertaking works where ground is broken have a fighting chance of planning safe routes and avoiding damages.
There also needs to be a mechanism in place to capture information on service location, depth and condition when services are damaged, with plans updated to give more accurate data.
I would argue that if you apply the principles in relation to CDM and pre-construction information you could question whether the asset owners are adequately discharging their duties.

Shaun stephen link

22/5/2022 11:12:52 am

In Australia I tell all our clients. What we do is a guide. To prove the exact location and depth. All services are required to be exposed by non destructive methods. Hand digging or by using the services of an NDD company. This then proves depth and location of all assets prior to works.

Goldie Beeton

30/5/2022 08:52:34 pm

(Certified Locator here) In NZ, there are specifications (including burial depths!) of how to lay utilities. All too often, the cheapest contractor wins the bid to lay the pipes/cables, and this requires them to take shortcuts to stay within budget, such as NOT including tracer wire, NOT surveying during installation, and NOT laying them at the specified depths. I WISH there was more control around this.

Ryan C

5/6/2022 10:15:56 am

Would have been avoided with a vacuum excavator.

Author

Phil Cornforth is a Damage Prevention, Health and Safety professional working in the construction and utility industry. He sits on the USAG Steering Group. The USAG has one goal - to avoid utilities and so prevent injury, damage, disruption and raise the standards of our industry.