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Digging in Roadside verges that minimises ergonomic and MSDs
Rank: Forum user 
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Can anyone please put me in touch with a utilities safety manager who have employees who are required to regularly dig in the roadside verges to a depth of up to 2 meters? How do these service providers undertake this task without causing MSDs and ergonomic problems for their workforce but while avoiding hitting cables, pipes – sometimes clay pipes.
The holes dug are approximately ½ meter square, dug using insulated long handled tools (grafter and shove-holer) with CAT beforehand. In most cases service drawings do not exist or are out of date.
I’d really welcome some discussion with utility companies who do a similar thing as to how they approach this.
Thanks
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Rank: Super forum user
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As a consultant I have inspected this kind of work, with sub-contractors who are working for the big construction companies.
Usually a method is agreed whereby :
after CAT scanning the earth is loosened with the hand-tools (sometimes a pick is necessary if there is rock)
and then an excavator is allowed to remove the loose soil.
the excavator bucket must be toothless, and a careful horizontal scraping motion used to remove soil.
This is seen by some (including me) as safer than men in the confined space with shovels.
It's also quicker.
Some companies have rules like not approaching cable closer than 50cms with the bucket, and I always argue against this if I assess that the excavator operator has the necessary skill to do the scraping job effectively and safely.
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Rank: New forum user
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Currently working with a civils construction company carrying out work within petrochemical sites so lots of buried services.
Our guys use air lances,(http://www.mbw.com/products/pick.aspx) other models are available, to loosen the soil and then use a shovel to remove the spoil.
The air lance will not cause damage to any services and as spoil is removed regularly the chances of hitting anything with the spade is reduced.
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Rank: Super forum user
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spritlove,
The method I described in #2 means a mechanical excavator bucket gets close to cables, closer than 50cms. This is not in line with guidance that you'll read in publications e.g. from NJUG or ukpowernetworks, but the contractor has written in their risk assessments how exactly this is done, and the procedure is adopted only if it has been agreed by the main contractor.
The method is necessary in some ground conditions e.g. heavy clay that hasn't been disturbed for decades, and very gradual scraping of the clay is allowed to avoid excessive manual work, poor ergonomics and MSD risks, because the time that would be needed if only hand digging. Also reduces risk of hand tool impacting cable in thick clay.
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Rank: Forum user
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Never dig with a machine within 500mm of a service. Most strikes I go to and the serious ones are those where people shrug their shoulders and go "how else are we supposed to do it?" This little box is too small to explain. But in response to the OP, if the ground conditions are suitable then vacuum excavation and/or air picks.
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Rank: Super forum user
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Yes Ian that is the best practice but some of the big contractors will agree to easier methods if strict procedures are followed by skilled excavators, I've sat in meetings to agree and audited work as described above, but yes some contractors will never agree on the quick methods and risk injury to the manual diggers
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Rank: Super forum user
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Just returning to this thread to clarify what I was saying, where I am agreeing with some streetwork contractors who allow the use of mechanical excavators near utilities. In the old HSG47 paragraph 69 prohibited the use of mechanical excavators close to services. The recently revised HSG47 has replaced that guidance with paragraph 99-100 Quote:
99 Excavation work should follow safe digging practices. Once a detecting device has been used to determine position and route, excavation may proceed, with trial holes dug (using suitable hand tools or vacuum excavation), as necessary, to
confirm the position of any detected services.
So the TRIAL HOLES should be dug manually (or with vacuum) not with mechanical excavator, to confirm location HSG47 goes on to say, Quote:
100 You should carefully plan and manage mechanical excavation, which is a common source of damage to services.
So I, and some contractors, interpret this as: once the service is detected a careful method of mechanical excavation CAN PROCEED. e.g. with difficult clay soil the method can be a careful horizontal scraping alongside the service. This clears the way afterwards for the manual digging to get under the service and expose it completely. HSG47 goes on to say, Quote:
Another person should assist the excavator driver, from a position where they can safely see into the excavation and
warn the driver of any services or other obstacles.
so, my interpretation again, the guidance is accepting that a mechanical excavator can operate near services.
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Rank: Super forum user
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and.... just another note to say the above applies to ELECTRICAL services/cables, later the HSG47 says in paragraph 150, Quote:
150 Gas pipes may have projections such as valve housings, siphons and stand pipes that are not shown on the plans. To allow for this, do not use mechanical excavators within 500mm of a gas pipe. The gas transporter may advise greater safety distances, depending on the pipeline pressure.
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Digging in Roadside verges that minimises ergonomic and MSDs
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