20 August 2004 - HSE Warns Contractors of Dangers of Digging Trenches After Fatalities Hit 7-Year High
The Health and Safety Executive (HSE) have had 3 fatalities reported within the excavation construction industry since April 2004, which has prompted them to advise the use of both old and new technology, in order to prevent collapses. These fatalities have brought the death toll in trench collapses to a seven-year high.
Trench collapse fatalities within the United Kingdom were 1 in 2001/02, 2 in 2002/03, 2 in 2003/04 and 3 so far this year.
HSE highlighted these 3 fatal accidents, which they say were avoidable:
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Scotland - in April, a man died when the 2.5 metre unsupported trench he was working in collapsed on top of him
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East Sussex - May, a man was killed whilst working on a conservation development when he jumped into a 3-metre deep trench which then collapsed on him
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Yorkshire - July, a man was killed and another injured when a 3-metre deep trench collapsed on them in an unsupported area of work.
Contractors are advised to consult an engineer while planning the work, taking into account the stability of nearby structures and vehicle movements close to an excavation.
The following list, as advised by the HSE, could avoid these fatalities:
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if appropriate, using trenchless technology such as directional drilling or impact moling, to avoid the need to excavate a trench in the first place
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if a trench is used, preventing the sides and the ends of trenches from collapsing by battering them to a safe angle or supporting them with proprietary support systems, trench sheets or timber
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providing suitable edge protection to prevent persons or materials falling into the excavation, and not entering unsupported excavations
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avoiding surcharging the ground adjacent to the excavation with plant, stored materials, spoil or foundation loads from existing structures
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never working ahead of the support
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ensuring there is a suitable means of access and egress
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remembering that work in shallow trenches can be dangerous, i.e. if the work involves bending or kneeling in the trench
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locating existing services in the vicinity of and above the line of the excavation.
Nigel Thorpe, HSE Specialist civil engineer commented:
"Trench collapses are entirely avoidable. Without suitable support, any face of an excavation will collapse; it's just a matter of when. The steeper and deeper the face, the wetter the soil, the sooner the collapse.
"Trenchless technologies are available which avoid many of the hazards of excavation, but if a trench is required modern proprietary systems allow the ground support to be installed without the need to enter the excavation."
HSE has published Construction Information Sheet No.8 (rev 1) Safety in Excavations and also, HSG 185, ISBN 0-7176-1563-4 - Health and Safety in Excavations: Be safe and shore priced price £8.50. Both can be found on HSE Books
Article by Alexandra Johnston
