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DIRECTIONAL DRILLING - CASE HISTORY
New Electric Cable Ducts from Perco
Perco Engineering Services Ltd
The Old Nurseries, Nottingham Road, Radcliffe-on-Trent, Nottingham, NG12 2DU Tel: 0115 933 5000 Fax: 0115 933 4692
Email: [email protected] Web: www.perco.co.uk
Perco were contacted to supply, weld & install an overhead and underground
cable upgrade and a system reinforcement of an existing supply line
in Wrexham, North Wales.
The scheme involved:
Drilling from within Legacy substation
to an adjacent field under a large earth bund that surrounded the
substation.
Crossing the A5 to North Oswestry.
Crossing under Whittington Lane and
three 1200mm water supply lines.
Each crossing would have three 225mm SDR11 and two 125mm SDR11
ducts installed. Upon a site visit, Perco
decided that the best method of installation would be via Horizontal
Directional Drilling using their Vermeer D36x50 drill rig as it was compact in
size, but still powerful enough to drill
through the hard ground conditions.
During, the works around the substation, extreme caution had to be
taken as it was still live. The rig and the support lorry were kept as far away
from the site as possible and a safety
watcher was on duty at all times. The ground consisted of soft clay with the
occasional boulder being encountered. Roughly 80mtrs of duct was installed
during the first crossing which took 3
days with great care being taken to
ensure a clean bore.
The second crossing provided sandy ground conditions and although the
road was on a small embankment,
Perco’s settlement calculations showed that one of the bundles of ducts had to
be installed at too great a depth. The client agreed that three 225mm and
two 125mm would be installed instead.
The final crossing proved to be more
difficult due to the ground conditions being very hard ground. The ducts had
to be installed individually. For more information please contact
Chris Brodie on 0115 9335000 or
07866 043382.
Scope: Horizontal Directional Drilling Project: Oswestry Substation, Wrexham Sub-Contractor: Perco Engineering Services