UK Power Networks
DSR 01 014
v6.0
Excavating Near Electricity Cables
Owner
Name
Peter Vujanic
Title
Head of Health and Safety
Signature
01 May 2016
Date
Authoriser
Name
Dudley Sparks
Title
Operational Safety Manager
Signature
01 May 2016
Date
This document forms part of the UK Power Networks Integrated Management System and
compliance with its requirements is mandatory. Departure from these requirements may only be
taken with the written approval of the above authoriser.
Revision Record
What has changed?
Distribution Safety Rules section numbers included in the references (sect
4.0). Form DSR 01 014a reviewed with no changes.
Version number
6.0
Date published
01/05/2016
Next review date
01/05/2019
Prepared by
D Milton
Version number
5.0
Date published
02/10/2015
Next review date
20/10/2018
Prepared by
D. Daintree
Why has it changed?
Clarity of wording
Version number
4.0
Date published
03/12/2014
Next review date
20/10/2017
Prepared by
C Shackell
What has changed?
Document owner and authoriser S2 additional paragraph” All works to be as
detailed in HSG 47, Excavation and cable installation manual and digging
card unless specified within this document”,S3 changes to wording “added
“injury to any person and” ,S4 update of reference documents,S5 minor
wording change replacement of “least “ with “minimum of “for encroachment
lines ,S8.1 remove ref to COP 00 005,S8.3 minor wording changes and
clarification of responsible persons and roles,S8.3.1 & 8.3.2 clarification of
responsible persons , roles and working practices
Why has it changed?
Clarity
What has changed?
Changes to last paragraph in Section 8.5 regarding the use of the Sniffer
and Safe Working Distances. DSR 01 014a Digging card v2.0 was reviewed
(now v3.0): Changes under title ‘Have you got all the information you need’,
‘On-site risk assessment’ changed to ‘Point of Work assessment’, 1/500 plan
changed to ‘cable records’; ‘Use a Pick…’ changed to ‘Use a Mattock…’.
Why has it changed?
Variations to working practises
This printed document is valid at 31/07/17, check after this date for validity.
Page 1 of 15
UK Power Networks
DSR 01 014
v6.0
Who needs to know?
☐ All UK Power Networks Staff
☒ Asset Management
☒ Capital Programme
☒ Connections
☒ Contractors
☒ Customer Services
☐ Finance
☐ G81 External website
☒ HR & Communications
☒ HSS&TT
☐ In Business HSS
☐ Safety Reps
☐ ICPs (Independent Connection Providers)
☐ IDNOs (Independent Distribution
Network Operators)
☐ Information Systems
☐ Meter Operators
☒ Network Operations
☐ EPN
☐ LPN
☐ SPN
☐ Commercial Services
☐ Logistics
☐ Network Control
☐ Network Operations Connections
☐ Transport Services
☒ Strategy and Regulation
☒ UK Power Networks Services
☐ Airports
☐ Rail
☐ HS1, DLR & Commercial buildings
☐ MUJV / Allenby
☐ Business Development
☒ Others (specify)
Contract Manager/Users
Contents
1.0
Introduction and Purpose ............................................................................................ 3
2.0
Scope ............................................................................................................................. 3
3.0
Objective ....................................................................................................................... 3
4.0
References .................................................................................................................... 3
5.0
Definitions ..................................................................................................................... 4
6.0
Responsibilities ............................................................................................................ 4
7.0
Records ......................................................................................................................... 5
8.0
Process Detail ............................................................................................................... 5
Appendix 1 Locating cables, marking the area of excavation and safe digging.............. 13
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Page 2 of 15
UK Power Networks
DSR 01 014
v6.0
1.0 Introduction and Purpose
This procedure is based on the Health and Safety Executive booklet HSG 47 “Avoiding
danger from underground services”. It describes how UK Power Networks staff and their
contractors should carry out excavations in the vicinity of underground utilities.
2.0 Scope
This procedure will apply to all UK Power Networks staff and their contractors carrying out
excavations in the vicinity of electricity cables. The safe digging methods described are also
relevant to excavation near other buried services.
This procedure includes safe excavation in the vicinity of cables which are or may be
defective due to fault or damage.
The procedure does not describe how to comply with the New Roads and Street Works Act
1991 which is covered in “Understanding Street Works”.
All works to be as detailed in HSG 47, Excavation and cable installation manual and digging
card unless specified within this document.
3.0 Objective
To reduce the risk of injury to any person and damage to any buried services during
excavation work and to provide guidance for safe excavation in the vicinity of cables that
may be defective.
4.0 References
Health and Safety Executive HSG 47
“Avoiding danger from underground
services”
New Roads and Street Works Act 1991
(NRSWA)
UK Power Networks Distribution Safety
Rules
UK Power Networks Understanding
Street Works
UK Power Networks Excavation and
cable installation manual
HSS 01 105
DSR 01 007
HSS 40 029
DSR 01 018
ECS 02-0019
EDS 08-0113
GTRA GRL 12
HSS 01 050
HSS 40 045
(Sections 3.9, 5.9, 8.2 and 8.3)
Putting People to Work
Identification of HV Cables
Unidentified Cables
Identification of LV Cables
Installation of Underground cables LV to 132kV
Guidance for the Application of ENA
Engineering Recommendation G88 and G81 –
Inset Networks (IDNO’s and other Licensed
DNO’s)
Excavation and Reinstatement
Behavioural Exchanges and Inspections
Basic Requirements for Live Working on Low
Voltage Apparatus
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Page 3 of 15
UK Power Networks
HSS 01 093
HSS 01 069
DSR 01 014
v6.0
Environmental Management of Street Works
Personal Protective Equipment (PPE)
5.0 Definitions
Buried Service
All underground electricity, gas, water, sewage, fuel pipe lines and
telecommunications equipment.
Defective Cable
A cable where there is evidence of external damage or a known or
identified fault condition such as an open circuit or phase to phase
fault.
Encroachment
Parallel lines marking out a distance at minimum of 300mm from
Lines
the outermost cable located in the excavation area.
Isolated
Disconnected from associated Plant, Apparatus and Conductors by
an Isolating Device in the isolating position, or by adequate
physical separation, or sufficient gap.
Safe Working
The minimum clearance between an operator and a defective cable
Distance
to provide adequate safety.
Service Connection A cable or pipe linking a distribution main with individual
SFRP
So Far as Reasonably Practicable
Site Co-ordinator
Suitably qualified person who will remain on site and have
responsibility for the work being carried out.
Personal
Supervision of a person such that they are continuously observing
supervision
and in the presence of that person as detailed in section 2 of the
DSRs
Limitation of
A safety document that defines the limits and nature of the works
access
which may be carried out as detailed in section 2 of the DSRs
6.0 Responsibilities
UK Power Networks Senior Managers will ensure that
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staff are appropriately trained to enable them to avoid danger when carrying out
excavation work and, when appropriate, are working on or near defective cables
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contractors have systems in place to ensure that they meet the same standards as
expected for direct staff
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robust auditing is carried out where staff and contractors are carrying out excavations
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a copy of HSE Guidance Note HSG 47 is held at each management location.
Those responsible for supervising the work
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will be responsible for the organisation of the work prior to the commencement on
site, and during the work, but are not required to be in attendance on site during the
work
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shall hold as a minimum a NRSWA supervisors qualification for all work on the public
highway. A NRASWA qualified Site Coordinator may undertake this responsibility.
For work away from the public highway, such as within substations or on private land,
a NRASWA qualification is not required providing an equivalent CDM arrangement is
in place.
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UK Power Networks
DSR 01 014
v6.0
Site Coordinators will
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take charge of the coordination of the work on site and ensure that all reasonable
precautions are taken to avoid danger
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ensure that where work is ongoing a new site coordinator is appointed and briefed
before leaving site
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Hold a NRSWA qualification appropriate to the work. In exceptional circumstances
this qualification may be held by another member of the working party.
Members of the working party will
 carry out all reasonable instructions of the Site Coordinator
 report any relevant site changes to the Site Coordinator
 as a minimum wear the PPE specified in procedures.
7.0 Records
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Records of the UK Power Networks apparatus and plant should be kept updated and
made available to anyone intending to carry out excavations
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A record of NRSWA qualifications will be maintained by the Training Centre
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Records of site audits will be kept as required by the Behavioural Exchanges and
Inspections procedure (HSS 01 050)
8.0 Process Detail
All cables and connected apparatus must be treated as live until proven dead.
Site staff, including the site co-ordinator, always have the right to make a cable or
cables dead, or request that they should be made dead, for safety reasons. Nothing
in this procedure should encourage any person to work near a live cable when there
is any doubt about their safety.
Unless a defective cable is involved work may normally be carried out safely on or near live LV
Cables. This work should comply with appropriate procedures including Generic Task Based
Risk Assessments.
The Site Coordinator, as person in charge on site, is responsible for taking all reasonable
precautions to avoid danger. This includes ensuring that an On Site (Point of Work) Assessment
is carried out and if necessary updated during the work.
Cables must be made dead if there are particular safety reasons or other special circumstances
including the outcome of the On Site (Point of Work) Assessment.
If site conditions are found to be inconsistent with the job instruction, or the safety of any person
may be put at risk through carrying out an instruction, then work shall be stopped
immediately and the problem reported to a supervisor.
Before work recommences a course of action must be agreed which safely overcomes the
problem. Every such agreed course of action must be written down. Where the course of action
is agreed over the telephone it must be written down by both parties and the person receiving
the instruction must read it back in full to the sender to make sure that it has been accurately
received.
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UK Power Networks
DSR 01 014
v6.0
Excavation and work in the vicinity of defective cables requires particular care and the additional
requirements for this work are specified in Section 8.5.
When it is felt that the procedures shown in Appendix 1 cannot be followed advice
should be sought from a suitably competent person. Any alteration must be recorded in
writing or the work must be carried out under the personal supervision of the competent
person.
8.1 Work Instructions
For any job, planned or un-planned, the instructions and information provided shall comply with
the requirements of HSS 01 105 Putting People to Work, or other relevant procedure.
The work instructions should cover any site specific issues including the possible presence of: Other cables especially EHV routes
 Third party cables such as inset or private networks
 Auxiliary plant such as pilot cables, gas or oil pipes
 Additional hazards when excavating within or near substations - Refer to Section 8.6
 High pressure national fuel pipelines
The Person issuing the job instruction must decide whether the excavation is to be carried out
with the cable(s) live or dead although this does not prevent cables being made dead as work
proceeds.
For planned work the instructions shall be issued to the Site Coordinator and shall
include:
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Clear written instruction of the work to be done and associated plans
Any precautions to be taken or special instructions to be observed. For example it may be
decided to specify that additional cables should be exposed to assist with identification.
For LV cables the approved method of positive cable identification to be used as detailed in
DSR 01 018.
For unforeseen work that occurs at such short notice that it cannot be planned in
advance.
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The job shall not commence unless network cable records (paper or electronic) are on site.
These should be sufficient to enable isolation of any damaged or faulty equipment.
Where practicable other utility plans should be made available on site.
There shall be a full On Site (Point of Work) assessment of the site.
The excavation should be carried out as though there are buried services in the vicinity.
8.2 Location of cables and marking of surface (Refer to Appendix 1 for
illustrations)
Cable Avoidance Tools provide information on the position of cables. They must be used in
conjunction with cable and other utility records (where provided). The depth and location of
cables shown on mains records may have changed because of subsequent site alterations.
An approved Cable Avoidance Tool shall be used before any surface is removed or any
digging is started. Reasonable steps shall be taken to establish the runs of cables both
along and across the length of the intended area of digging.
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UK Power Networks
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DSR 01 014
v6.0
The user should be competent to use the available cable avoidance tool which shall be
within its inspection date and shall be regularly checked for correct operation.
All markings shall be with a waterproof marker
The area of excavation should be marked using information from task instructions, plans
and cable location
The line of all known cables in the vicinity of the excavation should be marked. These lines
should be extended at least 300 mm past any excavation. Encroachment Lines should be
drawn at least 300 mm away from and parallel to the outer and innermost cable marker
lines. These lines should also be extended at least 300 mm beyond the edge of the actual
excavation.
8.3 Excavation of all cables
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All tools must be of an approved type.
Hand tools must be used in preference to power tools in the vicinity of cables unless site
conditions make this impractical, for example the removal of hard surfaces outside of
encroachment lines.
Hand operated manual tools should be used to progressively and carefully undermine any
hard surface from outside the encroachment lines towards the cable(s).
Hand held power tools may only be used to break up any undermined hard surface, keeping
pace with, but not going past the undermining.
Once all recorded and detected services inside the proposed digging area have been
exposed hand held power tools may be used below ground level to break up concrete or
similar structures only where it is not possible to use hand tools.
Extreme care must be exercised when using power tools above already exposed cables.
A cable avoidance tool should be used during excavation to check the location of known and
other cables.
Where cables or ducted cables are not exposed by undermining in their indicated position,
and/or are suspected or known to be embedded in or directly below any concrete, then that
concrete shall not be disturbed until the cables have been made dead, unless a Senior
Authorised Person can establish an alternative safe system of work.
Where it is established or suspected that cables have been encased in concrete then a safe
system of work will be agreed between the Senior Authorised Person and the excavation
team Supervisor. (see UKPN Preferred method of work where cables are encased in
concrete)
Where exposed cables are damaged during the excavation or are found with previous
damage then reference should be made to Section 8.4.
Use of power tools must stop if at any time the cutting rate quickens, indicating softer
ground. At all times, attention must be paid to the cable run marker lines outside the edges
of the hole.
Spades should be used in preference to forks. Extreme care should be taken when using
excavation tools
Digging tools must be used in a controlled manner and should never be thrown into the
ground.
Approved flame retardant coveralls, leather gloves and approved industrial footwear shall be
worn as a minimum at all times during excavation work. Where power tools are being used
or when the On Site (Point of Work) Assessment deems it necessary additional PPE such
as eye or face, hearing and head protection should be worn.
A serviceable portable dry powder fire extinguisher of at least 2kg capacity must be
available on site for all work near cables connected to the Distribution System.
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UK Power Networks
DSR 01 014
v6.0
Suitable precautions shall be taken to cover the following risks:
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Collapse of the sides of the excavation – this risk should be reviewed throughout the work
Materials falling onto people working in the excavation
People and vehicles falling into the excavation
Digging immediately adjacent to or undermining nearby structures including street furniture
Digging in the vicinity of trees
Working on contaminated land
Discharging surplus water from the excavation
Exposed cables which should be adequately protected and supported
Ensuring that where an excavation is left unattended exposed cables are marked with
Danger Live notices or that defective live low voltage cables are covered by a cable damage
blanket
Ensuring that any unattended temporary jointing has adequate mechanical protection
8.3.1
Cables Encased in concrete
Where cables are encased in concrete it is essential that the works are thoroughly planned to
reduce the risk SFRP.
Cables encased in concrete shall be made dead prior to any disturbance of the concrete. If they
cannot be made dead, then the justification must be documented and the procedure below
followed:
It is anticipated that this type of work would be subject to the Personal Supervision of a Senior
Authorised Person who will take into account the following
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Consideration should be given in the first instance to excavating in an alternative location, if
not possible then to overlaying the section by locating the cable at 2 suitable alternative
positions
Consideration should be given to lowering of the protection settings.
Consideration should be given to lowering of the fault level to the lowest practical level by
switching.
Dependent of the conditions on site, all cables that could be impacted by the intended work
should be identified and made dead or given adequate support and mechanical protection,
such as sand bags and timber.
Work with any adjacent cable or circuits energised should be subject to a site specific risk
assessment developed in conjunction with a Senior Authorised Person and agreed by all in
the working party.
8.3.2
Ducts Encased in concrete
Where cables are within multiple ducts in concrete it is essential that the works are thoroughly
planned to reduce the risk SFRP.
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It is anticipated that this type of work would be subject to the Personal Supervision of a
Senior Authorised Person.
Consideration must be given in the first instance to overlaying the section by locating the
cable at exit / entry points to duct systems.
Dependent of the conditions on site, all cables that could be impacted by the intended work
should be identified and made dead or given adequate support and mechanical protection,
such as sand bags and timber
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UK Power Networks
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DSR 01 014
v6.0
It may in some circumstances be possible to safely break into a duct system containing
cables using approved tools and methods (persons should wear full PPE with full face
protection and leather gloves when engaged in this activity).
Work with any adjacent cable or circuits energised should be subject to a site specific risk
assessment and work method statement developed in conjunction with a Senior Authorised
Person, and agreed by all in the working party
8.4 Additional precautions to be taken when working near defective
Site staff including the site coordinator may always make a cable or cables dead, or
request that they should be made dead. Nothing in this procedure should encourage any
person to work near a live cable when there is any doubt about their safety.
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Any damaged cable or other equipment, irrespective of voltage and condition, shall be
assumed to be live until it has been isolated and proved to be dead.
LV Control or Dispatch shall be advised immediately of all defects to commissioned LV
cables unless these are known to have been previously reported.
The HV Control Engineer shall be advised immediately of all defects to commissioned HV
cables unless these are known to have been previously reported.
The Site Coordinator shall consider a variety of factors, including those listed below, when
deciding whether to make cable(s) dead. These factors affect the likelihood and consequences
of any unplanned discharge from the cable.
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Whether the cable is single or multi-phase
The size of the cable
The voltage of the cable
The feeding arrangements of the cable
The depth of the cable
The extent and visibility of any defect
The accuracy of any fault location
The possibility of additional damage to any cables.
8.5 Safe Working Distance when working near defective cables
Even on an apparently healthy network there is a small risk of excavating on to a fault. These
additional precautions apply due to the increased risk involved when excavating specifically to
locate a fault.
The Safe Working Distance from a live defective or a possibly defective cable will vary but
decisions should be based on the assumption that the cable will fault and that PPE should not
be relied on to provide protection.
Site staff should assess the risk whether to make a cable dead based on site conditions but the
following are not allowed in any circumstances:
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Work within 5 metres of a known defect on a live high voltage cable
Work within 1.5 metre of a known defect on a live exposed multi-phase low voltage cable or
joint
Work within 1 metre of a known defect on a live exposed low voltage single phase cable (up
to and including 35 sq mm or 0.0225 sq in).
Where safe and appropriate an exposed low voltage cable may be covered by a cable damage
blanket.
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UK Power Networks
DSR 01 014
v6.0
In general the minimum Safe Working Distance shall be 1.5 metres but the following are
examples where a different distance may apply.
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The distance from a live defective high voltage cable should be considerably higher and the
cable should normally be de-energised without delay. There may be circumstances where a
high voltage cable, with possible damage, remains live and it may be considered acceptable
to provide protection from access until arrangements can be made for isolation and any
repairs.
Where a high voltage cable has been damaged it is often necessary to approach the cable
that should have been isolated to carry out further excavation and to spike to prove dead.
The person responsible for this work shall assess whether there is any risk that the wrong
cable may have been isolated. If there is any doubt or possibility that other cables may
have been damaged then a Safe Working Distance or further isolations may be required.
For a low voltage cable that is known to be at 450mm depth it may be appropriate to remove
the top 100mm of surface with the cable live. Cable records should not be relied on as an
indication of depth.
Additional care should be taken where more than one fuse feeds each phase of a LV cable.
Where there is a known point of defect on a single phase service cable it may be
appropriate to work closer than 1.5 metres, especially if a cable damage blanket can be
placed over the defect.
The accuracy of fault locating instruments should be considered when deciding the Safe
Working Distance. Fault locators normally have an accuracy of about plus or minus 10%.This
means that a reading to a fault of 50 metres may be 5 metres out either way. This does not
include any additional inaccuracy due to errors in plans. A 10% error on a distance of 15 metres
is 1.5 metres which would eliminate the normal Safe Working Distance. Depending on
experience, time since the fault, and the likelihood of ducts it may be possible to rely on a cable
sniffer to provide a more accurate location.
If by using evidence from the fault locating instrument, the sniffer, no supplies and any other
relevant information the actual fault position can be determined, the cable can be excavated a
minimum distance of 1.5m from the fault. In some circumstances negative results from the
sniffer can also be used to determine a suitable location to dig. Where this is not possible the
cables shall be isolated before or at an early stage of the excavation.’
8.6
Additional precautions for work in locations controlled by UK Power
Networks
These will apply for all excavation work including installing earth pins, rods, fence posts or any
activity causing disturbance to the ground.
A technically competent person shall issue those persons undertaking the work with a method
statement that is specific to the work. This shall include requirements for competency,
resources, plans, cable locators and any other relevant precautions such as consideration of
nearby overhead lines.
8.6.1 Where work is to be undertaken by a person who holds an Electrical
Competency under the Distribution Safety Rules:

For work in grid, primary or strategic sites a Limitation of Access shall be issued and the
appropriate Control Engineer informed.
For work in or in the vicinity of secondary substations
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UK Power Networks
DSR 01 014
v6.0
If following the pre-work site survey the technically competent person putting the person to
work considers it necessary a Limitation of Access shall be issued and the appropriate
Control Engineer informed.
8.6.2
Where work is to be undertaken by a person who does not hold an Electrical
Competency under the Distribution Safety Rules:-
A Limitation of Access shall be issued to a Competent Person who will provide Immediate
Supervision during the works. The appropriate Control Engineer shall be informed.
8.7
Personal Protective Equipment - Working near defective cables
Although eye protection should be worn for all excavation work involving defective cables it is
not normally practical for excavators to wear full face protection. Therefore where there is a risk
of injury from a discharge while working near a live cable this cable or cables should be
isolated.
There is always a slight risk of a second defect or an unexpected discharge. Where jointing staff
are working on or near a cable that may have a defect, consideration should be given to
wearing approved full face protection, in addition to Safe 6 PPE, especially until the cable is
proved dead.
8.8
Isolation and Proving Dead
Where a cable or cables are to be made dead then they shall be isolated and proved dead at
the point of work in accordance with the Distribution Safety Rules (DSR Sections 3.9, 5.9, 8.2
and 8.3).
An approved device, which shall be tested before and after each use, shall be used to prove a
cable dead.
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Where a property has one multi-phase service cable this may be proved dead when one or
more of the phases has remained live after the fault and those phases can be proved dead
by testing at the cut-out position before and after making the cable dead.
Where only one main cable or overhead line supplies a street, that is it supplies both sides,
a service cable may be proved dead by testing at the cut-outs located in adjacent premises.
Where local knowledge gives confidence that network records may be used as an indication
that the required cable has been made dead. This may apply when there is one main on
each side of a road and it is known that all services are connected to the nearest main.
If an identifiable cable is visibly damaged with associated losses of supply and one or more
fuses have operated and therefore the point of isolation is known.
AND
All cables which could credibly energise the fault in the event of incorrect records or labels,
and cables which might have been damaged by the fault, have been fused or made dead.
Because of the risk of a feed, such as from a customer’s generator, any work on cables
shall be carried out using live jointing techniques even after a cable is proved dead.
8.9 Fusing when working in the vicinity of defective LV cables in the London
interconnected system
No work shall take place unless the live cables to be worked on are protected by Safety Fuses
at an appropriate point in the system.
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UK Power Networks
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DSR 01 014
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Wherever practicable, safety fusing shall be by means of one set of fuse links of a size no
greater than 315A, installed at the nearest appropriate point of isolation. Permanently
installed fuse links of up to 400A, excluding fringe fuse links, may be left in place, where
multiple fusing operations would otherwise be required. The following alternatives may,
however, be adopted where loading conditions dictate:
One set of 400A fuse links, excluding fringe fuse links, installed at the nearest appropriate
point of isolation.
Two sets of fuse links of a size no greater than 315A, installed at the two nearest
appropriate points of isolation.
The decision whether or not to fuse or make dead such cables will be made by an Authorised
Person after considering the safety of those working and the conditions to allow live working
which are detailed in HSS 40 045 Basic Requirements for Live Working on Low Voltage
Apparatus.
Where more than one LV cable is present and it is not possible to identify the LV cable to be
worked on without disconnecting customers, then all LV cables adjacent to and including the LV
cable to be worked on must be fused as above.
Where it is not possible to comply with the above an Authorised Person will decide upon the
procedures to be followed.
8.10 Mechanical Excavators
Where site conditions are suitable mechanical excavators may be used to dig to within 300mm
of indicated healthy cables providing the requirements of section 8.3 are complied with.
Where a mechanical excavator is to be used and section 8.3 of this procedure cannot be
complied with, an Authorised Person must give permission for, and specify the limits and
method of its use on the task instruction sheet.
For trench work trial holes should be first dug by hand at intervals along the proposed route to
confirm the accuracy of the marking of cable runs.
If tile tape or cable slabs are uncovered use of the mechanical excavator must cease. The
cables must then be exposed by hand. Where “hand digging only” has been specified the Site
Coordinator must get permission from an Authorised Person before an alternative method of
excavating can be used.
Mechanical excavators which are used for digging near cables must have a toothless bucket.
9.0 Trenchless Technology
The use of trenchless technology should only be considered after the risks to all plant and
apparatus, including those belonging to other utilities, have been assessed and control
measures put in place.
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10.0
Superseded documents
This procedure replaces the following documents:
HSS 40 012 Work on or Near Damaged and Faulty Cables
HSS 40 014 Excavating in the vicinity of buried services
London Code of Practice 2 (Part only)
SPN Engineering Instruction 9/57/13 - Repairs to Damaged or Faulted LV Cables
Operational Bulletin HSS 406 OB 57
This printed document is valid at 31/07/17, check after this date for validity.
Page 12 of 15
UK Power Networks
DSR 01 014
v6.0
Appendix 1 Locating cables, marking the area of excavation and safe digging
A “Digging Card” based on this appendix is available for issue to field staff as
DSR 01 014a
Sweeping the proposed area of digging with a cable avoidance tool and marking out an
excavation and encroachment lines. (Both patterns must be used)
CABLE
AVOIDANCE
TOOL
SWEEPING
USING THIS
PATTERN TO
DETECT
CABLES
RUNNING
ALONG THE
HOLE
RUN OF
CABLE
CABLE
AVOIDANCE
TOOL
RUN OF
CABLE
SWEEPING USING THIS PATTERN TO DETECT
CABLES RUNNING ACROSS THE HOLE
Use of both power and radio modes will improve detection of other utilities and of cables
that are not supplying a load or are supplying a perfectly balanced load.
All cable runs either confirmed by use of the cable location device or indicated on mains
records must be marked out on the surface using a waterproof marker. Marked cable runs
must be extended at least 300 mm beyond the digging area, and must stay visible during
digging.
This printed document is valid at 31/07/17, check after this date for validity.
Page 13 of 15
UK Power Networks
DSR 01 014
v6.0
Marking out an excavation
LINES EXTENDED 300 mm
BEYOND AREA TO BE
DUG OUT
SERVICE CABLE
ROUTE MARKED
MARKED
LINES OF
CABLE
RUNS
MARKED
SIZE OF HOLE
TO BE DUG
Marking encroachment lines
To be parallel to and at least 300mm away from the outer and innermost cable marker
lines
BACK EDGE OF FOOTPATH
MARKED MAIN CABLE
AND SERVICE CABLE
RUNS
AREA OF SURFACE
TO BE REMOVED
ENCROACHMENT
LINES ARE TO BE
EXTENDED
300 mm BEYOND
ALL EDGES OF
THE HOLE
KERB
This printed document is valid at 31/07/17, check after this date for validity.
Page 14 of 15
DSR 01 014
UK Power Networks
v6.0
The method of removing a surface and undermining
where it is necessary to use power tools
Remove surface outside
encroachment lines and start
excavation with hand tools
Surface to be removed
Cables
Undermine surface using hand tools and where possible break off surface with
hand tools
Carry on undermining with hand tools and breaking off surface
Until all cables have been exposed
And the joint hole is open
POWER TOOLS SHALL ONLY BE USED
WHERE NECESSARY:
(1) TO REMOVE THE SURFACE OUTSIDE
OF THE ENCROACHMENT LINES
(2) AFTER ALL CABLES SHOWN ON THE
PLANS, OR PICKED UP BY THE
CABLE AVOIDANCE TOOL, HAVE
BEEN EXPOSED BY HAND
DIGGING
…
This printed document is valid at 31/07/17, check after this date for validity.
Page 15 of 15