ep 99 00 00 07 sp - substation fencing - transport for nsw · intruder resistant fence that...

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SUBSTATION FENCING

EP 99 00 00 07 SP

Engineering Standard Electrical

Version 3.1

Issued May 2013

Owner: Chief Engineer, Electrical

Approved by:

Neal Hook Chief Engineer Electrical

Authorised by:

Neal Hook Chief Engineer Electrical

Disclaimer This document was prepared for use on the RailCorp Network only. RailCorp makes no warranties, express or implied, that compliance with the contents of this document shall be sufficient to ensure safe systems or work or operation. It is the document user’s sole responsibility to ensure that the copy of the document it is viewing is the current version of the document as in use by RailCorp. RailCorp accepts no liability whatsoever in relation to the use of this document by any party, and RailCorp excludes any liability which arises in any manner by the use of this document. Copyright The information in this document is protected by Copyright and no part of this document may be reproduced, altered, stored or transmitted by any person without the prior consent of RailCorp.

UNCONTROLLED WHEN PRINTED of 21

RailCorp Engineering Standard — Electrical Substation Fencing EP 99 00 00 07 SP

© RailCorp of 21 Issued May 2013 UNCONTROLLED WHEN PRINTED Version 3.1 S

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Document control

Version Date Summary of change May 2009 Last Technical Review

3.0 May 2010 Application of TMA 400 format 3.1 May 2013 Update template


© RailCorp of 21 Issued May 2013 UNCONTROLLED WHEN PRINTED Version 3.1

Contents

1 Introduction .............................................................................................................................5 2 Scope........................................................................................................................................5 3 References...............................................................................................................................5 3.1 Railcorp Specifications..............................................................................................................5 3.2 Authority Standards...................................................................................................................5 3.3 Australian Standards.................................................................................................................5 3.4 International Standards.............................................................................................................6 4 Definitions................................................................................................................................6 5 Risk...........................................................................................................................................6 5.1 General......................................................................................................................................6 6 Fence Design...........................................................................................................................7 6.1 General......................................................................................................................................7

6.1.1 Design........................................................................................................................7 6.1.2 Maintained Level of Security .....................................................................................7 6.1.3 Aesthetics ..................................................................................................................8 6.1.4 Kerbing.......................................................................................................................8 6.1.5 Ground Level and Fence Height................................................................................8 6.1.6 Climbing Points..........................................................................................................8 6.1.7 Emergencies..............................................................................................................9

6.2 Perimeter Fence........................................................................................................................9 6.2.1 Welded Mesh Type Fence.........................................................................................9

6.2.1.1 Construction ...............................................................................................9 6.2.1.2 Gates........................................................................................................10 6.2.1.3 Hinges ......................................................................................................10 6.2.1.4 Locks ........................................................................................................11

6.2.2 Brick Wall .................................................................................................................11 6.2.3 Metal and Timber Clad ............................................................................................11 6.2.4 Toppings ..................................................................................................................11

7 Clearances .............................................................................................................................11 7.1 Horizontal Clearance...............................................................................................................11 7.2 Vertical Clearance...................................................................................................................11 7.3 Electrical Clearance ................................................................................................................12 8 Maintenance ..........................................................................................................................12 8.1 Regular Inspections ................................................................................................................12 8.2 Periodic Cleanups ...................................................................................................................12 8.3 Vegetation Control Management ............................................................................................12 8.4 Fence Upgrades......................................................................................................................12 9 Electrical ................................................................................................................................13 9.1 Step, Touch and Transfer Potential Mitigation........................................................................13 9.2 Earthing and Bonding..............................................................................................................13 10 Signage ..................................................................................................................................13 10.1 Danger Signs ..........................................................................................................................13

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10.2 Electrical Signs........................................................................................................................13 10.3 Railcorp Signs .........................................................................................................................13 Appendix A Drawings.................................................................................................................14

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1 Introduction The purpose of this document is to provide a minimum standard for security fencing for Railcorp owned substations and switchyards. This is to prevent the unauthorised access to railway electrical system infrastructure. This minimum standard is as described in the ENA standard “National Guidelines for Prevention of Unauthorised Access to Electricity Infrastructure”

2 Scope The scope of this document pertains to the perimeter fence surrounding all existing and new RailCorp owned system and distribution substations, section huts and switch-yards. Its primary concern is to provide information for the correct construction of the perimeter fencing. In addition some information is provided for signage, maintenance and appropriate measures to mitigate corrosion by stray currents.

For purposes of clarity, the contents of this document, does not deal with boundary fencing (refer Railcorp ESC 510 Standard), equipment enclosure fencing (high voltage cages etc refer AS 2067) or any other security related issues.

3 References

3.1 Railcorp Specifications EP 00 00 00 16 SP Electrical Power System Signage (draft) EP 12 10 00 10 SP System Substation Earthing EP 12 10 00 11 SP Distribution Substation Earthing EP 12 10 00 21 SP Low Voltage Installation Earthing EP 12 30 00 01 SP Electrolysis From Stray DC Current ESC 510 Boundary Fences

3.2 Authority Standards ENA DOC 015 – 2006 ENA – National Guidelines for Prevention of Unauthorised Access to Electricity Infrastructure NRS 193 Energy Australia – Intruder Resistant Fences SDI 524 Integral Energy - Fencing

3.3 Australian Standards AS 1725:2003 Chain-Link Fabric Security Fences and Gates AS/NZS 2312:2002 Guide to the Protection of Structural Steel against Atmospheric

Corrosion by the Use of Protective Coatings AS/NZ 1170 Structural Design AS 3600 Concrete Structures AS 2067 Switchgear Assemblies and Ancillary Equipment for Alternating

Voltages above 1kV

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3.4 International Standards BS 1722-10:1999 Fences – Part 10: Specification for Anti-Intruder Fences in

Chain Link and Welded Mesh BS 1722-14:1999 Fences – Part 14: Specification for Open Mesh Steel Panel

Fences

4 Definitions intruder resistant means a degree of resistance to climbing and breaching by an opportunistic intruder without the aid of tools.

Guidelines means the ENA – National Guidelines for Prevention of Unauthorised Access to Electricity Infrastructure.

fence intruder resistant fence that surrounds a substation, section hut or switchyard.

galvanised hot dip galvanised to AS 1650

perimeter fence the fence that surrounds a building or piece of internal property

boundary fence the fence on the boundary of two separate land titles

substations means Railcorp electrical infrastructure including system substations, distribution substations, section huts and switch yards

clearance zone the area around the fence that has no intermediate structures, hazards, climbing aids etc and is clear of any form of material buildup. Refer Section 7 of this Standard.

Railcorp approval approval required from Chief Engineer – Electrical Systems (Engineering Standards & Systems) to review electrical safety and compliance, Manager – Business Security Standards (Security Division) to review security and unauthorised entry, and the Regional Manager – Metropolitan Infrastructure to review maintenance, cost and general compliance.

5 Risk

5.1 General All Railcorp substations, regardless of location and local anti-social behaviour, are considered a high risk area. All substation perimeter fencing is to be high security fencing in accordance with this risk.

The high security fences that are available for installation around Railcorp substations are weldmesh, brick and timber type fences. This Standard defines the minimum high security fence as being the weldmesh type.

The detailed design of all types of fencing shall be submitted for Railcorp approval.

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6 Fence Design

6.1 General All sites, existing and new, shall be assessed prior to the design. This assessment may influence the fence type, and the design shall ensure that the fence has the appropriate level of security, and shall maintain a safe working environment.

The fence for the substations, whether new or existing, will require the following features.

6.1.1 Design For design purposes, it is preferred that the intruder resistant fence is constructed inside the boundary fence. i.e. two levels of fence protection. This ensures a higher level of protection by restricting vehicle access to the intruder resistant fence. If this is not practical, then traffic barriers or bollards are required to restrict vehicle access.

The substation fence shall be designed such that, any structures or fixtures that might aid a person climbing the fence, are positioned clear of the fence. The minimum climbing aid clearance required, is three metres on both sides. If this is not achievable then refer to Section 6.1.6.

The design life of the substation fence shall be a minimum of 20 years.

The substation fence shall have a pedestrian gate and double vehicular gates. The vehicular gates shall be internally accessed via the pedestrian gate.

The substation building can form part or whole of the perimeter fence, only if it has been approved to be so by Railcorp. The building may require a higher security rating for the doors, windows and or security systems etc as approved. Ensure that the exterior of the building is smooth to minimise hand and foot holds.

No perimeter fence is required if there is a building with no non-touch safe electrical equipment outside, provided that the building is approved as being adequately secure.

6.1.2 Maintained Level of Security All fences shall be maintained to ensure that the level of security is kept. Maintenance procedures shall ensure this by renewing any

a) Corroded sections

b) Ground subsidence or disturbances

c) Holes or penetrations

d) Damaged sections of fence and or concrete paths/kerbs

e) Missing topping

f) Signage

All fences shall be maintained so that its appearance and integrity is not compromised.

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6.1.3 Aesthetics Where required the following options may be applied to improve the appearance of the fence:

a) The weld mesh shall be galvanised and powder coated prior to installation. The colour of the powder coating shall be approved by Railcorp prior to manufacture.

b) Low level vegetation can be planted around the fence inside the clearance zone. The maximum height of this vegetation shall not be greater than 300mm. This ensures that there are no areas in close proximity to the fence, that allows coverage for intruders.

6.1.4 Kerbing Kerbs shall be included in the design of the substation fence. They prevent the integrity of the fence being compromised due to subsidence, erosion and burrowing.

Typically the kerb centre line shall be centred directly below the fence line, with the bottom of the fence no more than 50mm above the top of the kerb. The kerb shall be a minimum of 125mm wide by 300mm deep in clay soils and 600mm deep for sandy soils, with the top no less than 50mm above ground level.

If a kerb cannot be used, then a concrete path shall be constructed. This path shall extend a minimum of 600mm out from the fence line on either side. The path shall have a minimum depth of 75mm and finish flush with the existing ground levels. The bottom of the fence shall not be more than 50mm above the concrete.

The construction of the kerb and path is as shown on drawing EL 0450711. The kerb and path shall be constructed to AS 3600.

6.1.5 Ground Level and Fence Height If possible, the ground below the fence shall be level, and not be exposed to erosion or subsidence. The fence shall not be designed such that if the ground transitions from one level to the next, climbing points are created.

Areas where ground level is sloped such that the fence has climbing points, a retaining wall shall be constructed to provide support. The retaining wall shall be designed and constructed to support the integrity of the fence. The line of the fence shall progress down the slope in a series of level steps. The above kerb or path shall be included into the design of the retaining walls.

6.1.6 Climbing Points All climbing points must have measures to prevent entry. The fence design shall ensure that any climbing device is 3m or more away from the fence. If this is impractical then the following shall be considered:

a) Traffic bollards/barriers – relocate to 3m away from fence. If this is not practical then increase the height of the fence above the barrier to ensure minimum height. Refer drawing EL 0450710.

b) Window sills – place security grill/mesh flush over window so no finger or foot holds are available.

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c) Gate locks – the locks shall not create an external foot or hand hold. Refer drawing El 0450709.

d) Stairs – remove/relocate stairs and/or provide increase in fence height. Otherwise provide a security grill/mesh around the stairs.

e) Adjacent fence – where an abutting fence (non-intruder resistant) cannot be removed or relocated, then increase the height of the intruder resistant fence to 2.4m above the highest foot hold. Refer drawing EL 0450712.

f) Adjacent pole – if the pole cannot be removed or relocated then the fence will need to be redirected around the pole with a reduced clearance of 2m.

g) Overhanging vegetation – remove or prune back to 3m away from fence (and provide on-going inspections). If this is not possible trim trunk smooth to a height of 6m to remove any climbing points refer drawing EL 0450712.

h) Ground material – all material (cable and storage drums, steel work, containers, pallets etc) shall be kept in designated storage areas, or at least 3m away from the fence.

6.1.7 Emergencies The design shall allow for the possibility of fire, severe equipment failures and other emergencies to ensure the safe egress of personnel. If there is insufficient space inside the perimeter fence for a safe area to evacuate to, then an emergency egress gate in the perimeter fence is required to allow egress to the outside. For a typical emergency egress gate refer to drawing number EL 0455333.

The gate shall have a transparent impenetrable barrier (typically a high strength, high impact resistant acrylic or polycarbonate) surrounding the lock as shown. The gate shall have a welded plate across the gate to jamb gap on the lock side as shown, for the full height of the gate. The lock shall be a single down-ward thrust action for egress, and the gate shall open in the direction of the emergency egress.

6.2 Perimeter Fence This fence will be an intruder resistant fence in accordance with the Guidelines. It will also aid in resisting forced or covert entry.

6.2.1 Welded Mesh Type Fence Welded mesh fence shall be the standard perimeter fence design. The closed space welded mesh fence is the preferred type and shall be a single layer mesh fence with 4mm galvanised high tensile steel wire with an aperture size of 13mm x 76mm. The orientation of the mesh shall be such that the horizontal mesh aperture (76mm) is larger than the vertical mesh aperture (13mm) as outlined in ENA DOC 015-2006.

6.2.1.1 Construction The construction shall be as follows:

a) Plumb, level and true to design position.

b) All steel, fully welded, galvanised and powder coated black or dark green.

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c) As a minimum 2400mm high panels of mesh with 500mm of topping spaced 100mm off the finished ground level with top and bottom rails. Where the height of the fence increases due to an adjacent climbing aid then a mid rail shall be included in the sloping and heightened panels and have appropriate bracing.

d) The mesh shall be under tension or ensure there are no slack sections. If there are slack sections then a mid rail shall be installed and fixed.

e) Mesh to be installed with the vertical wire on the outside of the fence to reduce scalability

f) Foundations, braces, vertical and horizontal supports are required to withstand the loads imposed on a fence to AS/NZ 1170. This includes self support, wind loads, ramming and pulling over.

g) All vertical posts shall be set in concrete (minimum 25MPa).

h) All concrete to be reinforced to AS 3600

i) A straining post shall be installed for each end, corner, change of direction and acute variation in the level of the fence. For straight runs, a straining post is required every 50m minimum. Each straining post shall be supported by a brace in each direction of the fence line.

j) Mesh to mesh and mesh to post joins shall be with galvanised tamper resistant or locking, nuts and bolts.

k) Mesh to mesh joins (if any) shall overlap a minimum of 200mm. Each overlap shall have a securing every 100mm horizontally and 300mm vertically.

l) Any metal exposed during construction shall be coated with a two part epoxy corrosion inhibitor.

m) Final surface finish for all parts shall be homogenous and approved by Railcorp.

Refer drawing EL 0450708 for a typical installation.

6.2.1.2 Gates Both vehicular and pedestrian gates shall be made of the same material as the fence. Each gate shall have a concrete path or driveway provided underneath it.

The gate posts shall be of suitable strength to support the gate with reliable operation, for the duration of the fence life. Double gates shall have a top, middle and bottom rail. It shall be braced as shown in the drawings.

The gates and posts shall be all-welded and galvanised, and be typically constructed in accordance with drawing EL 0450709. The topping for vehicle gates shall be straight up not canted. The topping for the pedestrian gate can be a continuance of the adjacent topping.

The locking arrangement of the gates shall be as shown in drawing EL 0450709.

6.2.1.3 Hinges The hinges shall be of galvanised steel and strong enough to ensure reliable operation of the gate over the fence lifetime, and require minimum maintenance.

The hinges shall be designed to ensure the gate cannot be removed in the closed position.

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6.2.1.4 Locks For vehicular double gates, each gate shall be fixed by a galvanised padlock-able drop barrel bolt (minimum 16mm diameter) into the ground. The two gates shall then be locked together with a galvanised padlock-able sliding bar.

For pedestrian gates, the lock shall be a high security, exterior grade, sliding bolt deadlock type. The bolt shall travel a minimum of 20mm into the post on lock. The lock plate on the outside of the gate shall be flush mounted and tamper proof.

The position of all locks shall be as shown on the drawings and mounted between 900mm and 1200mm above the ground level.

6.2.2 Brick Wall Brick walls can be used but this needs to be designed for each specific site and is generally more expensive. Due to its blocking of external surveillance, further electronic intruder detection measures are required. Construction is not detailed in this standard.

6.2.3 Metal and Timber Clad Metal clad and timber clad fences can be used however surveillance is restricted which requires further electronic intruder detection measures. Construction details are not detailed in this standard.

Any designs using these brick or cladding types of fencing will require the approval during the design phase by Railcorp.

6.2.4 Toppings There shall be a minimum of 500mm of topping on the fence. This typically shall consist as a minimum of a role of 600mm diameter concertina short barbed tape (product minimum dimension of 550mm in diameter).

The topping shall be straight up and supported by the fence posts.

Where local issues determine that the concertina short barbed tape cannot be installed, the alternate topping and fence will require approval during the design phase by the Railcorp Security Division.

7 Clearances

7.1 Horizontal Clearance A 3m horizontal clearance zone shall be maintained around the substation. This area shall be kept free of any other materials, large vegetation or any other inappropriate items. If the 3m clearance is not practical, then the maximum possible clearance is required, and any possible climbing aids to be dealt with in accordance with this Standard.

7.2 Vertical Clearance The vertical clearance of the fence above a climbing aid (that cannot be removed or relocated), shall be a minimum of 2.4m including the topping. Fence posts shall be extended to allow for this on both sides of the climbing aid. Typical clearances will be in accordance with drawing EL 0450712.

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7.3 Electrical Clearance The electrical clearance will be in accordance with AS 2067. If the live equipment cannot be moved, insulated, shrouded or barred off, and the fence cannot be moved, then a non-penetrable panel can be installed in the fence. As a minimum, this panel shall be more than 350mm (for voltages up to 35kV) and 695mm (for voltages up to 72kV) away from the live equipment. If the horizontal clearance of the fence is less than 2790mm (for voltages up to 36kV) or 3135mm (for voltages up to 72kV) away from live equipment then a non-penetrable panel shall be used.

This non-penetrable panel shall be as shown in drawing EL 0450713. This panel will typically be two layers of compressed fibrous cement panel (2.4m x 1.2m x 18mm) one on the front and one on the back of the steel posts. All fixings shall be countersunk type and the holes back filled with a two part epoxy resin. The topping shall be a continuance of the adjacent topping.

This panel shall continue away from the live equipment until the above horizontal clearances are reached.

8 Maintenance

8.1 Regular Inspections Procedures are required to ensure regular inspections of all the substations, section huts and switchyards. The purpose of the inspections is to reveal what maintenance is required to the fence and to the surrounds. This maintenance would be for cleanups, vegetation control and or fence upgrades and repairs.

For any report of damage to the fence, a same day response is required. This response includes an inspection and recommendation of action to be taken. The action is to be carried out within 5 days.

Substation and section hut fencing shall be inspected in accordance with the Railcorp Specification ESC 510 Boundary Fences, Civil Technical Maintenance Plan Appendix 7.

8.2 Periodic Cleanups Periodic cleanups are required to ensure there is no build up of materials and rubbish. No “desirable” materials are to be left lying in the compound that may attract an opportunistic intruder. Typical “desirable” material that needs to be stored in proper areas include cable and conductors, busbars and other copper items.

8.3 Vegetation Control Management Vegetation encroachment requires periodic pruning to ensure the clearances are not breached.

In areas where the encroachment is from private property the owners require timely notification of the pending works.

8.4 Fence Upgrades As fences deteriorate, they will require upgrades to ensure the correct level of security. This includes replacing sections of damaged, perforated, corroded or weakened fence. The upgrades shall be performed to ensure the fence achieves an equivalent performance of an as new fence.

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9 Electrical

9.1 Step, Touch and Transfer Potential Mitigation The fence shall not form a continuous conductive path with any other metallic object adjacent to and or beyond the substation perimeter.

Where a junction with another fence cannot be avoided then an insulating panel shall be installed in the other fence. A typical insulation panel is as shown on Railcorp drawing CV 0041344.

Where a continuous metallic structure is in contact with the fence then an insulating section shall be included in the design (of either the fence or the structure) to stop transfer potentials through into and out of the metallic structure. This insulating section shall be sufficient to remove any step touch or transfer potential problems. Refer to the Railcorp Earthing Standards.

9.2 Earthing and Bonding The fence shall form a continuous conductive path with a grading wire included under the fence and bonded to every bay/panel. All aspects of the fence earthing, including gate bonding, grading rings etc shall be in accordance with the Railcorp Earthing Standards. The earth grading ring shall be located clear of any concrete path to ensure safe step potentials.

10 Signage Signs need to be installed to Railcorp Standard EP 00 00 00 16 SP Electrical Power System Signage (draft) and to bring attention to the fact that hazards exist. These hazards could be a danger from the fence itself or from the high voltages inside the fence. The signs shall be placed to ensure they are clearly visible and easily read.

10.1 Danger Signs If the fence construction includes barbed tape (“Razor wire”) or palisade spikes then danger signs are to be installed warning of their presence. These signs shall be placed around the site so that the information is noticed by any approach.

10.2 Electrical Signs High voltage signs are placed on the fence informing of the hazards inside the fence.

10.3 Railcorp Signs Signs detailing the owner of the site, the emergency contact number and the site identifier shall be installed to provide information to the general public.

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Appendix A Drawings Drawings that are attached to this specification are as follows:

EL 0450708 – Sheet 1 Typical Construction



EL 0450711 – Sheet 4 Details

EL 0450712 – Sheet 5 Clearances to Climbing Aids

EL 0450713 – Sheet 6 Non-penetrable panel

EL 0455333 – Sheet 7 Emergency Egress Gate

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© RailCorp of 21 Issued May 2013 UNCONTROLLED WHEN PRINTED Version 3.1 S

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ep 99 00 00 07 sp - substation fencing - transport for nsw · intruder resistant fence that...

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