Telecommunications Infrastructure

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1 Telecommunications Infrastructure Table of Contents Contents 1. INTRODUCTION DUCTING CAPACITY SUB DUCT SIZING DUCTING AND SUB DUCTING CONSTRUCTION AND COLOUR BUILDING ENTRANCE: BUILDING ENTRANCE: EXISTING BUILDS, BASEMENTS DUCTING LAYING DUCTING DEPTH DUCTING ROUTE DEVIATION DUCTING: TESTING AND PROVING DUCTING: RODDING AND ROPING DUCTING: MARKER TAPE DUCTING SEALS SUB DUCTS ACCESS PITS LABELLING: ACCESS PITS, DUCTS AND SUB DUCTS DUCTS: TESTING GLOSSARY REFERENCES NOTES

2 1.0 Introduction This document sets out to define the external ducting requirements for IT Infrastructure. The document is intended for use by installation and project teams and can be referenced in specifications and design briefs. Correct installation procedures must be adhered to. Any deviation from the standards listed below must be agreed in writing by representatives of the University of Bath. It is the responsibility of the Main Contractor (project coordinator or project manager) to ensure that the best practices listed within are adhered to.

3 2.0 Ducting Capacity To ensure ease on install or withdrawal, each duct must not be filled beyond the specified fill rates shown; 1 off cable/sub duct 53% 2 off cables/sub ducts 31% 3 off cables/sub ducts 40% When installing three or more cables/sub ducts avoid ratios of duct internal diameter to cable sub duct external diameter of 2.8 to 3.1 Example 1 - for a duct of 110/94 avoid cable/sub duct external diameters of 32 to 36mm Example 2 - for a duct of 65/50 avoid cable/sub duct external diameters of 16 to 18mm

4 3.0 Sub Duct Sizing Cables to be pulled into sub ducts must be of a ratio of 0.67 for Sub duct ID to Cable OD Sub Duct Inside Diameter (ID) Cable Outside Diameter (OD) Diameter Ratio = Sub Duct ID/Cable OD The ratio must be 0.67 Figure 1 The standard sizes for sub ducts for loose tube fibre cables are: Number of Cores Loose Tube Fibre Cables Fibre Cable OD (mm) Sub Duct Min. ID (mm) Sub duct size OD/ID (mm) 4 to / /12 24 to /20 Figure 2 All three sized sub ducts will not fall within the 32 to 36mm for a 110/94mm ducting system

5 4.0 Ducting and Sub Ducting Construction and Colour Ducts must be: Compliant to BS EN and BS EN BS EN IP47 rated twin wall construction Straight sections no coiled ducting to be used Must be 100mm internal diameter All ducts to be manufactured from HDPE Smooth bore internally New ducts to be green in colour Sub ducts must be: Compliant to BS EN and BS EN BS EN IP47 rated single wall construction Low friction permanent internal coating All ducts to be manufactured from HDPE Smooth bore internally New sub ducts to be green in colour

6 5.0 Building Entrance New Builds In new builds the external ducts must enter from under the building Slow radius 90 0 preformed bends must be used with a radius of no less than 600mm The slow radius bend must be fitted with spigots that can, and must be sealed with solvent cement The duct must enter the building at a height of between 350 and 450mm below ground level The duct must finish 25mm above the finished floor level The duct must be 50mm from the external wall All ducts to be green in colour New Builds, Basements In existing buildings that require a new building entrance the external ducts must enter from under the building An aperture will be made in the building fabric with core drilling rigs or other non-vibration method The aperture must be cut at 45 0 and the drilling rig must be anchored and set to this angle. It is not acceptable to core drill using hand held machines The aperture must allow for a 25mm gap around the duct to be installed Slow radius 45 0 preformed bends must be used with a radius of no less than 600mm The slow radius bend must be fitted with spigots that can, and must be sealed with solvent cement The duct must enter the building at a height of between 350 and 450mm below ground level The duct must finish 25mm above the finished floor level The duct must be between 50 and 100mm from the external wall The 25mm gap around the duct must be sealed with a bitumastic compound to a depth of no less than 300mm All ducts to be green in colour 50 to 100mm Finished floor level 25mm Ground level Bitumastic filler to a depth of no less than 300mm 45 0 preformed bend with a radius 600mm 350 to 450mm 100mm ID Figure 3

7 6.0 Building Entrance: Existing Builds, Basements In new builds where there is a basement level the external ducts must enter from the side of the building. The duct must enter the building at a height of between 350 and 450mm below ground level The duct must enter the building at a height of between 600 and 1800mm above the finished floor level The duct must finish 25mm clear of the finished wall All ducts to be green in colour Ground level 25mm 350 to 450mm 100m m ID Must be 1050mm 600 and 1800mm Finished floor level Figure 4

8 7.0 Ducting Laying The Installer is responsible for the planning, routing and excavation of the ducting. IT services and UoB Estates Department will have the final say regarding the proposed route and positioning of chambers and building entries. This information must be documented and signed off by the UoB Estates Department Electrical Services Manager and the IT Operations Team Manager and provided a minimum of 7 working days before any proposed work. This must be provided in the form of scaled PDF or DWF drawings. Ducting chamber proposals and appropriate data sheets should be included with any proposal (as require). The Installer must seek and gain clearances from IT Operations Team Manager and UoB Estates Department Electrical Services Manager before any excavation work commences. The Installer is responsible for any repairs required to services that are damaged during the works, unless previously identified as damaged. Straight sections of ducts must be secured to each other with the correct solvent cement for the socket and spigot ends or couplers. Ducts must be laid in as straight a line as possible. Duct organizers must be used to prevent undulations. One to be fitted either side of a joint and at 1m intervals along the length of a duct run The order of preference for duct positioning is as listed below. Unmade Surface Footway Verge Carriageway Newly installed ducting must be 600mm from any other non-telecoms services which run parallel to the intended route. See figure 5 Vertical separation of the ducting must be 150mm from other services which cross the ducting path. See fig 5 Telecommunications Ducting Other Services Running Parallel 600mm 150mm Other Services Crossing Figure 5

9 Recommended duct formations are as shown in fig. 6 No. of Ducts Formation 2 1 row of 2 columns 4 2 rows of 2 columns 6 2 rows of 3 columns 8 2 rows of 4 columns 9 3 rows of 3 columns Figure 6 Where more than 1 duct is installed, a minimum spacing of 50mm between each duct must be maintained. Duct spacers should be used and installed according to manufacturer s recommendations. See fig. 8

10 8.0 Ducting Depth Minimum depth of ducting for different surface finishes is as shown below in fig. 7. Ref: NJUG Publication Vol. 2 Environment Unmade Surface 350 Pavement or Grass 350 Verge 350 Carriageway 600 Figure 7 Min. Depth (mm) Minimum clearances of ducts within cut trenches are as shown in fig. 8 Reinstate to Original Surface Graded Backfill Ref Duct Depth Table Marker Tape Pea Gravel 100mm 50mm 150mm 100mm 100mm 50mm 100mm Figure 8 Infill surrounding ducts must be pea gravel. Sand is NOT to be used.

11 9.0 Ducting Route Deviation Where possible ducts must follow a straight route. Access pits must be installed where the route deviates more than 1:30 horizontally or 1:60 vertically. Preformed bends of 90 0 and 45 0 are only permissible at building entry points and there cannot be more than 1 preformed bend in any one run. Long slow curves are permitted but must exceed 50m in radius. Access pits must be positioned at no greater than 40m apart. For every 2m rise in between access pits the duct run must be halved.

12 10.0 Ducting: Testing and Proving All ducts must be tested prior to the installation of sub ducts or cables. New ducts are to be tested with a mandrel and brush connected together and pulled through the duct on a draw line to prove ducts against debris and excessive deflection. A mandrel of length 250mm and a diameter of 90% of the internal diameter of the duct must be pulled through the entire length of the duct. The brush should be at 200mm long with a diameter 110% of the duct. The mandrel/ brush must have a rope attached to both ends to allow the mandrel to be withdrawn in the event of a blockage Once the duct is clear of debris and a mandrel can be drawn through without obstruction a draw rope must be installed (See section 11)

13 11.0 Ducting: Rodding and Roping Ducts that require rodding may be undertaken with continuous or 3m section rods. The rod ends must be protected with leader and follower devices to prevent damage to existing cables. Only one draw rope may be installed into one duct at a time. Draw ropes that have been used to draw in a new cable must be replaced with a new rope. Draw ropes must be tied off onto the access pit furniture in a tidy manner. Draw rope lengths may be spliced together but it is not acceptable to joint using knots. Draw ropes must be made of polypropylene or other non-biodegradable plastic. Draw ropes must have a minimum draw strength of 550kg. Draw ropes should be 5000mm longer than the duct run.

14 12.0 Ducting: Marker Tape Fibre Copper Non-biodegradable plastic coated aluminium maker tape 150mm above the top duct Central to the duct trench 150mm in width Yellow in colour Marked at 1200mm centres with bold contract lettering FIBRE OPTIC CABLE BELOW Non-biodegradable plastic maker tape 150mm above the top duct Central to the duct trench 150mm in width Yellow in colour Marked at 1200mm centres with bold contract lettering TELECOMMUNICATIONS CABLE BELOW

15 13.0 Ducting Seals Where ducts and sub ducts are being installed the ends must be sealed with a blank duct plug to prevent the ingress of dust and water. Duct plugs must be installed at both ends of a duct run during non-working hours or working hours when it is raining. Where ducts and sub ducts enter an access pit and are left empty a duct plug must be installed. Where ducts enter a building or access pit a multi aperture duct plug must be used. The duct plug must be of a split design to allow removal without the cutting of cables or sub ducts. The multi aperture duct must have sealing plugs fitted to the correct aperture size for the sub duct or cable to be sealed against the ingress of gas and water. Empty apertures must be fitted with hole plugs to seal against the ingress of gas and water. Sub ducts with cables installed must be sealed with a simplex duct plug against the ingress of gas and water.

16 14.0 Sub Ducts Traditional fibre cables must be installed within sub ducts. The sub duct must be the correct size for the fibre cable. The sub duct run must be continuous. Sub ducts must not be tied to access pit furniture but must pass through the pit in a straight a line as possible. Sub ducts must not be coiled within access pits. Sub duct sections must be jointed a threaded connection and sealed with a collapsible cold seal or with compression connectors. Where a sub duct passes through an access pit in a straight direction the sub duct may be pulled through in one continuous pull or be jointed as detailed above. Where a sub duct passes through a chamber at an angle of 45 0 or more the sub duct must be cut at 100 to 200mm within entering the access pit to facilitate labelling. All open sub ducts with no cables installed must be sealed with a blank duct plug against the ingress of water and gas. All sub ducts with cables pulled into them must be sealed with a simplex duct plug against the ingress of water and gas.

17 15.0 Access Pits Preformed Access Pits EasyPIT Access Chambers or equivalent complying with BS EN 124:1994 loading specifications dependent upon installed location; see point (Load Bearing Capacity). Brick Built Pits Bricks Engineering bricks to Class B (BS 6100) Mortar 3:1 mix of sand to cement Cement EN197-1:2000 BS12 ordinary mix Pit Dimensions Where ducts are in a continuous straight run (no greater than 45 Degrees deviation in route). The pit dimensions must be a minimum of 900(l) x 600(w) Where ducts deviate by greater than 45 degrees, branch to other ducts, contain joint boxes or are at the entry to a building. The pit dimensions must be a minimum of 1300(l) x 900(w) Load Bearing Capacity Preformed Pits and all Pit Lids must be rated in accordance with BS EN 124:1994 to a minimum specification dependent upon location and predicted traffic. The access pit must be constructed on a floor slab of dimensions 150mm in depth and overhanging the access pit by 200mm on all sides. The depth of the access pit must be 850mm. A sump hole of dimensions 200(w) x 200(l) x 200(d) must be cast in the floor slab Ducts entering an access pit must. o Not be within 150mm of any corner. o Be 100mm from the floor slab from the bottom of the duct. o Enter at the required depth section 9. Duct Depth. o Finish flush with the access pit wall. o Be sealed to the access pit wall with bitumastic material. Where the depth of chambers exceeds 700 mm below the finished surface of the adjacent ground or carriageway, manhole steps complying with BS EN shall be built in, as specified in BS EN Steps should be located at the end remote from any side entry ducts bolts to be tied into one side wall to support the ironwork. Minimum of two off wall brackets at a spacing of 700mm apart on the longest wall side. Brackets must extend from 100mm from the floor slab to 100mm from the cover frame Two off cable bearer brackets to be fitted at each depth of ducting to enter the access pit i.e. if there are ducts entering at 600mm and 750mm there must be two off brackets at 600mm and two off brackets at 750mm. Pulling eyes of a diameter of 22mm to be installed 50mm below each duct or column of ducts as close as possible to the pulling alignment of the cable in all pits constructed for the purpose of pulling in cables. Pulling eyes shall be suitably located opposite the cable entries or ducts in the pit wall to assist with the installation of cables and have a safe working load not less than 10kN.

18 The safe working load of each pulling eye shall be clearly and permanently labelled on or adjacent to the pulling eye. When using a brick built pit, the cover frame must be set squarely on the access pit on a bed of mortar. The frame must be securely pinned to the wall structure on all sides Access covers installed in the UK should meet the requirements of the European Standard BS EN 124:1994 The appropriate class of manhole top or gully top to be used depends upon the place of installation. It is the responsibility of the engineer to ensure that the correct product is specified. Where there is any doubt the stronger class should be selected. Electrical cables rated higher than ELV must not share the same ducting or access pits as telecommunication cables Access pits must be positioned to provide a safe working area for maintenance and pulling in new cables Where ducts pass beneath roads access pits must be positioned at each side of the road crossing Where there is known future requirement for ducts, poke outs must be installed that run 0.5m to 1m from the access pit

19 1310mm 100mm 305mm 500mm, 600mm, or 750mm 700mm Cable bearer brackets aligned with bottom of duct 200mm 50mm 50mm 200mm 100mm Floor Slab Sump 150mm Figure 9 610mm 100mm 150mm 200mm 100mm Cable bearer brackets aligned with bottom of duct 200mm Floor Slab Figure 10

20 16.0 Labelling: Access Pits, Ducts and Sub Ducts All ducts and sub ducts must be labelled at each access pit and building entry/exit. The label must be engraved on a plastic tags. Plastic engraved tags must be black writing on a yellow background. There must be apertures at each end of the tag that can accommodate cable ties. The tag must be secured to the sub duct with two off external cable ties. Each bank of ducts must be labelled at all chamber entry/exit points and building entry points. The label must identify which building or chamber the bank of ducts is connect to. The individual duct labels must correspond at each end and not read left to right. Figure 11 Correct labelling of ducts Figure 12 Incorrect labelling of ducts To facilitate operations and administration, all jointing chambers and covers should be clearly labelled utilising plastic durable waterproof labelling. The labels should identify the jointing chamber as a telecommunications facility The labelling scheme should be consistent throughout the system of chambers and each chamber should have a unique identifier which must be referenced on the as installed drawing.

21 17.0 Ducts: Testing All ducts must be tested prior to the installation of sub ducts or cables. New ducts are to be tested with a mandrel and brush connected together and pulled through the duct on a draw line to prove ducts against debris and excessive deflection. A mandrel of length 250mm and a diameter of 90% of the internal diameter of the duct must be pulled through the entire length of the duct. The brush should be at 200mm long with a diameter 110% of the duct. The mandrel/ brush must have a rope attached to both ends to allow the mandrel to be withdrawn in the event of a blockage. Once the duct is clear of debris and a mandrel can be drawn through without obstruction a draw rope must be installed (See section 10).

22 18.0 Glossary ELV Extra-low voltage (ref: BS 7671) Duct / ducting Structure (usually cylindrical) used to convey and protect apparatus NJUG National Joint Utilities Group Sub-duct Longitudinal structure (usually cylindrical) laid inside ducts used to carry smaller diameter cables such as Fibre optic. UoB University of Bath

23 19.0 References NJUG Publication: Volume 1: Issue 8: , NJUG Guidelines on the Positioning and Colour Coding of Underground Utilities Apparatus NJUG Publication: Volume 2 Issue 4: , NJUG Guidelines on the Positioning of Underground Utilities Apparatus for New Development Sites BS EN 124:1994: Gully Tops and Manhole tops for vehicular and pedestrian areas. Design requirements, type testing, marking, quality control IEC 61140: Protection against electric shock Common aspects for installation and equipment. BS 7671 IET Wiring Regulations IEC : Low-voltage electrical installations Part 4-41: Protection for safety Protection against electric shock. BS EN 1917:2002 Concrete manholes and inspection chambers, unreinforced, steel fibre and reinforced BS EN 13101:2002 Steps for underground man entry chambers. Requirements, marking, testing and evaluation of conformity.

24 20.0 Notes