FTN design & development specification (D&D)
SP FTN (D&D) 005
Jointing, Terminating and Testing Optical Fibre and Copper Telecommunications Cables
Issue 4.6, Feb 2009 · FTN D&D specs & typical drawings
The installer's rulebook for joining, terminating and commissioning-testing FTN fibre and copper cables. Designers use it for sheath gap rules, splice and termination arrangements, free-issue kit names, splice loss acceptance figures and the OTDR/insertion loss test regime that the design pass marks feed.
Clause map — what each clause deals with
| 1 | Purpose | What the spec covers and who must work to it. |
| 2 | Scope | Applies to contractors' staff jointing, terminating and testing FTN & GSM-R cables; includes standards, test parameters and proformas. |
| 3 | Reference Documentation | Documents referred to: 008, 009, 010, copper cable spec, laser safety standard. |
| 4 | Definitions & Abbreviations | Acronyms (BFA, BOP, CSM, IDC, ILM, MB, ODF, OTDR, VL, VT) and definitions of node types, BOP, DI-SAC, fibre section, UP end etc. |
| 5 | General | Who produces the detailed design, free-issue cables, interfacing with existing cables, contractor's plant and test equipment calibration duties. |
| 5.9 | Free Issue materials | List of kit Network Rail normally free-issues: copper and fibre cables, joint closures, gapping kits, cabinets, IDC modules, termination kits, BOPs, repeater pulled fibre. |
| 5.10 | Work in ac Electrified Areas | Induced voltage hazards in ac areas: limits on continuous metallic lengths, screening conductors in place first, keep metallic elements earth-free, Hot Wire Working. |
| 6 | Jointing | All jointing requirements for fibre and copper cables. |
| 6.1 | General | Joint bay siting, vertical closure entry, twin-sheath sealing, traction hazards, and armour gapping and isolation practices (ungapped length limits, gap before buildings, moisture barrier, CSM). |
| 6.2 | Optical fibre jointing | FIST GCO2 closures, security, fibre colour codes for standard and DI-SAC cable, splicing rules, cross-splice schedule, temporary spur closures, DI-SAC insulation, repeater bundled fibre, ZHLS. |
| 6.3 | Copper Jointing | Telsplice connectors, pair-to-pair jointing, staggering, XAGA 500 closure, through joints only, UP end marking, continuity bond and moisture barrier treatment by electrification type, ZHLS change-over. |
| 7 | Termination | All termination requirements for fibre and copper cables. |
| 7.1 | General | Cable securing, gel cleaning, bottom entry preference, sheath gap before cabinets/buildings, bend radius, where to strip armour. |
| 7.2 | Optical fibre terminations | Fibre termination arrangements including DI-SAC and GSM-R repeaters. |
| 7.2.1 | General | ODF units and height, tray loading, splices per tray, SC/APC spec, collets, which cables are fully terminated, storing unused fibres, pigtail return, fibre storage length. |
| 7.2.2 | DI-SAC | The special DI-SAC manifold that insulates metallic parts and redistributes 2x12 fibres into six 4-fibre tubes for standard trays. |
| 7.2.3 | GSM-R Repeaters | Repeater enclosures on monopoles or wing walls, pulled bundled fibre through PE tube and gland, BPE/O closure, trunking, no termination at repeater end. |
| 7.3 | Copper termination | Module types by environment, linking plugs, gel and twist, moisture barrier termination incl. TEHs, cabinet dressing, jumpers, vertical A/B/C allocation, mileage changes, VL/VT pairs. |
| 7.4 | Tunnel Termination Boxes | What tunnel termination boxes are and why they are used for 10 pair tails in long tunnels. |
| 7.5 | Ten pair tail cables to tunnel boxes | Where tunnel box tail cables terminate in the next cabinet/BOP and moisture barrier isolation. |
| 7.6 | Cable Termination Order and Termination Labelling In Core Nodes and Access Nodes | Pair 1 at the top, one vertical per cable, order of terminating multiple cables, and what the termination label must show. |
| 7.7 | Jumper Wire | Jumper wire standard, colour code by application, A/B leg convention, and earth testing/bonding of MDF to the MSE. |
| 7.8 | Installation of HDSL Repeaters and Termination of Circuits | Pointer to the work instruction covering HDSL repeater housings on cabinets. |
| 8 | Marking and Records | Label to 016, record to 017. |
| 9 | Testing | Commissioning test principles: witnessing and notice, cover page, testing in agreed sections. |
| 9.2 | Optical Testing – General | Design-derived pass marks per section, use of 1 km buffer fibres at both ends, backscatter after termination, connector cleaning. |
| 9.3 | Copper cable testing – general | Safety of HV copper tests, test plan approval, discharging cables, section extents from the design. |
| 10 | Submission of Test Results | Self-assessing spreadsheets, submission timescale, OTDR trace format (.SOR, Telcordia/Bellcore), trace scaling. |
| 11 | Condition Testing of Cables While on the Drum | When drum condition testing is needed, the fibre and copper tests involved (moisture barrier IR/continuity, single-direction backscatter, conductor IR) and the report content. |
| App A | Schedule of Optical Tests | Optical test regime: OTDR set-up (pulse width, range, markers, refractive index), splice loss acceptance tiers, insertion loss method, permissible loss values, bare-end and repeater tests. |
| App B | Schedule of Copper Cable Tests | Copper test regime: continuity and resistance, moisture barrier IR/continuity, conductor IR, HV breakdown, attenuation incl. HDSL, NEXT, psophometric noise, temperature correction table. |
| App C | Test Sheet Pro Forma – Optical Fibre | Superseded by the live self-assessing spreadsheet. |
| App D | Test Sheet Pro Forma – Copper | Superseded by the live self-assessing spreadsheet. |