Level 2 specification
NR/L2/TEL/00013
Specification for cable troughing
Issue 4+ADD1, 06 September 2025 (addendum to Iss 4, Mar 2016) · Cable route, survey & installation
Clause map — what each clause deals with
| 1 | Purpose | Performance specification for cable troughing products |
| 2 | Scope | Applies to all products that protect and contain cables on NR infrastructure |
| 3 | Definitions | Definitions — trough, lid, elevated route and so on |
| 4 | Introduction | Background — the scale and types of NR troughed routes |
| 5 | Material make up and cable trough dimensions | Material families and standard trough dimensions (C/1/x sizes) |
| 6 | Material quality control | Manufacturer quality control |
| 7 | Product acceptance | Product acceptance route |
| 8.1 | General | General robustness for manual or mechanical installation |
| 8.2 | Traditional concrete troughing | Traditional concrete troughing |
| 8.3 | Cement based troughing | Cement-based (GRC) troughing |
| 8.4 | Reduced weight traditional concrete troughing | Reduced-weight concrete troughing preferred |
| 8.5 | Non-cementitious troughing | Non-cementitious (polymer/GRP) troughing and banned materials |
| 8.6 | Product service life | Service life |
| 8.7 | Immersion in water | Water immersion |
| 8.8 | Toxicity | Toxicity |
| 8.9 | Material fire performance | Fire performance of materials |
| 8.10 | Resistance to corrosion | Corrosion resistance of fittings |
| 8.11 | Traditional concrete troughing and cement based products | Sulphate-resisting cement requirements |
| 8.12 | Colour | Colour |
| 8.13 | Tolerance to climatic conditions | Temperature tolerance |
| 8.14.1 | For ground level cable trough | Lids for ground-level troughing — securing and fit |
| 8.14.2 | For elevated routes | Lids for elevated routes |
| 8.15 | Trough lid security for high vandal risk areas | Lockable lids for high-vandal areas |
| 8.16 | Trough alignment | Trough alignment inserts |
| 8.17 | Cable exit | Cable exits — knock-outs |
| 8.18 | Reinforcement for traditional concrete and cement based troughings | Reinforcement — steel mesh and non-cementitious |
| 8.19 | Surface finish | Surface finish — smooth internals |
| 8.20.1 | Troughing for ground level routes | Weight limits for ground-level troughing |
| 8.20.2 | Troughing for elevated routes | Weight limits for elevated troughing |
| 8.21.1 | Cable troughing for ground level routes | Dimensions and tolerances for ground-level troughing — the drawings |
| 8.21.2 | Cable troughing for elevated routes | Dimensions for elevated troughing |
| 8.22 | Installation instructions and guidance | Installation instructions supplied with deliveries |
| 9.1 | General | Qualitative acceptance tests — overview |
| 9.2 | Type testing | Type tests — deflection, compression, impact, temperature cycling, drop, cover, cable exit, vehicle |
| 9.3 | Type testing – additional for non-cementitious troughing | Extra type tests for polymer troughing — weathering, ESD, thermal movement |
| 9.4 | Production tests | Production tests — cubes, finish, flatness, slump, gauging |
| 10 | Sample tests | Sample tests on delivery |
| 11 | Delivery | Delivery and palletising |
| 12 | Documentation | Documentation for product acceptance |
| 13 | Accessories (including T-pieces, transition unit and curve troughing) | Accessories — T-pieces, transition units, curves |
| Appendix A | Surface finish | Acceptable surface finish photos |