Guidance note
NR/GN/TEL/31100
Telecommunications Failure Investigation (formerly RT/E/C/31100)
Issue 1, June 2002
Code of practice on how to investigate a reported safety related telecoms failure (SRTF): principles, non-destructive then destructive testing, referral, peer review and escalation, specialist investigation, records, serious incidents with BTP, independent investigation, a test guide index and logbook.
Clause map — what each clause deals with
| 1 | Purpose | Explains this code of practice shows how to meet RT/E/S/31001 when investigating reported safety related telecoms failures |
| 2 | Scope | Covers all operational telecoms kit and bearers, including Grant of Use services on finance lease assets, plus serious incidents and specialist investigation |
| 3 | Definitions | Defines terms such as check, test, like-for-like replacement, missing equipment, maintenance tester, SRTF, tail cable and temporary diversion |
| 4 | Principles | Every SRTF report is taken as true until proven otherwise; test guides split checks into non-destructive and destructive stages |
| 5 | Testing | Start only once line protection or signaller arrangements are in place; also follow GK/RT0105/0106; deviations from the flow chart need line manager approval |
| 6 | Flow Chart | Walks through the investigation steps: gather facts, when to refer, non-destructive then destructive tests, peer review, escalation, repair testing and handback to operations |
| 7 | Specialist Investigation of Equipment | When a fault is localised to an item but not pinned down, agree specialist lab investigation and pack and label it to preserve evidence |
| 8 | Keeping Records | What to note at the time (times, train, staff, witnesses, protection), who tested, use of the logbook, and recovering built-in logs and voice recordings |
| 9 | Serious Incidents | Agreed process with British Transport Police and the Rail Incident Officer for accessing, removing and testing evidence after a serious accident |
| 10 | Independent Investigation | After serious incidents, consider investigators independent of the normal maintainers, possibly from another company |
| 11 | Test Guides Index | Table of equipment types, typical failure symptoms and the matching test guide (concentrators, DOO CCTV, telephones) |
| Appendix A | Combined Telecomms Maintenance Testing & Failure Investigation Logbook | Sample logbook form for recording site, task, equipment, test plans or guides used and who did and checked the work |
| Appendix B | Test Guides (CONTFI001, DOOTFI001, TELTFI001) | Investigation checklists for concentrators, DOO CCTV and telephones, each split into non-destructive and destructive tests; replaced by the guides in NR/GN/TEL/31101 |