Telephone landline services were operated on behalf of British Forces by Deutsche Telecom
(there is a provision in the NATO Status of Forces Agreement Article 60
!). There were originally telephone interfaces
between civil lines and military network at each Garrison and some isolated detachments throught
the British Army estate. Much like a big firm each Garrison had a private network operating as extensions off a mainboard.
For the most part DT used either former Wehrmacht cabling (extensive) or built their own copper cable networks in the Barracks. The DT reprresentative used to come round every so often to disinfect the mouthpieces and ear "muschel", occasionally change the microphone or loud speaker capsules in the handset, check for cracks and damages to the black telephone dialler and check to see if any unauthorised extensions had been fitted - DT were paid in the rental agreement for the number of phones on the site. Clever expert extension installations were added to the bill - a shock for the QM and Pay Office.
On the training areas administered by the British Forces some telecommunications landlines (and handsets including Tele "L" and Tele "J" magneto calling sets) and twin cable pick up points, were supplied/fitted/maintained under the auspices of the "Signals Work-Services Troop - SWS Tp" located/based in Paderborn/Sennelager Garrison. They had offices, reels of copper wire and unopened boxes of handsets dating back to mid WW2, at the end at Alanbrooke Barracks Paderborn. Originally they had been based in Horrocks Barracks,(the Schloss at Neuhaus) with extensive storehouses in the Marstall buildings. These parts of th Schloss had been handed back to Paderborn Stadt in the late 1970s and early 1980s.
The SWS Tp was manned by civilian employees under direction of a military person much on the lines of the other artisan groups - MCAG RE, MCPG RE, MCTG RASC/RCT/RLC, some of their work was in the signals disciplines (16 and greater pair cables) although line laying, trenching, cable routing demanded RE skills.
SWS Tp were never home their real-estate extended from SHAPE, via Brunssum even to Berlin and they (German speakers) had constant contact with DT as voice or telegraph lines (and later the line of sight TV connection to UK and local down links) and then came line connected data links all systems were put in to use for the stationed troops and those arriving or moving to short-term/temporary exercise locations.
The workers were a colourful bunch and were well used to living, working or eating out in the open. One guy had a reputation for always working alone with his mechanical trencher since every morning he collected a substantial snack from any local butcher in the form a pound of mince, 2 onions, and four bread rolls.
One may have to wonder how much copper wire is built under Sennelager, Haltern or other Garrison Training Areas (connecting Firing Points to Butts or guard huts to control points), and as much on what had been rifle firing ranges. Sennelager Training Area was often struck by lightning - frazzling any landlines in the area - so SW were out re-laying safety comms.