I have been searching for this answer for a long time and I haven't found any info on the way severed lines are repaired. There must be tens of thousands of tiny wires that must reconnected, and in the proper order, before the line can be put back into service. What tool and technique is required to achieve such a daunting repair?

  • \$\begingroup\$ The phone signals are multiplexed onto (relatively) few wires, so it's actually not as daunting a task as you might think at first. \$\endgroup\$
    – Hearth
    Commented May 2, 2018 at 22:46

2 Answers 2


A cable for POTS (Plain Old Telephone System) service may have up to 200 or 250 pairs, if I recall correctly. The pairs are all colour-coded, with 25 different colour combinations, then a bundle of 25 pairs are wrapped with a coloured tape, and several bundles, each with a different colour tape, are used to build a large cable. (numbers may be wrong - it's a long time since I worked for a Telco)

I recall seeing technicians camped out in tents on the phone lines doing the splicing - haven't seen that for many years.

  • \$\begingroup\$ In Germany cables with up to 2000 pairs were used. \$\endgroup\$
    – Uwe
    Commented May 3, 2018 at 7:49
  • \$\begingroup\$ Wow, I had no idea all of those wires in the line had to be repaired one at a time! I have a new respect for the telephone lineman, makes me look like even more of a simpleton. I had an inkling of what a daunting task that is since I have had to repair severed engine and body harnesses on cars. However I only have to deal with a couple hundred wires and on most of them I do not have to worry about altered impedance across the spliced section (except air bags and lines that go to Hall effect sensors). My hat is off to you guys \$\endgroup\$ Commented May 3, 2018 at 22:42
  • \$\begingroup\$ I remember tents up on the poles. I don't think they do that anymore. I have noticed that in new installations they leave long loops of cable which they wrap up and tie using special plastic wheels. I suspect this is so that they can do the splices on the ground inside their trucks. \$\endgroup\$
    – David42
    Commented Sep 22, 2020 at 15:29

The answer is, sadly, just as daunting as it sounds. I've been involved in a few 500+ count fiber optics slicing repairs. It can take a team of workers several hours to complete.

Each wire (or optical fiber) needs to be identified, prepped, and spliced individually. Each wire is color coded and organized into further color coded bundles within the cable. Each bundle is organized in a tray within a splice enclosure (example below).

It's been a long while since I've been in the game, but at the time we were using "Scotchlok" gel filled pinch splices for copper and fusion splices for fiber.

enter image description here


Looks like copper splicing has come a long way, or I was just doing it the hard way before. Options exist (video) to simultaneously splice an entire bundle at once. Colored pairs still need to be organized and routed individually, but it may not be necessary to perform each physical splice individually. Fiber still seems to be a one or two at a time project though.


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