OT: All white wires ..

Or there were coloured wires with white protective sleeving at that point?

Were you close enough to see any small printed numbers?

I bought some multicore cable (I only needed a metre and it was the end of a reel) and it was all black, but numbered.

Probably military spec PTFE.

It's possible the wires were oversleeved with numbers at the ends, as every wire was added to the loom it would have been sleeved at both ends. Maybe there wasn't a requirement to be able to identify wires in the middle of the cabling run? After all, there's only a limited set of wiring colours, so a few hundred wires are going to run out very quickly.

(although you could identify them with the kind of frequency tracer used with phone lines)

Theo

When the scroats cut through the 400-pair linking our village to the exchange in the next village (and then had to abandon the cable 'cos they had no means of moving it), Openreach managed fairly quickly to source a drum with the right colour-pairs on it. 400 pairs with each pair coloured uniquely, perhaps two or more colours on each and mebbe dotting or dashing the colours too? Dunno - but they were able to splice it all back in within 18 hours. Messed up my broadband speed though.

Two basic colours per wire, but further identified by where in the bundle it is located.

Over the years I have seen many industrial control panels wired in a single colour (often black), with identifying cable markers at each end. Usually the same ID at each end, but in some cases, with each end having a different number, depending what terminal it is connecting to - that makes it hard to identify where a cable leaving one terminal is heading, during maintenance, but easy for wiring in the first place.

When I was replacing our electric-clock central heating timer with a Hive controller, I noticed that the switched live feeds for the central heating and hot water parts of the boiler were identical colours - grey.

So I made little tags which I fastened round the wires before I unscrewed them from the old controller, so I could attach them to the correct terminals of the Hive.

All went well until we came to move house. I wanted to remove the Hive controller to take it with us, and to re-fit the old timer controller. I unscrewed all the wires, with the ambiguous grey wires labelled, and pulled the bundle of wires through the hole in the backing box. This ripped off my labels and I was left with identical, indistinguishable wires. I had to make an arbitrary choice and see whether the hot water ran hot (or failed to do so) depending on whether the hot water circuit in the controller was turned on or off manually. I got it wrong, so I had to swap the wires round.

It would have been so much easier if the switched lives had been different colours.

Obviously the live/neutral/earth feeds from the fuse box were the correct colours (I forget whether they were brown/blue/green-and-yellow or red/black/green).

When I worked on an MOD project some 40 years ago, they used wire colour to designate if it were power, signal or whatever.

IIRC signal wires were all pink - rather disconcerting if you were trying to fault find.

Numbered wires would make more sense. It would allow technicians to work even if they were colourblind. Anyone know if colourblindness is a definitive condition for not allowing those suffering from it to become aircraft service technicians?

The TSR2 had woven glass over fine glass fibres for fire proofing the cables, all white with termination identifiers.

That's what your cabling database is for.

I was tested for colourblindness many moons ago when I became an apprentice at Marconi Instruments (1960 something!).

My boat has all black wiring but there are numbers built into the coating to identify them.

Woven glass on outside.

Or maybe they were all marked with sleeves or printed names.

A test was part of my interview for an electrical engineering apprenticeship. To test the electronic cabling for the 200ft. Clywedog reservoir scheme, we rigged up a temporary voice link. The cabling was multi-core sheathed pyrotenax stapled to the concrete with Hilti guns! Full marks to the contractors as no mistakes were found.

;)

You must be joking. 30+ year old marshalling cabinets with thousands of terminals and no databases, drawings or anything.

Even where there is, two wires leaving the same terminal and having the same number on them (relating to the terminal) does not tell you which of the two goes to which of the two destinations.

It is quite common with complex wiring looms to build them all up on a pin board first. This is a full size layout of pins in a sheet of ply or similar with all the termination points specified by a numbered pin. The wireman/lady would then route each wire in turn from point to point - following the twists and turns set by the pins, identifying each with numbered sleeving at each end, before the whole bundle is tied and finally sleeved before the actual connectors are added. Often there would be multiple connectors with cable forms splitting off at various points. The idea being that the loom would exactly match the physical layout required once routed in the airframe.

e.g.

https://epictures.homes/aircraft-wire-harness?

More a case of there being a vast number of wires, and the wire typically being a very high end PTFE or glass fibre re-enforced insulated wire that is very expensive, and not always available in many colours - it is usually bought on long spools of one or a few colours, and then custom looms wired up from that. Usually numbered sleeving is added at the terminations (and sometimes other locations). Sometimes wire painting machines are employed to over paint coloured identifications on plain wire down its full length. (usually multi colour stripes in various sequences)