UK Can anyone help date this cable please?

[MaintenanceSpark]

Hi guys,

Whilst renewing my loft insulation I came across a few runs of very old cable. (Please see attached pictures).

These cables are lead sheathed and looks to have a very brittle black insulation around the tinned copper or aluminium?

The red and black is wrapped around each wire in like a fabric cloth.

Any ideas how old this cable can be? Is this the original cabling from when the house was built say late 1920s early 1930s?

I find it very interesting. Every length is clipped to the side of the door frames. Very well clipped too. Had no movement when I was trying to pull them out.

Many thanks for any replies.

 

[timhoward]

Yes, I sometimes find a few inches on this loose under floors during rewires. I think it dates from the 1930's.
My usual observation is that the original 30's installation was much more carefully installed than the 60's / 70's rewire that I'm ripping out, and if the last rewire had been done more carefully some of it wouldn't be necessary even now.

 

[JBW175]

I agree with Tim here, as my house was built in the mid 30’s and I’ve found quite a lot of this lead sheathed cable in the walls from the original installation.

 

[MaintenanceSpark]

Thanks for the replies.

I was hoping to find a date stamped into the lead sheath or a date on the fabric cloth as the cloth is stamped with the manufacturer name but can't make it out unfortunately.

Seeing as it's been up there nearly 100 years I'm in inclined to leave it up there as a piece of history of the house.

The 30s installation is indeed a better install, clipped and bent lovely around the joists. The 70s rewire (ex council house) is just flung all over the joists with not a clip in sight.

 

[Lucien Nunes]

Probably 1930s, although if it was clipped to the door frame on the surface it seems likely to have been put in after the house was completed. It looks like tinned copper 1/.044 (i.e. one strand 0.044 inches in diameter) which was the imperial forerunner of 1.0 sq mm and the only non-stranded imperial cable in wide use in domestic work at the time.

Unlike PVC-insulated cable where the copper can be plain or tinned according to application, with rubber insulation the copper must always be tinned to prevent it reacting chemically with sulphur in the rubber. Aluminium was not used until much later, and then only for a short time, so the majority of slivery-looking cables that you will encounter (at least in the UK) are tinned copper. Aluminium is very soft and brittle by comparison, and larger CSA than you would expect for a given purpose as the conductivity is lower.

You might find if you strip it back, that the rubber is sound where it has been kept away from air by the lead sheath, and only the exposed parts are perished. Alternatively it might be crumbly all the way through. That is one of the odd things about rubber insulation; sometimes it lasts really well, sometimes it turns crumbly, sometimes gooey, but the original quality of the cable isn't the main decider. Some batches of rubber just last better than others.

Normal wiring cables of that era never have the date printed on them but we might have a clue in the print on the taping (which is there to prevent the rubber sticking to the lead or being damaged during extrusion.) From what I can see it says 'Callender Cable.' They were known for some time as Callenders with the 's', then BICC etc. I'm not sure whether there was a period for which it was officially Callender without the 's' but a look through my catalogues and tables from that era might confirm. Callenders were always one of the top quality brands of cable, and I think eventually the biggest.

 

[Dustydazzler]

Lots of old houses I work in I come across the old lead cables cut under the floors , I have only once found it still in use

 

[MaintenanceSpark]

Thanks very much for all the information on the cable. Very interesting.

You might find if you strip it back, that the rubber is sound where it has been kept away from air by the lead sheath, and only the exposed parts are perished. Alternatively it might be crumbly all the way through. That is one of the odd things about rubber insulation; sometimes it lasts really well, sometimes it turns crumbly, sometimes gooey, but the original quality of the cable isn't the main decider. Some batches of rubber just last better than others.

Normal wiring cables of that era never have the date printed on them but we might have a clue in the print on the taping (which is there to prevent the rubber sticking to the lead or being damaged during extrusion.) From what I can see it says 'Callender Cable.' They were known for some time as Callenders with the 's', then BICC etc. I'm not sure whether there was a period for which it was officially Callender without the 's' but a look through my catalogues and tables from that era might confirm. Callenders were always one of the top quality brands of cable, and I think eventually the biggest.

I'm going to strip a piece back on the weekend and see if I can get a nice bit of the taping with a clear manufacturer's print.

Thanks again!