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[waltergmw]

Gentlefolk,

I'm doing a little research into GPO and BT PCP history. I have observed what I suspect was:-

1.  The original design having long vertical strips of screw connectors

2.  An intermediate design with horizontal "Krone Blocks" i.e. 10pr IDC blocks

3. The latest "Birdsnest design" where individual pairs are crimped usually through a jumper wire.

If anybody has the equipment numbers / identifiers and the rough dates when that type of installation started I would be very pleased to have the information.

As an aside, I can just remember around 1950-ish engineers working on plumbed joints of paper insulated twisted pair cables with numbers on the pairs that looked suspiciously like German printing.

Kind regards,
Walter

[BritBrat]

Not sure what you are after and I guess you would have seen this site:
http://www.telephonesuk.co.uk

[burakkucat]

I understand that the PCP concept was first implemented by the GPO post WWII. As a new-born kitten of that era, b*cat remembers when there were PCPs leading to SCPs leading to TCPs. (Primary, secondary and tertiary.)

The former two were bigger and smaller (respectively), green cast-iron cabinets whilst the latter were asbestos cement pillars to be found at the base of every distribution pole. (At lest in the area of SE London, where b*cat then lived.)

In decreasing numbers this was what was seen in an average SE London street scene, 1950s era: TCPs > SCPs > PCPs.

As well as the link that BB has mentioned, there also is http://www.britishtelephones.com/

However, I suspect Walter is also very familiar with that site . . . 

[waltergmw]

Thank you gentlemen.

BB's link says

"Cabinets and pillars were introduced for subscriber's local cables schemes in 1946."

So perhaps I can assume the cabinet with vertical rows of screw terminals is probably from that era.

IDC blocks or Krone blocks in Europe seem to have been developed in the USA in the 1950s and in Berlin in the 1970s so perhaps the latest date was when they were introduced in the UK (and also in New Zealand) might have been in the 1970s

From that I'd guess that the blue bean crimp connectors could have arrived in the 1990s and jelly crimps in 2000.

If anyone can provide more accurate details I'd very much like to know.

Kind regards,
Walter

[razpag]

The vertical strips with screw terminals are what we nicknamed as 'Pinned Cabs'. They are an obsolete cab now and should really be changed out if found in the network.

The horizontal strips are what we call 'Shelve Cabs' and are goddamned awful to work on.

The Krone strips are by far and away the most user-friendly, closely followed by BICCS connectors.

[waltergmw]

Thanks RP,

Yet another piece of the jigsaw. I must admit that seeing a cabinet full of your BICCS connectors would fill me with horror but I suppose the tone tracer is your main saviour.

Kind regards,
Walter

[razpag]

Thanks RP,

Yet another piece of the jigsaw. I must admit that seeing a cabinet full of your BICCS connectors would fill me with horror but I suppose the tone tracer is your main saviour.

Kind regards,
Walter

Like I say Walter, the BICCS connectors (which are extremely similar to the Krone ones) are very easy to work on. They're basically a strip of 10 connections whereby the UG feed (permanent wiring) connects to the top of the strip, and the jumper wire (temporary wiring) connects to the bottom. They count 1-10 left-to-right, and start at the top left hand side of the PCP working down. Therefore, for example, the 5 strip down will be E-sides 41-50, and so on.

You are quite correct about the 'tone' being our saviour though. In other types of PCP (like the 'Shelf' type mentioned above) where the wires are all hanging there like a rats-nest, the tone is positively king.

[Ezzer]

The vertical strips with screws I would think you're refering to PC100. Didn't like them, you had to be so carefull with the screws so the heads don't shear off. Makeing sure any jumperwire wasnt stripped back too far or pushed in too far otherwise it would contact the other connection on the other side. They used a heavyer jumperwire with a red/blue insulation.

Birds nest ? I presume the strips cross connection. Unless a cab is in a really bad way (like crochet) its a lot simpler than it looks and a nice easy system to work with. There's the Midland shelf where horizontal mustard coloured shelfs had wires woven through them. Absolute nighmare. everyone hates them. Who ever approved there use nneds shooting let alone the one who invented the horrible things.

The krone style strips, theres a number of different types. the latest Quante strips I liked. as long as they were terminated properly they were space saving and easy to work on. Also easy to test with or without interupting the service.

[waltergmw]

Thanks again RP and Ezzer,

I must admit I was surprised to see the screw terminal blocks and you're correct that quite a few screws seemed to be missing, presumably sheared off. Yes the wiring was with red & blue wires connecting to the screw blocks on the E side but to crimps on the D side of the cabinet.

The horizontal Krone type blocks I saw were light green with alternate groups of 5 slots painted black with 25 connections per block using the modern yellow / blue jumper wire and with some translucent plastic covers marked with wire numbers up to about 400 if I remember.

The Birds nest I was talking about are presumably the later all-crimp cabinets but still with GPO cast into the lid.

Anyway many thanks for your thoughts on these items.

Kind regards,
Walter