''fibre optics ''

Did BT GPO use fibre under roadside manhole covers for anything before broadband ?
If so what year did it start and what was it used for ?

Andy

Yes, and many many years, knew people splicing fibre in 1996
Leased lines, and the old ATM network that linked all phone exchanges.

My first fibre service from BT was installed in 1989, previously 'high' speed services were delivered to the site over transverse screened copper cable.

The ISDN lines in this building came in on fibre in 1996 as part of a new build

BT used fibre many, many years ago for voice lines - the dreaded TPON - Telephony over Passive Optical Network.

This leap into new technology (60's and 70's I think?) caused problems with subscribers in TPON areas not being able to get ADSL until a "copper overlay" was installed - installing copper pairs instead of the TPON fibre.

Milton Keynes was the classic sufferer from this.

The logic of replacing optical with copper (for ADSL) and then with FTTC amazes me but GPO / BT always had a habit of either doing wonderful thing with old technology (the original STD dialing with Strowger electro mechanical kit) or getting stuck down a technical dead end (at the time) with TPON.

FTTC in 10 years time will probably seem a stupid move as well!

Fibre has been used in the trunk (national ) network since at least the 70s, and has been used in the local access network for leased lines since the 80s.
BT installed an extensive network covering the CIty of London during the 80s for banks/traders. TPON came in the early 90s to provide PSTN/ISDN services to new build sites but the electronics at the end was ultimately a dead end.

I remember back in about '80 or '81 being involved in a project which need fibre optics for control and communications. We brought in some of the technology from BT. And it was not cheap.

I bought some fibre from Tandy in 1986 for a little test project.

In reply to a post by greenglide:

BT used fibre many, many years ago for voice lines - the dreaded TPON - Telephony over Passive Optical Network.

This leap into new technology (60's and 70's I think?) caused problems with subscribers in TPON areas not being able to get ADSL until a "copper overlay" was installed - installing copper pairs instead of the TPON fibre.

Milton Keynes was the classic sufferer from this.

The logic of replacing optical with copper (for ADSL) and then with FTTC amazes me but GPO / BT always had a habit of either doing wonderful thing with old technology (the original STD dialing with Strowger electro mechanical kit) or getting stuck down a technical dead end (at the time) with TPON.

FTTC in 10 years time will probably seem a stupid move as well!

FTTC is unlikely to seem like a stupid move - BT have been careful to build their FTTC deployment in such a way that it's an easy step to FTTP (replace a VDSL2 DSLAM with a splitter, replace the copper tails with fibre tails to go from FTTC to GPON or XGPON). As long as we continue down the route towards fibre everywhere, it's a good first step.

The VDSL2 DSLAM may well be capable of voice too, meaning that in future the cabinet to exchange copper could vanish