Glasgow street lights - externally wired power supply

[WHBM]

Ever since I lived in Glasgow long ago, a thing about their older streetlights surprised me.

Why did/do they use externally wired power supplies up at post-top height. Typically three wires carried on insulators like old telegraph wires about 18' above the carriageway. I don't recall anywhere else doing this (open to correction) so why was Glasgow different.

https://maps.google.com/maps?q=glasgow& ... 6,,0,-8.13

This is a typical example where the wires are zig-zagged across the road between posts.

[michael769]

Those poles are actually the pylons that carried the power supply for trams. The streetlights were added on as an alternative to putting separate lamps in (which is actually undesirable where you have overhead power lines for hopefully obvious reasons).

The reason the cables are overhead is simply that the poles were never designed to carry power from the ground to street lights, and when the lights went in it was simply more economical to run the power on overhead lines. Given that at the time of installation there would already be all the tram catenary a few extra cables would not add much additional visual impact.

They were once quote commonplace along most tram routes - (they were everywhere on main roads in my youth), but have been gradually disappearing as the columns have been replaced with modern installations.

As to their extensive use in Glasgow that is merely a reflection of the scale of Glasgow's tram network (which was once the largest outside of London). I'm surprised any survive given the rate at which the old cast iron street lamp columns have been replaced in the last decade, but that whole area looks quite run down and I wonder if it is slated for redevelopment?

You do sometimes see overhead cables on modern columns but that is usually a temporary patch to bypass faulty underground wiring.

[Chris5156]

Leeds used to have plenty of these, and for the same reason - lights mounted on heavy cast-iron posts that were once part of the tram infrastructure. I remember the A660 was like that from Woodhouse Moor all the way up through Headingley.

For some reason the A656 Barnsdale Road just north of Castleford is still like this now, which is puzzling because it was never (to my knowledge) a tram route, and Leeds now has a lighting PFI. It looks rather a lot like the PFI contractor has put their shiny new lamps on the columns that were already there, rather than run a new underground power supply. The metal columns were erected by Leeds City Council 10-15 years ago to replace older concrete columns with wiring strung between them. What is it about this section of road that means the wiring has to be above ground?

[michael769]

What is it about this section of road that means the wiring has to be above ground?

I wonder if might be some issue with the ground conditions that prevents underground cables in that area? Given that is the line of a former Roman Road could it be to protect buried archaeology?

[traffic-light-man]

Many of the old Liverpool installations used overhead lines even when not on tram routes, too.

These columns have been replaced in the last few years, and the new cables were ducted as part of the work. On this side-road, the practise has been continued onto new columns past this new development. I believe these have all been replaced now, too.

[WHBM]

Well I agree they certainly look like old tram standards, but as I recall they are generally to be found in minor streets (as in the example), not on former tram routes.

It could be that the same council department was responsible for both trams and lighting, and although replaced on the main roads there is still this old stock in side streets. I know that in Glasgow, uniquely, the tramway was also responsible for the winter maintenance along tram routes, which was later passed on to the bus department who kept old buses fitted with snowploughs and salt trailers just for this, kept at the bus garages.

[Truvelo]

The A34 Green Lane in Walsall used to have some lamps with a piece of conduit running parallel to the column. About half way up the column was a control box. They lasted until about 10 years ago and I did post some pictures on Sabre but I can't find them.

[Nwallace]

There's still a few street lights on the power poles around here, definitely no trams though

https://www.google.com/maps/@56.4169964 ... !2e0?hl=en

[RichardA626]

I've seen some pictures of traction poles still being used for street lighting in Wolverhampton well into the 1980s.

Leith might still have some around.

[Gareth]

Well I agree they certainly look like old tram standards, but as I recall they are generally to be found in minor streets (as in the example), not on former tram routes.

I think it's just old standards. It's still fairly common in other countries. I very much doubt this road in Melbourne ever had trams either - https://www.google.co.uk/maps/@-37.8592 ... wZ-ivw!2e0

Perhaps in the older days, there wasn't always as easy access to the mains supply via the ground and so they connected the whole lot of them at a single point. Just a stab in the dark there.

[Chris5156]

Here's a rare sighting of some of the Leeds lights I was talking about earlier on Streetview - the poles and arms are identical to those that were all along the A660 (definitely a former tram route) and in a car park at Roundhay Park that was once the tram terminus, but I don't think this street ever carried trams, so perhaps in the days when the Corporation ran both trams and lighting in-house, it fitted the same poles and wiring for lights everywhere.

[Bryn666]

There were a few in Calderdale as well until recently.

Overhead power supply does avoid the need for costly ducting works but it's very vulnerable to the elements or vandals.

[Gareth]

The old Wardles that used to be on Barnfield Drive tended to fail when there was strong wind or rain. I always put that down to their age as much as anything else. That's the problem with catenary, as a fault at one point can potentially put the whole lot out of commission.

[wrinkly]

It's fairly common where road layouts are being altered to see lamp-posts linked by temporary overhead cables, but I think those are insulated.

[flyingscot]

Well I agree they certainly look like old tram standards, but as I recall they are generally to be found in minor streets (as in the example), not on former tram routes.

It could be that the same council department was responsible for both trams and lighting, and although replaced on the main roads there is still this old stock in side streets. I know that in Glasgow, uniquely, the tramway was also responsible for the winter maintenance along tram routes, which was later passed on to the bus department who kept old buses fitted with snowploughs and salt trailers just for this, kept at the bus garages.

They may be gradually disappearing but some major routes still retain this system!

[DunsBus]

I give you this - Melville Drive in Edinburgh. 65 out of 69 traction poles remain here, the only losses being for junction improvements. They are fed by underground cables and the lanterns seen here, WRTL Arcs, date from late-2003. Prior to then, gear-in-head Philips MA60s were employed.

https://www.google.co.uk/maps/@55.94007 ... QVEVGA!2e0

[AndyB]

Most villages in NI use wooden poles with 3 or 5 cables, one being thin for the lighting circuit and the thicker cables being for the domestic supply.

You can see the Belfast setup at the far left of this photograph - three cables on the back of the trolley pole.

[DavidB]

I remember seeing such lights with cables in Teignmouth on a family holiday back in 1967 and on checking Streetview it would seem they're still there, e.g:

https://goo.gl/maps/IHzim

[WHBM]

I remember seeing such lights with cables in Teignmouth on a family holiday back in 1967 and on checking Streetview it would seem they're still there, e.g:

https://goo.gl/maps/IHzim

I think there are telephone wires. If you turn the opposite way you see a telephone distribution pole with the wires running to each house. If I recall correctly open power supply and open telephone wires are not acceptable together.

[Truvelo]

Those are low voltage (240v?) power cables where each wire is separated vertically. Telephone wires are all strung together. Poles can be shared between power and phone but the power must always be on top.