Traffic Signal Spare Parts

[the dark lord]

Team I know there are a few signal experts here.

I've noticed a few signal failures recently which set me thinking.

When an engineer gets called out to a report of "lights out" where the problem isn't a power failure how likely is it a repair can immediately be made... What are the likely faults?

I assume there are hundreds of different systems in use and given the rate of obsolescence in the electronics world different parts / cards / chips etc in systems the number of spares must be mind boggling.

Is spares availability an issue?

[traffic-light-man]

In my experience, engineers responding to all-outs are not likely to be carrying all of the possible spares to repair failed parts there and then - like you say, there's numerous makes and models of all types of equipment out there (some areas are much worse for this than others), and obsolescence is a big problem for certain authorities. That might be less of a problem for areas with very little variety, but I still don't think they'll carry all the possible parts all of the time.

Fix times are often dependent on the availability and location of spares, assuming it's even repairable in the first place. The maintenance contractor often has a big part to play in this as well - their spares pool and technical support capability will naturally lean towards their own products, and so repairing third party equipment can sometimes be more problematic for them. It goes without saying really, spares availability is heavily affected by what it is, too - spares for something like a Peek halogen signal head will be available, but spares for an incredibly rare Philips controller from 40 years ago almost impossible to find.

Depending on what's failed causing the all-out, sometimes a temporary arrangement can be enacted to get the site back up and running until a proper repair made, other times the site will have to stay off until a proper repair can be made and this might even entail an entirely new piece of equipment being installed.

[Conekicker]

In my experience, engineers responding to all-outs are not likely to be carrying all of the possible spares to repair failed parts there and then - like you say, there's numerous makes and models of all types of equipment out there (some areas are much worse for this than others), and obsolescence is a big problem for certain authorities. That might be less of a problem for areas with very little variety, but I still don't think they'll carry all the possible parts all of the time.

Fix times are often dependent on the availability and location of spares, assuming it's even repairable in the first place. The maintenance contractor often has a big part to play in this as well - their spares pool and technical support capability will naturally lean towards their own products, and so repairing third party equipment can sometimes be more problematic for them. It goes without saying really, spares availability is heavily affected by what it is, too - spares for something like a Peek halogen signal head will be available, but spares for an incredibly rare Philips controller from 40 years ago almost impossible to find.

Depending on what's failed causing the all-out, sometimes a temporary arrangement can be enacted to get the site back up and running until a proper repair made, other times the site will have to stay off until a proper repair can be made and this might even entail an entirely new piece of equipment being installed.

In which case a temporary set should be installed (if practical) until the permanent set can either fixed or replaced. Something like the SRL Urban 64, for example.

[traffic-light-man]

In which case a temporary set should be installed (if practical) until the permanent set can either fixed or replaced. Something like the SRL Urban 64, for example.

Indeed. Portables are often the immediate answer, but it's still (mostly) better than nothing.

[Octaviadriver]

We have a page on the Powys County Council website where you can report problems with street signs and I've used it a few times when I've noticed an aspect in traffic lights not working and usually they're repaired quickly. I reported that the offside green aspect wasn't working on these pedestrian lights in Brecon on 8 July 2022:
https://goo.gl/maps/HZKv3wdE72f8xjvQ8

They replied on 12 July 2022:
"Dear Mr O
Thank you for your report. However, this fault was reported to our traffic signals maintenance contractor (Siemens/Yunex) some weeks ago. I have been advised that an internal part is required (it’s not that the bulb has failed) and as soon as that part is acquired, it will be installed within the secondary signal head. Thankfully, the primary head is functioning correctly and clearly displaying a green light.
Sincerely"

The Streetview is from August 2022 and it was some months after that when the light was repaired, so I assume they had difficulty in obtaining the parts they needed.

[wallmeerkat]

Any traffic signal repairs I see done in NI tend to be Siemens branded vehicles.

[Conekicker]

In which case a temporary set should be installed (if practical) until the permanent set can either fixed or replaced. Something like the SRL Urban 64, for example.

Indeed. Portables are often the immediate answer, but it's still (mostly) better than nothing.

I always find it amusing when a permanent set fail and the junction works better whilst they are off.

[AndyB]

Any traffic signal repairs I see done in NI tend to be Siemens branded vehicles.

Yes, Siemens have the maintenance contract.

Peek has done a number of new installs, but that will have been a matter of subcontracts. It’s now some years since I’ve seen a new Peek install.