Location Cabinets in hot weather

[alxndr]

I’ve left REB/relay room doors open to try and achieve some cooling, but never a loc.

Perhaps they were trying to dry the boxes out following the heavy storms that affected parts of London overnight?

Locs are generally water tight, I can’t think of any which have actually let water in providing the doors have been shut. I have come across a wet dis box that we went back to the next sunny day and left it propped open and then sent the night shift back to secure it.

We also see locs made out of a shiny unpainted material, stainless steel I assume, with louvred doors as mentioned above. Some also have a second top above the main one, presumably so that can take the heat from the sun without conducting it through to the inside of the cabinet.

The additional top has been discontinued as it’s now thought that the angle of the sun is too low at this latitude to be effective. We snapped up the last two in the country when looking for solutions to location cases which were severely rusting due to their position under bridges that allow the salt water from gritting to drip onto them in the winter. (If any S&T bods have any going spare we’ll take them!)

I've seen relay rooms with air conditioner units on the side.

Most tend to have them now in my experience. It makes a huge difference if they’re working, but unfortunately they’re not always. Maintenance of them needs to be more proactive rather than reactive IMO, as you only notice it’s gone wrong when either the temperature alarms (if monitoring is fitted), or if something within starts failing in the heat.

The original doors (which lift off) also used galvanised sheet steel, but were very heavy, so a lighter metal was used instead (I don't know what).

We had only one of the galvanised doors left before resignalling. Twelve or so years later I can still recall exactly where and which of the bank it was on because it wouldn’t half catch you out if you were expecting one of the lighter ones!

And yes, electronic signalling equipment does fail if the air temperature in them gets too high. There have been failures of axle counter evaluator racks as a result... Network Rail learned the hard way that they needed to install an extra air conditioning unit in them...

I recall that a lot of the evaluators rapidly had their doors taken away too.

I’ve also wondered the sense of tending to put point and signal modules next to each other as they tend to generate a bit of heat themselves, and don’t seem too fond of overheating. It would seem prudent to me to intersperse them with other equipment so that they stand something of a chance of being able to dissipate the heat.

 

[Annetts key]

I recall that a lot of the evaluators rapidly had their doors taken away too.

Every single 19" cabinet containing evaluators (all in REBs) in my area has had the cabinet doors (both front and back) removed because of the heat problems during a previous sumner.

What bemused me was that there was not much provision for vertical airflow in these 19" cabinets. Meanwhile, previously, many years before, the telecoms side of BR S&T had multiple equipment fans fitted as standard in many of their 19" cabinets (which themselves were mostly located in air conditioned rooms).

I’ve also wondered the sense of tending to put point and signal modules next to each other as they tend to generate a bit of heat themselves, and don’t seem too fond of overheating. It would seem prudent to me to intersperse them with other equipment so that they stand something of a chance of being able to dissipate the heat.

Things like this remind me of the difference between Western Region 1960s and 1970s relay room racks and later designs of racks. The Western Region racks had mounting holes drilled such that BR930 relays were spaced as pairs with a slight gap between adjacent relays of each pair. Thus, allowing the technician to be able to clearly see the contacts inside (through the clear case), but also allowing better airflow.

With SSI signal, point and datalink modules or other electronic equipment (TI21/EBI Track 200 transmitters or receivers for example) some space between them would improve airflow IMHO.

Also, again telecoms are ahead of signalling. Some of their outside equipment enclosures have ventilation/cooling fans included as standard, along with some kind of variable speed thermostat control.

 

[neill]

On a topical note here are a couple of brand new cabinets at Cambridge South station today. Both sounded like they had powered ventilation hard at work in the sun. I don't know if they are Signalling or station services but they look suitably industrial.

 

[Annetts key]

On a topical note here are a couple of brand new cabinets at Cambridge South station today. Both sounded like they had powered ventilation hard at work in the sun. I don't know if they are Signalling or station services but they look suitably industrial.

Given that they are new and on the platform, most likely something to do with station facilities.

 

[Elecman]

On a topical note here are a couple of brand new cabinets at Cambridge South station today. Both sounded like they had powered ventilation hard at work in the sun. I don't know if they are Signalling or station services but they look suitably industrial.

I suspect they are something to do with station facility systems rather than any signalling/ operational telecoms equipment

 

[alxndr]

Agreed, they don't look signalling related. Not a style I've seen and signalling locs are typically (although not always in some older styles from the 90s which had integral locks) locked with a yale padlock.