Latest Excuse - Overhead power lines saggin in the heat!

[ThinLizzy]

Cos thats when they are under most pressure and do the most work.

Yeah, but their dropping like flies when working in the normal environment they were designed for?

Bet you'll find that 28 + is not the designed temperature range.

28 is about the maximum

[buffy500]

Yeah, but their dropping like flies when working in the normal environment they were designed for?

Bet you'll find that 28 + is not the designed temperature range.

28 is about the maximum

So when its been in the mid 30's for a week, its kind of not 100% suprising.

[ThinLizzy]

Would help if the guard didnt open all the windows {sealing the train will cool it}

[Chris23]

Odd weeks of 30 degrees are not that uncommon in the UK.

Why I am prepared to guess that Swiss Railways have not suffered in their much hotter heatwave?

[kevarc]

I work for a utility here in the states and this is a common problem. Not only do you have the heat of the day, but the transmission of electricity generates heat. When 99% of the transmission systems were built the had a large extra capacity for transmission. But remember, most of these systems are old and have not been upgraded. With today's demands for electricity the older transmission systems cannot cope. The continued stress on systems without the investment in new, higher capacity cables means that this will get worse over time and not better. But with transmission systems, the NIMBY syndrome kicks in and makes it difficult and expnesive to add to the system.

[mattvince]

Sagging OHL - theoretically should happen if the tension system has got to its limit. Perhaps adding a bit more weight to the OHL tensioners should straighten things out. Ideally some form of auto-tensioner should be devised - provided you can electrically isolate it, not a problem. However, never is a good time to fiddle around with live 25kV.

[GavinW]

Why do aircon units always fail in the hot weather?

Thats because the air cons heat in the Winter (and most of the rest of the time in our climate).

The heating circuit has not so much in it to go wrong as the cooling circuit (which would still be as unreliable in the winter, but you don't realise this as it doesn't work then).

So therefore the air con would fail in the winter as well if you wanted it to cool, but you don't, so you only notice it in the Summer !!

[bjdick]

As long as the tensioner weights don't touch the ground,the tension should be constant.IE the wire lengthens due to heat,but the same tension is applied.

The air conditioning units,if designed properly,don't know if it's summer or winter,they just pump heat in the direction required to maintain a proper temperature\humidity level.IE the condenser heats you in winter,then it becomes the evaporator in summer to keep you cool.

However,I'm of the opinion that the actual units don't run in this mode,with the compressor being idle for most of the year,as it'll only run on hot days,and any heat required being provided by electric elements in winter.IE another British bodge job.

[Horgy]

Why do aircon units always fail in the hot weather?

Thats because the air cons heat in the Winter (and most of the rest of the time in our climate).

The heating circuit has not so much in it to go wrong as the cooling circuit (which would still be as unreliable in the winter, but you don't realise this as it doesn't work then).

So therefore the air con would fail in the winter as well if you wanted it to cool, but you don't, so you only notice it in the Summer !!

Also, it's down to the design of the unit. The units where i'm currently work draw in air from the surroundings and cool it, then pump it into the restaurant. Thing is, it's also extracting air, which is just vented next to the air con unit. Coupled with the very high temperatures, the unit actually starts to heat up itself and cant cool the air properly...

Horgy

[ThinLizzy]

Why do aircon units always fail in the hot weather?

Thats because the air cons heat in the Winter (and most of the rest of the time in our climate).

The heating circuit has not so much in it to go wrong as the cooling circuit (which would still be as unreliable in the winter, but you don't realise this as it doesn't work then).

So therefore the air con would fail in the winter as well if you wanted it to cool, but you don't, so you only notice it in the Summer !!

Also, it's down to the design of the unit. The units where i'm currently work draw in air from the surroundings and cool it, then pump it into the restaurant. Thing is, it's also extracting air, which is just vented next to the air con unit. Coupled with the very high temperatures, the unit actually starts to heat up itself and cant cool the air properly...

Horgy

I did wonder that {units drawing in hot air}. I know now that drivers are advised to avoid stopping in a tunnel in the event of a fire, due to the air con unit drawing in air from surrunding area {so basically, if you're train was on fire, in a tunnel, and the air con continued to run, it would fill the train full of smoke}.

[pgmetcalf]

Yeah, well, the weather is an excellent chance to bury bad news lol .... where have I heard that before? The thing is, it's just a ready made excuse we people spread to cover all failings.

Paul