[psi75]

When these designs were made, 40 °C in the UK was a once-in-5,000-years event. Now, it seems to be about 1 in 30 years (we don't have enough data to be sure).

Also, the problem usually isn't the 40-degree air temperature itself, because that's usually in the operating range--it's the rails and machinery and confined spaces hitting 60+ that fucks everything up.

New York considered shutting down its subways in July 2011 when it was "only" 40.5. Why? Because the underground stations were hitting 50, which (esp. in New York humidity) is dangerous for the most heat-sensitive people.

[AHappyCamper]

I'm sorry, but that's a whackadoodle approach to engineering. 40C is well within the range of expected temperatures, and the men who designed it failed epically. There have been heatwaves in the UK since 1911 where the temp approaches 40C.

https://www.theguardian.com/uk-news/from-the-archive-blog/20...

[jfax]

All of those temperatures are multiple degrees below 40.

[retrac98]

I doubt it's a once every few decades event anymore. It got to 38 in several places in the country a few years ago. It seems to get up to the mid 30s every year now.