Why don't rails get hot in Europe?
The truth is, they do.
But in countries typically hotter than ours,
rails are stressed to withstand higher temperatures.
The climate is changing and this unprecedented weather is
hotter than our infrastructure was designed for.
It's a challenge we and hotter countries are all dealing with.
Rails are pre-stressed to help them resist the effects of high
temperatures. In Britain,
our rails have a stress-free temperature of 27 degrees,
halfway between the coldest and hottest we expect our rails to
get in the UK.
We also tension our overhead line equipment to cope with
heat. When the air temperature reaches 30 degrees Celsius, the
temperature on the rail can be up to 20 degrees higher.
One of our hottest ever recorded rail temperatures was
62 degrees.
If we stressed our rails for exceptionally hot weather,
they wouldn't be safe for the winter and we'd have broken
rails because it's too cold.
That's why other countries choose different temperature
ranges depending on their climate.
More than three-quarters of our track is on modern concrete
sleepers, which can help rails withstand very hot weather. But
sometimes, steel rails get so hot they expand and bend or break.
When very hot weather is forecast,
we introduce emergency speed restrictions.
Slower trains mean less pressure on the rail,
which means the rail is less likely to buckle -
keeping you safe by avoiding derailments.
Speed restrictions also help avoid damage from overhead line
equipment that's expanded and sagged.
This doesn't happen in much hotter countries, does it?
Well, although it doesn't often make big news over here,
railways in countries with very hot summers have the same
issues we do.
Their rails may be stressed for higher temperatures,
but that's because they typically have long, very hot
summers, while our summers tend to be much less predictable. Even then,
if they have hotter days than their infrastructure is
designed for, they have to respond in the same way we do.
That's why you may have heard about rails in Spain,
Italy and Switzerland being painted white to keep the steel
cool - and slower trains to prevent buckling.
At the end of the day,
we and other European countries are all dealing with the impact
of climate change and our priority is do everything we
can to keep you safe.