Tim meets the engineer behind this 1980s engineering triumph, which was essential to safe journeys when coal was discovered beneath the East Coast Main Line from London to Scotland in the 1970s.
Watch this video to find out more from engineer Gareth Dennis about what makes the Selby Diversion so historically important:
Coal fuels concerns for railway safety
The National Coal Board proposed a new drift mine under the East Coast Main Line between Selby and York in June 1974.
But British Rail had concerns over its effect on the railway, especially when it came to subsidence risk, according to Proceedings of the Institution of Civil Engineers.
The 1983 report said: “Due to the extensive presence of sand under the railway, coupled with the very high water table, mining subsidence would have a serious adverse effect on the track and structures, with a substantial element of unpredictability.
“It was concluded that the proposed mining operations would make the track from Selby to York totally unsuitable for Inter-City services and hazard the availability of the track for running trains at all on a day-to-day basis.”
George Cunningham, then Member of Parliament for Islington South and Finsbury, had said in the House of Commons in March 1978: “The present line between Selby and York lies over the new Selby coalfield. Unless the line is moved, it will not be possible fully and efficiently to extract the coal. If the line stays where it is, it would need to be supported by the coal underneath which would otherwise be extracted.”
Instead, it was recommended that the East Coast Main Line be diverted away from the coalfield before any mining took place in the area.
Here’s an original plan from the Network Rail archive of the proposed route:
High speed history and modern architecture
The Selby Diversion holds a special place in our railway history, as Britain’s first ever line purposefully designed to enable trains to run at up to 270 kilometres per hour.
In fact, the Selby Diversion is where British Rail installed our very first high speed switches – the track equipment that allows trains to switch from one line to another.
This created an approximately 14-mile long railway line capable of carrying the East Coast Main Line’s new high speed trains despite the huge challenges British Rail faced in the area.
Gareth said: “The Selby Diversion was the UK’s first high speed line built to modern standards … To get nerdy for a moment, the International Union of Railways’ definition for new high speed railways are ones that have been designed to allow speeds of 250km/h or more.
“Whilst the track was laid for 125mph (200km/h), the route alignment and infrastructure was built to allow for up to 270km/h, making it Britain’s first high speed line by the modern definition that remains in place today.”
He added in a Twitter thread: “[A] planning enquiry established that the extraction of coal underneath the [East Coast Main Line] would result in the need for repeated speed restrictions due to subsidence, completely undoing all of the time benefits gained by the new 125s [Inter-City trains] and associated infrastructure upgrades.”
But it’s not just fast trains that make this line so historically important, according to Gareth. He said: “Actually, the thing that makes, that merits this line justifying a place on The Architecture the Railways Built is actually the fact that engineers, for the first time in decades, had to work out, what should a railway look like? What should railway structures look like?
“There are 20 bridges between here and the other end of the line down at Temple Hirst. Each of those bridges, the engineers had to work out, not only they had to work out what they should look like, but they had to design them in record time – two and a half years going from right, we need a railway, to here are the final designs ready to get it built. And the result is a fantastic high speed railway.”