Here’s why high speed trains don’t always save that much time

A train zooms through China. Image: Getty.

It’s not often you hear anyone say people had it easier in the old days, but there is one group for whom  perhaps things have got a bit harder: transport pioneers.

In 1731, the first stagecoach from London to Birmingham took two and a half days. A decade later, simple improvements to the poor quality roads meant that journey time had been reduced by 12 hours.

Today, a train from London to Birmingham takes about 1hr20. In a decade, if the construction of High Speed 2 goes to plan, the most expensive and technologically advanced railway project in British history will have reduced that by… 30 minutes. You can’t help feeling a bit short-changed.

Italy last week rejected a plan to increase the speed of its high-speed Milan to Rome line from 300kmph (185 mph) to 350kmph (220 mph). This would have been a fairly big speed increase – but the trains would only reach Rome 10 minutes earlier, and the transport ministry decided it simply wasn’t worth the cost of the extra power needed and the damage to the tracks caused by faster trains.

This all comes down to a cruel twist of mathematics: a small improvement to a slow mode of transport saves far more time than a much bigger improvement to fast one. If you double your speed then, ignoring complications like acceleration and corners, you halve the journey length. But each doubling requires a bigger increase in speed, while each halving results in less time being shaved off.

Here’s a quick example. Let’s say you want to go 640 miles – that’s roughly the straight-line distance from Paris to Vienna, or from London to Edinburgh and back. How long will that take you?


On foot, your average walking speed without roads would probably be about 2-3 mph. Let’s assume 2 mph for now. Walking those 640 miles would take you 320 hours, or about 13 days (not taking into account time to sleep or rest).

With a fit horse, your walking speed could be a sustained 4 mph. That tiny 2mph increase doubled your speed, and halved your travel time, cutting the journey by an incredible 160 hours – almost a week.

With a few more horses, good roads and some regular coaching inns, a stagecoach could do 8 mph. That lets you cut another 80 hours off the journey.

Once railway technology arrives, we can double the speed again to 16 mph – roughly the limit on early lines like Stockton-Darlington or Manchester-Liverpool. At this speed, your journey takes 40 hours. The savings aren’t as great as they were before, but cutting nearly 2 days off the journey isn’t bad.

Double the speed to 32 mph, the journey now takes 20 hours. Double again to 64 mph, it takes 10. At 128 mph – just about the highest speed possible on the British train network outside High Speed 1 – those 640 miles can be covered in just 5 hours.

But now things start getting difficult.

To double the speed again means increasing by another 128 mph, to 256 mph. No regular train runs at this speed anywhere in the world, but there is one contender: the Shanghai maglev. This can reach speeds of 270 mph but at a huge cost. The line is incredibly expensive, and makes a loss every year. If you travelled those 640 miles at 256 mph, the journey would take around 2.5 hours. For all that effort, you’ve saved 150 minutes. It might still be worth it – but it’s a lot of investment for a small gain.

Finally, we can double it one more time to 512 mph. This is roughly the cruising speed of an Airbus A320. Flying all the way, those 640 miles are covered in 75 minutes. The time savings are getting very limited now.

Speed (in miles per hour) and time taken (in hours) to cover 640 miles. The introduction of the horse was probably more important than maglev. Sorry.

Take into account the time needed to accelerate up to top speed and stop at stations along the way, and all this explains why the benefits of exciting high-speed rail projects can be underwhelming. Most intercity transport in the western world is already quite fast: eking out a few more miles per hour makes little difference to journey times except on the longest journeys.

This doesn’t mean there’s never a case for high-speed rail – its convenience can attract air passengers, and the (relative) glamour of express trains can attract passengers who wouldn’t otherwise use railways. But saving time is not necessarily a major advantage.

There is an exception: very long journeys. Over thousands of miles those small time savings can still add up. France and Germany have highly successful intercity high speed lines, because their routes stretch right across the country and beyond into neighbouring countries. If the government ever extends High Speed 2 into Scotland, or manages to integrate cities like Manchester into the Eurostar network, rail passengers might get to enjoy some really good time savings.

For an extreme example, see China, where the 1,400 mile long Beijing-Guangzhou high-speed line more than halved journey times between the two cities. Given that the slower train took over 21 hours, shaving 13 hours off meant it was well worth it (even if many people prefer to fly). Just don’t expect anything quite so dramatic on our little island.

 
 
 
 

Why exactly do Britain’s rail services to the cities of the South West keep getting cut off?

You see the problem? The line through Dawlish. Image: Geof Sheppard/Wikimedia Commons.

If you’ve ever looked at some picturesque photos of British railways, perhaps in a specialist railway magazine – we’re not judging – then you’ve probably seen images of the South West Railway sea wall, with trains running tantalisingly close to the sea, either framed by blue skies and blue water or being battered by dramatic waves, depending on the region’s notoriously changeable weather.

Designed by Isambard Kingdom Brunel and open since the 1840s, the line was placed so close to the water to avoid the ruinous cost of tunnelling through the South Devon hills. From Dawlish Warren to Teignmouth the line is, with the odd interruption, exposed to the sea, affording the striking images so beloved of rail photographers. Its exposed placement also inevitably leads to speed limitations, closure and damage to the infrastructure. This would be a matter of purely local interest were it not for the fact that the sea wall is an unavoidable link in rail routes to the South West.

Main line trains run from London Waterloo and Paddington down to the Devon hub of Exeter St Davids, before continuing on to Plymouth, Truro and other destinations on the peninsula. Trains leaving St Davids reach the bottleneck very quickly, following the river Exe and its estuary, before dipping behind the sand dunes and emerging on to the sea wall.

What happens to the track at the small seaside towns of Dawlish Warren and Dawlish therefore has an impact on the whole region. South Devon and Cornwall are inaccessible by rail when the sea wall is temporarily closed or, as happened in January 2014, when storms breached the sea wall altogether, damaging it so severely it took weeks to repair.

While it’s easy to understand the economic logic of building the sea wall in the first place, unsurprisingly the economics of maintaining the damn thing have proven less compelling. The sea wall is considered to be, per mile, the most expensive stretch of Network Rail’s network to maintain. It’s also baffling to modern eyes why the main line rail services for a whole region would flow through such a vulnerable bottle neck.

The Devon rail network. Image: Travel Devon.

As with so many oddities of the British rail system, these perversities emerged from the rapid change that came in the mid 20th century through war, nationalisation and Dr Beeching.

The need for a Dawlish Avoiding Line was identified as early the 1930s. This would have diverted from the existing route at Exminster, and rejoined the line between Teignmouth and Newton Abbot, passing through Dawlish inland. Tweaks to the plan were made, but by 1939 construction was under way, only to be suspended when war broke out. Work on the project did not resume after the war, and when the Great Western Railway became part of the nationalised British Railways it was not a priority. The land for the Dawlish Avoiding Line was later sold by British Rail and has subsequently been built on, so that was that.

In the 1960s, Dr Beeching’s axe fell on rail routes across Devon, including the lines through North Devon that had provided an alternative rail route through the county. Those closed lines have also been extensively built on or converted to other uses, leaving a single main line through Devon, and rendering the sea wall unavoidable.

In recent years the condition of the sea wall has become increasingly precari


ous. That’s not only due to storm damage to the wall itself, but also due to the potential for erosion of cliffs overlooking the rail line, resulting in falling rocks. While this has been an ongoing issue since... well, since the sea wall was opened over 150 years ago, the storm of 4 February 2014 brought the matter to national attention. The visual of twisted rails hanging out into empty space illustrated the problem in a way pages of reports on the precarious nature of the line never could.

An army of Network Rail workers descended on Dawlish to get the line re-opened within two months. But repairing the damage hasn’t resolved the base problem, and climate change increases the likelihood of further major storm damage. In October 2018 the line was hastily closed for weekend repairs when storms resulted in a six foot hole appearing under the tracks near Teignmouth.

Supportive noises of varying intensity and occasional oblique funding commitments have come from government in the last five years, and investigations and consultations have been conducted by both Network Rail and the Peninsula Rail Task Force, a group set up by local councils in the wake of February 2014. Proposals currently on the table include Network Rail’s plan to extend a section of the sea wall further out to sea, away from the crumbling cliffs, and reopening the Okehampton line across Dartmoor to provide an alternative rail route between Exeter and Plymouth. 

But in spite of talk about investment and grand plans, no major work is underway or funded, with Network Rail continuing their work maintaining and repairing the existing line, and the situation seems unlikely to change soon.

Massive spending on rail infrastructure in the South West is a hard Westminster sell, especially in the Brexit-addled political climate of the last few years. And with the parliamentary map of the region dominated by blue there’s been little political will to challenge the vague commitments of government. One of the South West’s few Labour MPs, Exeter’s Ben Bradshaw, is particularly damning of the failure of Tory MPs to put pressure on the government, using a recent column for Devon Live to describe them as “feeble”.

But regardless of the political will to solve the problems of rail in the South West, barring a string of unusually gentle winters, the issue isn’t going away soon. If the South West is to be an accessible and successful part of the UK, then it needs stable rail infrastructure that can survive whatever the weather throws at it.