The maximum speed currently possible in the UK is 186mph, achieved by Eurostar trains on the HS1 line between London and the Channel Tunnel. The HS1 line is used by Eurostar services and "Javelin" commuter services from Kent, although the latter have a max speed of 140mph.
Across the rest of the UK, trains have a maximum operational speed of 125mph, although many are capable of speeds of up to 140mph.
Work is ongoing on HS2, a high-speed railway joining London, Birmingham, Manchester and Leeds. This will facilitate speeds of 225mph, with a journey time between Birmingham and London of 49 minutes.
And if you're curious about high-speed rail on the continent, have a read of our information on high-speed trains in Europe.
There are five lines in the UK which allow for high-speed rail travel. On four out of five lines, the maximum speed is 125mph, while the purpose-built HS1 line allows for speeds of 186mph.
Length: 68 miles
Completed in 2007, the High Speed 1 (HS1) line connects London St Pancras to the Channel Tunnel. HS1 is used by Eurostar services and Southeastern’s ‘Javelin’ trains, which ferry London-bound commuters from Kent. Eurostar trains hit speeds of up to 186mph on HS1; Javelin trains reach up to 140mph.
High-speed rail certainly isn’t cheap – HS1 came in at £51 million per mile – but the line has revolutionised rail travel from London to the continent. Indeed, it takes just 2h 16m to reach Paris on the fastest services.
HS1 calls at stations in East London and Kent; these include St Pancras, Stratford International, Ebbsfleet International and Ashford International.
Length: 393 miles
Completed in the mid-1840s, it’s a testament to Victorian-era engineering that trains can hurtle up the East Coast Main Line (ECML) line at 125mph to this day. The ECML links Edinburgh and London via several major destinations on the East Coast, including Doncaster, York and Newcastle. The line was served throughout the mid-twentieth century by the iconic “Mallard” steam locomotive, which holds the record as the fastest steam train ever built (126mph). Today, the ECML it operated by London North Eastern Railway.
Length: 399 miles
The West Cost Main Line (WCML) is one of the UK’s most pivotal railway lines, connecting London, Birmingham, Manchester, Liverpool and Glasgow. As one of the main arteries in the railway network, several train companies operate services on the WCML, but the principal operator is Avanti West Coast. Avanti use a mixture of Class 390 Pendolino and Class 221 Super Voyager trains on the line, which can reach the WCML maximum operating speed of 125mph.
Length: 118 miles
Running between London Paddington station and Bristol Temple Meads, the Great Western Main Line links the capital to the West Country and beyond into South Wales. There are several notable pieces of Grade 1 listed architecture along the line, including the Wharncliffe Viaduct in Ealing and the River Avon Bridge. Great Western Railway is the main operator of services on the GWML.
Length: 397 miles
The Midland Main Line (MML) runs from London St Pancras to Leicester, Derby, Nottingham and Sheffield. The principal operator of services on the line is East Midlands Railway, who operate Class 222 Meridian trains on the route. The line is electrified between London and Bedford; this section comprises the northern half of the Thameslink network.
There are several train types in the UK built to travel at speed. The fastest are Eurostar’s e320 and e300 trains, followed by Southeastern’s Javelin trains.
Class 374s are currently the fastest trains currently operating on UK shores. Known to most as Eurostar e320 trains, Class 374s have a top speed of 199mph, but are limited to 186mph while in operation. Along with their elder Class 373 cousins (Eurostar e300), operate exclusively on the HS1 line.
Class 374 trains are made up of 16 cars stretching 1,280ft, so can also lay claim to being the longest trains in operation in the UK. They can carry up to 900 passengers; indeed, the Eurostar has become the primary mode of transport between London and Paris.
Introduced in 2009, Southeastern’s Javelin trains had an instant impact, cutting journey times from Ashford to London by up to 45 minutes. They have a top speed of 140mph and are the only other passenger locomotives to operate on HS1. The Javelin service also loops through suburban areas in Kent, including Margate, Folkstone and Dover – check out our Javelin route map to see all its major stops.
The name ‘Javelin’ derives from the inclusion of the trains in the bid for the 2012 Summer Olympics as a shuttle service to the Olympic Park in Stratford. Most of the fleet has since been named after ‘fast’ Britons, including Dame Kelly Holmes, Sir Chris Hoy and Rebecca Adlington.
You’ll see Pendolino trains flying up and down the West Coast Main Line (WCML) – the entire fleet was originally built for Virgin Trains (now operated by Avanti West Coast) for use on the WCML. With a design speed of 140mph, but limited to 125mph while in operation, Pendolino trains make use of tilting technology to navigate the various bends on the WCML. Carriages can tilt up to 8 degrees from horizontal, allowing the train to better manage forces between itself and the track as it rounds bends in the track. Tilting technology also gives a smoother ride to the passengers, as anyone who has travelled on a Pendolino will certainly appreciate!
Class 800 trains are used by Great Western Railway (GWR) and London North Eastern Railway (LNER), branded as Intercity Express Trains and Azuma respectively. The trains are bi-mode, meaning they are powered by overhead electricity lines and an onboard diesel engine. This allows the trains to operate on partly unelectrified lines.
Capable of 140mph but limited to 125mph while in operation, Class 800 trains will eventually replace the InterCity 125 and InterCity 225 trains currently operating on the East Coast Main Line (ECML) and Great Western Main Line.
High Speed 2 will be the second major high-speed railway in the UK, with construction on the line beginning in 2020.
Once completed, HS2 will link London, Birmingham, Manchester and Leeds via a network of high-speed track, allowing for speeds of 225mph. The construction of the line will happen in two phases; Phase 1 (underway), will link London Euston to a new terminus in Birmingham, Birmingham Curzon Street. Phase 2 will connect Birmingham to Manchester and Leeds via two branch lines, forking off the main line after Birmingham to create a “Y”-shaped network. Phase 1 is due for completion between 2029 and 2033, while Phase 2 is targeted for completion in 2035.
HS2 has received both support and criticism. The project’s critics have questioned the environmental and financial viability of HS2, while the supporters have emphasised the economic benefits of high-speed inter-city links and environmental benefits of shifting travellers off the roads.
Image: Commemorative plaque for Birmingham Curzon Street station. Curzon Street closed to passengers in 1893 but will be completely rebuilt as an HS2 terminus. Credit: Erebus555 at English Wikipedia, CC BY-SA 3.0.