The new trains on the Marston Vale line have their origins, unusually, on the London Underground. By the time I first moved to London in 2005, the Tube had adopted a form still recognisable today: Oyster cards were already in widespread use, and its trains were uniformly presented in its corporate livery of white with a lower blue bar and red doors.
Well, not quite uniformly. The trains on the District line were an anomaly: they were unpainted bar half-red cab-fronts, otherwise being dirty aluminium on the outside. Inside, they had wooden slatted floors, beige formica and a somewhat run-down 70s ambience. They were the most obviously old-fashioned looking trains on the network, a throwback to how the Underground had been from the post-war period until the 1990s. But they were different, and therefore more interesting.
Appearances can be deceptive, though: these were relatively new trains – certainly newer than those in service at the time on the Victoria, Piccadilly, Circle, Metropolitan, Bakerloo and Hammersmith and City lines. They were D-stock trains, or D78 stock in reference to the year they were specified (though they entered service only from 1980). They were the last of the fleets of Underground trains to receive refurbishment and repainting into modern Underground colours: the process started in mid-2005, just after I arrived in London, and was completed in 2008.
So, what exactly are D-stock trains? As they ran on the sub-surface District line, rather than the deep-level tube, they aren’t actually ‘tube’-shaped. They have the rectangular cross-section of ‘normal’ trains. Built at a time when passenger numbers were falling on the Underground, they have single-leaf doors – by the time of their replacement in 2015-17, this had become a real problem, as it created longer dwell-times in stations while passengers got on and off. Mechanically, they had an upgrade in the mid-1990s, with new bogies being fitted.
As you’ll have spotted, in 2015-17 the D-stock wasn’t particularly old – and their bogies, a critical component, particularly not. Rolling stock should typically last between 25 and 40 years, and London Underground has stretched some trains beyond 50 years of working life (and seems likely to take the current Bakerloo line trains close to, or even beyond, 70). But they were just old enough for Transport for London to be able to justify their withdrawal on the grounds that it enabled them to create a homogeneous fleet of trains across all the ‘sub-surface’ lines (District, Circle, Metropolitan, Hammersmith and City) – the ubiquitous air-conditioned S-stock trains.
This is where we come to the D-stock’s second lease of life. In short, they’ve followed me up to Bedford.
The bulk of the D-stock fleet was purchased by Vivarail, a start-up company with three aims: to produce low cost, low maintenance rolling stock; to develop systems and designs that would make use of emerging technologies; and to bring innovative and smart ideas to benefit passengers, operators, the environment and the wider rail industry.
This has translated into a strategy to build innovative new trains, in two phases: the first involves developing diesel, battery and hydrogen power systems that can be attached to the D-stock, turning them into ‘go-anywhere’ trains for the national network; and the second will deploy those same technologies on entirely new-build trains. The first phase of the plan is coming to fruition, with the introduction of three ‘D-trains’ – now designated class 230 – on the Marston Vale line (with a further five on order for use in Wales).
The Bedford to Bletchley services will be getting three D-trains. Unlike the DMUs they replace, the 230s will only be working on the Marston Vale Line, and for that reason will be running under the London Northwestern brand (whereas the old trains have had West Midlands Railway branding stuck over their ex-London Midland liveries, as they also see use elsewhere on the franchise). A bespoke version of the London Northwestern livery, specific to the Marston Vale Line, has been applied to them.
The interior of the unit has been fitted out to a specification designed for the Marston Vale services, though it is obvious from photos online that certain elements of the mid-2000s TfL refit have survived, including some of the grab-bars and longitudinal seating – plus, of course, the notorious single-leaf doors (though only one at each end – the larger number of doors needed on London Underground trains aren’t necessary on a rural branch line, so the middle two doors in each coach are now blanked off) .
As well as the eye-catching new battery and hydrogen technologies, the innovations include diesel generators that can be serviced or even swapped out at the lineside, which should make maintenance much easier and address the woeful reliability problems that currently afflict the Bedford to Bletchley services.
Unfortunately, like every other fleet of new trains currently being introduced on the British railway network, the D-trains are late. They were supposed to start operating last December, but Vivarail announced that technical problems with the first of the three trains had led to delays while they were remedied on all three sets. However, all three of the two-coach trains have now been delivered and have been increasingly visible on test runs in and out of Bedford over the first part of 2019, so they should be in service very soon.
If it’s not too close to trainspotting for your sensibilities, you might like to look out for their names. London Northwestern announced plans to give each of the three trains a name to reflect their duties: 230 003 will be named after someone or something connected with Bletchley, 230 004 will get a name relating to Bedford, while 230 005 will be named in connection with the Marston Vale as a whole. (And if you’re wondering about the numbers, 230 001 and 230 002 are prototype trains used by Vivarail in developing their technology, 001 being a diesel and 002 the first battery train, so they’re not expected to enter regular passenger service any time soon, if ever.)
Compared to the massive new fleet of class 700s on Thameslink, or the optimistic plans for bi-modes on the Midland Main Line, the three D-train DMUs are unglamorous little trains. But their combination of London Underground heritage and innovative technology makes them among the most interesting developments in rolling stock anywhere in the country. And most importantly, they should provide a considerably more reliable and more pleasant service for the users of the Marston Vale Line.