Inside Vivarail’s D-Train

Cost has proved to be something of a contentious issue. Vivarail has gone to great lengths to explain that it cannot provide a cost for the new production trains - instead, it all depends on the many choices that the client must make.

Will it cost more than a refurbished Class 144? Potentially. It all seems vague, and the rapid speed at which Vivarail produces ideas and reworks its creations suggests a lack of clarity of vision in the project’s initial aims. Further development seems to be happening before the bog-standard version has even been finished.

The trains themselves are being converted from D78 London Underground electric stock, and the conversion process for each car takes (at the moment) several weeks to a couple of months. The reason it’s currently so slow is because the project is still in the test stages. This isn’t a full-blown train production line - this is a toe in the water.

The bogies are stripped out for refurbishment and the motors removed. The Ford power units are modified for rail use by Revolve Technologies (Brentwood in Essex), while Strukton Rail works on the bogies and train management systems. The wiring and electrics are all stripped out and redone at Long Marston. 

The advanced engine management systems in the D-Train (Class 230) means that it’s more efficient and more fuel-efficient than before. It also simplifies the driver’s job, and makes maintenance a lot easier than on the previous electro-mechanical systems. 

The new engines are essentially held in place with friction, rather than being bolted in. Once again, this makes maintenance and removal easier.

On the test train, the bodyshells are barely altered. Door positions, windows and other parts can be moved or modified as per the future client’s specifications, but for now they still look like Tube trains. The famous image released of a D-Train’s front end with sloping angular lines is an ‘optional extra’ that Creactive Design has come up with. 

However, the cab is rebuilt, with a lot of steel in there that wasn’t in it originally. The point of this is to create a ‘survival space’, so that in a collision a driver can walk away, rather than being trapped in his cab.  

Technically, the D-Train is quite advanced for a small DEMU. It has stop-start engine technology to improve efficiency - a feature that is only now being applied to some Class 66s here and other locomotives abroad (RAIL 783). The potential for hybrid engines is also being investigated, which would make the D-Train the first production hybrid DMU in British history. 

As it stands, the design is supposed to provide a decent fuel consumption of 0.5 litres per car per mile. (A Class 142 uses around 0.75 litres per car per mile.) This level of performance is something Vivarail is very keen to promote, and the promotional material calls it “the UK’s newest, greenest train”. Possibly a trifle misleading, considering the age of much of the structure of the units and the number of electric trains in the UK, but the intention is clear. These are supposed to replace older, less efficient and less comfortable stock that in the eyes of the public is very much life-expired. 

Shooter was confident on the day of RAIL’s visit in mid-August that the test train would be ready in about one month. The men who are actually building the train, wiring up the cab and installing the cab controls seemed to think it would take a little longer. One engineer estimated it would be closer to the end of October. 

The first driving car was all but complete. Wiring up for the main systems was ready, and the engines and bogies were in and ready, although the cab and carriage controls still needed to be populated. This includes the CCTV monitor for the cab, windscreen wipers, LED lights, door buttons and alarms for passengers, information displays and destination boards. 

Although this is relatively quick and easy work, the other two cars still needed to have their engines, bogies and wiring finished.

Since RAIL’s visit, the driving car that was almost ready has now been internally gutted, ready for new interiors to be installed once again. This means it will not be complete until the end of November, potentially days - or even hours - before it’s due to go on test with GBRf. The front end of the cab will take approximately another six weeks to complete, according to Bates.

All that’s really left to do now is wait. Come November, we will see whether the D-Train test model is ready, and we will see if it successfully tests on the main line. 

If it does, there may very well be a flood of eager train operators bidding for the new ‘crowdbusting’ cheap DEMU of the future. If not, Long Marston may be a much quieter place. 

• This feature was published in RAIL 784 (September 30 - October 13 2015)