The government’s decision to go ahead with a scaled-down version of the Intercity Express Programme (IEP) will see bi-mode diesel/electric trains running on the UK network, replacing the ageing fleet of Inter-City 125s. The trains, to be made by Agility Trains, a consortium led by the Japanese firm Hitachi, will be capable of travelling on electrified routes, switching to diesel operation where overhead lines cease.
The decision was announced in tandem with a plan to electrify the Great Western main line from London to Cardiff. But the government has ruled out a further extension of electrification to Swansea, hence the need for bi-mode operation.
The go-ahead for the IEP means that Hitachi will build a carriage and train-building facility at Newton Aycliffe in County Durham – bringing the prospect of hundreds of new jobs to North East England.
But the £4.5 billion project isn’t without controversy. The order for 500 carriages has been notably scaled back from the £7.5 billion programme for 1,400 carriages for which Agility Trains was named preferred bidder in February 2009.
And some railway engineers have questioned the sense in operating bi-mode trains, which comprise a level of technical complexity unproven on UK railways.
Any form of diesel propulsion is likely to be heavier, with implications for track maintenance, and cost more to maintain than electric alternatives. In specific relation to IEP, there have been concerns centred on the capability of a single diesel generator carriage to power long-distance through-trains (that is trains which will also have pantograph/transformer carriages), especially in the hilly regions of the South West peninsula where they would be most used in the absence of electrification.
Bi-mode trains are, for long-distance travel, an untested innovation. Such trains operate in France but under different circumstances on regional services. Whereas the French bi-mode has small, low-power diesel engines, the IEP requires high speed, high performance and high power to serve a variety of intercity purposes. Some critics therefore feel reliance upon bi-modes on the IEP scale is a risky solution.
There is also risk concerning the long-term viability of the diesel generator carriages. Many of them could be surplus to requirements, over a 10-20-year period, should the electrified network further expand to Swansea. As there is no other application in the world for the diesel generator (as opposed to a diesel locomotive, which could be used on freight services, for example), it risks becoming an expensive stopgap, say critics.
Nevertheless the government has decided to push ahead with the bi-mode trains. Transport secretary Philip Hammond said London-Cardiff journey times would come down to one hour 42 minutes, while 22 minutes would be saved on London-Bristol journeys.
Hammond said the government had also established “that a strong high-level case may exist for electrifying some of the valley lines north of Cardiff”. The Department for Transport will work with the Welsh Assembly to develop a “full business case for the electrification of the Cardiff valley lines during the next rail investment control period beginning in 2014”.
Labour MPs representing constituencies west of Cardiff, where electrification will end, said their voters would be disappointed and angry. Sian James (Swansea East) said: “I have to go back to my constituents in Swansea and explain to them they are not as important and that transport and modern infrastructure, opportunities for investment and tourism, are not on the cards for them.”
Hammond said: “I understand people in Swansea will be disappointed by the announcement because of the expectations the previous government raised without bothering to establish there was a sound business case.”
Agility Trains said the new Newton Aycliffe rolling stock manufacturing and assembly centre wouldgenerate at least 500 new jobs.