Great Western electrification shambles – will bimodal trains save or sink the scheme?

Last week’s announcement that electrification to Bristol has been deferred by the DfT followed a devastating NAO indictment cataloguing poor management practices with the ongoing Great Western Electrification Programme (GWEP).

Electrification between Paddington and Cardiff should now commence in December 2018 (18 months later than planned). However, electrification to Bristol from the north (via Bristol Parkway and Filton Bank), and from the south (via Thingley Junction and Bath) is now expected to occur some time during the next control period, CP6 (2019-24).

Electrification between Oxford to Didcot Parkway, and the Thames Valley Henley and Windsor branches have also been deferred.

The funding (put at between £146m and £165m) for these four schemes could not be accommodated under existing CP5 arrangements.

Current cost estimates for GWEP infrastructure works are £5.6bn (at 2012-13 prices) – an increase of £2.1bn since 2013 – and the new IEP (intercity Express Programme) trains will add another £4.1bn (2014 prices) to the overall bill. Additionally, the DfT has had to stump up another £330m for changes in the rolling stock specification.

In diesel mode the maximum speed of GW bimodal trains is likely to be less than the 40 year old HSTs they will replace.
In diesel mode the maximum speed of the GW bimodal trains is likely to be less than the 40 year old HSTs they will replace.

The NAO verdict about both DfT and Network Rail mismanagement was scathing:

“Before 2015, the Department (DfT) did not plan and manage all the projects which now make up the Great Western Route Modernisation industry programme in a sufficiently joined up way. The Department did not produce a business case bringing together all elements of the programme until March 2015, more than two years after ordering the trains and over a year after Network Rail began work to electrify the route . . .

“Network Rail’s 2014 cost estimate was unrealistic. It was too optimistic about the productivity of new technology. It did not work out a ‘critical path’ – the minimum feasible schedule for the work, including dependencies between key stages – before starting to deliver electrification. It also did not conduct sufficiently detailed surveys of the locations for the structures, which meant that some design work had to be repeated . . .

This is a case study in how not to manage a major programme. The Department’s failure to plan and manage all the projects which now make up the Great Western Route Modernisation industry programme in a sufficiently joined up way, combined with weaknesses in Network Rail’s management of the infrastructure programme, has led to additional costs for the taxpayer.”

NAO cited numerous examples of this lack of ‘joined up thinking’. On the infrastructure side Network Rail’s original plan was based on its ‘factory train’ (for pile diving) but this turned out to be far less productive than anticipated (and resulted in delays). Also, the DfT maximum line speed specification was unclear with NR initially working to a more costly (and technically rigorous) 140 mph limit before realising it was 125mph.

NAO said there was no ‘controlling mind’ with information and authority to make critical decisions.

On the rolling stock side this lack of ‘joined up thinking’ was even more evident.

The IEP (Intercity Express Programme) rolling stock procurement – like the Crossrail and Thameslink schemes – was initiated by an external government agency, not the franchised TOC. In the case of IEP, this was the DfT.

The original 2007 plan was for an all diesel fleet but that changed in 2009 to a mix of 21 electric and 36 ‘bimodal’ (electro-diesel, or hybrid) trains. In May 2016 the specification changed again to an all bimodal fleet.

The reason for this was that the electric (only) trains would have been available before the delayed electrification works were completed but the leasing charges would still have to be paid:

“If it had not done this, old trains (the HSTs and Class 180s) would have continued to operate services. The Department would have had to pay £400,000 per day to Agility Trains (the rolling stock owner) to lease new trains that could not be used until the overhead electrification was complete. We estimate that this would have cost the Department about £400 million over the three years that it took to complete electrification.”

The  situation does not end here. Upon completion of electrification some ‘bi-modal’ trains might be converted to pure electric stock:

“When using electric power, bi-modes cause more damage to the track and incur higher energy costs than electric trains as they weigh more. The top speeds of the new bi-modes when operating under diesel power are probably lower than the existing high-speed diesel trains and the Department is exploring the overall effect of using these trains on journey times . . . Bi-modes used in diesel mode are also noisier and emit more pollution than electric trains. For the Department to deliver the benefits originally expected from electrification, some of the bi-mode trains would need to be modified to remove diesel engines once the line has been electrified.”

The higher running costs of diesel traction will also result in lower premiums to the DfT from the Great Western franchise holder. Delays in completion have also meant that seven additional bimodal trains will need to be leased in the interim period (five for the Oxford and two for the Bedwyn services).

The BCR (benefit: cost ratio) for the GWEP was put at 2.4:1 in March 2015, which came within the DfT’s ‘high’ value-for-money band. But that was before DfT went for the bimodal only option. The BCR has since been downwardly revised and is now placed at 1.6:1 within DfT’s ‘medium’ vfm bracket. The NAO says further deterioration is possible:

“If costs increased by a further 3-4% we estimate that the benefit–cost ratio would fall below 1.5:1. The Department defines this as ‘low’ value for money.”

The NAO also questioned the electrification case:

“The Department’s May 2016 decision to procure all the new Intercity Express trains for Great Western as bi-modes, rather than a combination of bi-modes and electric trains, affects the assumptions underpinning the March 2015 business case. This recent change calls into question whether the full extent of electrification under the programme is still justified, as the new trains will now all be able to run on non-electrified route sections.”

FirstGroup-owned GWR ranked 2nd and 7th in the 2015 tables for worst performing trains
GW electrification delays will be felt across the network as it has impacted the rolling stock cascade . Some  GW HST sets will later be retained and modified for use in Scotland but it will now take longer for them to get there.

So the decision to go for a 100% bimodal fleet was not based on its much vaunted operational flexibility – which appears to have been a secondary consideration – but was motivated instead by the short term need to get the DfT off the funding hook by avoiding astronomical leasing charges. Assuming that electrification to Bristol and the other deferred sections takes place during CP6 (2019-24), the GW franchise holder will eventually end up with more bimodal stock than it needs and with trains that are unsuitable.

They will cost more to run and maintain than pure electric stock, but conversion from bimodal to electric – as hinted at in the report – would also entail a hefty cost penalty.

Is this the way to run a railway?

This kind of situation would not have happened in the old pre-fragmented order; then a premature rolling stock delivery would have lost revenue but it could have been stored without incurring costly leasing and stabling charges.

The case for bimodal traction is gaining  ground at the moment as it is seen as a cheaper option to extending existing electrified lines.  This appears to have happened already. Following the recent Hull Trains order for bimodal trains, electrification to that city now looks highly improbable.

But is the DfT placing too much faith in bi-modal trains? Electro-diesel traction has been used in the UK before but on nothing like the scale currently contemplated. Have all the technical issues associated with been fully resolved? Is long term electrification of the network being jeopardised by the apparent appeal of this short term expedient?

If bimodal trains fail to live up to expectations they might turn out to be more expensive in the long run than the  ‘proper’ electric trains they are expected to replace – and not just on the GW but elsewhere as well.


Red: delays of 2+ years Yellow: delays of 1-2 years Grey: completion date undecided. The Paddington to Maidenhrad section comes under the Crossrail programme and is separately funded).
GWML electrification; current state of play                                                                  Red: delays of 2 + years
Pink: delays of 1-2 years
Grey: completion date undecided.
(The Paddington to Maidenhead section comes under the Crossrail scheme and is separately funded).

NAO: Modernising the Great Western Railway














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