Informed Sources

Who will win the battle of the bi-modes?

On borrowed time: power car No 43048 T. C. B. Miller MBE passes over Trowell Junction with the 5B57 13.15 Neville Hill to Nottingham empty coaching stock move on 24 March 2019. No 43083 is on the rear. Steve Donald

Back in the days of photo reconnaissance, interpreters would flick backwards and forwards between the previous and latest material so that any changes would jump out. Applying the same principle to official announcements has been Standard Operating Procedure since the birth of ‘Informed Sources’ and the latest interesting anomaly has shown up in separate sections of the same announcement.

To accompany the announcement of the award of the East Midlands franchise to Abellio, the Department for Transport published an ‘interactive map’. Select a route from a drop-down menu and a box appeared with details of the franchise commitments; the route was also highlighted on the map.

This is what the box said in the case of Sheffield-Derby-London: • From May 2020, modern diesel trains will begin to replace ageing HSTs. Timetable changes will enable faster journey times from December 2020. And for Nottingham-London: • From May 2020, modern diesel trains will replace some ageing HSTs. Timetable changes will enable faster journey times from December 2020.

For both routes the longer-term message was identical: • Brand-new 125mph trains will be introduced into service from April 2022 with more reliable service.


Just to get one little inconvenient quibble out of the way, note the ‘more reliable service’. No, not my hyphen pedantry this time.

Network Rail’s upgraded infrastructure should be more reliable by 2022 and, possibly, even the knock-on impact of the Thameslink timetable on Midland main line services might be reduced: but the trains?

East Midlands Trains’ Class 222 Meridian fleet, which will go in this latest mass extinction, are Golden Spanner winners and second only in the inter-city reliability rankings to Greater Anglia’s Class 90 loco-hauled sets. The Class 222’s 39,776 Miles per Technical Incident moving annual average (MTIN MAA) is more than four times that of the Great Western Railway bi-modes. The EMT IC125 fleet, at 10,202 MTIN MAA, is just below the Thameslink Class 700s.

Still, 2022 is three years away. That said, Abellio has clarified that perennial weasel of ‘from 2022’, which could mean the appearance of the first units some time in 2022 or commissioning of the whole fleet. All the new and refurbished trains will be in service by December 2022.


Back to the photo reconnaissance. How do we reconcile ‘will begin to replace ageing HSTs’ and ‘replace some ageing HSTs’? Well, it depends on what is going to be available to replace EMT’s current 12-strong IC125 fleet.

So, what’s around? Class 68s plus Mk 4s have been touted in some quarters, but I can’t see many Mk 4s being released off the East Coast in time to be refurbished and altered for Class 68 head-end power by next May, and even if such combos were to be around in time there would be performance issues by comparison with the fleet-of-foot Meridians. As far as I can tell, the only 125mph-capable ‘modern diesel train’ from outside the East Midlands which could replace IC125s ‘from May 2020’ are the four Hull Trains Alstom Class 180 Coradia DMUs (currently on 7,291 MTIN MAA). These are due to be replaced by Hitachi AT300 (800 Series) bi-modes by the end of this year.

Hence my querying the semantics. Four DMUs could replace ‘some’ of EMT’s 12 IC125 formations.

But if they ‘started’ replacing, the replacement programme wouldn’t last long, since you would diagram three out of four.

However, the Class 180s would show willing, with a third of the IC125 diagrams replaced. Not that the IC125s are intensively diagrammed. Meanwhile, in May 2020, the Corby electrification should be commissioned (p52, March issue).

Driver training can then begin for the new electric commuter service which is scheduled to start with the December 2020 timetable. The arrival of the Kettering/Corby EMUs should release some Class 222s which could, in turn, displace more of the remaining IC125s.


Here we have another case of ‘hunt the total extinction cascade’. Leading candidate for the Corby electric stock is the Greater Anglia Class 360 Siemens Desiro fleet. These number 21x4-car units and are compliant with the Persons with Reduced Mobility Technical Specification for Interoperability (PRM-TSI).

However, their release is contingent on delivery of the Bombardier Class 720 Aventra EMUs to Greater Anglia (‘Informed Sources’, February 2019), which are running late. The first Aventras were due to enter service in January this year, with delivery completed by September 2020. This has now slipped back to the end of the 2020.

Here the good news is that the Office of Rail & Road has at last authorised the entry into service of the London Overground Class 710 Aventra EMUs. Well, good-ish, since the authorisation comes with a list of conditions. Hopefully, the authorisation reads across to the Class 720 Aventras that are scheduled to replace the bulk of Greater Anglia’s 500 or so Class 317 and 321 vehicles, which are not PRM-TSI compliant.

PRM-TSI compliance is mandatory from 1 January 2020. Thus, if replacement of non-compliant stock is running late, the Class 360s are likely to be the last to be released.

Stadler deliveries could release the Stansted Express Class 379s earlier, but the Stadler EMUs are already three months late. May 2020 may be a bit optimistic for the start of driver training for the Corby electric service.


What all these dependencies would seem to indicate is that some IC125s will have to run on for up to a year past the January 2020 deadline for PRM-TSI compliance. This is reflected in DfT’s authorisation for East Midlands Trains’ and Porterbrook’s current investigation of ways of mitigating some of the non-compliance of the Mk 3 coach (p11, last month). For those responsible for this quest, the world is full of known unknowns.

You don’t know what is going to happen to your job when, or if, Abellio takes over the franchise. Both losing bidders, Stagecoach and Arriva, are challenging the franchise award.

Then there’s how long the period of non-compliance will last beyond 1 January 2020, and whether you can find someone, or somewhere, to carry out whatever PRM-TSI work is affordable and feasible in the time remaining. Finally, can the mitigated Mk 3s be out-shopped in less time than it takes whoever wins the replacement fleet contract to deliver their replacements?


Meanwhile, three manufacturers have submitted bids for the new 125mph bi-mode trains which the Department for Transport required the potential franchisee to procure. In alphabetical order they are Bombardier, Hitachi and Stadler.


Bombardier is bidding a bi-mode derivative of the Aventra platform. This offers 125mph performance under both diesel and electric modes. Its overall performance and passenger ambience ‘will exceed any bi-mode currently on the market’, according to Bombardier.

When I asked which diesel engine it has selected for this paragon of performance, Bombardier made its excuses and left, as they used to say in the News of the World.

While Abellio is already buying Aventras in bulk, the bi-mode remains a paper train and Bombardier’s problems with the Aventra software have been well documented. That said, informed sources are unanimous in tipping Bombardier as the winner. Kitten Quotient: 75%.

While the factory is busy, ‘East Midlands-built trains for East Midlands’ passengers’ is a line that always plays well.


Newton Aycliffe’s finest are also bidding a development of an existing product. We should not forget that the Intercity Express Programme was on the verge of being cancelled when Hitachi came up with its cunning plan. When the HST2 was launched it was a like-for-like IC125 replacement with a diesel power car at each end.

Following authorisation of the Great Western main line electrification, DfT specified two versions of what had become IEP: an all-electric train, plus a bi-mode with one diesel power car and one electric, both feeding distributed traction.

For the all-electric version DfT also specified a diesel Auxiliary Generator Unit (AGU). This would maintain hotel power for a longer period than batteries if the wires came down. The AGU could also move the train at low speed.

Sir Andrew Foster’s critical review of IEP, published in June 2010, raised near-terminal questions over value for money. In response the preferred bidder, Hitachi, came up with what Ian Walmsley wittily called the Boija (Japanese for ‘Voyager’).

Out went the end diesel power car. Instead, intermediate vehicles would have souped-up AGUs providing power for traction. This was viable when the bi-mode was seen as running on secondary routes beyond the wires. But when electrification was terminated, re-purposed ‘auxiliary’ power was not enough.

A simple paradigm for performance is kilowatt per tonne (horsepower per tonne). A 2+8 IC125 comes in at 8.1kW/tonne (10.9hp/tonne). With its engines at the full commercial rating, a nine-car bi-mode Class 800 on Great Western Railway with five MTU 1600 R80L diesels under it gives 8.0kW/tonne (10.7hp/tonne). Now, the IC125 is a nearly 50-year old design. And we are told that the new East Midlands fleet will produce faster journey times. So, the appropriate power-to-weight comparator should not be IC125 but the modern Class 222 Meridian.

These are conventional pure DMUs with 560kW (750hp) of Cummins grunt under each vehicle. This gives 11.2kW/tonne (15hp/tonne) with the potential performance to match.

A nine-car Class 800 with full-power AGUs under all intermediate vehicles gets close to these numbers.

Hitachi tells me it has developed a 125mph-capable bi-mode AT300 variant. But as with Bombardier’s similar offer, no further detail was offered. Kitten Quotient: 90%.

The factory urgently needs a major contract to maintain output when IEP and AT300 deliveries end next year. Deferment of the South Eastern franchise award, which required 800 vehicles for another mass extinction, is a blow to all the main suppliers with UK plants.


In theory, Stadler should be in pole position. It is also supplying Abellio’s Greater Anglia franchise, where Flirt bi-modes are running on test.

As they haven’t had any serious issues yet, and they are Swiss, everyone thinks they are amazingly efficient and wonderful. Which may indeed turn out to be the case.

On top of that, the Stadler locos being acquired by Beacon Rail provide a further reference. Yet informed sources put it in third place.

One suggestion is that the Stadler offer struggles to meet the specified journey times. However, modelling is an imprecise art. For example, do you make allowance for the time modern diesel engines, with all their emissions kit, take to wind up to full power when you select Notch 7?

There is also the issue of passenger comfort. LNER recently published a promotional video comparing the acceleration of an Azuma under electric traction with an IC125. The Azuma belts away like a demented Victoria Line train, while the IC125 crawls in comparison. GWR ran a similar video comparison with an IEP bi-mode under diesel power.

All great fun, but I’m not sure that inter-city passengers still walking down the train really appreciate 0.7% g-force as they balance luggage and a cup of coffee.

An imperceptible transition from stationary to moving is, at least for me, the way inter-city journeys start. And where a bi-mode under diesel soon hits the downward slope of the speed tractive effort curve, electric traction keeps the power coming.

Kitten Quotient: 0%.

So overall, a hard one to call and I don’t envy the Abellio procurement team. They have to juggle deliverability of unproven designs, performance and cost, all the while under the threat of potentially significant political fall-out.