A tale of two Desiros

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Two recent train launches represented both the end of one era and the start of another. Siemens Desiro trains have been running in the UK since 2003. The first Class 360 four-car units started running with First Great Eastern in August of that year on services from London Liverpool Street.

Desiro is Siemens’ family name for diesel or electric multiple units, mostly used for commuter or regional services. Due to the UK’s specific loading gauge, a sub-set of Desiro UK trains have been built, including Classes 185, 350, 360, 380, 444 and 450. While all have similarities, the design has been continuously developed over the years.

Last month, the latest member of this family entered service. Ten 4-car sets designated 350/3 have been delivered to London Midland to increase capacity on West Coast main line services.

Earlier examples

This is the third (or actually the fourth) version of the class. 350/1 was introduced by Central Trains in 2005 on services around Birmingham. The thirty 4-car units were transferred to London Midland in 2007 at the franchise change and upgraded from 100mph to 110mph running in 2012 for use on the West Coast main line.

That’s not as simple as it sounds. The design had been optimised for 100mph running so the upgrade included modifications to the traction motors and dampers. The software that runs the train management system also had to be upgraded and even the pantographs needed alteration. Then there were full-load braking tests before the class could be cleared to run at just 10mph faster.

The 37 Class 350/2 trains which followed arrived in 2008/9. They operate on AC only (Class 350/1 is AC/DC dual voltage) and have a maximum speed of 100mph. Because they are primarily used for commuter operations, they also have 3+2 seating.

Both classes are primarily operated in combinations of 8 or 12-car trains.

Latest version

Now, ten Class 350/3 trains have been delivered as part of a combined order with First TransPennine (they also received thirty 4-car trains, designated 350/4) placed by the leasing company Angel Trains. They are approved for 110mph running from the start and have other upgrades in that they are fitted with GSM-R radio and TPWS mark 2 signalling. Seating is 2+2, as is the 350/1 seating, but with green upholstery similar to that on the 350/2.

350 Desk with new TPWS DSC_7889 [online]

The Desiro UK fleet has been very reliable in service. As managing director Steve Scrimshaw said at the launch, Siemens turns 360 trains out into service every day and the fleet has won several awards for reliability. Each of the new units has had to complete 1,000 miles of trouble-free running at Siemens’ Wildenrath test track in Germany, and then another 300 in the UK.

As well as the new GSM-R radio and TPWS (train protection and warning system), which now has three new warning lights and a vocal alarm, there are other differences in the new trains. As part of the European drive for interoperability, they are fitted with new fire detection equipment which shuts down the traction motors and auxiliary converter units in the case of a fire.

London Midland’s drivers have welcomed a new design of seat with increased support and (roll of drums!) a redesigned and stronger cup holder.

The operator’s commercial director Richard Brooks explained that seven of the new trains will boost the West Coast main line services, either in 8 or 12-car consists, while the other three will add to capacity for commuters around Birmingham.

The Class 350/3 is the very last of the classic Desiro UK family that will be built. When asked whether an order for new carriages, say from an operator who wants to turn four-car into five-car trains, would be refused, Steve Scrimshaw thought for a while and then said: “Yes – probably.”

His reticence is natural as who wants to turn downanorder? Butthereasonforhisfinal answer is that Siemens’ new train for the UK, the Desiro City, broke cover at InnoTrans in September.

First time in public

A completely new train, although it shares the Desiro family name, 1,140 carriages have been ordered for the Thameslink route from Peterborough and Bedford to Brighton.

Designated Class 700, a mock-up was shown off earlier in the year but the first three production cars were at InnoTrans in Berlin.

Once again, a proud Steve Scrimshaw showed The Rail Engineer around the new train, this time accompanied by Ian Macleod, technical development manager for the Thameslink project. “This is the first of the eight-car Desiro trains for Thameslink and the fifth train that we have built so far,” he said. “It’s not bad going when you consider that we signed the contract in June last year and here we are having the first five trains on test and the first three vehicles here.

“This is the first second-generation train in the UK. And now we have won an order from South West Trains for thirty 5-car trains, which is very important as it means that the Desiro City is no longer the ‘Thameslink train’ but is the new platform for the UK in general.

“We’ve spent about £70 million developing this train. There has been a lot of involvement from the people from Desiro maintenance so that all those little things that annoy you about a train design are actually taken account of into the train specification. It’s had all that input and, in the case of Thameslink, there was a detailed specification for passenger loading, dwell times and so on, so all of that had to be taken into account. The design team for this train has actually been involved in designing all the Desiros in the UK so they have that experience which they have brought to bear on the design of this train.”

Second generation

So how does the Class 700 Desiro City differ from a Class 350/3 Desiro UK? And what makes it be called a second-generation train?

From a passenger’s point of view, it is certainly a decent train. The cars are connected by full- width gangways, giving the whole interior an open feel. There is plenty of space around the wide doors so that people can get on and off easily and quickly. And there is a good passenger information system which can show a lot of detail and even movies!

But there must be more to the ‘second generation’ statement than that. Ian Macleod explained: “The big difference for the operators is the cost of maintenance which is about 20-30% less. There is a new train control system which is integrated with passenger information and can be customised to show whatever the operator wishes.

The new Class 700 undergoing climate testing in Vienna.

new desiro windkanal003resize [online]

“On the previous trains, we had all of the equipment in body-end cubicles. With the big open gangways, we don’t have those cubicles any more and all of the control equipment is in the ceiling behind the LED lighting panels.

“About six years ago, we had all of the engineers over from Germany and we created a 180-point list of improvements we wanted to make to the train – the things that take a long time to do during maintenance and could be improved. For example, to change a luggage rack takes two hours as we have to take part of the ceiling down. Now, on this new train, we can do it in 15 minutes. We don’t do it often, but it’s annoying when we do. So those are the kind of things we wanted improving next time around.

“We used to have body-side heater elements which needed cleaning every twelve months, and it was a very time-consuming thing to do. Now we just have empty ducts with blowers in the air conditioning systems in the roof, so we don’t have to do that job at all, saving more time.

“The doors are purely electric, there are no longer any pneumatics involved, and they will need only one overhaul in the life of the train, so that cost is substantially reduced as well.”

Out of sight

Ian is quite passionate about all of the systems that the passengers never see. “One of the most exciting features for me is behind the scenes and that’s the train control system. One of the biggest things we’ve got is distributed software loading. Previously, if we’d wanted to update the software that controls door closing, we’d have had to re-write the code and then go to each

door unit and upload the software. Now, we can update all 48 doors from one central point using in-built parameters – which takes ten minutes rather than hours of work. So if the operator wants to make a change to the way doors close, it is now a simple change.”

The train also sends its own fault reports to the depot so that engineers can plan both routine and exceptional maintenance. There are almost 10,000 diagnostic codes from the various sub-systems which can all be used to notify the depot of exactly which fault has occurred.

For example, there is a flood sensor in every toilet so if a toilet floods the driver knows immediately, the control centre knows immediately, and a cleaner can be dispatched to rectify matters. And because the system is counting every toilet flush, it also knows how much water may be needed and when it should be replenished.

That’s a tremendous level of detail, all available in real time to the control centre operators.

So it’s the economy of operation and the ease of maintenance which makes this a second- generation train. Yes there are all the major technical improvements, the lighter bogies which The Rail Engineer has mentioned before for example, but it is all the wizardry behind the interior panels which really makes the difference.

With five trains now complete, it hopefully won’t be long before we see one in the UK. And then passengers can take a train to Bedford or St Pancras, walk from the last Class 350/3 Desiro UK onto a new Class 700 Desiro City, and experience the difference for themselves.