The Desiro can be built as a diesel or electric multiple unit (DMU or EMU). Most common are two- and three-parts layouts. Although there are various differences between these trains, the body design is the same. These trains are mostly used for regional services. They are part of a new generation of light, modular trains which have become widespread in many European countries; sometime referred to as light train. These trains are relatively cheap to build and operate. Fast acceleration makes them suitable for train services with a short station distance. However, they are sometimes criticized for their lack of passenger comfort.
Class 642 is equipped with two MAN diesel engines with 275 or 315 kW each (hydro-mechanic transmission, with retarder). It typically has 100 seats. Up to three units can be operated together, connected by Scharfenberg couplers. The Desiros are quite popular with most passengers due to their good acceleration. As they often replaced push/pull trains, the shorter travel times, for example on the Müglitzbahn, led to an increasing number of passengers.
Originally DB intended to jointly operate modern DMUs of different manufacturers, but due to incompatible software this was not possible. Therefore Class 642 can only mechanically be coupled with other DMUs like the Class 643.
Siemens uses the name Desiro UK for new DMU and EMU trains used by various United Kingdom train operators. These trains have a completely different design to the above light train variant. The trainsets have modern facilities, such as biological waste storage tanks, ergonomic seats and spoken announcements. All the electric units are owned by Angel Trains, whilst the diesel units are owned by HSBC Rail. Angel and HSBC Rail then lease the units to the train operators.
|Class||Operator||Introduced||Number||Power||Carriages||Door configuration||End gangways|
|350||London Midland||2004||30||AC/DC electric||4||High-volume||Yes|
|360||National Express East Anglia||2003||22||AC electric||4||High-volume||No|
|360||Heathrow Connect||2005||5||AC electric||5||High-volume||No|
|444||South West Trains||2004||45||DC electric||5||Low-volume||Yes|
|450||South West Trains||2003||127||DC electric||4||High-volume||Yes|
The first electric Desiro UK units were ordered by South West Trains for both short and long distance service out of Waterloo station to Alton, Basingstoke and the Hampshire/Dorset coast. They became two different classes, both use the 750V DC third rail power supply.
Class 450 units consist of:
DMSO (Driving Motor Second Open) + TCOL (Trailer Composite Open Lavatory) + TOSLWB (Trailer Open Second Lavatory Wheelchair Bicycle) + DMSO (Driving Motor Second Open)
Class 444 units consist of:
DMSO (Driving Motor Second Open) + TSOLB (Trailer Second Open Lavatory Bicycle) + TSOLB (Trailer Second Open Lavatory Bicycle) + (P)TOSRMBLW (Trailer Open Second Restaurant Micro Buffet Lavatory Wheelchair + DMCL (Driving Motor Composite Lavatory)
Class 444 units differ in appearance from Class 450 units in many ways, most obviously the livery. Class 444 units also have 23m long cars instead of 20m, and the frontal design is also different, with the Class 444 units having no alcove for the springs on the corridor connections by the dumb buffers.
The entire fleet is limited to 100mph, but the Class 444 units were limited to 85mph during their introduction. Class 444 units are used on express services, whereas Class 450 units are generally used on suburban trains. The units can often be found working together in any of the following combinations:
450 + 450
450 + 450 + 450
444 + 444
450 + 444
450 + 444 + 450 (exceeds 12 cars)
444 + 450 + 444 (exceeds 12 cars)
The only ones commonly found in service are the first four as all the other combinations exceed the 12 carriage limit.
Department for Transport proposals for rail services following the completion of modernisation of the West Coast Main Line (planned for 2008) call for these units to be employed on an improved regular-interval stopping train service from London Euston along the Trent Valley route (Northampton - Rugby - Nuneaton - Tamworth - Stafford) to Crewe or possibly be extended to Liverpool. In the interim period, the trains are operated by London Midland between London Euston and Northampton, and between Northampton, Birmingham, Crewe, Liverpool, and Preston.
A further 37 units have now been ordered. These will be designated class 350/2 and will be operated by London Midland. Deliveries are expected to commence in late 2008.
Caile Ferate Romane (CFR), the national railway operator of Romania, is one of the largest users of Siemens Desiro trainsets (the light train variant). CFR, which is currently going through a process of modernisation has bought many Desiro trainsets and uses them on all train types, including Intercities, "Rapid", "Accelerat" and "Personal", but a large part on "Rapid" trains, an express train type. There was some criticism on the use of Desiros for long-distance trains, because they were found uncomfortable. CFR has recently refitted them, and is now using Desiros mainly on medium- and short-disstance routes. It is for example planning to use them as part of a proposed commuter railway in Bucharest and Ilfov county. For more information on routes, see Caile Ferate Romane.
In Greece eight (8) diesel DMU2 Desiro trains were in use temporarily by the Hellenic Railways Organization (OSE), during 2004-2005 and again in 2007 for Athens-Chalkis, Athens-Kalampaka, Athens-Corinth and Athens-Airport services. Afterwards they were returned to their owner (Hellenic Shipyards S.A.) who sold them to another customer abroad, possibly CFR.
Also OSE operates twenty (20) electric EMU5 Desiro trainsets equipped for the 25 kV overhead catenary system. They operate on the Neratziotisa-Athens Airport suburban section and on the newly electrified Thessaloniki-Litochoro mainline section for a stopping service (advertised as suburban). This service is expected to reach Larissa within 2008.
These EMUs have a commercial maximum speed of 160 km/h