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Pendeltåg X60 EMU takes shape

01 Sep 2003

Harry Hondius MSc reports from Salzgitter

NOW UNDER construction at the Alstom LHB plant in Salzgitter are the first cars for a fleet of innovative articulated low-floor cars to operate Pendeltåg suburban services in Stockholm. Ordered last year by Storstockholms Lokaltrafik AB, they are derived from the Lirex experimental multiple-unit now being tested in Germany.

Since January 2000 the Pendeltåg network has been operated for SL by Citypendeln AB, a consortium of which the leading partner is Keolis of France. It carries an average of 232000 passengers a day using a fleet of 146 two-car EMUs inherited from national operator SJ. The 94 Class X1 sets date from 1967-75 and the 52 Class X10 units were built in 1982-93. Each two-car unit is 49·5m long and 3·15m wide, and can run in multiple up to four units, forming a 200m train carrying 1180 passengers.

With the oldest X1 units in urgent need of replacement, SL ordered 55 Coradia Lirex EMUs in 2002, at a price of €6·9m per set, with an option for a further 50. The X60 units will be articulated six-car sets, that can be joined by automatic Scharfenberg couplers to form a 214m long train, carrying 1800 passengers, of which 748 will be seated. Low-floor entrances at 760mm above rail will provide easy access from the existing 730mm high platforms.

As an interim measure, Citypendeln has leased 15 Class X420 three-car EMUs from German Railway through a new subsidiary, DB Regio Sverige AB, with an option on a further 15. The former DB Class ET420 'Olympia' S-Bahn units have had their cabs modified radically to meet the requirements of the Citypendeln drivers. The trains have been equipped with Swedish ATP and new footboards to suit their smaller width and lower platforms at a cost of €750000 per set. Eight units will be in operation in the autumn of 2003.

Unveiled at the InnoTrans exhibition in Berlin in 2000 (RG 11.00 p763), the Lirex prototype has now covered over 200000 km on test and in revenue service. Reporting on the initial testing phase (RG 10.01 p668), I suggested that for reasons of axle loading, the series production could well be a bogie version. Last month I described the e-transformer to be tested on the prototype next year (RG 8.03 p488). Overall availability of the prototype has been good, and the roof mounting of equipment has not shown any significant inconvenience. On the contrary, in the case of snow and ice, it seems that cleaning of essential equipment has been easier than when this is mounted under the floor.

X60 in detail

The X60 will have a steel bodyshell, laser-cut, and automatically laser and spot welded from corrosion-resistant steel. The ends will be reinforced, and fitted with shock-absorbing elements capable of absorbing 2·5 MJ. Each set will comprise two driving vehicles (A1 and A2) and four middle cars (M1-M4). The six bodies will be connected by spherical joints, and the four M cars will be connected to the articulation bogies by traction bars. Double corrugated bellows from Hübner will cover the gangways.

There are 12 sets of double doors 1300mm wide on each side of the unit. Where possible, cantilever seats are used to simplify internal cleaning. The cars are designed to meet DIN 5510-2, step 2 fire protection regulations.

The bogies have been developed by Alstom Schienenfahrzeuge AG of Neuhausen, derived from the SIG bogie family, and based on the design for the Trenitalia Minuetto EMUs; they are being built in Salzgitter. The end motor bogies have a primary suspension consisting of axle guides, coil springs and a vertical shock absorber. Secondary suspension is by air springs with auxiliary rubber springs inside, and vertical shock absorbers. A torsion bar serves as a roll stabiliser, and yaw dampers are connected between bogie frame and car body.

Traction forces will be transmitted by a traction bar linked to a central mounting under the carbody at low level. Horizontal movement of the body is limited by bump stops, and dampened by two horizontal shock absorbers. The traction motors are fully suspended from the bogie frame, with a toothed coupling connected to the gearbox, which is partially suspended from the frame so that only half of its weight rests on the axle. All wheels have electro-pneumatic disc brakes and spring-loaded parking brakes, and each unit has three pairs of magnetic rail brakes.

The floor above the end bogies is at 1080mm above rail, reached by two steps of 145mm from the 790mm main floor level. The seats above the low-profile articulation bogies are mounted on 1080mm high boxes, enabling passengers to pass from one car to the next with only a slight ramp. In principle these articulation bogies are the same as the end units; the two main differences are that the auxiliary springs are mounted separately to gain height and a simple traction bar links the bogie frame to one of the car bodies. The traction drive is the same, except for the bogie linking M3 and M4 which is unpowered.

Each unit has three transformer/four-quadrant rectifier/inverter groups, feeding sets of four 250 kW water-cooled three-phase traction motors. One pantograph at the end of car M2 feeds via a high voltage compartment and a self-induction coil, and for redundancy there is a similar arrangement at the end of car M3. Transformer/inverter group 1 is located on the roof of car A1, feeding the motors on bogies A1 and A1/M1. Group 2 is located on car M2, feeding bogies M1/M2 and M2/M3, whilst group 3 on car A2 serves bogies M4/A4 and A2. All cars have their own air-conditioning and heating unit. Cars A1 and A2 carry the batteries and auxiliary inverters, M1 and M4 the compressors and A1, M3 and A2 the coolers.

Each of the three traction circuits consists of two four-quadrant rectifiers fed by a 1200 kVA oil-cooled transformer, which converts the 15 kV 162/3Hz overhead line supply to the intermediate bus voltage of 1·8 kV DC. This is fed into a common rail which feeds the six roof-mounted heaters as well as the three water-cooled Onix 1500 IGBT traction inverters and the two auxiliary inverters. This arrangement permits regenerative braking. Recovered energy is initially fed to the auxiliaries via the 1·8 kV DC bus rail, and the surplus is returned to the overhead line via the four-quadrant converter.

The traction inverters are controlled by the electronic Agate-Link 32-bit system, which has 100% redundancy. Essential subsystems are connected by a multiple vehicle bus with a wireless train bus between sets for control of multiple-unit operation.

The two auxiliary inverters on the roofs of A1 and A2 are fed from the 1·8 kV DC common rail, and supply a 400V DC circuit via a DC/DC converter. This in turn feeds two inverters, which supply 3 x 400/230 V AC to the compressors, cooling pumps, and fans, three inverters which supply 3 x 80/480 V AC, 10 to 60 Hz for the air-conditioning compressor drives, and two DC/DC converters supplying 110V DC to charge the batteries.

There is no doubt that the X60 is an interesting addition to the suburban EMU family. It looks as if SL has once again been able to purchase a high quality train at a reasonable price.

Probably the closest comparison is DB's Class ET425 S-Bahn unit, of which 40 are on order for use in Stuttgart. These 67·1m long by 2·84m wide four-car units are carried on four powered bogies and one trailer bogie. With a floor height of 798mm, 206 seats and installed power of 2350 kW, the 114 tonne sets were priced at €4·6m each, or 24121 k/m2. If the width were 3·15m the price would fall to €21747, and the weight would average 598 kg/m2. Installed power is 20·6 kW/t, and the top speed 160 km/h.

 

TABLE: X60 suppliers

Main contractor Alstom LHB, Salzgitter

Design Idesign/Haslacher

Cab air-conditioning Faiveley

Pantographs Schunk

Transformers Sécheron

Traction Motors Alstom, Ornans

Electronic controls Alstom, Villeurbanne

Traction inverters Alstom, Charleroi

Static inverters SMA, Kassel

Brakes SAB Wabco

Air-conditioning Faiveley HFG

TABLE: Technical data for Coradia Lirex X60

Power supply 15 kV 162/3Hz

Continuous rating kW 12 x 250

Maximum speed km/h 160

Steepest gradient 4%

Axle arrangement Bo' (Bo)' (Bo)' (Bo)' (2)' (Bo)' Bo

Overall length mm 105674

End cars mm 20750

Intermediate cars mm 16400

Overall width mm 3250

Height above rail mm 4180

Buffing load kN 1500

Empty weight tonnes 199

Maximum axleload tonnes 20

Wheelbase, end bogies mm 2400

Wheelbase, articulation bogies mm 2700

Wheel diameter new/used mm 850/780

Bogie centres m 15·5 + 4 x 16·4 + 15·5

Seats 374

Standees (at 5/m2) 565

Doorways per side mm 12 x 1300

Door height mm 2000

Door span mm per m of car length 291

Specific power kW/t 15

Specific weight kg/m2 579

Weight per seat kg 532

Price k/m2 20110