S-train

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S-train
S-tog.svg
4th generation S-train at Copenhagen Central Station.jpg
An A S-train ready to depart from Copenhagen Central Station.
Background
LocaleMetropolitan Copenhagen
Transit typeUrban rapid transit
Number of lines7 with 7 services
Number of stations85
Daily ridership357,000 daily[1]
Operation
Began operation1934
Operator(s)DSB S-tog
Technical
System length170km
Track gauge1,435 mm (4 ft 8 12 in)
Electrification1650 V DC Overhead lines
Top speed120 km/h (75 mph)
System map
S-train diagram (dec 2011).svg

Current system map, valid from December 2011
 
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S-train
S-tog.svg
4th generation S-train at Copenhagen Central Station.jpg
An A S-train ready to depart from Copenhagen Central Station.
Background
LocaleMetropolitan Copenhagen
Transit typeUrban rapid transit
Number of lines7 with 7 services
Number of stations85
Daily ridership357,000 daily[1]
Operation
Began operation1934
Operator(s)DSB S-tog
Technical
System length170km
Track gauge1,435 mm (4 ft 8 12 in)
Electrification1650 V DC Overhead lines
Top speed120 km/h (75 mph)
System map
S-train diagram (dec 2011).svg

Current system map, valid from December 2011
For the German S-trains, see S-Bahn.

The S-train (Danish: S-tog) network is a combined urban rapid transit and suburban rail network serving Metropolitan Copenhagen, Denmark. It connects the city center with the inner suburbs of Copenhagen, and has close to half of the stations within the urban city. The first line was opened in 1934. Today the network forms the heart of the public transportation infrastructure in the city, serving more than 357,000 passengers a day. It is entirely owned and run by DSB S-tog A/S. Along with the S-bahns in Berlin, Vienna and Hamburg, the S-train system in Copenhagen is a metro system unlike many other S-bahns.

The system is complemented by the Copenhagen Metro and an extensive bus network. Although owned by different companies, the systems use interchangeable tickets. The rail systems serve more than half a million people a day, and the city's bus terminals are often located adjacent to an S-train or Metro station. As of January 2009 there are 170 km of dual tracks and 85 S-train stations. At most of the end stations other types of trains are at hand for travel to the most remote suburbs of greater Copenhagen - or for travel across the Øresund to Scania and its main city Malmö. These trains are L-tog (diesel driven local trains), Re-tog (trains of the entire island of Zealand) and Oresundtrain (train to Sweden).

In the city center, the trains run below ground level on some parts (i.e. Boulevardbanen, 1.5 km), with one underground station. Outside the inner city it runs in the open, often on embankments. A short section on the ring line including one station runs on elevated track. Although the S-trains run parallel to the outer suburban/regional/intercity mainline tracks between Høje Taastrup and Klampenborg, they have their own separate trackage all the way with different signalling and power standards from the mainline tracks. A handful of track connections between S-train and mainline tracks exist but are used only in special circumstances (mostly by maintenance diesel powered vehicles).

Contents

Network

The S-train rail network consists of a central section that splits into three radial lines at each end, as the lines reach the outer regions of Copenhagen. The northern radials are:

The southern radials are:

The six radials are additionally connected by

See articles about each of the seven components for station lists and service patterns.

Services

The current timetable (December 2009) organizes the trains on the network into 7 services, each with a letter designation. Most services run from about 5 AM to about 1 AM each day, with a train every 10 minutes in daylight hours and one every 20 minutes in the early morning and evening/night, and on Sundays. Exceptions are service F, which runs twice as often as the others; service H, which runs every 20 minutes all day and only continues to Farum during rush hour; and service Bx, which runs in peak hours only.

Some services (E, H and Bx) skip certain stops to provide faster travel time, but no trains skip stops inside the ring line.

NameSouthern endRuns whenNorthern end
S-train service A.svgAll stops to Hundige,
every second train continues to Solrød Strand
KøgebugtbanenMo–Fr, daytimeHareskovbanenAll stops to Farum
All stops to HundigeAll other times
S-train service B.svgAll stops to Høje TaastrupVestbanenAll week, all dayNordbanenAll stops to Holte
S-train service Bx.svgLimited stops to Høje TaastrupVestbanenMo–Fr, morning(Terminates at Østerport)
S-train service C.svgAll stops to Ballerup,
every second train continues to Frederikssund
FrederikssundbanenMo–Sa, daytimeKlampenborgbanenAll stops to Klampenborg
All stops to BallerupAll other times
S-train service E.svgLimited stops to Hundige, then all stops to KøgeKøgebugtbanenAll week, all dayNordbanenLimited stops to Holte, then all stops to Hillerød
S-train service F.svgAll stops to Ny EllebjergRingbanenAll week, all dayRingbanenAll stops to Hellerup
S-train service H.svgLimited stops to FrederikssundFrederikssundbanenAll week, all dayHareskovbanenLimited stops to Farum (only during rush hour, Mo–Fr)

Before 2007, the timetable followed a principle that each named line would run on a strict 20-minute schedule. In periods where more than 3 trains an hour were needed, the extra trains would be given separate service designations; for example there was a service B+ which ran on the same route as B, but only in the daytime and with its departure times offset 10 minutes from B.

Earlier timetables also had express services that skipped stops inside the ring line.

Night services

Starting November 2009, the S-train system has had distinct night services that depart either once or twice every hour, every Friday and Saturday night. The night services are:

NameSouthern endRuns whenNorthern end
S-train service A.svgAll stops to KøgeKøgebugtbanenOnce every hourHareskovbanenAll stops to Farum
S-train service B.svgAll stops to Høje TaastrupVestbanenOnce every hourNordbanenAll stops to Hillerød
S-train service C.svgAll stops to FrederikssundFrederikssundbanenOnce every hourKlampenborgbanenAll stops to Klampenborg
S-train service F.svgAll stops to Ny EllebjergRingbanenTwice every hourRingbanenAll stops to Hellerup

With this system, there is exactly one service for each of the radials at night, stopping at every station.

Future

There are no decided expansions of the system. The needed expansion in the inner city is being performed through the Metro, which has narrower tunnels and shorter stations and therefore lower construction cost.

There has recently (especially as a result of the 2010 and 2011 winters) been suggestions by politicians and others to convert the Kystbanen railway Klampenborg-Helsingør to S-train railway, since its present traffic, the Øresundstog trains, originates from far away in Sweden and has frequent delays. This would have high cost since new rolling stock and new technical system would be needed, so this is postponed.

Technical overview

The S-trains run on standard gauge railway tracks and are powered by overhead wires. The voltage is variously quoted as 1500 or 1650 volts DC (negative overhead wire), indicating that it varies considerably with the loading and distance from a feeder station. Power is drawn from the national grid through 38 feeder stations spread around the network. The feeder stations have to be relatively close to each other because the large currents in the overhead wires (caused by the relatively low voltage) would lead to unacceptably large transmission losses otherwise.

The primary signalling system is a fixed-block cab signalling system called HKT which transmits data to the trains through low-bandwidth audio frequency induction loops between the rails. Different frequency combinations encode different target speeds; when a train enters a block with a lower target speed than its current speed it will initiate a service braking until the two match. This allows blocks to be much shorter than the full-speed braking distance, but as the braking profile is encoded in the transmitted target speed it only works where all trains have similar braking characteristics.

Lineside light signals are also provided for use in case of HKT failures or the occasional visit of a non-S-train, but the lineside blocks are longer, so capacity in this mode is reduced. Together with the finished ring-line, the exact train positions are now visible on all lines in Byens puls (see links below).

Rolling stock

The S-train has seen four types of rolling stock throughout its history. Currently, only the fourth generation trains serve the S-train network, after the retirement of the second and third generation trains in 2007 and 2006 respectively.

First generation (1934-1978)

1st generation S-train, August 1969

The first generation rolling stock (DSB class MM-FM-MM) was introduced in 1934 on the opening of the S-train, and consisted of 3 carriages per trainset (2 motor cars and 1 trailer car) which were manufactured from 1934-1962. Frichs A/S supplied the electric components while Scandia (now Bombardier Transportation Denmark) supplied the car bodies and non-electric components. The first generation trains were retired in 1978, and was kept as a heritage train until 2003, when DSB decided to permanently discontinue the use of these trains. The first generation trains are also the longest serving rolling stock on the S-train system to date, having been in continuous service for 44 years.

Second generation (1967-2007)

2nd generation S-train, August 2001

The second generation rolling stock (DSB class MM-FU-MU-FS) were built from 1967-1978 by Frichs A/S (motored cars) and Scandia (trailer cars). These trains saw the introduction of the signature red colour that was to characterise the next two generations of rolling stock.

There have been 3 different types of train units used in the second generation trains: the first (2-car) type featuring a motor car with first-class seating (can be converted to second class) and a second-class trailer car; the second (2-car) type featuring only second-class seating; and the third built as a 4-car set featuring a motor car with driver's cab, a motor-less trailer car, a motored trailer car and a driving trailer without motor.

The second generation trains ran until January 7, 2007. All MM units have been retired and scrapped except for a few set aside for museum use. An official ceremony was held on February 3, 2007 with the last ride of the 2nd generation S-trains. One of the spared museum trains will hopefully be prepared by DJK (Danish Railroad Club), who now are the owners of the train, and will eventually make its way to the tracks again on special occasions such as anniversaries.

Third generation (1986-2006)

3rd-generation S-train, 2006

The third generation trains (DSB class FC-MC-MC-FC) were built by the Swedish industrial firm ASEA from 1985-1986. Despite possessing a much improved level of passenger comfort as compared to the previous two generations of rolling stock, it suffered a much higher rate of failure as compared to its predecessors. A total of 12 trains in 4-car formation (48 cars) were built (a further 32 4-car trains were not built), and it first entered service in 1986 on the Vestbanen and Nordbanen (B service) between Holte and Høje Taastrup. The third generation trains were the first S-train rolling stock to feature electronic chopper control. In 1995, 4 trains (16 cars) were scrapped and the remaining 8 trains (32 cars) were refurbished and reassigned to the Ringbanen (F service), where they remained in service until an incident where a child was trapped between the doors of a third generation train eventually forced their early retirement in June 2006. When attempts to sell the third generation trains failed, they were transported to Holbæk harbour on August 23, 2007 to be scrapped.

Fourth generation (1996-present)

Valby station with an 8-car 4th-generation S-train, April 2002
A 4-car 4th-generation S-train with graffiti, January 2012

The fourth generation trains, in service since 1996, are currently the only train type to be serving the S-train system. They are distinguished by their plump appearance due to their curved sides.

The trains are usually 8-car articulated units (DSB class SA-SB-SC-SD-SD-SC-SB-SA, also known as Litra SA) supplied by Linke-Hofmann-Busch/Siemens with prefabricated friction stir welded aluminium roof panels made by Marine Aluminium from Sapa extrusions, and were manufactured from 1996-2007. The cars are shorter than conventional railway cars; each has a single axle under one end of the car; the other end is supported by the neighbouring car. (The end cars are exceptions and have two axles each). The units have automatic Scharfenberg couplers at the ends; in peak hours most trains consist of two coupled units, giving a total train length of 168 meters.[2] These trains are capable of speeds of 120 km/h (75 mph), but only on selected stretches of the S-train network; these trains usually reach a speed of 90 km/h (56 mph)-100 km/h (62 mph) due to the limitations of the existing signalling system, and on the Ringbanen these trains travel at 80 km/h (50 mph). These trains also feature video surveillance to ensure passengers and staff security and also to prevent against acts of vandalism. The fourth generation trains also introduced regenerative braking on the S-train network, increasing energy efficiency. At present, there are 105 8-car trains (840 cars) serving the S-train network.

An accident involving an 8-car fourth-generation train in 2002 causing it to be scrapped in Aarhus necessitated the construction of 4-car sets to relieve the shortage of trains. These 4-car units (DSB class SE-SH, also known as Litra SE) can run solo in low-traffic intervals. The top speed is 120 km/h (75 mph), although in many parts of the network their speed is limited to 90 km/h (56 mph)-100 km/h (62 mph) due to the limitations of the existing signalling system, and on the Ringbanen these trains travel at 80 km/h (50 mph).[3] At present, there are 31 4-car trains (124 cars) serving the S-train network.

Origin of the name

The letter S in "S-train" does not abbreviate any particular word. It originates in hexagonal illuminated "S" signs which were put up at stations some time before the opening of the first electrified lines in 1934. These signs may have been inspired by similar signs at the S-Bahn systems in Berlin and Hamburg, but their official purpose seems to have been to mark the location of a Station.

In February–March 1934, the newspaper Politiken asked its readers to coin a name for the new system of commuter trains. "S-train" was the winning proposal, made independently by several readers. The judges' panel (headed by the director-general of the DSB) cited a long list possible expansions in their motivation, including choices such as "state railways", "city railway", "Greater Copenhagen", "sun", "lake", "forest", "beach", "snow", "skiing", "skating", "sleigh", all of which start with an S in Danish. (It shows that the initial marketing of the S-trains emphasized recreational day trips from the city to the countryside).

See also

References

External links