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Sydney CityRail's bi-level M-set ("Millennium Train") M33 at Hurlstone Park, July 31st, 2006. Photo by Stuart Jackson from Perthtrains |
Some general points are valid throughout the series. Don't think in lines, think in networks. Coordination, between different modes of transport, rather than rivalry, is essential. Even just in rail, one shoe doesn't fit them all. Different public transport modes for for differing kinds of travel are best different levels in a system, say:
- high-speed rail,
- express rail,
- normal stopping trains,
- rapid transit,
- metro (subway/elevated),
- light rail,
- buses.
This five-part series charts the specialities, differing best uses, and newer developments of the four categories of local rail (nos. 3-6 on the list), trying to give ideas and good examples to quote for local initiatives. This part covers rapid transit.
This series was inspired by BruceMcF's diary on various local transport modes as potential 'recruiters' for high-speed rail. Jerome a Paris was kind enough to guest-post Part 1 (on 'normal' stopping trains), while BruceMcF wrote a parallel diary emphasizing the connections to high-speed rail.
Rapid transit/commuter rail/S-Bahn
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Need for space: the eight-car SA sets (an Alstom-Siemens coproduction) on Copenhagen's rapid transit (S-tog) are wider where they can be, above platforms. Here two of them stop at Valby on line B+, October 4th, 2003. Photo by Heinz Steiner from RailFanEurope.net |
The dense inner parts of a city's commuter belt can bring very heavy traffic for a railway line, say 10-50,000 trips a day. To manage it, railways often added extra tracks, built more frequent stops, built elevated platforms to ease and accelerate boarding. They also purchased rolling stock with high acceleration and many doors, and while seats are still foreseen for most passengers, due to shorter trips toilets can be spared. Such service could even spin off as a separate network. Thus rapid transit formed, already in the steam era.
A North American example could be the Long Island Railroad.
Recognition as separate category was the clearest in late 19th century Germany, where it was called Stadtschnellbahn ( = city fast rail). Today the short form S-Bahn is a household name. By the 21st century, all major German, Swiss and Austrian cities got S-Bahn networks as the backbone of their transport system, with other networks from subways down to buses tightly integrated at stations. Most S-Bahns use electric multiple units (EMUs) with high acceleration or locomotive-pulled double-deck trains. As opposed to normal local service, the ideal is not connecting two hubs, but connecting two commuter lines: e.g., trains crossing the city, so less passengers have to transfer.
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Schematic map of Munich's S-Bahn (rapid transit) network, with U-Bahn (subway) also shown in light grey. Almost all lines pass through an East-West central artery. The inner white zone (which is magnified) is the city proper. Original map as pdf |
Often, multiple lines share the same central section in the city, which functions as an artery. This can be in tunnel, elevated, or in a loop. At any rate, the daily trips load on such sections can be in the hundreds of thousands. (In Japan, even in the millions.) There'll be more about these central arteries in the next part.
These S-Bahn networks carry the bulk of local rail passengers, and demand sustains a high level of further investments even if elected leaders aren't progressives, a level comparable to that spent on high-speed rail.
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Another high-capacity Scandinavian: Two of Stockholm rapid transit's (pendeltåg) six-car EMUS of the new X-60 series (Alstom type Coradia Lirex) at Karlberg, March 21st, 2006. Photo by Günther Glauz from Bahnbilder.de |
As an example, the Swiss canton and city of Zürich (the former has 1.27 million, the latter 370,000 inhabitants) voted in a referendum to build an S-Bahn network instead of further road construction. The plan included some new lines (mainly in tunnel under the city), new tracks and stations along existing lines, and 115 new purpose-built four-car double-deck EMUs, which should enable a timeplan that on some relations is faster than for express trains. The system started in 1990, and evolved into a monster since.
Currently, 26 lines along 380 line-kilometres serve 171 stations, carrying more than 320,000 daily passengers. Traffic growth called for several enhancements. A few years ago, a two-track line was 'doubled' by adding another two tracks for express trains in a 10-km tunnel. 120 new-generation double-deck EMUs are in delivery, while the old ones remain in service. The $1.2 billion project of adding a second central artery in a 6 km tunnel is underway. (Compare to the incredible $8.7 billion cost estimate for the 3 mile long North-South Rail Link tunnel for Boston.)
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One of Zürich S-Bahn's second-generation bi-level EMUs on a test run: RABe 514 004 on the Winterthur-Etzwilen line, March 22nd, 2006. Photo by Reinhard Reiss, from RailFanEurope.net |
So far I described systems with rather dense cores. However, less centralised areas can be served by more grid-like networks, too. The population distribution in the densest part of the Netherlands and Belgium, or the Ruhr area in Germany are more like a decentralised US sprawl. But say the Ruhr area has a well-developed S-Bahn network, overlaid on other, more local, subway and light rail systems.
There are even systems in truly countryside areas. Near the source of the Danube, lines connecting half a dozen major towns form a circle. This circumstance inspired the Ringzug concept: the integration of all local services into an S-Bahn-type service, with lines 'bending around' the ring in horseshoe shape, platforms rebuilt, new stops and some extra track. A not yet complete ring is in service since 2003, and brought significant growth.
For US conditions, I note that the 3er Ringzug system uses diesel railcars. Sydney's CitryRail also uses DMUs on some lines.
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A CityRail DMU of type Endeavour en route to Newcastle overtakes a Pacific National freight train at Maitland NSW, Australia, July 24th, 2006. Photo by Stuart Jackson from Perthtrains |
Outlook
In North America, subways and elevateds aren't treated as a category separate from rapid transit, unlike elsewhere -- so why make the distinction? What about the rapid transit systems in French-speaking areas, called RER? Find out in the next episode, to be posted on Friday (again around 13h EDT [19h my time]).
In later parts, you will also read more about the technology in newer vehicles, especially in the fourth. For a view on overall public transport development, wait for the concluding part.