Tram-train


A tram-train, also known as a dual-system tram, is an interoperable urban rail transit system in which specially designed vehicles operate as trams on urban street-level networks and as trains on mainline railway tracks, alongside mainline trains.
By complying with both light rail and heavy rail technical and safety standards, these vehicles can use existing tram infrastructure as well as railway lines and stations, enabling a single service to operate across both networks. A tram-train combines the urban accessibility of a tram or light rail with a mainline train's greater speed in the suburbs.
The modern tram-train concept was pioneered by the German city of Karlsruhe in the late 1980s, resulting in the creation of the Karlsruhe Stadtbahn. This concept is often referred to as the Karlsruhe model, and it has since been adopted in other cities such as Mulhouse in France and in Kassel, Nordhausen and Saarbrücken in Germany. It can be regarded as an evolution of the earlier interurban operations model.
An inversion of the concept is a train-tram – a mainline train adapted to run on-street in an urban tramway, also known as the Zwickau Model.

Technology

The tram-train often is a type of interurban — that is, they link separate towns or cities, according to George W. Hilton and John F. Due's definition.
Most tram-trains are standard gauge, which facilitates sharing track with main-line trains. Exceptions include Alicante Tram and Nordhausen, which are metre gauge.
Tram-train vehicles are dual-equipped to suit the needs of both tram and train operating modes, with support for multiple electrification voltages if required and safety equipment such as train stops and other railway signalling equipment. The Karlsruhe and Saarbrücken systems use "PZB" or "Indusi" automatic train protection, so that if the driver passes a signal at a stop the emergency brakes are applied.

History

The idea is not new; in the early 20th century, interurban streetcar lines often operated on dedicated rights-of-way between towns, while running on street trackage in town. The difference between modern tram-trains and the older interurban and radial railways is that tram-trains are built to meet mainline railway standards, rather than ignoring them. A few interurban services did share tracks with mainline steam railroads, such as the Daisy Line or East Bay Electric Lines.
In 1924, in Hobart, Australia, sharing of tracks between trams and trains was proposed.

List of tram-train systems

Asia

Europe

North America

South America

Proposed systems

Africa

Models of tram designed for tram-train operation include:

Europe