Annotation page

Fast DMUs for solving timetable problems

When looking at options for rail transit in the Rogue River Valley, DMUs with very good acceleration have been considered as a possible path, but rated second. Nonetheless, information about it is added on this annotation page.

Silver DMU mirrored in a lake.
Fast, but not fast enough: The new "GTW 2/6" for revitalizing the abandoned Val Venosta line in Northern Italy.

If a railroad in Europe needs really high acceleration, it will electrify. In the USA, the economic framework is different, making high performance diesel solutions more attractive:

If high performance has to be provided with diesel, this is no technical problem, it is well within reach for DMUs. One hot candidate is the GTW 4/8 offered by Stadler (Switzerland). At this moment (April 2005), Stadler hasn't sold a single unit, because European railroads electrify instead.

Red DMU in a rural environment.
Possible appearance of a GTW 4/8. The picture was created by image editing.

But they have sold several hundred units of the base version, the GTW 2/6, a few of them to New Jersey Transit for its "River LINE" service. Current production units offer about 100 seats, have a weight of 73 tons, and provide 1046 hp for a dieselelectric AC transmission. This standard version needs 143 seconds for reaching its top speed of 87 mph, which is acceptable, but not really high performance.

A standard GTW 2/6, like the one pictured at the page top, has one engine room in the middle, and two articulated passenger compartments. A GTW 4/8 has two engine rooms, which are connected by articulations and a link car without wheels, similar to some streetcar setups. Because this version hasn't been sold yet, I have used a graphics editor for creating an image of it.

2092 hp in a rather light train, plus superior traction control with dieselelectric transmission using AC traction motors, allows to provide the acceleration of a true rapid transit system. Another possibility is provided by a completely new Stadler product, the FLIRT. At this moment (April 2005), only electric versions of this train have been sold to operators in Switzerland and Germany.

White and red articulated EMU travels through the snow.
Stadler's "FLIRT", here an EMU version for local traffic, provides level boarding at 1.8 feet platform height.

The EMU version of the "FLIRT" is one of those trains, which set the standard for modern transit solutions on mainline railroad track. With all seats occupied, it reaches 60 mph after 28 seconds, and 90 mph after 55 s. It was developed for requirements of the SBB in Switzerland. By using better performing trains, the SBB was able to establish a new service with less infrastructure upgrades, similar to the Rogue Valley example on page 47, but on a much bigger scale.

Stadler offers a diesel version of this train, shorter, 2 x 888 hp, with AC traction motors. Since the FRA's judgement is deeply rooted in the traditional ways of building railcars, it might not be prepared for calculating the dynamics of railcars without any wheels. For this reason, the FLIRT is probably the better option for the USA.

Unit conversion for text on this page.
73 tons 66000 kg
1046 hp 780 kW
87 mph 140 km/h
2092 hp 1560 kW
1.8 feet 55 cm
60 mph 97 km/h
90 mph 145 km/h
888 hp 662 kW

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Last modified: 2005-04-19