DB Class E 40

Deutsche Bundesbahn

Company type	State railway company
Industry	Rail transport
Founded	1949 (1949)
Headquarters	Germany

The Baureihe E 40 represents a German standard electric locomotive (Einheits-Elektrolokomotive) introduced by the Deutsche Bundesbahn in 1955 specifically for freight service. Following the renumbering in 1968, these locomotives were designated as Class 140 and Class 139.

Development

File:Lok E 40 128 (2010-04-03 39).jpg

Locomotive E 40 128

In the year 1950, the Deutsche Bundesbahn launched two primary categories of electric locomotives built with standardized parts: a twelve-wheel freight locomotive (UIC classification Co′Co′) intended to succeed the DRG Class E 94, and an eight-wheel multipurpose locomotive (UIC classification Bo′Bo′) designed as a replacement for the DB class 144. A notable innovation was the introduction of seated driver positions, replacing the previous standing arrangement.

During development, the speed criteria for a general-purpose locomotive—initially referred to as E 46 and later renamed to DB Class E 10—were raised to levels suitable for express train operation. Since only two locomotive types could not meet all operational demands, the standard electric locomotive program expanded to include four distinct categories: a light passenger train locomotive (DB Class E 41), an express train locomotive (DB Class E 10), a freight train locomotive (class E 40), and a heavy freight train locomotive (DB Class E 50). These four classes were engineered to maximize component commonality across models.

Production and Design of Class E 40

File:BR 140 bei Unkel am 25.05.2005.JPG

A BR 140 hauling a freight train north of Unkel in 2005.

The Class E 40 is essentially a variant of the Class E 10, distinguished by the absence of an electric brake, a modified gear ratio that reduces top speed while increasing tractive effort, alongside several minor modifications.

Like other locomotives in the Einheitslokomotiven series, the Class E 40 featured welded bogies with central pivot pins. Instead of the previously used axle-hung motors, it employed a quill drive system incorporating a circular rubber spring ("Gummiringfeder" in German) to connect components, which helped lower the unsprung mass. The control system offered 28 distinct power levels.

A total of 879 units were produced, establishing it as the standard locomotive of its generation.

Initially designed for a maximum speed of 100 km/h, this was increased to 110 km/h in 1969 to enhance its suitability for commuter services. A specialized subgroup, designated as 140.8, was equipped for push-pull train operations.

In 1968, the Class E 40 was renumbered to Class 140.

Subclass E 40.11

Beginning in 1959, a batch of 31 locomotives was outfitted with electrical braking systems (similar to those on all Class E 10 units) to manage steep gradients such as those near Erkrath-Hochdahl between Düsseldorf and Wuppertal, as well as on the Höllentalbahn in southern Germany. Today, these locomotives primarily operate around Munich, occasionally running services into Austria where their electric brakes are particularly advantageous. In the early 1990s, additional units classified as Class 139 (the renumbered designation from 1968) were created by fitting Class 110 locomotives with bogies and gearboxes sourced from retired Class 110 models combined with Class 140 components.

Both Classes 140 and 139 are gradually being phased out in favor of newer models like the Class 145, Class 185, and Class 189. Although it was anticipated that all units would be withdrawn before 2010, an unexpected surge in rail freight demand has led to some shortages in traction power, prompting refurbishments on selected Class 140 locomotives.

External links

• Detailed profile and photographs of the E 40 on Trainspo