The Rhaetian Railway ABe 4/4 III is a class of metre gauge electric multiple unit railcars of the Rhaetian Railway (RhB), which is the main railway network in the Canton of Graubünden, Switzerland.
The class is so named because it was the third class of railcars of the Swiss locomotive and railcar classification type ABe 4/4 to be acquired by the Rhaetian Railway. According to that classification system, ABe 4/4 denotes an electric railcar with first and second class compartments and a total of four axles, all of which are drive axles.
Acquired in 1988 and 1990, the six railcars in the class are numbered 51 to 56. They operate on the 1,000 V DC powered Bernina Railway, where they have helped to cope with increasing traffic. Over the years, they have also displaced the earlier ABe 4/4 I class railcars into lower level services.
The ABe 4/4 III class was manufactured by the Swiss Locomotive and Machine Works (SLM) and ABB in two series, each of three cars. They were the first motive power on the Rhaetian Railway to use frequency changer technology together with AC induction motors. In addition, they were the world’s first DC powered railway vehicles with GTO thyristors.
Each ABe 4/4 III class railcar has a top speed of 65 kilometres per hour (40 mph) and weighs 47 tonnes (46 long tons; 52 short tons). At the time the class was delivered, it had, at 1,016 kilowatts (1,362 hp), the highest hourly power output of any Rhaetian Railway DC motive power. The class’s towing capacity is 90 tonnes (89 long tons; 99 short tons) at a gradient of 7%, and 95 tonnes (93 long tons; 105 short tons) if only bogie coaches are being hauled. The ABe 4/4 IIIs are also equipped with 12 seats in first class, and 16 second class seats.
Thanks to multiple-unit train control, each individual railcar can be operated in combination with other members of the class, and also with older ABe 4/4 II class railcars, as well as Gem 4/4 class electro-diesel locomotives. Much use is made of the ABe 4/4 IIIs’ multiple unit control systems in the Bernina Railway’s daily operations. Combined operation of two ABe 4/4 IIIs under multiple unit control theoretically leaves sufficient power reserves for the haulage of no more than a further 50 tonnes (49 long tons; 55 short tons), as the maximum towing capacity of 140 tonnes (140 long tons; 150 short tons) cannot be exceeded.
For the ABe 4/4 III class of railcars, the Rhaetian Railway chose a livery that corresponds with that of the Ge 4/4 I, Ge 4/4 II and Ge 4/4 III class electric locomotives. The dominant colour of the railcar bodies in this livery is red. Each cab front is emblazoned with a Graubünden coat of arms. Underneath a low level white coloured cheat line surrounding the railcar bodies, the chassis is dark grey. This livery was also subsequently applied to the ABe 4/4 II class railcars and the Gem 4/4 locomotives.