Developed in cooperation with the
Swiss Federal Railways (SBB CFF FFS), these 98 m long four-part trains are built in 1957. Being configured as first class only, they were composed of:
- a power car with compartments for luggage, customs and the train conductor;
- a nine-compartment trailer car with 54 seats in total;
- a kitchen-restaurant trailer car with a 32-seat dining section, and an 18-seat open saloon;
- a driving trailer car with 42-seat open saloon as well as a small sleeping compartment for the on-board mechanic.
The power cars hold a pair of RUHB 1,000 metric horsepower (740 kW / 990 hp each) diesel engines as generators for the electric propulsion-engines in the motor car's bogies (maximum speed: 140 km/h) and a third 300 metric horsepower (220 kW / 300 hp) diesel engine to provide electricity for the onboard systems (like train heating, lighting, air-conditioning and for the kitchen in the dining car). These units are built by
Werkspoor (Netherlands), with electrics by
Brown, Boveri & Cie (BBC) (Switzerland).
The trailer cars are designed based on SBB's Einheitswagen I (EW I) standard carriage design. Only one entrance vestibule was provided at the front end of the cars, doors were of the folding aluminum type, and windows were double-glazed with a passenger-operated venetian blinds between the panes. These units are built by
Schweizerische Industrie Gesellschaft (SIG) (Switzerland).
A total of 5x units of this type are built:
- 2x units for the
Swiss Federal Railways (SBB CFF FFS) registered
RAm TEEI 501 - 502;
- 3x units for the
Dutch Railways (NS) registered DE4 1001 - 1003.