Forchbahn is a narrow gauge light railway in the suburbs of the city of Zürich. Its route begins at the Stadelhofen train station near the lake Zürichsee. For the first three kilometres Forchbahn trains run on the tram rails of Zürich's tram system using 600V DC. The tramline ends at Zürich Rehalp and from there Forchbahn continues on its own tracks using 1200 V DC electricity. Forchbahn is a part of Zürich's common transportation system and its line is designated as line S18.

This is one of Forchbahn's newest trains called Be 4/6. These were built by Stadler since 2004. One unit is just like half a train: it has a driver's cab only at one end. Often a full train consists of three such new units.
Picture from Stadelhofen 9.5.2023 by Ilkka Siissalo.

The same train as above. It consists of three Be 4/6 units and is therefore really long.
Picture from Stadelhofen 9.5.2023 by Ilkka Siissalo.

The previous generation of Forchbahn trains. The motor wagon is designated Be 4/4 and they are usually operating together with motorless wagons named Bt. The Be 4/4 is based as a design on the trams of the type "Tram 2000" of the city of Zürich. There are individual motor wagons Be 4/4, then there are pairs of them coupled permanently back to back and designated Be 8/8 and then there are the motorless driving trailer wagons Bt already mentioned. These entered service since 1976.
Picture from Stadelhofen 9.5.2023 by Ilkka Siissalo.

One Be 4/4 motorwagon seen from behind.
Picture from Stadelhofen 2.10.2015 by Ilkka Siissalo.

A Forchbahn train consisting of two motor wagons Be 4/4 pus one driving trailer (behind, cannot be seen). On the left a Zürich city tram of the tram type Tram 2000 which is very similar.
Picture from Stadelhofen 2.10.2015 by Ilkka Siissalo.

Zürich trams of the type Tram 2000 are articulated, they have a bending joint in the middle. They are also much longer than Forchbahn's Be 4/4 motor wagons.
Picture from Stadelhofen 2.10.2015 by Ilkka Siissalo.