Power was provided by two large Déri repulsion motors that filled almost the entire engine room.

The E 3301, equipped with auxiliary transformer windings for 15 kV operation, was tested on the Spiez - Frutigen line.

Otto Tschanz [de], the SBB's senior mechanical engineer, suggested converting the surplus locomotive into a test vehicle for the new technique of individual axle drives that were replacing coupling rods.

It was returned to Brown-Boveri and the original rod drives, traction motors and electrical equipment removed.

[i] This Tschanz drive transmitted torque via a spur reduction gear and a cardan shaft running inside a hollow axle.

The two transformers were replaced by a single one behind the first driver's cab, balancing the traction motors, and with a tap changer for power control.

On 1 June 1922, it was assigned to the Erstfeld depot to haul trains on the Erstfeld–Arth–Goldau and Erstfeld–Lucerne lines and covered an average daily distance of 224 km.

In 1925, Viktor was transferred to the Lucerne depot and hauled trains to Rotkreuz (in the Canton of Zug), Zürich and Arth-Goldau and still travelled 202 kilometres daily average.

In May 1927, traffic to Rotkreuz and Arth-Goldau increased and Viktor was put back into service and travelled 135 km every day.