Ever since the installation in 1981 of a switchable catenary section above track 3 at Pontresina station, the Bernina Express through coaches from Chur have been hauled as far as Pontresina by a core network electric locomotive powered by 11 kV AC current. After the train stops in Pontresina, the core network locomotive is uncoupled, and the catenary section is switched to 1,000 V DC. A Bernina Railway railcar train is then manoeuvred onto the existing train. The rolling stock so added is usually made up of ABe 4/4 II or ABe 4/4 III railcars, sometimes mixed with a Gem 4/4. At the conclusion of the timetabled seven-minute halt in Pontresina, the train continues further under the DC wires and over the Bernina Pass towards Tirano.