The locomotive, No. 3301, will operate on standard-gauge bogies for the duration of the trials at Velim. A second locomotive, No. 3302, was delivered to Finland in January for trials on the national 1524mm-gauge network.

Last April Siemens sent a Vectron fitted with broad-gauge bogies to Finland for testing ahead of the delivery of the locomotives for VR Group.

The 25kV ac 50Hz 6.4MW mixed-traffic Sr3s have a maximum speed of 200km/h and the 10 pre-series locomotives will enter service next year. Series production will begin in 2018 and the final locomotives are due to be delivered to Finland in 2026.

The locomotives have been adapted to operate in temperatures as low as -40°C and minimise the risk of water ingress from fine snow. In order to shunt non-electrified sidings at timber loading terminals, the Sr3 is also equipped with a 360kW last-mile diesel engine and remote control.

The locomotives are being assembled at Siemens' Allach plant in Munich.