ZSSK plans six battery-electric shunting locomotives ahead of ETCS rollout

Slovakia’s national passenger operator ZSSK plans to invest €43.9 million in six battery-electric locomotives for shunting and auxiliary operations. The Slovak Ministry of Finance's Value for Money Unit (ÚHP) has recommended battery-electric traction over diesel-electric alternatives in its October 2026 assessment of ZSSK's investment plan. The six locomotives, estimated at €7.3 million each including VAT, would be divided equally between the Bratislava and Žilina regions. They would handle heavy shunting, assemble and reposition passenger train formations, transfer rolling stock between maintenance facilities and assist during operational disruptions. Implementation is planned by the end of 2030, with financing envisaged under Slovakia's 2021–2027 EU funding programme. Unlike conventional diesel shunters, the proposed locomotives would draw electricity from the overhead line on electrified tracks and use batteries on non-electrified sections. ETCS requirements drive the investment A major reason for the procurement is Slovakia's planned introduction of ETCS-only operation on the Bratislava–Žilina and Žilina–Čadca–Czech border corridors from 2031. ZSSK currently operates 45 locomotives in auxiliary services, although its regular operational requirement is 24. Their average age exceeds 40 years, and some have been in service for more than six decades. None of the locomotives currently assigned to auxiliary duties is equipped with ETCS. The replacement programme would eventually enable ZSSK to withdraw eight older locomotives: two class 210 electric locomotives and six class 721 diesels. The fleet renewal would involve cascading existing vehicles. The new locomotives would primarily replace classes 736 and 742 in Bratislava and Žilina, allowing these diesel locomotives to move elsewhere and release older class 721 machines for withdrawal. The investment is separate from ZSSK's previously reported plans for mainline dual-mode passenger locomotives, intended for routes with partially electrified infrastructure. Battery traction offers lower lifetime costs The economic assessment found that diesel-electric locomotives would cost approximately 15–20% less to purchase, but their operating expenditure would be 11–18% higher than that of battery-electric alternatives. The potential for reducing diesel consumption is substantial. Although approximately 83% of the relevant auxiliary operations take place on electrified tracks, electric locomotives currently perform only 30% of the work. The proposed battery-electric fleet could perform all these duties using electricity. The ministry estimates that operating expenditure accounts for approximately 51% of discounted lifetime costs over a 30-year period. It therefore recommends evaluating tenders on total lifecycle expenditure, including maintenance, spare parts, battery replacement and electricity consumption, rather than primarily on acquisition price. The assessment also identifies a limitation in ZSSK's economic calculations. Its baseline scenario uses the operating costs and fuel consumption of older class 721 locomotives, although the vehicles actually performing the relevant duties are classes 736 and 742. The ministry consequently considers the investment likely to deliver a positive socioeconomic return, but says the study's calculations cannot reliably establish its magnitude. Ministry recommends examining a seventh locomotive The planned allocation of three locomotives per region covers the identified operational requirement but provides no dedicated reserve. ZSSK intends to use ETCS-equipped passenger locomotives when one of the new machines is unavailable. However, this could require diesel traction for operations beyond electrified tracks. The ministry has therefore recommended examining the economic case for a seventh locomotive as an operational reserve. The final procurement evaluation will also need to account for battery replacement costs, which represent an estimated 10%…