Driveline Technology Selected for Hamburg U5 Metro

ZF Friedrichshafen will provide drivetrain technology for the new U5 subway line in Hamburg, Germany’s largest metro infrastructure project. The company will supply newly developed two-stage spur gear drives for 374 DT6 electric multiple units manufactured by Alstom for the operator Hamburger Hochbahn. The total order covers 2,992 gearbox units to support both the new line and modernization of the existing fleet.

Automated Metro Line for Urban Mobility
The U5 metro line is planned to include 24 stations across more than 29 km of track. The system will operate with fully automated, driverless trains running at intervals as short as 90 seconds. According to current estimates, the line could carry approximately 315,000 passengers per day.

To support this capacity, Hamburg ordered a new generation of DT6 metro vehicles from Alstom. These electric multiple units will operate on the U5 line while gradually replacing parts of the current fleet across the wider network.

Two-Stage Spur Gear Drive for Metro Vehicles
ZF developed the drivetrain for the DT6 vehicles as a new gearbox design tailored to urban rail applications. The two-stage spur gear drive is engineered to support a maximum axle load of 10,000 kg while transmitting motor power of 95 kW or torque of 378 Nm at 2,400 rpm.

The design incorporates an aluminium housing that reduces overall system weight. The dry gearbox weighs approximately 210 kg. Engineers also optimized the housing contour and gear geometry to reduce noise emissions during operation.

Lower oil requirements compared with alternative designs contribute to reduced maintenance needs and lower operating costs.




Maintenance and Lifecycle Considerations
The gearbox architecture includes a defined separation plane through the output shaft, allowing the gearbox to be removed more easily from the wheelset axle. This configuration simplifies wheelset overhaul procedures and reduces vehicle downtime during maintenance.

ZF will manufacture the gearbox at its facility in Friedrichshafen before delivering it to Alstom for integration into the DT6 vehicles. The first test gearbox is scheduled for delivery at the end of 2026, with series production starting in the first quarter of 2027.

Long-Term Production Program
In the initial phase, ZF will produce 384 gearboxes for the first batch of 48 vehicles. Afterward, an option allows production of approximately 20 additional vehicles per year.

Over the expected construction and deployment period of around 15 years for the U5 line, ZF plans to manufacture and deliver a total of 2,992 gearboxes for the DT6 fleet, supporting the long-term expansion of Hamburg’s automated metro network.