The renewal of the metro fleet is a key component of the Berliner Verkehrsbetriebe (BVG) strategy for greater operational stability. The ongoing test runs with the new trains for lines U5 to U9 mark an important milestone. Ten cars, delivered specifically for testing, are now regularly in use for measurement runs and can often be spotted between passenger trains on the Berlin network by observant riders.

At the Friedrichsfelde depot, a completely walk-through six-car train of the new J type is now stationed for the first time. Instead of the new BVG seat pattern, the vehicle currently features a lot of exposed technology. The current tests focus on the braking behaviour of the new trains. For this purpose, the J train is being used as a six-car unit for the first time. The tests also examine how the individual components of the approximately 100-metre-long vehicle communicate with each other.

The test program leading up to approval and the start of passenger service covers all operationally and safety-relevant functions of the new trains, as well as environmental aspects. Recently, for example, noise tests were conducted. Thoroughness is the top priority in all tests, as this new generation of metro trains is expected to shape the image of Berlin’s metro system for decades to come—and, most importantly, ensure high reliability.

“The results so far make us very optimistic,” says BVG CEO Henrik Falk. “The new trains are a crucial element for more stability in the system. But it’s not just about the technology working. The trains should also help people feel comfortable in the metro — with modern design, a sense of space, and comfort. Our employees are already excited about the fleet’s modernization. Soon, our passengers will also get to experience what the future of Berlin’s metro feels like.”

In addition to the spacious interior that is immediately noticeable in the Stadler trains, passengers can look forward to several other innovations. These include newly developed and powerful passenger information systems, a new lighting concept, generous door areas, and plenty of space for all travellers — whether on foot, in a wheelchair, with a stroller, or without any luggage. Accessibility has been further improved, and BVG drivers will benefit from new controls and a more comfortable workspace.

The wider J-series vehicles are expected to enter passenger service in summer 2026. Training for drivers, maintenance staff, and station managers will begin in early 2026 to familiarize them with the new trains.

The process is already further along for the narrower JK series (K stands for “Kleinprofil” or small profile, i.e., lines U1 to U4). Staff training is in full swing. As promised, passenger service will begin after the summer holidays. At the same time, series delivery will commence. The goal is to deploy up to 140 new JK-series cars on the lines by the end of this year. Development of the smaller vehicles was prioritized because fitting the necessary technology into the tighter space is significantly more complex. The design experience gained was then applied to the development of the wider trains.

“The new J and JK series metro trains represent a technological quantum leap for Berlin’s passengers. With a fully walk-through train design and state-of-the-art communication technology, we are setting new standards in safety, comfort, and accessibility together with BVG,” says Jure Mikolčić, CEO of Stadler Division Germany.

The J and JK series represent the largest procurement order in BVG’s history. According to the framework agreement with Stadler, up to 1,500 cars can be delivered by 2035. With a total volume of up to 3 billion euros, the contract also includes spare parts supply for 32 years. The current orders cover a total of 484 cars to be delivered by 2027.