Two pre-series type 1K sets will be delivered to BVG next year under a contract which includes an option for 34 production trains for delivery from 2017 onwards. "We will be carrying out extensive tests in everyday conditions in order to prove that the trains meet the high demands of regular service on the U-Bahn," says Stadler Pankow CEO Mr Michael Daum. "By working in close co-operation with BVG we have developedmodern and innovative vehicles that offer the people of Berlin and visitors to the city more comfort."

Over the next few weeks bodyshells for the pre-series second train will be fabricted at Stadler Pankow's Reinickendorf plant near Berlin.

The new trains are intended to replace the A3L71 fleet, which dates back to 1972-73. Each 51.6m-long four-car set will accommodate 330 passengers and seat 80, with full-width gangways and level boarding to aid accessibility.

The vehicles will be unusual in that they will feature a slightly curved bodyshell. This so-called "ballooning" will allow interior space to be optimised within the constraints of the narrow-profile tunnels. This provides a maximum width of 2.4m, 10cm wider than BVG's existing narrow-profile vehicles.