The order for production trains is being funded by the Berlin Senate through its Special Infrastructure Fund for a Growing City (Siwa).
The vehicles feature a slightly curved bodyshell, which enables interior spaced 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. Each 51.6m-long set will accommodate 340 passengers,80 of them seated with full-width gangways and level boarding to aid accessibility.
The trains will be assembled at Stadler Pankow's Velten plant near Berlin with delivery scheduled for 2017.
The type IKs are intended to replace the A3L71 fleet, which dates back to 1972-73.