The proposal for an Alster Northern Railway was put forward by the civil engineer Heinrich Lönnies to implement the axis concept that the Hamburg architect and urban designer Fritz Schumacher had introduced in the 1920s. This provided for the Langenhorn–Kaltenkirchen area to be developed as an extension of the axis formed by the Hamburg U-Bahn line, which was operated by the Hamburger Hochbahn, but only as far as Ochsenzoll. There was no connecting line from there to Ulzburg and Henstedt. The Alster Northern Railway was opened on 17 May 1953. Though it was initially planned as a simple tramway or the like, it was built as a standard gaugelight railway to EBO standards and was thus the first newly built railway line in the Federal Republic of Germany. The tracks were, and are, only attached to the north to the Hamburg-Altona–Neumünster railway at Ulzburg Süd. In Ochsenzoll there was neither a connection to the now closed Deutsche Bundesbahnfreight railway to Ohlsdorf nor to the U-Bahn line. The line was managed from the beginning by the AKN and it also supplied the staff. It was initially operated with new battery electric multiple units from MaK and from 1956 with MAN railbuses. From the outset, the railcars were equipped with FM radio facilities. This was the first VHF train radio in Germany. The few passing places on the single track line were fitted at that time with relapse switches, so that a low-cost train control system could be carried out with little manpower. In 1981, the ANB was taken over by the AKN, which had already supplied rollingstock from 1977 onwards, and the ANB sold its rollingstock in the same year. Meanwhile, the line—now called the A2 by Hamburger Verkehrsverbund —was shortened with the gradual extension of the U-Bahn line U1 to Garstedt in 1969 and to Norderstedt Mitte in 1996. The line was duplicated between 1992 and 1996, using the Norderstedt industrial railway which had run parallel to the main line between Ulzburg Süd and Friedrichsgabe since 1973, and now ends as a single track in Norderstedt Mitte station, where there is a cross-platform transfer to the U-Bahn. In 1992, the infrastructure was transferred to Verkehrsgesellschaft Norderstedt, a subsidiary of Stadtwerke Norderstedt, the Norderstedt municipal utility. AKN continues to operate traffic on the A2 line with diesel-electric two-car multiple units, with four DMUs being the property of VGN. Freight has operated only since 20 October 1971 and only on the northern part of the line, since the connection from the Hamburgische Electricitäts-Werke was put into operation. Since 1 January 2004, it has been operated by DB Schenker Rail.
Current operations
Today, the passenger traffic on the Alster Northern Railway is operated by the AKN as line A2. Trains generally run daily between 5 am and 1 am every 20 minutes. Services are thinned out after 11 pm and on Sundays to every 40 minutes. In the Monday-to-Friday peaks between 6 am and 9 am and between 4 pm and 6 pm there is a 10-minute interval service.
