The Hamburg U-Bahn is a rapid transit system serving the cities of Hamburg, Norderstedt, and Ahrensburg in Germany. Although referred to by the term U-Bahn (the "U" commonly being understood as standing for "underground"), most of the system's track length is above ground. Many of the system's stations offer passenger interchanges with the city's S-Bahn system, which also has underground sections. It is operated by Hamburger Hochbahn within the Hamburger Verkehrsverbund (HVV). It was opened in February 1912, and comprises four lines serving 93 stations, with a route length of in 2019.
History In 1906 the Senate of Hamburg awarded a contract for the Elevated and Underground Railway to Siemens & Halske and AEG of Berlin. The first stretch was completed on 7 October 1906. This was followed in 1911 with the founding of the Hamburger Hochbahn Aktiengesellschaft (HHA). Thus Hamburg became the third German city (after Berlin, 1902 and Schöneberg, 1910) to have a U-Bahn (then known as the Elevated and Underground Railway (Hoch- und Untergrundbahn) as it is largely either elevated or in tunnels – not much at street level).
The construction of such a railway had long been discussed, meanwhile an elevated train was also considered. In 1906 a circular route was begun, connecting Hamburg Hauptbahnhof – Berliner Tor – Barmbek (earlier spelling: Barmbeck) – Kellinghusenstraße – Schlump – Landungsbrücken (earlier designation: Hafentor) – Rathaus – Hauptbahnhof with branches to the quarters of Eimsbüttel, Ohlsdorf and Rothenburgsort. On 15 February 1912 the first stretch of the future Ringbahn (Circle railway) between Rathaus station and Barmbek was inaugurated. The stretch included both underground and elevated sections.
Network development
By 1915 the Ringbahn and the three spurs, from Kellinghusenstraße to Ohlsdorf, from Schlump to Hellkamp (today: disused station between Oster- and Lutterothstraße) and from central station to Rothenburgsort were completed. By 1934 the extensions from Ohlsdorf to Ochsenzoll (Langenhorner Bahn), from Kellinghusenstraße to Jungfernstieg (KellJung line), and the Walddörferbahn (Forestvillages line) from Barmbek to Großhansdorf and Ohlstedt were completed.
In 1943, during the Second World War, the subway was badly damaged during 'Operation Gomorrha,' the RAF bombing of Hamburg that summer. The stretch from Hauptbahnhof to Rothenburgsort was not repaired because the district it passed through had been completely destroyed. It was five more years before the remaining network was once more completely intact.
Further additions to the network were made, starting in 1960. The KellJung line was extended via Meßberg to the central station (Hauptbahnhof). Later in 1962 the extension reached Wandsbek Markt and in 1963 Wandsbek-Gartenstadt. The total network length was .
The construction of a Durchmesserstrecke (diameter route) began in 1963. The plan was to connect Billstedt with Stellingen. The Eimsbüttel branch formed the western part of the line. The branch was extended up to Hagenbecks Tierpark in 1966. The existing terminus at Hellkamp was withdrawn from service in 1964 and a new station was built at Lutterothstraße further northwest.
The connection between Berliner Tor and Horner Rennbahn was opened in 1967. In the same year this eastern branch was extended to Legienstraße. Further extensions took place in 1969 to Billstedt and in 1970 towards Merkenstraße. The extension Ochsenzoll – Garstedt came into service in May 1969. Thus, the network total length reached .
A new core stretch of the line U2, between Schlump and Berliner Tor, became a direct connection through the city centre. Next to be brought into service were sections from Hauptbahnhof Nord to Berliner Tor in 1968, and from Schlump (low) to Gänsemarkt in 1970, then the last section, with two new platforms on the lowest level at the station Jungfernstieg under the Binnenalster, in 1973. This station, as well as Hauptbahnhof Nord, was developed as part of the U4 line that was planned at that time.
In 1985 the section to Hagenbecks Tierpark was extended to Niendorf Markt and again in 1991 as far as Niendorf Nord. In 1990 the extension Merkenstraße – Mümmelmannsberg was opened. The line extension opened in 1996 between Garstedt and Norderstedt Mitte, which replaced the southern part of the Alsternordbahn.
In 2005 the Hamburg U-Bahn had a length of some , of which are underground. It had 89 station stops.
In 2009, the U3, beginning in Barmbek, traversed the complete ring line, thereby taking over the stretch between Berliner Tor and Barmbek, which was formerly served by the U2. In order to realise a problem-free service, a redesign of the current track layout to the west of Berliner Tor was necessary. An originally planned grade separated crossing of the two lines was realised, which was left undone before due to cost. Trains coming from the city centre leave the ring at Barmbek and continue via the viaduct stretch to Wandsbek Gartenstadt. One branch leads via the Walddörferbahn to Wandsbek-Gartenstadt, a stretch formerly served by the U2.
In 2012, the U4 started operations between Billstedt and HafenCity University, sharing most of its route with the U2 and thereby increasing service on the highly used line between Berliner Tor and Billstedt. The U4 was extended further east to Elbbrücken in December 2018, providing a future S-Bahn connection.
Future development
Abandoned projects The eastern branch of the "Walddörferbahn" was originally intended to terminate at the station Beimoor, just to the north of Großhansdorf, in order to connect a proposed housing development to the public transport system. By the time work was abandoned, the station platform had already been finished and tracks had been laid. Today the remains of the station are used as a winter home for bats in the middle of a dry grass biotope.
Plans for a fourth line have been discussed since the 1970s. In those days it was planned for the line to lead from City Nord and Uhlenhorst via the city centre (Hauptbahnhof Nord and Jungfernstieg) and Altona to Lurup and Osdorfer Born. In order to link the green-field housing development at Osdorfer Born to the rest of the city as quickly as possible, a limited service on the stretch between Altona und Osdorfer Born was planned. Until the connection with the rest of the network was ready, it was intended to transport trains to the main service depot in Barmbek by flatbed trucks for maintenance. Platforms and track beds for this stretch were completed in the stations Hauptbahnhof Nord and Jungfernstieg. Preparations for tunnel constructions were made in the area of Hamburg-Altona railway station and under the motorway A 7 in Bahrenfeld. In preparation for the junction with the U1, an extra platform was built at the new station Sengelmannstraße. All these constructions remain unused to this day.
The northern surplus platform area at Hauptbahnhof Nord is currently used for the art installation Sterne by Raimund Kummer and Stefan Huber. Here several concrete stars lie over the whole platform area as if they had fallen from the sky. At the same time the southern surplus platform area is still unused in any kind of way in 2018, displaying the station as it was opened in 1968 since changes in terms of advertising spaces, station signs etc. were never applied there. However, none of those two unused platforms are accessible as they are locked with fences. Today both unused platforms appear deteriorated and large segments of the wall coverings are missing, which is because the complete station already suffered from water damage in the 1970s (and, to a smaller extent, still frequently does so today) and it was necessary to remove those segments in order to fix the leaking ceiling and walls. This also had to be done at the U2 platforms, but as those have been in service, the coverings were mounted to the walls again after all repairs were finished.
Current projects In 2015 major subway extension plans were published. They include: building a new branch from Horner Rennbahn to Horner Geest with two stations, transferring the eastern terminus of the U4 from Billstedt to the new branch terminus building a whole new U5 line running from Osdorfer Born in the west of Hamburg to Bramfeld in the east via Uhlenhorst, representing a modified and extended version of the old U4 plans from the 1970s. The first part of the route is intended to be built between Sengelmannstrasse and Bramfeld between 2022 and 2028.
Original plans also called for the U4 to be extended southward to the S-Bahn station Harburg Rathaus via Wilhelmsburg, in order to provide a second rapid transit line to serve the south of Hamburg and relieve the busy S3/S5 that is - since its opening in 1983 - the only rapid transit service for the complete borough of Harburg and nowadays operates at its capacity limit. These plans are subject of discussions in 2018 still, no actual plans have been made so far. However, the new Elbbrücken station has been constructed in a way that allows a further extension of the line in the future.
Network The Hamburg U-Bahn consists of four lines:
Line Route Trains used Firstopened Length(km) Stations Norderstedt Mitte – Jungfernstieg – Hauptbahnhof Süd – Ohlstedt / Großhansdorf DT4, DT5 1914 55.4 km 46 Niendorf Nord – Jungfernstieg – Hauptbahnhof Nord – Mümmelmannsberg DT4, DT5 1913 24.5 km 25 Barmbek – Circle – Barmbek – Wandsbek-Gartenstadt DT5 1912 20.7 km 25 Elbbrücken – Jungfernstieg – Hauptbahnhof Nord – Billstedt DT4, DT5 2012 13.3 km 11 Total: 106.4 km 91