Hamburg-Altona link line


The Hamburg-Altona link line is a railway line in Hamburg, Germany. It now connects the lines from the north and west of Hamburg and Altona station with Hamburg Hauptbahnhof and the lines to the south and east. It was initially designed as a freight line only but is it now one of the busiest lines in Germany. It includes the suburban tracks of the Hamburg Stadtbahn, originally the core of the Hamburg S-Bahn.

History


The first railway connection

In 1842 the Hamburg-Bergedorf Railway Company opened a 16.5 km line from Hamburg to Bergedorf. In 1846 this line was extended to Berlin. Two years later, the Altona-Kiel Railway Company opened a line to Kiel. There was originally no link between Altona and Hamburg, so freight moving from one line to the other had to be reloaded several times, which was time-consuming and expensive. A two-track link line was therefore built between the stations.
The route of the line is affected strongly in the Hamburg area by the city's former walls. A pile bridge was originally constructed for crossing the Alster river, which was replaced in 1868 by a new bridge, the Lombardsbrücke. The railway was opened in two sections:
South of Klosterthor Station, there were provisional communication rail tracks in the streets to Berlin Station and from 1872 to Venlo Station.
30 years later, the line had already reached its limit and extra capacity had to be added.

Adding capacity and extension of the line

On 30 December 1898, Prussia, the city of Hamburg and the Lübeck-Büchen Railway Company agreed to the following elements of the link line:
The widening of the Lombardsbrücke was completed in 1901 and 1902, including the addition of the suburban line.
Even as this construction work was underway a new agreement was signed on 12 December 1904 known as the Ohlsdorfer Vertrag providing for:
Electrification was decided on by the Prussian State Railways as track operator, after it had already carried out extensive tests on the Schöneweide–Spindlersfeld line in Berlin, using overhead lines with 6.3 kV 25 Hz AC, the system which it selected for Hamburg.
In late 1906 work was completed. The urban and suburban line to Ohlsdorf was put into operation on 5 December 1906; one day later the new Hamburg Hauptbahnhof was commissioned. About a year later operations with electric trains started on the Stadtbahn and all suburban railways, making the Hamburg network the first electrified suburban rail network in Germany.

Conversion to DC and expansion of the S-Bahn

AC operations continued until the late 1930s with few service problems. However, in the meantime electric operations had been established on the Berlin S-Bahn using direct current. Since the technology in use in Hamburg had to be replaced anyway it was decided to switch to using third rail DC current. Even before this decision was made the Stadtbahn and suburban railways were designated as the S-Bahn in 1934, four years after the Berlin network was so named.
Unlike the 800 volt power used in Berlin, the voltage chosen in Hamburg was 1200 volts, which was technically, the maximum voltage that could be used in rail operations. Similarly, it was decided to use bottom contact third rail, which had a clear advantage at points, as the third-rail power would not have to be interrupted. In 1940 transition to the new system began, but, due to the war, conversion could not be completed until 1955.
From the 1960s, there was continuous expansion of the suburban rail network. Although the link line as the core of the S-Bahn had good passenger traffic, it only touches the city centre at its northern edge. Thus, a new central underground line was planned through the central area, which had more than 300,000 jobs. This required some alterations for the old main line, to allow the connection of the new underground line to the main line at the Hauptbahnhof and its reconnection to Altona station from the south. The entire Altona station building was demolished and subsequently rebuilt in a plain 1970s style. The reason for the new station building was the danger that the old station building would collapse during the construction of the tunnel. The underground S-Bahn station was built with four tracks, which allows trains to be reversed.
Since the construction of the City-S-Bahn, S-Bahn services between the Hauptbahnhof and Altona is split: lines S1, S2 and S3 now run through the tunnel and lines S11, S21 and S31 run on the old main line.

Stations

Klosterthor station is at the end the actual link line. From 1902 to 1906, the Stadtbahn was extended parallel with the Lübeck–Hamburg line to Hasselbrook where it turns toward Ohlsdorf.
On 11 December 2008, the underground S-Bahn line opened from Ohlsdorf to Hamburg Airport.

Operations

S-Bahn lines S11, S21 and S31 run on the two northern tracks of the link line. The two southern tracks are used by long-distance and regional trains. Many trains to or from the south serve not only the Hauptbahnhof, but also Altona station. The original purpose of the link line, the handling of freight traffic, is now served by the Hamburg freight bypass, running through the northern suburbs.

Footnotes