the first electrified line to Zurich. By 1927 all routes from Zürich Hauptbahnhof had been electrified. In 1933, the station's simple concourse and the iron and glass train shed were created with seven and a half arches to cover 16 tracks. As part of that work, the main shed was shortened by two segments. In the 1940s, the line between Zürich and Geneva served as a "parade route". The first lightweight steel express train had entered service on this route in 1937. By 11 June 1960, the SBB network was largely electrified. In the following year, the SBB introduced its first four-system electric trains under the Trans Europ Express banner, and thereby increased the Zürich Hauptbahnhof's international importance. In 1963, about 500 metres before the concourse, an imposing six-storey concrete cube arose in the station yard. It was designed by SBB architect , and it has been the home of the Zentralstellwerk Zürich (central signalling control) since 1966. The then state-of-the-art relay-controlled interlocking system replaced the decentralised mechanical and electro-mechanical signal boxes in the station throat, including the Stellwerk «Seufzerbrücke» ("Bridge of Sighs" signal box), which had spanned the entire station throat just east of the Langstrasse. The signalling control system was modernised to coincide with the commissioning of the Zürich S-Bahn. It is equipped with a computerised controller that performs the standard operations. Apart from the tracks and points (switches) of the "Sihlpost station" (which are controlled by an electronic control system), the entire control of the points and signals in the Langstrasse–Concourse section is still largely under relay control, in some cases with the original relay sets installed in 1966. The immense station yard, with its platform tracks and station building, is a bottleneck for the city of Zürich. The Limmat and the Sihl were further bottlenecks, and the combination of the three led to gridlock in the 1950s and 1960s. In parallel, there were plans for a subway system. Although the people voted against it in 1962, the city's Civil Engineering Department had already started to convert the Bahnhofplatz for the purpose of a possible underground line. ShopVille and S-Bahn On 1 October 1970, construction of the Bahnhofplatz, as well as the pedestrian and shopping arcade ShopVille was completed. Upon its opening, the Bahnhofplatz became a pedestrian-free zone, and the underground ShopVille the only access to the station. Contrary to expectations, ShopVille did not capture the support