Two tunnels with a length of 426.5 metres connect the northern harbour edge by the St. Pauli Landungsbrücken Piers with Steinwerder island. It’s a route that around 45,000 people took every day when the underwater crossing went into operation on 7 September 1911. It was the expansion of the “Gateway to the World” that initiated the construction of the Elbtunnel with the growing number of workers who had to get from the city to the harbour and the boatyards.

It was Europe’s first river tunnel at the time and a technical sensation that was created under the direction of the architect Otto von Stockhausen. A hydraulic shield was used to drill the tunnels through the substrate with a diameter of around 6 metres (shield tunnelling method). Approximately 4,400 workers were involved in the project, shovelling sand and soil out of the way in front of the drill shield. The hollow space created in this manner was secured with riveted steel segments (the predecessor to the modern-day tubbing method). This compressed air process prevented water from penetrating the sandy subsoil thanks to excessive pressure. The tunnel’s architecture is just as impressive now as it was then, as an antique-looking domed building leads down from the piers to the tunnel under the Elbe. The southern entrance is located on Steinwerder island and was heavily damaged in the Second World War. Originally, both buildings featured the same design, except that the building on Steinwerder island was made with red bricks so that it blended in with the surrounding customs and boatyard buildings. Tuff, basalt and granite were used in St. Pauli to complement the Landungsbrücken Piers.

Four lift cars for vehicles and bicycles, two small passenger lifts and a stairway lead almost 24 meters down the shaft buildings. It is from here that passengers reach the bright, tiled tunnel adorned with stone relief carvings depicting the Elbe world with maritime images such as sea creatures. Nowadays, the underwater tunnel has mostly lost its infrastructural significance, particularly since the construction of the New Elbtunnel. Nevertheless, numerous tourists, cyclists and pedestrians continue to use the tunnel every day, although it will soon be permanently closed to vehicles. Hamburg can no longer be imagined without its Old Elbtunnel, which has become a popular tourist attraction and a sought-after location for events, film and photo shoots. In 2003 it received landmark status and in 2011 it was declared a Historic Landmark of German Engineering by Germany’s Federal Chamber of Engineers and Hamburg’s Chamber of Building Engineers.

The project was a tremendous responsibility and a great structural challenge for Hamburg’s Port Authority (HPA), which is planning and supervising the comprehensive renovation work on the St. Pauli Elbtunnel on behalf of the city of Hamburg. The entire tubbing construction in the eastern tunnel has already been uncovered and assessed, with rivet and screw connections having been replaced and joints being sealed. The wall tiles, lane and lighting have been renewed and restored using traditional methods in close cooperation with the Foundation for Monument Protection. The tunnel was also fitted with modern technical equipment including an automatic payment system, smoke detectors and much more. After renovations on the eastern tunnel were successfully completed and it was reopened on 26 April, the restoration work has continued in the western tunnel since 3 June 2018.

Two new flights of stairs are being built for pedestrians as part of the tunnel’s renovation. The fischer injection mortar FIS EM Plus was used together with an M27 threaded rod to secure the 20-metre-tall structure on the south side. “The chemical fixing system is the safe choice for permanently carrying heavy loads in concrete even under extreme conditions such as areas prone to earthquakes”, emphasises Arne Saggau, fischer Application Field Engineer, who is providing substantial support to the project. “The ETA of our FIS EM Plus confirms a working life of up to 100 years. A report by the IEA engineering firm even confirms a working life of up to 120 years”.

In addition to secure fixing solutions, the client was also impressed by the comprehensive range of services that fischer provided to all those involved in construction throughout every stage of the project. Arne Saggau adds: “So far we have succeeded in supporting the renovation project with all fixing queries throughout the planning and implementation stage and will continue to do so until the end, be it through tension tests with 150 kN or on-site technical support”.