‘The overhead line is extremely sensitive’, explains Zuidasdok foreman Weijnand Stijger. ‘If it breaks, the train has to stop running. Because we’re working so close to public transport here, we need to be extra careful to prevent that. By slightly moving the overhead line by means of a temporary structure, we’re creating space, ensuring that train traffic can pass through. That means we’re also simultaneously increasing the size of the construction site where we’re building two roof sections for the extra station passageway.’ It is only possible to turn off the power if the train is not running. That’s why the work happens at night. In order to prevent disruption to normal services, the work is being done between 01.00 and 05.00.
Tubular steel piles
For the temporary overhead wire structure for the tracks, we are installing eight tubular steel piles that will be positioned at platform 2 and metro track 1 to the west of Amsterdam Zuid station. Most of the piles – 6 in all –will be drilled into position using vibration-free methods, enabling us to minimise any night-time disruption to residents. ‘Unfortunately, we can’t rule out noise altogether’, says Stijger. ‘We need to use vibratory-driven methods for two of the piles, rather than drilling. This is because of their location on the platform. We cannot access that area effectively using a drill.’ The vibratory-driven insertion of the two piles is expected to happen in the night from Monday into Tuesday (16 and 17 November). If the work is not completely finished by then, it will be resumed on the following night. The insertion itself will take no longer than 15 minutes for each pile. ‘We expect it to take us five nights to put all of the piles into position, meaning we’ll be finished by Friday.’
During the day, work will continue as normal on the second section of the additional passenger tunnel, the Brittenpassage. Stijger: ‘We’re currently working on the wooden formwork and adding reinforcement to strengthen the concrete. In December, we will pour 250 cubic metres of concrete into the formwork and this roof section will then be ready to dry. After we’ve added a protective coating and sand to this new roof section, we’ll be working from here on the next roof section in April 2021. That will ensure efficient use of the limited space.’
Second and third roof sections
Since September 2020, we have been working on two of the seven roof sections of the new passenger tunnel for Amsterdam Zuid station. The construction site we are currently using is intended for the second and third roof sections. The site is located between the metro tracks, meaning space is very limited. Despite the limited space, we are gradually making progress. The first roof section was inserted into position in November 2019, we are building the second one now, and we will work on the third next spring. Both the second and third row sections will be manoeuvred into their ultimate location in August 2021. But that is all in the future. Before we reach these milestones, there are numerous smaller jobs to complete that are no less essential. These include the work we are now doing on a temporary structure for the overhead line for the train.