There is not just one but two separate construction pits in Grafenbrück. The reason for this is the existing road bridge over the lower head, which was rebuilt in 2013 and will be retained. In order to be able to progress the work in the lock chamber regardless of any difficulties that may arise, it was decided to divide the excavation pit into two sections.
The demolition next to and below the bridge is being carried out with constant measurement of settlements and therefore separately from the lock chamber. The aerial photo clearly shows the bridge on the left in the construction area, whose road connections had to be completely dismantled. The heavy use of construction machinery requires sufficient freedom of movement, which is why it is not possible for public road users to cross the bridge during construction.
