German Unity Transport Project 8

Tunnel lining production

Around 48,000 tunnel lining segments are being made for the two tunnel tubes in an on-site factory. That amounts to 16 tubing rings a day.

(Graphic: DB AG)

A ring is 2 metres wide and consists of 6 tubbing segments and a keystone segment, which is about half the size. The rings are screwed together and encircled by a seal. The tunnel becomes 2 metres longer every time a tubing ring is put in place.

(Graphic: DB AG)

The tubing segments are made on site. In the on-site factory there are a number of casting moulds or formwork systems.

(Photo: DB AG)

The reinforcing steel is placed in them first,

(Photo: DB AG)

and they are then filled with concrete.

(Photo: DB AG)

The concrete hardens in a few hours.

(Photo: DB AG)

The finished tubing segment is then removed from the formwork and transported to the storage yard.

(Photo: DB AG)

Depending on requirements, up to around 1000 complete rings are kept in stock. That corresponds to about 7000 individual tubing segments.

(Photo: DB AG)