Otter passage

Pressurized water sealing and turnbuckle connect precast components

Fig. 1 The otter passage beneath the federal highway B430.

Fig. 2 The turnbuckle and the precast component sealing.

“The fundamental idea of a tunnel for otters arose due to the fact that the existing tube passage was permanently blocked with branches and leaves. That the result would finally be that nice, nobody dared to imagine at the beginning,” said Helmut Brodowski, chairman of the “Gewässerunterhaltungsverband Kossau” (a water authority) and his deputy, Manfred Koch, who inspired the idea of building an underground passage at the federal road B430 in Engelau for otters and other small animals.

By means of precast elements manufactured by Fritz Witt of Weddingstedt/Germany, a locally well-known company in the field of building structures for water control and special buildings, the construction could be carried out in an extremely short period of time. The pressurized water sealing RubberElast of B.T. innovation and the corresponding tension system, the B.T.-turnbuckle (Fig. 1), allowed to connect the special precast elements immediately in a force-locked way and impermeable to pressurized water. The fact that it was not necessary to place any in-situ concrete for connecting the...