Underwater tunnel construction in Rotterdam
The Calland Tunnel is a part of the project “The second Maasvlakte” whose purpose is to enlarge the Rotterdam harbour.
The Calland Tunnel is a underwater tunnel. The lowest level is at 27 metres below sea level.
There are 2 kinds of concrete elements: the on-shore ones and the tunnel elements (the sink ones).
The sink concrete elements are produced outside, in a dry dock on the offshore repair yard of Verolme Botlek in Rotterdam. They are 115 m long and 35 m wide. As they are so heavy and must be sink under water, it is more convenient to produce them in the yard and float them to their location rather than lift them.
There are 6 concrete elements, that after the construction will be refloated and pushed by tug-boats to their final location.
Our Dutch Distributor, together with our LARZEP Engineers the Hydraulic System to make possible this project and carry out the customers needs and specifications.
LARZEP got this big contract facing a very strong competition.
We produce and supplied 100 cylinders, 100 ton capacity and fully made of Aluminium.
There are 36 cylinders working in the “on-shore” concrete construction and another 36 units working in the dry dock for the sink elements. The rest are for other different uses and for spares.
The cylinders are used to support the metallic frame, the movable casket.
LARZEP had to handle the following problems: Low budget of the customer, very low weight required for each jack, simple to operate system and the need of mechanical load holding.
We upgraded the design of our standard lock-nut cylinders by including a stop ring and a spring for the retraction of the piston.
Eventhough the use of the spring, our distributor had to offer to the customer an electric pump provided with a vacuum system to improve the retraction of the piston, what was an excellent technical solution to meet the customer needs.
We supplied 100 special aluminium cylinders STMA/W10715, single acting, spring return with lock nut, stop ring and tilting saddle. Capacity 107 ton and 150 mm stroke.
Total weight of the cylinder only 39,4 kg.