A Foster type dry dock gate was replaced in MB92 (Barcelona ).
The works involved the extraction of the old one and its hinges,
the construction of an equal replacement in the neighbouring
quay and the launching and installation of the new gate.
The key element for the extraction and installation works was the development of a set of flotation tanks that made the gates work as a barge. This tanks were installed on both gates to guarantee their buoyancy while it was towed to the scrapping or to the installation place.
The new gate was built as a replica of the old one, but improved with a series of upgrades that made it easier in operation and tougher to galvanic corrosión. The gate was preassembed in the workshop in easy moving modules, shipped by ground means and finally assembled on-site.
The hinges had to be replaced by a diver team, who disassembled the old ones from the framework, made the drills for the new screws and mounted the new hinges in a perfectly accurated operation, since a minimum deviation would had repercussions in the tight seal of the gate.