The following works will be carried out in May and June: The western part of the Middle Lock island (number 1 in the picture) will be cleared; the cofferdam for the lock sill of the outer head (number 2 in the picture) will be removed; testing will be carried out on the new lock gates in Amsterdam and IJmuiden (number 3 in the picture); and riverbed protection will be installed behind the new fender system of the inner head of the Middle Lock.
Western part of the Middle Lock island
In the coming period the western part of the Middle Lock island will be cleared (number 1 in the picture). Various objects in this area will be dismantled and removed, such as the old flood defence structure, the old public road, several items in the subsoil, and the rip-rap protection (basalt and stone rubble) of the shore and underwater slope of the island. In this way, the island will be made ready to be dredged away in its entirety by cutter dredger 'De Biesbosch’ at a later date. In the final situation, this area will become the future approach channel to the new sea lock.
Lock sill cofferdam of the outer lock gate chamber
The lock sill cofferdam of the outer lock gate chamber (number 2 in the picture) will be removed in the coming period. This removal will take place in two phases. The upper strut frames (the large steel tubes that have kept the walls of the cofferdam in place) and the upper part of the cofferdam were removed in April. The lower strut frames will be removed as phase one in May. The remainder of the cofferdam will be submerged and subsequently removed as phase two.
Testing of the lock gate installations
Testing will be carried out on the lock gate installations in Amsterdam and IJmuiden in the coming months. Two lock gates are moored at the OpenIJ quay at Amsterdam; the third lock gate at IJmuiden (number 3 in the picture). Various installations, not visible from the outside but very important for the functioning of the new sea lock, have been installed into the lock gates. The most important parts are the 16 levelling slide gates, each measuring 3x3 metres and driven by hydraulics. During the testing process, all 16 gates will be opened and closed from a control screen several times to check if they function properly and to see if the system is reliable. In addition, the gates are equipped with a warning installation, consisting of a total of 15 signalization units and flash lights. The gates are also equipped with large water jets that will keep the rails under the lock gates free of sand. A lighting system has been installed in all the three lock gates. All these components will be extensively tested.
Riverbed protection near Middle lock
Scheduled maintenance works will be carried out by multi-technical services provider SPIE during a closure of the Middle Lock. In this period, OpenIJ will apply riverbed protection behind the new fender system of the inner head of the Middle Lock (number 4 in the picture). Part of these activities will be carried out by a crane ship while a duty cycle crane will be working on the dividing dam - the strip of land next to the fender system. The duty cycle crane will carry out the necessary digging work and will also assist the crane ship to position the riverbed protection elements in the correct place.