Standard Cofferdams

With DZI Cofferdams, Acotec is able to restore and protect sheetpiles in submerged areas in active ports and canals without disturbing the port or canal activities. This means that this structure upgrade can be finished while a continued income of the structure is guaranteed for the client!

The proprietary DZI Limpet Cofferdams (=Dry Zetting Installations) are used to dewater a quay wall construction in a safe and dry manner. Divers are not necessary to place or dewater the cofferdam. The caisson is standard about 6 meters wide and can be built up to the requested depth as it is modular. The maximum depth so far is 20 meters down from the capping beam. These structures are usually found in ports and harbors where transatlantic ships anchor.

A cofferdam is provided with different safety features, dewatering equipment, underwater illumination, air separation equipment, liftable grit flooring, an automated electrical cabinet, ladders, adjustable sealings, etc…

The cofferdam can be attached to a wide variety of quay walls. The patented sealings attach themselves to a number of different structures. Alternative solutions can be found under ‘specials’.

The cofferdam can be used from the dockside with a crane or from a fully equipped barge from the waterside. This is most practical as all equipment travels along with the barge.

A typical setup starts after dewatering with cleaning of the biofilm and vegetation with high pressure water blasting. In cases where the marine growth is too strong, power tools are used. After cleaning, the corroded holes in the sheetpiles are closed by weld repairs. After sandblast and the proper surface preparation according to ISO12944 one-layer solvent-free modified epoxy coating, HUMIDUR®, is applied. More information on the Humidur coatings can be found on the link below.
A full setup of this technology can be seen on the animation as follows:

This completely environmentally safe and accepted system is able to contain all pollution coming from the repair process: marine growth, grit from gritblasting, overspray, dust, etc…

Acotec is the only owner of this technology and works with several units every day. For local use of this technology, Acotec trains and certifies exclusive contractors who have this technology in their portfolio.

In case of interest or to find the closest licensed contractor, please contact the Acotec-headquarters.