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Engineering challenge

Saltwater was contracted by Damen for the engineering of several foundations for new machinery, the engineering of structural adjustments and providing the production- and demolition drawings on a diving support vessel.

Challenging project / Limited workspace
On board of this vessel a new Air Handling Unit and a compressor skid had to be placed. Due to the limited space on board and the size of the AHU and compressor skid it was a challenging project. Two engineers went to the vessel and had to measure the whole area where the machinery would be placed. For the AHU and compressor skid a foundation had to be designed.

The challenging part of this project was to create a foundation that did not clash with the existing structure, piping and electrical components. To place the AHU in the designated area, some structural modifications had to be done. A bulkhead had to be removed, knees and stiffeners had to be redesigned. Therefore some FEM models were made to make sure the structure was sufficient enough to withstand the loads.


Hydra A854
The Hydra is a diving support vessel that was built in 1992 and is sailing under the flag of Netherlands. The crew of the support vessel clean up explosives in the Dutch waters and are responsible for the underwater maintenance of Dutch navy vessels.


Redesigning the skid
The compressor skid had to be placed in the bow thruster room of the Hydra. The space in this room was also limited and it was not possible to fit a standard skid. The engineers created a solution for the compressor skid and created, together with the fabricator, a new design. For the loading of the machinery a hole had to be made in the hull. Therefore the construction of the vessel had to be modified. The remaining structure had to be checked for the strength of the vessel.

Hydra modifying vessel structure

Specific project data

Project information

Scope of work:

  • Foundation design of the AHU / Compressor skid
  • FEM calculation foundation
  • Production drawings


  • Production drawings of the foundations
  • Demolition drawings of the structural parts
Engineering challenge
Engineering challenge
Engineering challenge