Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering Transport Technology
J.G.A. van den Akker Subsea installation vessel.
Masters thesis, Report 89.3.OS.2652, Transport Engineering and Logistics / Offshore Engineering.
Installations of seabottom structures, with a dry weight of 500 tons and more, are usually carried out by semi-submersible crane vessels. Dock Express Shipping has developed a concept that is based upon a submersible barge equiped at the stern with outriggers on which a gantry crane is placed. This concept combines the good behavior in rough seas of the semi-sumersibles during installation, with the advantages of a monohull during other phases. To evaluate the opportunities this concept offers, a technical feasibility study is needed.
The technical feasibility of this concept depends on two problem areas: the stability of the vessel during various installation conditions and the dynamic behavior of the load lowering system.
If the dynamic behavior is not acceptable various methods can offer a solution. The selection of the best solution is a financial issue, of course. For a good judgement of this problem a dayprice of the vessel must be known. In the end, this dayprice also determines the decision to continue with this concept or to stop.
Reports on Transport Engineering and Logistics (in Dutch)
