Refitting tankers

In 2006/2007 a design concept was devised and elaborated in more detail by our office together with Nederlof Shipbuilding in Geertruidenberg to convert single-walled tankers into double-walled tankers. In the mean time two tankers (“Calendula 12” and the “Treasury”) have been very satisfactorily refitted using this design concept.

Extensive refits have been completed in the shipyard in Geertruidenberg, for which the refit drawings for the Class and the so-called working drawings were first completed by our office for the shipyard. Intact and damage stability calculations were performed professionally.

First the self-propelled tanker was professionally surveyed and mapped in minute detail. Then a design concept was devised, in which straightforward construction using new materials at a reasonable price was the objective.

First the tanks were made and after this the ship was put into dry dock, ensuring that it was perfectly aligned. The “Calendula 12” was first metal-cut through the middle, for the purpose of extending the length of the tanker by another 20 meters. After this the extension section was fitted inbetween and the new tanks were hoisted and lowered down into the existing and extended hull.

A big job that was perfectly completed and for which it was established that surveying and mapping the existing ship in minute detail during the start phase proved very important and crucial for the success of this project. This was also experienced as crucial for the second ship.

In short, two projects that ran very successfully and are worth emulating. They are also a good example of how two serious businesses that start to work with one another can actually guarantee success.
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Engineering work
Do you know that, in addition to the routine survey work, we are also able to assist you in preparing, implementing and finishing your
(re-)construction work?
Propeller shafts
With renewal of the certificate after 01 January 2015, all the shaft ceilingducts of rudder stocks and of (propeller)shafts need to be conducted, so, that no water polluted lubricants can come out. This means that, also for existing ships, rudder stocks and propeller shafts should provide an outer seal. We advise you, when a rudder stock or propeller shaft must be disassembled for example (damage)repair, to use the opportunity to place an outer seal, including any modification of the rudder stock or propeller shaft.