Alewijnse Marine from Nijmegen the Netherlands, has completed a computer control system refit of the integrated hopper control system on board three trailing suction hopper dredgers (TSHDs) belonging to DEME group, Belgium, that were built between 1999 and 2002.
With a constant drive for efficiency and the implementation of innovations, developments in automation and information technology move extremely fast. As a result, after an average of 10-15 years, systems become obsolete and are difficult to maintain due to abandoned support and a lack of spare parts.
DEME therefore, decided to refit the dredgers Nile River, Lange Wapper, and Uilenspiegel, and migrate them from the old PLC-5 i/o modules to modern CompactLogix controllers manufactured by Rockwell Automation of Milwaukee in the United States. Alewijnse has carried out the refits in a way that has saved a lot of time and money.
Traditionally, refitting a programmable logic controller (PLC) system requires a large effort in re-cabling and adapting the housing of the system.
On top of that, a re-cabling operation encompasses the risk of wiring errors. This can cause a significant downtime for the ship.
ln this case, the downtime of each dredger was limited to only a few days. First, a large part of the work was done in advance onshore, making use of components that allow a quick plug-and-play operation on board. This included the application of a special conversion kit.
Furthermore, a dedicated testing environment was created on shore. This allowed the system to be tested and any bugs repaired before work started on board'
Johan van Rikxoort, product manager for dredging and offshore at Alewijnse, also told that the company was currently working on a new project to create an innovative virtualization platform on the bridge of a dredger.
This platform will be characterised by the integration and centralisation of alt onboard systems. Systems, whatever their origin, operating system, or year of release can be migrated or connected to this centralised platform.
This will have several benefits. The most obvious is that it wilI create a clear situation for all systems on board, meaning no more different computers installed in different places, such as on the bridge and elsewhere. ln addition, it wilI save enormously on hardware costs. Two aspects considered highly important by
Alewijnse for this project are redundancy – all data is saved and synchronised in at least two different places - and safety from intrusion.