In 1997, Verolme shipyard at Heusden, in the Netherlands, completed the construction of the world's largest trailing suction dredger, the W.D. Fairway. Built for Royal Boskalis Westminster, it has been equipped with the latest registration and control technology, assembled in a newly developed IMC (Integrated Monitoring and Control) system. The IMC was developed and installed, in the main, by GTI Rotterdam Industrie BV with Omron supplying PLCs and system displays.

A new concept for integrated guarding and control system

W.D Fairway is the newest flagship of the Boskalis world-wide dredging fleet, which includes thirty trailing suction dredgers. The173 metre ship is built to comply with the environmental protection directions of the Green Award Association, with processing functions specifically designed to protect delicate marine environments. The ship is also equipped with leading-edge computer technology providing fully automatic guarding and control of all on-board systems and processes. The IMC-system contains Omron PLCs for control, Fast/Tools SCADA system for process visualization and operating, a number of operating stations - and Boskalis' own systems for Dynamic Positioning and Dynamic Tracking (DPDT), allowing the ship to manoeuvre and dredge within very precise parameters.

Critical Functions

The PLC control section contains seven Omron CVM1 systems, coupled by a redundant token ring fibre optics network which, in turn, is linked to the SCADA-system via a redundant Ethernet connection. All critical functions are spread over several PLCs, ensuring the uninterrupted continuation of operations in the unlikely event of a unit failure.Amongst others things, the PLC configuration controls the frequency controllers for the dredging pumps and winges and supplies the serial communication with the gyrocompass, the suction pipe angle encoders and the main motors. Additionally, statutory alarm systems have been integrated within the PLC configuration and redundant alarming is identified via twelve Omron NT-displays.

Firm agreements

The W.D. Fairway is the first dredging vessel to be built in ten years. Industrial Automation of GTI Rotterdam Industrie project managers, Marcel van Dijk and Bas Bickel, stressed the importance of the project for client and contractors alike. "The complex technologies and high investments required for the construction of a modern dredging vessel require us to look at long-term standardization. Boskalis are looking for an operational life of 25 years and demanded firm support guarantees. As a result, Omron had to guarantee the long-term availability of the hardware with an upward compatibility path for all products to ensure that older systems will be fully compatible with new developments. What's more, while all Omron equipment has a Lloyds approval, Boskalis demanded additional Bureau Veritas certification. As a result Omron has undertaken substantial investment to ensure that all devices reach BV standards."

Sister ship

The automation project was characterised by its short lead time. The initial order was placed in February of 1996 and, following an intense development programme, testing began in March 1997. Marcel van Dijk added, "Meanwhile, Boskalis had decided to construct a sister ship with GTI and Omron supplying an important part of the control automation. And because the testing software makes a perfect simulation of the hundreds of possible I/O ports, testing of the systems went very smoothly. Previously we worked with masses of switches at a test set-up; now we have a graphic reproduction of the systems on the screen. This substantially simplifies and shortens the test procedures, so installation is much quicker."

Competitively priced

Omron also distinguished itself in other fields. Bas Bickel: "There was a lot involved. They proved itself not only in the development stage, but offered total support until the day the ship departed. GTI are very pleased with Omron's equipment and people as well as their competitive pricing. Omron's field sales manager, Toon Pullens, was always on hand to help solve any problems. And our involvement with the construction of the new ship makes Boskalis Westminster's satisfaction self-evident. "
Other dredger operators have also shown their interest. It would seem that the W.D. Fairway will prove to be a promising start to a productive co-operative partnership.