Safer Navigation With Disc Navigation System From Robertson Tritech

Recently conducted trials of Robertson's Disc Navigation System, an Electronic Chart Display and Information System, aboard a Norwegian paper carrier may have a great deal of impact on the future of navigation safety.

Knut Magnus Skaar, director of Seatrans A/S, a Norwegian shipping company which operates the paper carrier Nornews Express, said, "We believe this system will have the same impact on safer navigation as radar had when it was introduced in the mid-1940s." As a result, Seatrans has asked for the prototype system to be left on board pending delivery of a production Disc Navigation unit. Additionally, the company has placed orders to similarly equip two chemical tankers under construction in Germany.

Working in collaboration with Det norske Veritas, the Norwegian Hydrographic Service and the Norwegian Maritime Directorate, the Robertson Tritech A/S of Egersund, Norway, participated in the threemonth- long "Seatrans Project" to test and evaluate its Disc Navigation System on the 4,568-dwt Nornews Express during normal commercial operations in the North Sea plying between Trondheim, Oslo, Hamburg and Amsterdam. Results from these trials are being used to define final IMO and IHO standards for Electronic Chart Display and Information Systems (ECDIS).

Interfaced with a variety of sensors including GPS, ARPA radar, log, autopilot, gyrocompass and sounder, the Robertson Disc Navigation ECDIS system is intended to form the main bridge workstation.

The information received is used to superimpose the vessel's position, and that of all other vessels in the area, onto a digitized chart appearing on a large format screen and held on disc within the system.

However, it also compares the ship's position with preplanned track, navigational hazards and the course of other ships in the vicinity for any potentially dangerous situations.

Robertson Tritech's system uses official digitized charts—the legal equivalent to papers charts—prepared by the Norwegian Hydrographic Office. Some other electronic chart systems, however, may only be used as aids to navigation.

Robertson is enlisting the services of other national hydrographic agencies, incorporating standardized digitizing procedures, in order to form a database equivalent to the 2,000 paper charts needed for worldwide coverage. Each vessel can input information from its own sensors onto the chart and updates can be made automatically using the Inmarsat C satellite communication system. These updated details are stored on separate discs to avoid contamination of the official chart.

At a recent conference held aboard Nornews Express, the vessel's master, Capt. Atle Grindheim, said that he believed one of the biggest advantages was the quality of advice the system provided. For example, his ship's draft plus a suitable safety margin had been programmed- in to produce an individual safety depth color. On the Nornews Express depths shallower than this selected contour are clearly shown on the chart screen as dark blue and an alarm sounds if the vessel is on course to cross areas so colored—a feature which might have prevented the Exxon Valdez accident.

It has been suggested by some that Robertson's Disc Navigation System may well represent an economic alternative to double hulling and Seatrans regards its antigrounding features to be of pivotal importance.

Johan Hvide, vice president of Seatrans said that he thought ECDIS would become mandatory in certain areas and expected that vessels equipped with the system would be preferred by charterers with hazardous cargoes to ship, anticipating reduced cargo and hull insurance premiums.

According to DnV's principal nautical surveyor Capt. Per Larsen, it also represented the last element necessary for a true oneman bridge in all types of water.

Even before completion of the Seatrans Project, another Norwegian owner, Riebber Shipping A/S, had installed a Robertson ECDIS system on the icebreaking research/ passenger vessel Polar Circle, the latest addition to its fleet, which operates in Antarctic waters.

For free literature detailing Robertson Tritech's Disc Navugation System, Circle 97 on Reader Service Card

Other stories from May 1991 issue


Maritime Reporter

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