“SAILING THROUGH FOG”
GEM elettronica’s fiber optic gyrocompass (FOG) program is sailing smartly right on course. After having established a firm standing with its FOGs in the defense sector, the company decided two years ago to introduce the high-tech navigation system into commercial markets. Once European type approval certification was issued by Germanischer Lloyd, a first “Polaris FOG-100” was fitted last May in a sophisticated parcel chemical tanker owned and operated by one of Europe’s leading shipping companies.
The unit replaced one of the ship’s two original spinning-mass gyros; the other, housed in the wheelhouse steering console, was left in place for purposes of sensor comparison and redundancy. For the first 6 months the ship master maintained a gyro reading log where the headings of the two dissimilar gyro systems were recorded once on every 4-hour bridge watch. The vessel trades worldwide, mainly in Asia, and depends on its gyrocompasses for unwavering accuracy and stability. The ship owner, being a large company careful and methodical with introduction of new technologies into its fleet, had decided to conduct its own live testing of the new solid-state gyrocompass. The 6-month long documented testing showed that the Polaris FOG-100 gives exactly what the company was looking for: accurate heading and rate-of-turn values over time, dependable operation without breakdowns and, very importantly, zero maintenance. Shipping companies like this one spend fortunes keeping traditional “spinning-mass” gyrocompasses running. Complex instruments built around intricate clockwork mechanisms, they need regular overhauls and preventive maintenance. On the contrary, FOGs have no moving parts. In fact, the only thing moving inside them is light. No maintenance is ever needed.
“Of course,” points out Robert Edrington, director of the company’s marine electronics products division, “FOGs cost more than spinning-mass gyros and so we are currently selling to that fairly small share of ship operators willing to outlay a bit more capital today in order to enjoy a return around 7 years afterward. That’s just fine … the technology is still quite new to the commercial shipping community. Widespread adoption will take time.
That it will happen, however, there is little doubt. The design principle underlying the spinning-mass gyrocompass is now over a century old; replacement by the fibre optic equivalent is imminent.”
