Maintaining tanker and supply vessel position relative to FPSOs is critical to safe loading operations and is particularly challenging in harsh environments and high latitudes poorly served by GNSS.
In response to laser targets suffering from ice riming and snow accumulation Guidance developed their RadaScan range of radar positioning sensors. Both the RadaScan (good to 1000m+) and miniRadaScan (600m) have XT (Extreme Temperature) versions capable of working to -40˚C. In 2014 these will be joined by a 10km version of Artemis for shuttle tanker operations.
Following problems in the Kara Sea with heavy sea fogs and early laser solutions, Guidance developed their CyScan sensor instead to operate in the near infrared thereby mitigating the effect of sea fog. In tests for a paper to be presented at the Houston DP conference in September the sensor was shown to work perfectly with prism targets 130m away where visibility was below 40m.
Recognising the importance of vessels being able to work in all weathers, independent of the FPSO, Guidance have developed a target-less solution for close range work. Two Guidance Range Finders triangulate the measurements from two microwave cones to provide a range and bearing into the DP system offering a year-round, all weather ³lock down² capability. This is particularly useful when supply vessel mobility is restricted when connected to the FPSO with hoses and provides users with a completely independent, additional level of safety, critical in regions where weather and currents can be harsh and erratic.
For more information at www.engineerlive.com/iog
Guidance Navigation Ltd is based in Leicester, UK.