I recently wrote an article on the Future Of DP Systems but apparently left out an important technology; inertial navigation.
These systems have long been in use by submarines and the basics are simple. Using technology similar to the motion sensor in your iPhone, but significantly more advanced, inertial navigation tracks real time vessel motion outputting an accurate dead reckoning position of your location.
The latest implementation of this technology, Kongsberg’s DPS 4d, was recently tested by an Ocean Rig semi-submerisble on a transit through the busy Bosporus Strait. They tell us:
Ocean Rig’s semi-submersible drilling rig Leiv Eriksson has successfully navigated the Bosporus Strait using the sophisticated new DPS 4D Differential Positioning System developed by Kongsberg Maritime’s specialist position reference and satellite positioning division, Kongsberg Seatex. Leiv Eriksson is one of the first vessels to apply DPS 4D, which uses the latest advances in GPS/GLONASS technology, aided by inertial technology utilizing Kongsberg Seatex’s new high performance Motion Reference Unit, MRU 5+, to optimise signal tracking, integrity and availability for Dynamic Positioning (DP) applications under challenging GNSS conditions.
Ocean Rig reports that DPS 4D provided continuous, accurate position data during the transit of the Bosporus Strait, demonstrating integrity and availability of position data at all times.
“The Bosporus Strait is well recognised as being a hazardous area for navigation. Despite the bridges and other obstacles, which actually interrupted other satellite-based reference systems onboard, we were able to reference our position continuously, only because we had DPS 4D. The availability of position data helps to improve safety and efficiency of operations and I’m confident that DPS 4D will enhance future navigation and manoeuvring operations for Leiv Eriksson,” comments Stein Egil Svendsen, Marine Manager at Ocean Rig.