In its latest newsletter, the Port of Montreal said it continues to be at the forefront of electronic navigation projects that will further enhance the information that is available to the 116 members of the Corporation of St. Lawrence Central Pilots. These pilots ensure the safe passage of ships between the Port of Montreal and Quebec.
“The pilots have at their disposal tools that integrate real-time data – or ‘nowcasts’ – and forecasts for essential information such as water levels and tides, as well as the position of other ships that are moving on the river,” said Daniel Dagenais, director of operations for the Montreal Port Authority.
Electronic navigation was launched about nine years ago in the port. Projects have been carried out in close collaboration with the Canadian Coast Guard, the Canadian Hydrographic Service, the Laurentian Pilotage Authority, the Corporation of St. Lawrence Central Pilots and the Corporation of Lower St. Lawrence Pilots. The federal Department of Transport, Infrastructure and Communities has invested $500,000.
Among the next electronic navigation projects is the development of a tool to measure air draft – the distance between the surface of the water and overhead obstacles. This distance fluctuates constantly because of variations in the water level. The main obstacle for ships sailing between Quebec and Montreal is the old Quebec Bridge. Water depth there varies mainly due to tides and winds. A sensor linked by a cable to a GPS antenna has been installed under the deck of the bridge and is now providing air draft information in real time. “The idea is to model the fluctuation in the air draft from the analysis of variables on which it is determined. We can then come up with a very precise forecast and provide that information to the pilot,” Dagenais said.
Fine-tuning the calculation of a ship’s under keel clearance is another project that is currently underway. A vessel’s squat refers to the hydrodynamic effect of lower pressure pulling the ship down as it moves. It is affected by the vessel’s speed in the water combined with the volume of available water around its keel, and can vary by more than one meter. To ensure safe passage, a pilot must reduce the variation by reducing the ship’s speed. Current ship squat tables do not take into account the volume of available water around the keel and the channel bed. As a result, the squat is generally overestimated, resulting in the needless reduction of a vessel’s loading capacity. The next electronic navigation tool will be able to calculate in real time the squat of a moving ship to the nearest centimeter. “The ultimate goal is make optimal use of our natural resource – water – in 2014,” Dagenais said.