"la société des traversiers du quebec"Statement by Pierre-Paul Desgagnés, Director of Maritime Services at STQ,
quoted in the Magazine Maritime no. 22.

"The first systems tested were ultrasound flowmeters, in 1985. This was a system whose level of precision was very mediocre. In 1989, a French company replaced our ultrasound system with its own device, which consisted of two mechanical volumetric meters (with oval gears) very similar to those on supply pumps. The system did not include any means of compensating for the expansion of fuel caused by the variations of temperature.

This system produced much better results, even though we often doubted its precision, and we kept it for ten years. However, many chief engineers were dissatisfied with the results obtained. In 1997, the STQ decided to install another system on the Felix-Antoine Savard - a ferry equipped with two Caterpillar 3608 engines. This system includes a volumetric flowmeter with broad tolerance; it measures the flow in both supply and return lines. The prototype tests led us to conclude that the measurement principle was correct, even though the precision attained did not entirely meet our expectations.

So, the engineers drew up a technical specification for the product: ability to compensate for the expansion of fuel due to temperature differences; ability to compensate for changes in viscosity; enough clearance for the fuel supply to the engine not to be cut off in the event of a blockage attributable to the penetration of foreign bodies into the circuit; solid,robust construction to withstand the extreme hydraulic pulsation produced by the machine; simplicity in terms of design and installation; durable precision and reliability.

The real difficulty was in neutralizing the effect of variations in temperature; the only way in which we were able to achieve this was by using smart microprocessorized sensors. On-site testing began in 1994, in partnership with the Société d'Énergie des Territoires du North-West (SETNO). The flowmeters, sensors and calibration techniques required modification in order to improve the system's precision and reliability. During the Félix-Antoine Savard's first outings, the device was used to determine the load representing the best energetic efficiency. We compared the results obtained by operating the machines at 85% and at 95% of maximum continuous power(MCP). At 85% of MCP, the surface speed was 15.5 knots, as against 16.5 knots at 95%. The difference in fuel consumption was, however spectacular. The 10% difference allowed us to make savings of 100 litres per hour per engine. In other words, an increase in speed of one knot costs 200 litres an hour ! Without this new technology, it would have been impossible to measure this increase precisely.

In the light of the initial success obtained on board the Félix- Antoine Savard, the STQ purchased devices to equip for of its other ships. We then began to endeavour working with the officers: it was decided that the officers would record the total consumption used during their watch. They would compare their individual results during a determined period and, in the light of data provided by the system, establish a strategy aimed at optimizing consumption without sacrificing safety or reliability. They were united in this way of looking at things, and set themselves realist consumption objectives, both short-term and long-term.


Since then, on average, STQ has made savings of 45 to 50 litres per hour on each ship on which the system is used. STQ ships are in service 5,000 hours per year - by adopting a prudent hypothesis of reduction of 45 litres per hour, STQ has made savings of 225,000 litres per ship - or 48,375 dollars - per year.

STQ officers are now very much at ease with the system, and they trust both its yield and its precision. The next stage will be to set up a preventive maintenance programme based not on the hours of service, but rather on fuel consumption, which constitutes the best indication of the work of a motor."

"Last winter, an incident which arose on board the Jos Deschênes helped diagnose a problem. The chief engineer had replaced an injection-pump rack washer on one of the engines. The captain, who was unaware of this, noted that the consumption of this engine, which was normally 295 litres per hour with the normal position register, had fallen to 276 litres per hour. The consumption of the other engine was still 295 litres per hour. A more in-depth investigation revealed that the temperature of the exhaust and the resumption pressure of the engine in question were also lower.The chief engineer re-examined the washer installed and noticed that the rack needed adjustment. He used the fuel consumption monitoring system to make the adjustment, and both the temperature of the exhaust and the resumption pressure returned to normal. This anecdote confirms the usefulness of the system."