Shipping Company Relies on Viscometer for HFO Combustion

Cambridge Viscosity

A Greenwich, Conn.-based shipping company has purchased a VISCOfuel 2000 viscosity control system from Cambridge Viscosity. The VISCOfuel viscometer was installed onboard one of their cargo ships this fall to monitor the viscosity of heavy fuel oil (HFO) combustion.

Prior to the VISCOfuel, the cargo vessel had been running with a malfunctioning OEM viscometer. Without consistent viscosity control, the vessel had a number of maintenance issues including blocked injectors and inefficient combustion. The new VISCOfuel directly replaced the original OEM viscometer without any modifications to the plumbing. The chief engineer and port engineer had worked with Cambridge’s VISCOpro system in the past, and came to Cambridge first because of their first-hand experience with the dependability, accuracy and robustness of the product. The upgrade was the first of the fleet, with additional upgrades planned in the near future.  

“Cambridge Viscosity viscometers were selected because of their reputation in the industry as a superior product and the company’s rapid response to the shipping company’s installation schedule,” says Cambridge president Robert Kasameyer.

The shipping company will integrate the VISCOfuel 2000 into a third-party controller already on board the vessel to maintain the viscosity of marine fuel for proper combustion.

Controlling the viscosity of heavy fuel oils has long been a challenge for the industry. In the past, machine operators maintained proper viscosity by controlling fuel oil temperature. This required establishing the proper temperature control set point to yield the correct viscosity for a given grade of fuel oil. Oil manufacturers developed viscosity vs. temperature tables for the various grades of fuel to assist operators in determining the proper set point. The problem with this method was that fuel oil viscosity/temperature tables were based on expected values for the various blends of heavy fuel, not the actual fuel oil batch that was to be burned.

In reality, the viscosity index for heavy fuel blends varies considerably from batch to batch. These batch-to-batch variations of viscosity index make it impossible to maintain proper viscosity control with one specific temperature set point. The difficulties caused by the inconsistency of fuel can include emissions problems, excessive maintenance and the overall inefficiency of burning.

The industry realized that not all heavy fuel oils are created equal and that in order to achieve optimal combustion, the variability of heavy fuel viscosity needed to be controlled. The result has been the successful use of inline viscometers, the ‘cruise control’ of heavy fuel viscosity management.

Operators simply enter a control set point and the viscometer maintains it even if the viscosity index of the fuel oil supply increases (uphill) or decreases (downhill) compared to the specification. The Cambridge viscometer used by the shipping company operates on patented electromagnetic-based sensor technology that analyzes the piston’s two-way travel time to provide a direct measure of fuel oil viscosity. The VISCOfuel 2000 also features software designed specifically for fuel oil combustion applications.

About Cambridge Viscosity
Cambridge Viscosity, a leader in advanced laboratory and production viscometer systems, provides automated viscometers used worldwide by pharmaceutical and medical device companies to optimize their product and process performance. Cambridge Viscosity's sensors and viscometer systems conform to ASTM, DIN, JIS and ISO standards, with a range of models designed to meet specific industry and application needs. Certifications include ATEX, CE, and FM. CSA certification is available upon request.

Contact Cambridge Viscosity at 781-393-6500 or e-mail For more information, visit

Subscribe to Machinery Lubrication