Diesel engine fuel switching from heavy oil to low sulfur content marine distillates as ships enter the 24-mile offshore Emission Control Area (ECA) of the California Air Resources Board has not always gone smoothly. Now comes an electronic control device, the Diesel Switch MK ll, culmination of ten years' R&D by Swedish manufacturers JOWA Technology, a tool designed to speed up the whole process while removing the wrinkles from a procedure that demands meticulous attention by ships' engineers. Earlier in the week the company, whose technology has been given a stamp of approval by classification society Germanischer Lloyd, reported orders for installation in ten ships of Norway’s Jo Tanker fleet, as well as in its newbuildings.
Tanker Jo Sycamore: Photo credit JOWA Technology
Over the past year USCG and other regulators (those in the European Union ECA too) flagged reports of failed main engine start-up, stalling, variable engine speeds at low loads as well as instances of being unable to bring an engine up to full speed following the fuel change-over. Such hiccups, some coming with an expensive rap over the knuckles, are likely to multiply exponentially as an increased number of ships enter the new North American Emission Control Area (extending 200 nautical miles from the coasts of the United States, Hawaiian Islands, Canada and the French territories) when 1% maximum sulfur-content fuel controls take effect later this year.
Research findings by the California Maritime Academy last year concluded that most operational difficulties were caused when the viscosity of the distillate fuel being injected had not been raised by heating to the recommended minimum level. This in combination with low fuel injection pressures was found to be a common cause of loss of propulsion incidents, but the research also firmly recommended that crew should be trained in the detail of proper fuel change-over procedures.
JOWA Technology Diesel Switch DS MK ll
This compact electrically powered 230 VAC computerised device, using control air at 4-6 Bar to remotely operate valves in response to received data from sensors, helps overcome most of the problems mentioned here, claimed even to allow controlled operation of the engine below the permissible temperature gradient, and then subsequent control of the minimum fuel viscosity.
The Diesel Switch will automatically precede a controlled change over of fuels (HFO to MDO and vice versa) or initiate and control a blending process, under the hands of the engineer at the software control cabinet's ‘touch screen’. A nice finish to the device comes from added data storage on SD card, with print-out to the ‘Fuel Change-over Record Book’ ready for inspection by Port State Control officials on demand.
Diesel Switch Mk ll by JOWA Technology (front & back view): Photo credit JOWA Technology