IUMI warns shipowners about damage caused by fuel impurities

International Union of Marine Insurers says there has been an increase in damage to engines from “cat fines,” with incidents costing anywhere from $300,000 to $1 million, adding that “the trend has now turned encouragingly downward.”    This is one ship’s cat you don’t want on board
   The International Union of Marine Insurers (IUMI) has warned shipping companies about the potential harm that “cat fines” can cause to ship engines in a position paper published this month.
   “Cat fines are small particles of metal that are deliberately introduced to ‘crack’ fuel to improve the efficiency of refining,” IUMI explains. “Unless removed by purification, the cat fines become embedded in engine parts and cause serious and rapid engine damage.”
   “There is an increasing requirement for ships to use low sulfur fuels, and as these require more refining the level of cat fines will increase. Low sulfur fuels are less lubricating and this, combined with the introduction of increased amounts of abrasive materials, causes damage,” it said.
   According to IUMI, “The problem has mainly affected large two stroke engines, but cases involving four stroke engines have also been reported,” with the costs of claims ranging from $300,000 to $1.5 million, “especially if ship owners take the wrong actions after the problem is diagnosed.”
   It said a rise in claims was thought to be “largely due to a lack of awareness or good practice by crews in fuel handling at the same time as global environmental legislation to reduce the levels of sulfur in ships fuel made fuel changes more common.”
   However, IUMI reports “the trend has now turned encouragingly downward,” in part due to the increased use of gas oil in Emission Control Area, where shipowners must use low sulfur fuel, and possibly because of increased awareness by owners.
   It says engines need fuel with a concentration of cat fines at no more than 15ppm, but fuel is produced and sold at 60ppm and more. Fuel must be filtered, purified and managed to prevent damage.
   IUMI noted that 40 percent of hull claims are for damaged machinery and that they make up 30 percent of claims costs.
Upcoming FreightWaves Events
Compliance

Brokerage Compliance Symposium

The day before F3. Every compliance issue you face - fraud exposure, carrier liability, FMCSA rules, cargo theft, insurance gaps - navigated by attorneys and operators defining best practices in a changing industry.

October 26, 2026
The Signal at Chattanooga Choo Choo • Chattanooga, TN
Register Now
Awards

F3 Awards Dinner

The night before F3. FreightTech100 companies honored. FreightTech 25 and Shipper of Choice winners revealed live. Cocktail reception into dinner and live music - 300 industry leaders in one purpose-built room.

October 26, 2026
The Signal at Chattanooga Choo Choo • Chattanooga, TN
Register Now
FreightTech

F3: Future of Freight Festival

Industry-defining keynotes, rapid-fire technology demos, and industry leaders networking in experiences across Chattanooga - plus the inaugural F3 Awards Dinner featuring the FreightTech and Shipper of Choice reveals.

October 27, 2026 – October 28, 2026
The Signal at Chattanooga Choo Choo • Chattanooga, TN
Register Now
Compliance Brokerage Compliance Symposium Oct 26 • The Signal at Chattanooga Choo Choo • Chattanooga, TN

The day before F3. Every compliance issue you face - fraud exposure, carrier liability, FMCSA rules, cargo theft, insurance gaps - navigated by attorneys and operators defining best practices in a changing industry.

The Signal at Chattanooga Choo Choo • Chattanooga, TN Register Now
Awards F3 Awards Dinner Oct 26 • The Signal at Chattanooga Choo Choo • Chattanooga, TN

The night before F3. FreightTech100 companies honored. FreightTech 25 and Shipper of Choice winners revealed live. Cocktail reception into dinner and live music - 300 industry leaders in one purpose-built room.

The Signal at Chattanooga Choo Choo • Chattanooga, TN Register Now
FreightTech F3: Future of Freight Festival Oct 27 – Oct 28 • The Signal at Chattanooga Choo Choo • Chattanooga, TN

Industry-defining keynotes, rapid-fire technology demos, and industry leaders networking in experiences across Chattanooga - plus the inaugural F3 Awards Dinner featuring the FreightTech and Shipper of Choice reveals.

The Signal at Chattanooga Choo Choo • Chattanooga, TN Register Now

Chris Dupin

Chris Dupin has written about trade and transportation and other business subjects for a variety of publications before joining American Shipper and Freightwaves.