Fuel oil quality survey sheds light on problems faced by owners during transition to LSFO

An industry survey into the transition to using compliant low-sulphur fuel oil since the beginning of 2020 shows that the switch hasn’t been completely pain-free for shipowners as fluctuating fuel oil properties lead to a myriad of issues.

Illustration; Image by Navingo

The survey focuses on issues such as increased sludge discharge, clogging of fuel pipes, preheaters, fuel separators and fuel filters, fuel pumps getting stuck, problems with fuel injection and poor ignition of fuel oil.

It also covers other issues regarding incomplete combustion, wax appearance and increased wear and tear of cylinder liners. These are problems that may lead to a loss of propulsion and/or black out.

The survey was carried out by BIMCO, International Chamber of Shipping (ICS), INTERCARGO and INTERTANKO from February 24 to May 6, 2020.

It targeted at shore-based personnel not the ships’ crews. Consequently, the three most frequent respondents were from technical departments (52.6%), operational functions, such as fleet and vessel management (21.9%), and bunker departments (8.3%). The dataset being analysed is based on 192 responses.

“The survey gives us valuable insight into the magnitude and nature of problems encountered by the industry in the transition to using low-sulphur fuel oil. The industry had widespread experience with how to manage heavy fuel oil, and the survey provides insight into which parameters of the new fuel types are posing the biggest challenges for onboard fuel management,” says Christian Bækmark Schiolborg, Manager, Marine Environment at BIMCO.

The survey indicates global challenges with fuel characteristics and limits being off specifications most frequently when it comes to total sediment, aluminium plus silicon, pour point, ash, flash point, acid number and viscosity.

It also indicates that most common operational problems experienced are increased sludge deposits and wax appearance after switching to the compliant fuel oils with a sulphur content not exceeding 0.50%. 

Lastly, the survey shows that when commercial fuel oil samples are tested after bunkering, sulphur content is among the most frequent parameters to be indicated as off specifications and consequently, an indication of potential non-compliance with MARPOL annex VI.

Key findings:

  • 14% of the respondents answered ‘no’ to all ten questions (Q2 to Q11) regarding off-spec and operational quality issues, which shows that some respondents had not experienced any problems at the time when responding to the survey.
  • 62% of the respondents have to some extent experienced increased sludge deposits in the fuel oil system including increased sludge discharge from the ship’s separators.
  • 32% of the respondents answered that they had experienced wax appearance in the fuel oil system e.g. in fuel oil tanks, filters etc.
  • 31% of the respondents answered that they had experienced operational issues caused by increased wear and tear of cylinder liners, piston rings or other components, assessed to be due to increased amounts of catalytic fines (cat fines) in the fuel oil.
  • 22% of the respondents answered that fuel oil had been de-bunkered as a consequence of fuel oil properties.
  • 21% of the respondents answered that they had experienced problems with fuel injection, poor ignition or incomplete combustion of the fuel.
  • 18% of the respondents answered that they had experienced fuel oil pumps seizures.
  • 10% of the respondents answered that they had experienced loss of propulsion and/or black out as a consequence of fuel oil properties.