Bunker Fuel Quality

VPS: How elevated catfines can damage marine engines

VPS’ latest article highlights the dangers catfines can cause within vessel engines and how to avoid damages by using its fuel system check service.

Published

5 months ago

May 7, 2026

Admin

Marine fuels testing company VPS on Wednesday (6 May) released an article highlighting the dangers catfines can cause within vessel engines and how to avoid damages by using the VPS fuel system check service:

A common concern of maritime chief engineers, regarding vessel engine damages, is the presence of highly abrasive “catfines” within marine fuel. To fully understand the seriousness of this issue, we first need to understand the source of the problem.

Oil refineries use catalysts in their Fluid Catalytic Cracking Units (FCCU) or “Cat Plants” to process crude oils in the production of numerous products from the source crude. These catalysts are high in aluminium silicate (Al+Si) content and over time and repeated use, can breakdown and fragment into smaller particles, or catalytic fines. These catalytic fines, known throughout the industry as “Catfines” can eventually find their way into the heavier refining streams and consequently the HSFO and VLSFO fuels being burnt onboard vessels. Higher levels of catfines within the fuel can be extremely abrasive and damaging to ships engines.

It is critical to note the ISO8217 specification limit for Al+Si for residual fuels delivered to the ship, is 60 mg/Kg for all revisions post-2005. This level is significantly greater than the OEM engine inlet limit of 15mg/Kg and therefore the fuel requires efficient onboard purification, monitored via a frequent fuel-system-check, process in order to avoid potentially catastrophic engine damages.

From a recent review of more than 3,000 Fuel System Check samples taken before-purifier and after-purifier, VPS found 16% of the fuels after-purifier catfine concentrations were above the 15mg/Kg OEM limit. This indicates that some 480 vessels had purifiers failing to operate to their optimum efficiency in order to protect the engine.

At this time of the Middle East military conflict, one might suspect that refinery output around the wider region to have been impacted by crude availability, thus reducing the ultimate throughput of any refinery. However, under certain refinery operating conditions, reduced throughput may lead to higher relative concentrations of catfines in heavier streams. Thus these catfines can potentially end up in marine fuel supply chains.

In 2-stroke crosshead engines, ineffective removal of catfines can result in their entry into the combustion chamber, where they cause abrasive wear between piston rings and cylinder liners. Conversely, medium speed engines tend to be generally more tolerant, due to continuous oil circulation and filtration, but still vulnerable if catfine levels are excessive.

Another consideration within this equation is that cylinder oil (used exclusively in 2 stroke engines) is “single use” and exhausted after first use. Thus it’s overuse, in any attempt to combat catfines and minimise wear can be commercially punitive, unnecessary and in some cases contribute to damages, exacerbating the “grinding paste” effect occurring within the cylinder liners.

Cylinder lubricants are primarily a base oil, plus an additive “pack” (a combination of carefully selected compounds focused on providing various qualities e.g. Base Number (BN) to combat fuel sulphur and detergency to clean etc). However, inappropriate cylinder oil selection, or excessive feed rates may contribute to deposit formation on piston crowns and ring zones.

Over-lubrication is not an effective mitigation strategy as it may increase deposit formation and will certainly increase operating costs.

A first step to prevention of catfine damage would be in the selection of a reputable supplier, known for delivering low-catfine fuel. Data in relation to this is highlighted in the VPS PortStats application. However, its recognized on numerous occasions, the owner/operator of the ship dealing with sub-standard fuel is not the entity who purchased the fuel. Therefore, further practical considerations should also be made including, appropriate tank cleaning, circulation and movement to avoid catfine settling and concentration at much higher levels than the original test results obtained from the vessel manifold sample.

In the case of managing catfine levels above OEM engine entry limits, effective purification remains key. Statistically, a vessel will suffer one to two instances of main engine damage over the course of her operational lifetime. These costs can reach millions of dollars, far more than the average main engine damage costs of $650K highlighted in the Swedish Club paper “Engine Damage”. https://www.swedishclub.com/uploads/2023/12/TSC-Engine-Damage-WEB2023.pdf

Monitoring and Quality Control – Fuel System Checks (FSC)

It is essential that fuel samples are taken both before and after purifier. This should be carried out at regular intervals (on a quarterly basis), with increased frequency when high catfine levels are identified. In addition, whenever VPS see a vessel manifold sample with a catfine level >40kg/Kg, an alert is automatically sent to the vessel, with the instruction to take additional before and after purifier samples, as a cautionary procedure.

There are numerous reasons why regular fuel system checks are critical:

Help identify potential risks & operational issues before major damage occurs.
Confirm that the system’s flow rate, temperatures, discharge cycles are properly adjusted to handle the specific fuel that is being treated
Verify that the fuel treatment system is properly maintained
Reduce operating cost and increase lifecycles of critical components
Identify presence of unusual components that can enter fuel post- delivery.

Periodic sampling from the fuel treatment system will also identify problems such as water ingress from ballast systems, leaking heating coils and cargo contamination.

Core Operating Conditions

In addition to the FSC programme it is key to undertake the following practices:

Maintain the correct inlet temperatures as purifiers rely on centrifugal separation, enhanced by density differences. The fuel must be heated to the manufacturer-specified temperature for optimal separation and reduced carry-over.

Ensure the separator is correctly configured and operated (e.g. gravity disc selection in conventional units or proper control settings in automated systems) to avoid reduced separation efficiency, which could allow water or catfines to pass through to the engine.

Keep the feed-rate of fuel slow and steady. Running purifiers in parallel at minimum feed-rate improves separation and reduces carryover.

Match settings to oil density. Density changes with fuel grade, so adjusting settings ensures proper bowl separation.

Maintenance Practices that Directly Improve Efficiency

Clean filters and heaters regularly. Blocked filters or fouled heaters reduce flow and temperature stability, lowering purification quality.

Clean fuel tanks at scheduled intervals. This prevents high sediment and catfine concentrations from overwhelming the purifier.

Avoid by-passing any fuel-treatment equipment. By-passing risks engine damage and eliminates the purifier’s protective function.

Ensure adequate spare parts are onboard. Worn seals, gaskets, or disc stacks, reduce bowl pressure and separation efficiency.

Follow the vessel’s preventative maintenance schedule and manufacturer’s intervals. Planned maintenance ensures consistent cleaning, inspection and overhaul cycles.

Summary

So, with the recent survey by VPS finding 16% of fuels after-purifier catfine concentrations were above 15ppm, this highlights the fact, these purifiers are failing to operate to their optimum efficiency and their primary function to protect the engine.

All the above, monitoring, quality control and operational steps, are key to ensure a vessel’s engine is protected from the abrasive wear catfines can cause. Plus, by following this advice, the vessel will see an improvement in combustion efficiency due to burning cleaner fuel. This will all result in reduced downtime and repair costs, avoiding purifier failures which can lead to major engine issues.

Photo credit: VPS
Published: 7 May, 2026

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Winding up

Singapore: Marine fuel testing firm CCIC Singapore faces winding up application

Application for the winding up of CCIC Singapore Pte Ltd was filed by Hong Kong-registered CCIC International Holding Limited on 7 September, according to Government Gazette notice.

Published

1 week ago

September 15, 2026

Admin

An application for the winding up of marine fuel testing and surveying firm CCIC Singapore Pte Ltd (CCIC Singapore) was filed by Hong Kong-registered CCIC International Holding Limited on 7 September, according to a Monday (14 September) notice on the Government Gazette.

It noted the winding up application is directed to be heard before the Judge sitting in the General Division of the High Court at 10am on 2 October.

Manifold Times previously reported US Department of the Treasury’s Office of Foreign Assets Control (OFAC) sanctioned nearly two dozen firms operating in multiple jurisdictions, including CCIC Singapore.

OFAC alleged that Sepehr Energy “consistently relied” on CCIC Singapore to accomplish not only the necessary pre-delivery cargo inspections required before oil is transferred to China, but also to conceal the oil’s Iranian origins.

In late 2024, CCIC Singapore provided inspection services during a ship-to-ship transfer of approximately two million barrels of Iranian oil from the sanctioned vessel and Sepehr Energy-affiliated SIRI (IMO 9281683), formerly known as the ANTHEA.

In June 2025, CNA reported that the company laid off hundreds of workers after it was hit with the sanctions. Later, the CCIC Singapore told CNA that the layoffs were due to the impact of the sanctions which was greater than expected, and that it has ceased operations in Singapore.

According to the Government Gazette notice, any creditor or contributory of the company desiring to support or oppose the making of an order on the winding up application may appear at the time of hearing by himself or his counsel for that purpose.

A copy of the winding up application will be furnished to any creditor or contributory of the company requiring the copy of the winding up application by the solicitors of the applicant’s, Oon & Bazul LLC, on payment of the regulated charge for the same.

The Applicant’s address is 29/F, East Tower, Shun Tak Centre, 168-200 Connaught, Rd Central, Hong Kong, China.

The Applicant’s solicitors are TKQP Law LLP of 1 Wallich Street, #07-02 Guoco Tower, Singapore 078881.

Note: Any person who intends to appear at the hearing of the winding up application must send notice of such intention to the abovenamed TKQP Law LLP, the Claimant’s solicitors, within the time and in the manner set out in rule 70 of the Insolvency, Restructuring and Dissolution (Corporate Insolvency and Restructuring) Rules 2020. The notice must be in Form CIR-15 and state the name and address of the person, or, if a firm, the name and address of the firm, and must be signed by the person, firm, or his or their solicitor (if any) and must be served and, if sent by post, must be posted in such time as in the ordinary course of post to reach the address of the Claimant’s abovenamed solicitors, at least 3 clear working days before 2 October 2026 (the day appointed for the hearing of the application).

Photo credit: Manifold Times
Published: 15 September, 2026

Bunker Fuel Quality

VPS: High bunker prices meet declining fuel quality

Of the current 29 Bunker Alerts issued by VPS from January to July 2026, the combination of abrasive issues due to elevated cat-fines, plus fuel stability issues, account for 72% of these alerts.

Published

4 weeks ago

August 25, 2026

Admin

Steve Bee, Group Marketing and Strategic Projects Director of marine fuels testing company VPS, on Monday (24 August) reviewed 2026 marine fossil fuel quality to date and the high number of issues being witnessed:

Marine fuel buyers entered 2026 facing a perfect storm, suffering some of the highest bunker prices ever experienced, paired with a sharp and concerning decline in fuel quality. Across the traditional marine fossil fuel supply chain, VPS has seen a marked rise in fuel quality issues, with the Middle East conflict playing a major role in driving both price volatility and quality deterioration. For ship owners/operators, the message is clear, today’s fuel market is not only more expensive, it is also becoming more complex and unpredictable, with a higher degree of operational risk.

This deterioration is already showing itself in the test data VPS have produced. Between January and July 2026, VPS issued 29 Bunker Alerts, more than the total issued across the whole of 2024 and already closing in on the 37 alerts recorded throughout all of 2025. In just seven months of 2026, the scale and frequency of these alerts underline a clear, accelerating rise in fuel quality problems across the industry. Of the current 29 Bunker Alerts issued so far, Jan-Jul 2026, the combination of abrasive issues due to elevated cat-fines, plus fuel stability issues, account for 72% of these alerts. The ports requiring cat-fines and/or stability-related bunker alerts were, ARA, Balboa, Busan, Callao, Hamburg, Houston, Las Palmas, Philadelphia, Piraeus, Rotterdam, San Roque, Singapore and Valencia.

What is of additional interest is that marine gas oil does not account for a single Bunker Alert so far in 2026. It is HSFO and VLSFO dominating the fuels requiring such warnings.

VPS: High bunker prices meet declining fuel quality

Looking at the rate of off-specifications across each of the main marine fossil fuel types, HSFO is currently running at 8.87% of samples tested, being off-specification for at least one ISO8217 test parameter, whilst VLSFO has 9.88% off-specification level, MGO has 9.03% and ULSFOs is at 19.58%. ISO 8217 provides specification requirements for marine fuel as delivered to the ship. From a commercial perspective the fuel is only required to meet the specification at the point of custody transfer, ie at the ship’s manifold. However, compliance at this point, is not a guarantee of assurance that the fuel can be used without operational difficulties throughout its onboard lifecycle. This includes, how the fuel is stored, treat and consumed in main engines, generator engines, boilers, or other machinery. The condition of the fuel which ultimately reaches the machinery, is also strongly influenced by onboard fuel management, including storage and settling temperatures, settling time, purification temperature and throughput, purifier configuration and desludging arrangements, filtration, maintenance of the correct injection viscosity and other operational factors.

This is why knowing the characteristics of the bunkered fuel is critical to managing it correctly onboard. Appropriate testing can identify characteristics which, although not necessarily resulting in an ISO 8217 specification failure, may warrant additional operational attention. VPS therefore evaluates bunker fuels not only against the applicable specification requirements, but also provides operational advice where analytical findings indicate that additional precautions may be appropriate during storage, treatment or consumption.

VPS testing and observations, based on over 45 years of marine fuel testing experience and expertise, strongly align with a recent Linkedin post by marine and energy consultants, Brookes Bell. Their post highlighted a growing concern within the industry, stating a P&I Club had reported that bunker-related claims are up 50% this year, with many of the fuels involved having technically passed ISO8217 standard specification testing.

The same post noted that some ISO8217-compliant fuels have still caused operational damage. This has left shipowners to manage complex evidentiary disputes after problems arose. Its key warning was clear: Standard compliance testing alone isn’t catching the problem. If “passing spec” is not necessarily the same as being “safe-to-burn”, then the critical question becomes, “What additional testing is needed to identify the real operational risks?”

VPS have recognised that for some time, the ISO8217 standard is not an all-encompassing set of tests providing the highest level of asset, crew and environmental protection. For this reason, VPS offer a range of additional tests, as well as our Additional Protection Service (APS) test bundles. For example in the case of avoiding damages from cat-fines, the Fuel System Check (FSC) service, can provide valuable information in regard to monitoring purifier efficiency and the removal of cat-fines, protecting the engine to a higher degree. Whereas, Separability Number testing, is a key compliment to the hot filtration stability tests of TSP, TSA and TSE in mitigating stability risks. Should additional cold-flow information be required, the VPS proprietary Wax Appearance Temperature (WAT) testing provides key storage and fuel transfer temperature information. Whilst the VPS chemical screening services can identify potentially harmful chemicals within a fuel before the fuel is burnt. Then more detailed Gas Chromatography Mass Spectrometry (GCMS) forensic analysis provides key information to potentially support the fuel claims process.

VPS account managers and technical specialists can help shipowners and operators determine which laboratory tests are most appropriate for their fleet, based on the fuel characteristics, vessel operations and potential risk exposure. This guidance can support the mitigation of risks linked to engine damage, SOLAS compliance, legislative requirements and wider operational reliability.

The VPS Technical Advisory Team reviews bunker analysis results together with the vessel operational observations to provide practical advice on fuel storage, handling, purification and overall fuel management. Where appropriate, additional laboratory tests, or test bundles, may be recommended to further evaluate the fuel and assist in identifying the cause of an operational issue, supporting more informed decision-making.

VPS continues to monitor regional and global fuel quality trends through its laboratory network and customer feedback. Information received from vessels experiencing similar operational issues is valuable in helping VPS identify emerging trends and provide timely technical guidance to the wider shipping industry.

Photo credit: VPS
Published: 25 August, 2026

Bunker Alerts

Low flashpoint found in Indonesia bunker fuels, alerts Maritec-Naias

Firm tested eight bunker samples representing LSMDO and B40 fuel grade from vessels that took fuel oil /bunkered in Indonesia ports, which indicated flashpoints as low as 39.5°C.

Published

1 month ago

August 13, 2026

Admin

Bunker fuel testing and marine surveying business Maritec-Naias on Wednesday (12 August) issued an alert regarding bunker samples from vessels that took fuel oil/bunkered in Indonesia showing flashpoints as low as 39.5°C:

During the period of 21 July to 04 August 2026, Maritec-Naias tested eight bunker samples representing Low Sulfur Marine Distillate Oil (LSMDO) and B40 fuel grade from vessels that took fuel oil /bunkered in Indonesia ports, which indicated Flashpoints as low as 39.5°C.

All eight fuel samples tested were sourced from a single supplier.

Regulatory Implications:

Based on the results of the eight samples tested, the fuels do not comply with the minimum flashpoint requirement of 60 °C set by SOLAS and ISO 8217.

As per SOLAS requirements, the minimum flashpoint of any fuel carried in the tanks of a ship should be not less than 60 °C (with exception of fuel for lifeboats, which can be grade DMX with a flash point min of 43 °C).

ISO 4259 interpretation for tested flashpoint temperature is not taken into consideration here as the safety of onboard crew and vessel is of higher precedence.

Since 01 May 2024, it has been a MARPOL Annex VI requirement that the Bunker Delivery Note (BDN) includes either the actual flashpoint of a fuel as supplied or a declaration that its flashpoint has been determined as being at or above 70°C.

From 1 January 2026, SOLAS amendments clarified that the flashpoint requirement applies to fuels, which were specifically intended to have a flashpoint not less than 60°C as required under SOLAS II‑2/2.1.1 These amendments now align with MARPOL by requiring flashpoint details to be recorded on the BDN. Additionally, prior to bunkering, suppliers must provide the ship’s representative with a signed declaration confirming that the fuel meets the SOLAS flashpoint standard.

MARITEC-NAIAS RECOMMENDATIONS

When ordering fuels from Indonesia it is advised to insist on getting the actual flash point values from the supplier. If your vessel has bunkered a low flashpoint fuel it is prudent to observe/implement the precautions below:

Flame screens on tank vents should be maintained in good condition and there should be no sources of ignition in the vicinity of the vents. This will assist in safe natural ventilation of volatile components in the fuel.
No Smoking, no naked flame and no hot work must be allowed at any areas near to tank air vents.
Send additional tank(s) samples upon arrival in port to check the fuel properties and flash point results especially if there has been co-mingling of fuels in bunker tanks
If the vessel is out at sea, it may be possible to obtain dispensation from your Flag State Administration up to the next arrival port.
Put the supplier on notice promptly and notify your P&I club.

Photo credit: Shaah Shahidh on Unsplash
Published: 13 August, 2026