Debris in an engine’s lube oil system led to a diesel engine failure and an engine room fire aboard a passenger vessel docked in Portland, Maine, the National Transportation Safety Board (NTSB) said Tuesday (22 April).

The passenger vessel Ocean Navigator was moored at the Ocean Gateway Terminal on 18 October 2023, when the no. 2 auxiliary diesel generator engine suffered a catastrophic mechanical failure that seriously injured one crew member and resulted in an engine-room fire. Crewm embers secured ventilation to the engine room, and the fire self-extinguished. None of the 128 passengers onboard were injured, and no pollution was reported. Damage to the vessel was estimated at USD 2.4 million. 

After the fire, third-party technicians disassembled all components from the no. 2 auxiliary engine and found the crankshaft, several main bearings, connecting rod bearings and the no. 14 fuel injector were damaged. An additional inspection found abnormal wear on the connecting rod bearings and main bearings, which showed signs of cavitation erosion bearing damage, as well as damage from debris, which had been introduced at some point into the lube oil system.

NTSB investigators found the engine failure was caused by debris in the engine’s lube oil system—possibly due to the crew exceeding manufacturer-recommended intervals for changing the lube oil and oil filter elements—which caused catastrophic mechanical damage to the engine and a subsequent fire from the ignition of atomise lube oil released through the engine’s ruptured crankcase.

The crew had last changed the entire quantity of lube oil for the no. 2 auxiliary engine in September 2022—about 13 months before the engine failure—but the engine had operated more than 5,000 hours with this lube oil in the engine, five times longer than the manufacturer’s recommendation. Additionally, since the last change of the lube oil filter elements in May 2023, the engine had run over 3,000 hours. 

The engine manufacturer’s recommendation is to replace filter elements at every oil change or after the filter elements had been used for 1,000 hours.

“Manufacturers provide maintenance recommendations and intervals (schedules) to ensure equipment operates safely, optimally, and reliably throughout its service life,” the report said. 

“By regularly reviewing equipment manufacturer manuals and guidance, operators can ensure conformance with recommended maintenance plans and mitigate the risk of equipment malfunction or failure.” 

NTSB also found the crew’s quick action to secure engine room ventilation and engine fuel sources prevented the fire from spreading.

“Engine rooms contain multiple fuel sources as well as mechanical ventilation, making the spaces especially vulnerable to rapidly spreading fires,” the report said. 

“After an engine room fire ignites, it is imperative to remove the sources of available fuel and ventilation to the fire to prevent it from spreading. Vessel crews should familiarise themselves and train frequently on machinery, fuel oil, lube oil, and ventilation shutoff systems to quickly act to contain and suppress engine room fires before they can spread to other spaces.”

Note: Marine Investigation Report 25-13​ is available online.​

Photo credit: National Transportation Safety Board
Published: 24 April, 2025

Japan Engine Corporation (J-ENG) on Monday (21 April) said the first Japanese-developed and manufactured commercial full-scale, low-speed, ammonia-fuelled two-stroke engine has started co-firing operation with ammonia, which will be installed in a vessel. 

J-ENG is developing the engine under the “Green Innovation Fund Project: Next-generation Ship Development” of the New Energy and Industrial Technology Development Organization (NEDO). 

Since May 2023, when J-ENG started the world's first ammonia co-firing operation of a large, low-speed, two-stroke engine in a test engine, J-ENG has obtained many results and knowledge, including stable operation at high ammonia co-firing rates and safe handling of ammonia, through various test operations over a period of about a year and a half. 

J-ENG will conduct verification operations on the full-scale engine and plans to ship the engine in October of this year. The engine will be installed on an Ammonia-fuelled Medium Gas Carrier (AFMGC) and then demonstration operations of the vessel will be carried out then.

In order to accommodate a wide variety of ammonia-fueled vessels, J-ENG is also concurrently developing an ammonia-fueled engine with a cylinder bore of 60cm, following the first engine with a 50cm cylinder bore mentioned above, for several promising follow-on projects.

Furthermore, after achieving the development and social implementation of these engines, the company has decided to construct a new plant with the support of a subsidy project by the Ministry of the Environment and the Ministry of Land, Infrastructure, Transport and Tourism through the GX Economic Transition Bonds. 

The new plant, which is scheduled for completion in 2028, will expand the production of ammonia fuel engines (in the product mix with fuel oil engines) and promote the spread and expansion of zero-emission ships.

“J-ENG, as a first mover of next-generation fuel engines, will contribute to the development of the Japanese shipping and shipbuilding industries through the early launch and expansion of these engines, and at the same time, contribute to the reduction of greenhouse gases (GHG) in international shipping and the achievement of carbon neutrality by 2050,” the company said on its website.

Photo credit: Japan Engine Corporation
Published: 23 April, 2025

Steve Bee, Group Marketing and Strategic Projects Director of marine fuels testing company VPS, on Monday (14 April) explored how Fuel System Check Monitoring can play a vital role in protecting a vessel’s engine as engine damage can be a very costly risk for vessel operators:

Statistically, data indicates that a vessel will suffer between one and two incidences of main engine damage over the course of its operational lifetime. The average damage costs have been estimated at around $650,000 per incident, with even more damaging incidents costing up to $1.2 million per claim. Therefore, it is important to identify the main causes of this damage and understand how it can be prevented.

Prevention of damage is, of course, preferable to cure. Fuel quality and handling issues remain a leading contributor to critical main engine failures. VPS frequently observe that such issues could have been prevented through the implementation of a robust and well-structured fuel management programme onboard vessels.

A common misconception is that a fuel meeting the international marine fuel quality standard, ISO 8217, means it is “fit for purpose”. But this is definitely not the case as even fuels that are “on specification”, at the point of delivery to the vessel, can cause major engine damage if not properly managed post-delivery. ISO 8217 specifies the requirements for petroleum fuels for use in marine diesel engines and boilers, prior to appropriate treatment before use, which means that fuels should then be treated onboard between delivery and being burnt

Catalysts used in petroleum refining are made of Aluminium Silicates, which over time breakdown. The resulting, coarse, dense fragments composing of aluminium and silicon, eventually reside in the residual portion of the refining stream. Known as “Cat-Fines”, these particles are highly abrasive and can cause severe damage to vessel engine parts.

Major marine engine manufacturers recommend a fuel should contain less than 10-15 mg/kg Aluminium plus Silicon (Al+Si) at the engine inlet. However, assuming a delivered fuel meets the stringent ISO8217:2024 limits of 40-60 mg/kg Al+Si, dependent upon the fuel grade, the fuel treatment plant would have to operate at an efficiency level capable of removing 75%-83% of these highly abrasive particles in order to meet the engine manufacturers’ requirements.

Furthermore, the International Council on Combustion Engines' (CIMAC’s) recommendation regarding fuel quality states “Fuel analysis is the only way to monitor the quality of fuel as delivered at the time and place of custody transfer, before and after the fuel cleaning onboard and at the engine inlet. Regular monitoring of the fuel cleaning plant will provide information, which will help to make decisions about the maintenance cycles of the equipment as well as potential engine problems resulting from malfunctioning or inadequate operation.”

Yet one of the most important, but often overlooked processes, is that of regular Fuel System Checks (FSCs) in order to assess the level of aluminium and silicon catalytic fines within fuel. The presence of “cat-fines” within fuel can be extremely damaging, causing rapid engine-part wear. Monitoring cat-fine levels before they can enter vessel engines, can prevent such damage. Therefore, sending samples for analysis which are taken Before & After purification processes, on a quarterly basis is the most effective way to monitor cat-fine levels. FSCs will also help comply to the engine manufacturers general recommendation of a maximum of 10-15 mg/Kg level of cat-fines in the fuel, entering the engines and assess purifier efficiency.

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. The last thing anyone wants to see is a purifier working as a pump!

A prime example and case study is highlighted below:

An LPG Tanker bunkered HSFO in Fujairah where its fuel met ISO 8217 specifications. However, after using the bunkered fuel, the Chief Engineer reported the main engine expansion tank low level alarm, with the main engine exhaust gas temperature high on cylinder unit 2 & 4. The vessel commenced a gradual slowdown of the main engine. The Chief Engineer reported the vessel was unable to run the engine due to suspected leaks on the main engine cylinders. The vessel drifted for about 10 hours before dropping anchor off the coast of India.

Upon dismantling the engine, the following findings were made:

The VPS Technical Advisor recommended the vessel submit fuel system samples and upon checking, the results from the system, these indicated that the purifier was in fact only working like a pump.

The screening size of Al+Si on the before engine sample further confirmed why the vessel was having problems, as the physical size of Al+Si particles ranged: 5-45 µm.

The ideal particle size range of cat-fines that can be effectively removed by a marine vessel's purifier system typically falls between 5 to 15 µm. Purifiers are designed to target these smaller particles, as they are the most common size found in heavy fuel oil and can cause significant wear and damage to engine components

If the particle size of catalytic fines is greater than 15 µm, it can pose significant risks to marine engines. Larger particles are more abrasive and can cause severe wear and damage to critical engine components such as cylinder liners, piston rings, and fuel injectors.

Note: The full article by VPS can be found here. 

Photo credit: VPS
Published: 15 April, 2025