Chevron – New Images Released Of Engine Damage Caused By Experimental Low Sulfur Ship Fuel VLSFO

Newly released images last week reveal the damage being caused by the experimental low sulfur (VLSFO) ship fuel that the global shipping industry was required to use since January last year.

The images were released by Chevron Marine Products, who have been working with ship owners and operators around the world to minimize the impact of these fuels on their ship engines.

In a press release on 18 January, the California-based company said, “Some ship owners using very low-sulfur fuel oil (VLSFO) have reported build-up of red deposits on piston crowns and top edges, sometimes combined with red iron burrs in scavenge ports. The deposits are associated with abnormal liner wear (or scuffing) since the fuel switch, particularly on older two-stroke marine engines.”

The rapid wearing out of the piston crowns can be seen in the headline image that shows the red deposits, compared to how a piston head should look like (image on right), which is more metallic and with a tight seal of piston rings around it to keep the combustion of the fuel in the correct part of the engine cylinders.

Fuel causes stress to key engine components

Chevon goes on to describe how they were working with ship owner customers to “identify and manage a distinctive engine condition challenge associated with the widespread switch to low-sulfur fuels.”

Chevron used a four-step laboratory analysis to narrow down likely causes of the abnormal liner wear on ship engines. In its statement, the company said, “Chevron found that the VLSFO blends involved showed differences from others in two fuel characteristics, typically a lower calculated carbon aromaticity index (CCAI) and high estimated cetane number (ECN).”

Heavy Fuel Oil was the dominant source of fuel until the the UN shipping regulator, the International Maritime Organization introduced regulations in January 2020 that made it compulsory to use lower sulfur fuels, known as VLSFO fuel. This resulted in one of the fastest uptakes of a new fuel in history.

In last week’s press release, Chevron described the harsher conditions that VLSFO fuel could cause to engine components and the increased stress on engine components. “Although VLSFO has been found to offer a typically higher energy value content than heavy fuel oil (HFO), and therefore can offer value for money, its combustion engine density properties can result in harsher operating conditions and more stress on the engine components. While most users transitioned smoothly, these properties can cause trouble for older engines,” said Luc Verbeeke, Senior Engineer, Chevron Marine Lubricants.

Chevron also noted that the vessels that were most at risk were older vessels that were closer to an engine overhaul. “While newer ships do not have a problem using these fuels, engines already closer to an overhaul did struggle sometimes,” said Luc Verbeeke. “Cylinder units that could have run for another six months or a year on Heavy Fuel Oil (HFO) did not survive the tougher conditions with the new fuels.”

Chevron also specifically identified deposits in the cylinder of a ship’s engine as being particularly at risk. “the deposits were found to include a compound of materials including harmless detergent additive residue and iron oxide. The detergent residue was determined not to be a source of wear as the deposits were only found in single cylinders rather than across the engine.” So although these deposits were not toxic, the physical wearing down of the engine parts poses a significant risk.

The use of specialized care for ship engines were recommended by Chevron’s engineering teams consisting of a maintenance program and routine testing. In their statement, Chevron Lubricants said, “An engine maintenance program recommended by Chevron Marine Lubricants – supported by routine testing with Chevron’s DOT.FAST onboard testing kit – helped to provide protection against liner wear and damage. Incidences of red deposits and scuffing that were relatively frequent in the early days of VLSFO operation have since reduced significantly.”

Oil sludge damage to ship engine filters

Ship engine manufacturer, Wärtsilä Marine Power, identified excessive sludge as a major issue that formed when VLSFO fuel is used, and called for ship engines to be properly maintained.

Chief Expert for Engine Fluids at Wärtsilä Marine Power, Kai Juoperi, describes the instability issues of VLSFO ship fuels. “What has been seen is mainly related to fuel treatment. Some VLSFOs have been unstable and have caused issues in separation and filtration when asphaltenes have precipitated out from solution and can caused excessive sludge formation and clogging of fuel separators and also clogging of fuel filters. If abnormal wear has taken place in power train engine components, that can be seen mainly only when scheduled engine overhauls are done and that action can take several years depending on yearly accumulated service hours of the installations in question.”

Another major ship engine manufacturer, Volkswagen-owned MAN-Energy Solutions also observed increases wear and tear for ship engines with the use of VLSFO fuels. A spokesperson for the company said, “we saw already in December 2019 – when the new low-sulfur oil began to be used – an increased wearing in the liners, both for our mechanically and electronically controlled engines. That is, scuffing, where you have accelerated wearing – metal against metal – between the piston ring and liner.”

Both Wärtsilä Marine Power and MAN-Energy Solutions have recommended a regular program of monitoring and maintenance for ship engines that use VLSFO fuels.

Environmental risks of VLSFO ship fuel

In addition to the engine risks associated with VLSFO ship fuel (Lloyds Register reported a doubling of ship cylinder related issues in 2020 associated with fuels when VLSFO was introduced compared to the same period the previous year), environmental groups have been highly critical of this new type of experimental fuel.

An alliance of 21 major environmental groups called the Clean Arctic Alliance described VLSFO fuel as a super-pollutant ‘Frankenstein Fuel’ for the way it had been mixed and how toxic it would be if leaked into the ocean. They have been calling for the fuel to be banned from the Arctic and other biodiversity sensitive regions, following reports from the German and Finnish Government that associated VLSFO fuel with having a more damaging impact on the climate.

The first time this ‘super-pollutant’ fuel was spilled into the ocean was last August in Mauritius. The 13 year old Japanese bulk carrier, the Wakashio which grounded on the reefs of Mauritius last year was using a two-stroke marine engine, which Chevron had identified as being particularly vulnerable to the effects of VLSFO ship fuel.

The vessel had been fueled in Singapore on 14 July 2020 with low-sulfur VLSFO fuel and satellite analysis by UK-based satellite analytics company Geollect, showed that the vessel had come to a complete stop in the middle of the Indian Ocean on July 17, just prior to turning toward Mauritius. The vessel operator, MOL, has not explained the sudden stop in the middle of the Indian Ocean, nor the reason to turn toward Mauritius on July 21. Photos have not yet been publicly released of the pistons of the Wakashio’s engines.

Although the Wakashio oil spill was the first time that VLSFO fuel had ever been spilled into the marine environment, unusually for a major oil spill, no chemical signature was ever taken by scientists of the oil from a sample of the oil that had not been contaminated by seawater. Officials at the U.S. Department of Interior and Woods Hole Oceanographic Institution have found this highly unusual and have called for fresh samples to be sent to them for analysis.

Trust and Transparency

As the investigation continues into the cause of the Wakashio grounding and oil spill, the newly released images of engine damage caused by VLSFO ship fuel is revealing the very real risks seafarers have to face operating such heavy machinery in the middle of the ocean with such an experimental fuel.

The only way to navigate the introduction of such fuels among regulators, seafarers, environmental groups, the shipping industry and fuel industry, is in the spirit of full transparency, backing decisions with science, and mutual trust. These are three values that the global shipping industry sorely lacks for now.