Fuel Contamination: What went wrong in Houston?

The investigation into what caused the contamination of fuel in the Houston area earlier this year has so far come up empty handed, with the seemingly random nature of those affected adding confusion to the task

The latest investigation into problems encountered by vessels that used residual fuels bunkered in the Houston area earlier this year has failed to come up with an explanation as to why some vessels were unaffected, while others suffered a wide variety of problems, some of them serious.

The International Council on Combustion Engines (CIMAC), organised by the International Bunk Industry Association, remains baffled and investigations are continuing.

But as more evidence emerges, the extent of the problem only grows. A number of ships had to resort to tows when their engines completely failed after bunkering the contaminated product, while others lost electrical power. According to CIMAC, the main problem involved sticking engine fuel pumps, but separator sludging and filter blockages were also reported.

While it has not been possible to identify the root cause of the incidents, the CIMAC investigation noted that a number of suppliers were affected, which indicates that an upstream incident probably contaminated the fuel delivered. The investigation has revealed that the problematic fuels were supplied by about 10 different suppliers from a range of barges. But otherwise the working group looking into the affair, which is composed of refiners, suppliers, ship operators, fuel-testing laboratories and classification societies, has come up empty-handed.

“As more evidence emerges, the extent of the problem only grows”

The absence of a definitive explanation highlights the importance of more reliable fuel testing, as lower-sulphur fuels become obligatory after January 2020. It also raises the issue of existing standards, as all the analysed fuels met the ISO 8217 Table 2 requirements.

The investigation has however turned a light on the results of the contaminated fuel, if not the cause of the contamination itself. A review of the reported cases revealed the incidences were not isolated to any specific machinery, make of components or brands of the affected separators, filters, two-stroke or four-stroke engines.

The difficulties faced by the CIMAC committee also illustrate the shortcomings of fuel-testing in general. “To complicate matters, the analytical investigations revealed that not all of these fuels had the same fingerprint parameters. And further to this, a vast majority of the ships bunkering in the affected ports during this period [May] did not report any issues, despite having received fuels which seem to have originated from the same source,” the committee reports.

Extensive analyses of the fuels was undertaken by a number of the laboratories represented within the working group. These revealed a range of “chemical species” in the fuel oils used; most were present at “very low levels” although they showed up in “more significant concentrations” in certain samples.

One of the troubling issues here is that nobody is able to say whether these unwelcome chemical species are also present in ‘good’ fuel. That means it is impossible to say at this stage whether the blending process was deficient in some way, or even whether the chemical species arrived by accident or design.

Source: www.mpropulsion.com