Ferry fuel: from too dirty to measure to ISO 16/14/11

A ferry operator had its fuel examined at two stages: as delivered by the fuel supplier to the operator’s bunker barge, and as delivered on from the barge to the ferries.

The delivered fuel already failed: ISO 20/18/12 with 7,274 particles above 4 µm per ml, where the engine manufacturer’s requirement for engines with common rail and unit injectors is ISO 18/16/13 and no more than 2,500. The fuel from the bunker barge’s own tank was worse still. The independent laboratory could not measure it: the sample was too contaminated to give a meaningful particle count, because the barge’s tank added its own contamination on top.

A 20-litre drum of fuel from the barge’s tank was sent to the manufacturer and filtered with a DX-1001-T-PT fitted with an inline particle counter. The counter went from ISO 24/23/22 at the start to 15/14/13 after 15 minutes and 14/13/12 after 25 minutes, and the micropatch samples changed from dark grey to white. The independent laboratory analysis of the filtered fuel showed ISO 16/14/11 with 434 particles above 4 µm per ml, well within both the minimum standard and the engine manufacturer’s requirements.

The test was carried out on a sample at the manufacturer’s facility, not as an installation on board. It documents two things: that fuel can already be outside the requirements on delivery and then be further contaminated by the tank it is stored in, and that filtration can bring it back within the requirements.