If delegates at the recent Asian Emissions Technology conference in Singapore were not aware of the care that must be taken when changing over from high sulphur to low sulphur fuel, then a presentation by a UK based ship manager was certainly a strong warning of the serious consequences of not getting it right.
A visit by Port State Control inspectors in Rotterdam resulted in a vessel being detained for 5 days – a pointer to what can happen, not only in an ECA, but also when the global sulphur limit drops to 0.50% in 2020.
What went wrong?
The vessel in question frequently moves in and out of the North Sea ECA. As such ship staff are well versed in the changeover process and had an ISM procedure clearly stating the need for pre-planning to ensure that on ECA entry the total main and auxiliary engine fuel system only contained compliant fuel, including the settling and service tanks and all associated pipelines.
The changeover process was also documented in the Chief Engineer’s standing orders and the date, time, ship position, tank volumes and relevant BDN numbers recorded for sign-off by the Chief Engineer at each changeover. The ship had a MARPOL sample and supporting BDN, showing the fuel to be compliant, so what went wrong and why was the vessel detained for so long?
Firstly, the vessel bunkered a 0.10% sulphur fuel oil as this offered a saving over the Marine Gas Oil it had used previously. While the MARPOL sample showed the fuel oil to be compliant it was bunkered into the vessel’s forward storage tanks. A transfer pump system to move fuel forward to aft was common to both high and low sulphur storage and it is believed that cross-contamination occurred during such an event.
Although MGO had quickly flushed the system of high sulphur fuel during past transfers, the 0.10% sulphur fuel appeared not to have the same cleaning effect. Laboratory analysis of a fuel sample taken by PSC inspectors showed 0.18% sulphur at the main engine. Analysis of the settling and service tank samples showed 0.15% and 0.13% sulphur.
PSC commented that the changeover procedure had not been sufficiently ship specific and did not cover the forward – aft bunker transfer process and refused to let the ship sail.
So much for so little?
Storage tanks were emptied and flushed with ultra-low sulphur automotive diesel and the settling and service tanks were hand cleaned, however, permission was not given for the vessel to depart or even to run the engine until non-compliant fuel between the service tank and engine had been removed. This required fuel pumps and pipelines to be dismantled and hand cleaned, resulting in the 5-day delay.
In this case, laboratory analysis of the samples taken by PSC was performed in a matter of hours and it is known that some authorities are using handheld x-ray fluorescence (XRF) devices for on the spot checks. The presentation made it clear that training and careful planning are vital and that there must be proper procedures and record keeping. However, while these may have all been done and the MARPOL sample and BDN may be OK, there must be attention to detail as it is the sulphur content at the engine that matters.
If a ship has to change fuels a mistake can be very costly. Just 2kg of 2.70% sulphur fuel in 1 tonne of compliant fuel risks non-compliance and action against the ship!