The project defines VHFO as fuel oils with a viscosity at 50ºC of 380 cSt or higher. Experiences of previous spills including the Erika in 1999 and Prestige in 2002 demonstrated such oil is difficult, time consuming and expensive to clean up. While UK resources are focused on dealing with spills through the use of dispersants, there are limited stocks of the heavy oil recovery equipment such as the booms and skimmers required for heavier fuel oils.

Oil spill trajectory and weather modelling for a 16,000 m3 spill over two days at five UK locations assessed the probability of and the effect of such a spill on the coastline, taking into account environmental and economic factors. The southern England coast was considered particularly vulnerable. A review of available counter-pollution equipment concluded that sufficient resources are readily available in the UK.

Assistance from Bonn Agreement partners and commercial contractors would however be required to deal with a spill in the longer term beyond the initial response phase. This support could include the vessels that are part of the European Maritime Safety Agency’s pool of responder vessels (pictured above and reported in Maritime Journal February 2008).

It was noted however that while speed of response is less critical when dealing with lighter oil spills (by spraying), a rapid response was essential when dealing with VHFO (by skimming) as recovering the oil once it has increased in viscosity and density over time becomes more difficult. As the response vessel would usually be engaged in trading, time would be required to prepare and reposition them. The report suggested that consideration be given to the spill response vessel arrangements.

The project has produced a number of other recommendations noting that a down side of the reduction in the number of oil spills in recent years has been a reduction in the response equipment that spill contractors retain. Another factor is that the increase in VHFO cargoes (particularly from Russia) transiting UK waters has increased significantly and rapidly in recent years.

The project has produced some interesting findings and the recommendations are clearly based around the changing balance of risk that now exists between the two types of potential oil spills. While all will hope that a VHFO spill never happens, clearly a different response is required. This response will probably also involve the resources and support of other EU states, EMSA and Bonn Agreement members.

This all of course applies whichever country's waters the spill originates in. Pollution does not stop at national boundaries.

By Peter Barker