BURNING heavy fuel oils (HFO) can be an alternative for some fishing vessels being hit by today's crippling fuel costs.

A whole raft of measures to reduce fuel costs are currently being investigated, including the use of bio fuels, re-engining and improving the efficiency of fishing gear.

HFO is an option that has already been taken up by the new Dutch beam trawler Catharina (KW 145), which is reported to have much reduced operating costs.

Now, Seafish in the UK has produced a guidance document outlining the pros and cons of HFOs. This document's main message is that converting to HFO is not an option for the vast majority of vessels in the UK fleet.

This is because most vessels use high revving engines.

HFOs are also unsuitable for propulsion units below 745 kW (1000 hp). However, vessels with larger engines such as beam trawlers - or those already using the newer medium speed HFO ready propulsion units - have the capability for conversion.

Generally, an engine won't require many changes if it has already been updated with the latest technology, particularly with anti-polishing rings in the cylinders.

Definitely required, however, is new auxiliary equipment for handling, storing, transferring and treating the heavy fuel oil on board. This equipment is of crucial importance because HFO is not as refined as diesel and, therefore, needs to undergo a complex process of cleaning and heating.

In particular, the oil needs to be of the correct viscosity before being injected into the engine.

Seafish estimates that it would cost about £170,000 ($331,500) to convert a 1490 kW (2000 hp) beam trawler to run on HFO. If the engine needed to be converted as well, then the cost could soar by an additional £50,000 ($97,500).

The research estimates that, from the resultant fuel savings, it would take from 199 to 405 days at sea to recoup the initial outlay of making the conversion (see table) depending on the grade of HFO used.

While this may initially seem like an option worth considering, Tom Rossiter, Seafish's technology implementation manager, is quick to sound a note of caution.

"Converting to heavy fuel oil is simply not an option for the vast majority of the UK fleet because the most common types of engine used are unsuitable, " he says.

"Even for vessels that are deemed suitable, there are a large number of uncertainties that need to be considered.

For example, the price differential between HFO and diesel is not index-linked.

"Therefore, while heavy fuel oil is currently cheaper than traditional diesel, there is no guarantee that this will always be the case and the gap is already narrowing.

"In addition, there may be supply problems in sourcing HFO at certain fishing ports."

There is also the problem of stricter environmental legislation, with the EU and IMO (International Maritime Organisation) setting much tighter limits on the sulphur content of heavy fuel oil which, in turn, will inevitably push up costs.

A further cost implication that needs to be considered is the employment of a suitably qualified or experienced engineer to maintain the engine. The engine would also need to be overhauled within four years.

Another downside is that a considerable amount of space may be taken up by the additional equipment necessary to run the vessel on HFO.

The Seafish document, Reducing Fuel Costs by Converting to Burning Heavy Fuel Oils, is available free from the Seafish Library in Hull, Tel: 00 44(0)1482 327837.

The paper is also available on the Seafish website www. seafish. org/sea - then go to the Raising Standards section.

News

Factors for burning heavy fuel