Crew transfer or ‘turbine support vessels’ play a significant role in the operation of offshore windfarms and have an ever increasing scope of work, sometimes well beyond the transport of engineers.

Traditionally, the majority of turbine support vessels have not carried more than 12 passengers and have been certified under national rules for service in the waters of a flag state, the majority being certified under the UK Maritime & Coastguard Agency’s (MCA) Work Boat Codes.

Vessels operating in non-UK waters have either been certified under very strict national rules, and built to classification society standards, or operate as MCA Work Boat Code vessels under limited term exemptions. The increasing demand for vessels to operate in Germany and Denmark has resulted in more vessels being built to class rules, with the DNV WFSV 1 notation being the most popular choice.

As windfarms move further offshore, more attention is being placed on total logistical cost rather than just charter rates, resulting in the industry facing increased requests for vessels that are fast, can carry cargo and more than 12 passengers, as well as being fuel-efficient.

However, increasing the number of passengers carried by a vessel raises a significant problem in that there are no clear, practical rules for the construction, certification or operation of vessels carrying more than 12 passengers.

The Safety of Life at Sea Convention (SOLAS) only distinguishes between crew and passengers, with the latter being defined as any person other than the master or members of the crew. A passenger ship is defined as one carrying more than 12 passengers.

At the time of the first Solas Convention, it was not envisaged that people other than crew and passengers would be transported, so the convention did not take account of what might be termed ‘industrial personnel.’

As the maritime industry has evolved, however, the International Maritime Organization (IMO) has adopted new codes that seek to amend SOLAS to meet the requirements of specific ship types. The Special Purpose Ship Code (SPS 2008), for instance, allows for the fact that some ships carry personnel who are not crew but work in connection with the special purpose of that ship. However, it excludes ships where the industrial personnel do not work on board the vessel, so it is not a suitable code to solve the problem with turbine support vessels.

The High Speed Craft Code (HSCC 2000) was developed specifically to address the need for alternative rules that allow for lighter construction, so that vessels could travel at higher speeds. It was developed with a focus on the carriage of pure passengers and/or cargo on fixed services between specific ports. It traded standard passenger ship construction for higher operational safety, such as type approval training for crew, high levels of structural fire protection, and strictly approved operating envelopes. However, the authors of the HSCC 2000 did not contemplate the carriage of windfarm engineers who have basic safety training, are medically fit and are familiar with basic safety equipment, such as life jackets and immersion suits, which are part of their daily equipment.

Vessels constructed to meet the requirements of HSCC 2000 have a construction price at least 25 per cent greater than a similarly-sized 12-passenger vessel and have much higher operating costs due to additional crew certification requirements and higher operating costs. This is coupled with the need for operating on pre-approved routes which does not allow the flexibility needed for windfarm service.

The classification society DNV has attempted to solve this issue by proposing windfarm service vessel rules, in the form of its WFSV 2 notation. Other class societies are doing likewise (see box) and are producing similar rules. DNV’s rules propose a practical interpretation of the HSCC 2000, directed towards services such as windfarms.

DNV’s concept has generated a positive response from regulators and industry alike, but is limited by the fact that they are class rules and not statutory regulations. Germany has spearheaded a proposal for a solution based on the DNV approach through IMO, but this is a slow process, with the direction coming from the IMO’s design and equipment sub-committee meeting (DE57) in early 2013 at the earliest.

Given all of the above-mentioned, the IMO agrees that requirements for the carriage of industrial personnel such as offshore windfarm engineers, certainly need to be clarified, but a quick, local or regional solution such as the acceptance of WFSV 2 is unlikely due to the European Union’s approach to passenger vessels in general. Other flag states are proposing solutions of their own, but no clear path has emerged and these face the risk of not being accepted by coastal states in which vessels will operate.

For the time being, it seems, operators are faced with the risk that vessels built to comply with rules in force today could be at an extreme commercial disadvantage in the future if rule changes allow the construction of less expensive vessels. If they attempt to push the regulatory envelope, they could find they are not allowed to operate by a port state.

Without definitive guidance from the IMO or from states bordering the North and Baltic seas, the industry is left with an uncomfortable level of commercial and regulatory risk, and inevitably, this risk will be passed on to the windfarm developers and, in the end, electricity consumers.