Chartwell Marine Unveils CTV Design for Legacy Offshore Wind Turbine Support

June 12, 2025, by Adnan Memija

The UK’s NR Marine Services has commissioned its compatriot Chartwell Marine to design a new crew transfer vessel (CTV), which will be capable of supporting older generation assets, now referred to as legacy turbines.

The CTVs will be built and outfitted with modern technology to maximise vessel fuel efficiency and technician comfort, said Chartwell Marine.

The company has developed the Defiant class, a 20-metre vessel designed to Workboat Code Edition 3 with IMO Tier 3 compliance, featuring a step-free forward deck, a mounted superstructure, and modern furnishing and materials used in larger CTVs.

Chartwell Marine CTV — *Source: Chartwell Marine*

The Defiant-class vessel is designed to support a wide range of legacy turbines and can be adjusted for different needs. It can use water jet systems for shallow areas and hybrid systems if the budget allows, and has a flexible interior that can be changed to fit different seating or equipment setups.

“Working closely with Chartwell Marine and Diverse Marine we have looked at incorporating as many of the recent CTV developments as possible into a smaller package. Step free access from deck level to bow step over point, tiered seating, male and female heads, a comprehensive galley suite and an optimised hull design for near-shore projects,” said Richard Thurlow of NR Marine Services.

“Following an internal fleet review along with external market research, the data shows that there is a potential to replace older tonnage, which is between 10-15 years old, for near-shore projects which have a lifespan that warrants investment in new CTVs”.