HST Ella during sea trials

First Hybrid Chartwell 24 CTV Heads to East Anglia 1

HST Marine has taken delivery of HST Ella, a new hybrid crew transfer vessel (CTV) designed by Chartwell Marine.

HST Marine
HST Ella during sea trials
Source: HST Marine

HST Ella is the first hybrid Chartwell 24 vessel to hit the water, following her completion at the Isle of Wight shipyard Diverse Marine.

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”Rapidly maturing hybrid technology means that environmental consciousness can sit hand in hand with operational excellence, and in the HST Ella, we have a vessel that delivers both, following a consultative design process with Chartwell Marine, and a high-quality build at Diverse Marine,” Tom Nevin, Chief Executive Officer, HST, said.

The HST Ella reaches transit speeds of 10 knots on electric propulsion and 30 knots on diesel, while during port operations, the vessel’s electric operation mode is said to allow for quiet and zero-emission low-speed maneuverability.

This is enabled by the vessel’s unique hybrid propulsion system. An electric motor sits alongside a diesel engine to drive a high-performance changeable pitch propeller (CPP) system, ensuring superior maneuverability and operational flexibility, HST said.

The system is coupled with the vessel’s advanced hull form for reduced frictional resistance, and its use of Hydrotreated Vegetable Oil (HVO30) as fuel – a market first for a newbuild CTV.

The 26-metre vessel is able to carry 24 industrial personnel alongside a maximum payload of 15 tonnes.

Following its launch, the HST Ella will depart to begin her maiden contract at the East Anglia 1 offshore wind farm.

”Whether designing a diesel-powered CTV with an innovative hydrofoil system propelled by waterjets, or, as in this case, a large hybrid-electric CTV using HVO fuel with a changeable pitch propeller, we always look to ensure that the proven characteristics of the Chartwell 24 platform are built in,” Andy Page, Managing Director, Chartwell Marine, said.

”Designing for hybrid operations brings specific challenges, but our central philosophy is that we design with the vessel’s eventual operational profile front and centre, and we have been proud to work with Diverse Marine and HST to incorporate lessons learnt from best practice CTV operation into this vessel.”