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Environmentally-sound hybrid ferries to be built on the Clyde

29 Feb 2012
Preliminary drawing of the CalMac hybrid ferry showing the stern ramp configuration

Preliminary drawing of the CalMac hybrid ferry showing the stern ramp configuration

In a rare reversal of fortunes for the UK shipbuilding industry, Ferguson Shipbuilders in Port Glasgow, Scotland has been selected to build the world’s first two sea-going ro-ro diesel electric hybrid ferries.

The announcement follows the tender process which began after Caledonian Maritime Assets (CMAL) was granted funding by the Scottish Government for the new project back in February 2011. Ferguson will work alongside Glasgow-based ship designers Seatec UK and Dutch electrical specialists Imtech Marine & Offshore to deliver the project. In conjunction with the shipbuilder and Imtech, Seatec will develop the detailed design for the new ferries, undertake all the naval architecture and marine engineering, and prepare all of the drawings and documentation necessary for the shipyard to construct the vessels.

The deal, said to be worth over £20 million, was awarded to Ferguson following a competitive tender process against strong foreign competition. The contract covers construction of two sea-going ro-ro passenger and vehicle diesel electric and battery powered hybrid ferries. Each ferry will accommodate 150 passengers and 23 cars or two HGVs and will be fitted with a Cargotec ship to shore stern ramp.

The vessels will be powered by three diesel generator sets, each rated at about 330kWe, with one in operation for normal conditions, lithium ion batteries being used to provide at least 20% of the power. The gensets will feed power to a 400V switchboard, which will supply power to two 375kW electric propulsion motors (0-600rpm). The propulsion system is completed by two 1,375kW Voith Schneider propellers, type VSP 16 R5 EC/90, to provide a service speed of 9 knots. The battery banks will provide additional power to operate the vessel.

SUBSTANTIAL CUTS IN FUEL USAGE

Innovative ‘green’ technology supplied by Imtech Marine includes the two lithium battery banks of about 700kWh, reducing fuel and CO2 consumption by at least 20%. The vessel design and power configuration additionally realizes 19%-24% savings of power input to the propulsion units compared with a conventional diesel mechanical solution.

When in port, the ships will completely turn off the propulsion power plant and switch to batteries and, ultimately, shore connection which will result in significant cost savings and further reduction of the carbon footprint. Next to a substantial reduction in fuel consumption and CO2 emissions, noise levels will be reduced. The ferries will charge overnight and, in the future, CMAL aims to use energy from wind, wave or solar systems for charging the batteries, making the vessels even more environmentally friendly. 

Imtech Marine’s office in Glasgow, UK, will coordinate the supply and installation, handle the day-to-day project management and will offer after-sales support for the pioneering project. Imtech will train CMAL employees in the operation of hybrid systems. The ferries will undergo a week of sea trials and this will be followed by an additional 21 days to test the vessels on all routes operated by CMAL. The first vessel is expected to be delivered in the summer of 2013 and the second a month later.

It has been four years since the last commercial ship was fully built and delivered on the Clyde and this project will save existing jobs and create new jobs and apprenticeships in the area. Alex Neil, cabinet secretary for Infrastructure & Capital Investment said: “The technology will be cleaner, quieter and cheaper to operate and maintain than ever before. It will help Scotland reach our ambitious climate change targets, and demonstrates the vast economic potential of developing green technology and moving to a low carbon economy”.

With a length of 43.50m, a breadth of 12.20m and a draught of 1.73m, the newbuildings will have an estimated gross tonnage of 450tons and 135dwt. They will be operated by CalMac Ferries and will be used for many of the short crossings between the Clyde and the Hebrides. The first of the two new vessels is expected to be operational on the Sconser-Raasay route on Skye by May 2013, with the second vessel coming into operation in August of that year.

 “The technology will be cleaner, quieter and cheaper to operate and maintain than ever before”

Images for this article - click to enlarge

Preliminary drawing of the CalMac hybrid ferry showing the stern ramp configuration Diagram showing the hybrid machinery arrangement

Image copyright © Mercator Media 2014, or image used with permission of the copyright holder.