Dutch company Iskes Towage & Salvage has contracted Damen Shipyards Hardinxveld build two ASD 3212 'Green Tug' harbour tugs, designed to reduce emissions by 30 percent.
Iskes recently took its first Damen tug into operation, the ASD 2810 'Argus'. Since 2009, the company has sought to reduce emissions. Triggered by the commitment of the ports of Rotterdam and Amsterdam to the World Ports Climate Initiative, Iskes teamed up with Offshore Ship Designers to develop the Green Tug. Other stakeholders included the Marin research centre and tug operator Smit. The project is now in the final, detailed design stage, involving close co-operation with Damen Shipyards Hardinxveld and Damen Research, especially over propulsion and bollard pull.
According to Damen, the Green Tug has several similarities with its Damen E3 project to produce environmentally friendly, economically viable and efficiently operating ships. The Green Tug's azimuth thrusters, bow thrusters and winches use diesel-electric propulsion. In order to reduce emissions while mobilising to a job, the tug will sail on battery power. The energy management system ensures that the master of the tug always gets the power he needs regardless of whether the power comes from batteries or from one or more diesel generators. When sailing at cruising speed only one generator is used, cutting down on fuel consumption and maintenance.
The vessel will have 70 tonnes of bollard pull and will be equipped with a double drum, creating an independently controlled forward winch system. The idea is to pay out two tow-wires at the same time and control each wire independently. This is very practical when manoeuvring in narrow spaces.
The contract marks the first time Damen will build a vessel that it has not designed in-house. The two new tugs will be delivered by mid 2013.