In an effort to fight climate change, New Zealand’s Ports of Auckland has signed a contract with the Damen Shipyards Group to buy the world’s first full-size electric port tug. The Dutch company (Damen Shipyards) will build the tug and expects to deliver it in 2021.
The new tug, a Damen RSD-E Tug 2513 will have 70-tonne bollard pull, the same as the port’s strongest diesel tug Hauraki, which was also built by Damen and consumes 120 liters of diesel per hour. It will have dimensions of the 6-meter draft and a length of 24.73 m (19.68 x 81.13 ft), have two azimuth thrusters with 3 m (9.8 ft) diameter props.
RSD-E Tug will be able to do three to four shipping moves per charge of its 2,800 kWh batteries, or around three to four hours of operation. A fast charge will take about two hours. Damen is also working on the supply of the 1.5 MW charger, that is based on technology already deployed in the automotive industry.
Besides, the electrical system has built-in redundancy, with the batteries arranged in strings; if one battery in a string fails, the others carry on the work.
To ensure absolute safety, the RSD-E Tug 2513 will also be fitted with two 1,000 kW back-up diesel generators. They will provide enough power for the tug to operate at 40 tonnes bollard pull in the event of an electrical systems failure or in case the vessel needs to operate beyond its battery capacity. The generators will not be used during the port’s normal operational needs.
“In 2016 we set ourselves the goal of being zero-emission by 2040,” said Tony Gibson, CEO, Ports of Auckland. “We set this goal because we recognize that urgent action is needed on climate change, and we wanted to be part of the solution. However, setting that goal created a tough challenge. We have a lot of heavy equipment, like tugs, and in 2016 there were no zero-emission options.”
The cost of the battery-electric tug will be roughly double that of a diesel tug. However, the operating cost will be less than a third of the cost of running a diesel tug. “So while we pay more upfront, over the life of the tug we’ll save around $12 million in operating costs, making our electric tug cheaper in the long term,” said Gibson.
The RSD-E Tug 2513 completes the cycle of sustainability, being not only clean on emissions, but also in its source of power.