WorldWise Marine, a partner in the Offshore Ship Designers group (Holland), has launched a new harbour tug design which it says will cut emissions to zero during most of its operating hours. The Hydrogen Hybrid Harbour Tug (HHHT), developed by WorldWise Marine working with Dutch tug operators Iskes and Smit, is a 50 tonne bollard pull tug fitted with fuel cells and hydrogen tanks.

The fuel cells, in combination with batteries, are able to provide sufficient power to operate the tug during standby and mobilisation/demobilisation periods, which according to WorldWise Marine is 85% of the time. It only needs to use diesel generator sets when substantial bollard pull is required to actually perform a berthing operation.

The new design has also worked on reducing emissions when the tug is operating in diesel mode by ensuring its engines always operate under optimal load conditions. This helps to cut fuel consumption and associated emissions, especially of particulate matter. The new tug design uses Proton Exchange Membrane (PEM) fuel cell technology developed by the Dutch firm NedStack. It was said to deliver substantially better efficiency comparing to the efficiency of conventional diesel direct drive installations. The first of the new tugs are expected to be built by Dutch companies for use in European harbours.

"This new harbour tug will be able to remain on standby, and mobilise/demobilise with zero emissions, and will save up to 98% of SOx, NOx and particulate matter and 30% of CO2 emissions in total compared to a conventional harbour tug over the whole employment cycle. This is a major step forward for tug operators who have tugs operating in densely populated areas" said Michiel Wijsmuller, managing director of Offshore Ship Designers.