Green tug project

Developing a tug with 30% reduction of CO2 emissions

The Netherlands is a country where ports and cities are inextricably intermingled. So it should be no surprise that the project initiated by Offshore Ship Designers and Iskes Towage & Salvage for a zero emission tug has picked up wide support in the Dutch shipping community.

Hydrogen Hybrid Harbour Tug (HHHT)

The IJmuiden/Amsterdam tug operator Iskes and IJmuiden-based Offshore Ship Designers (OSD), also asked the global tug major Smit to the table and together it is the aim to bring a hydrogen-powered tug into service in 2010. They have now been backed by the Dutch government, which has given Iskes a support grant from the Ministry of Transport, Public Works and Water Management to further develop the technical concept of the Hydrogen Hybrid Harbour Tug (HHHT) under the Subsidy for Maritime Innovation (SMI) scheme.

The HHHT will be able to remain on standby, mobilise and deploy to where it is needed with zero emissions, and will save up to 98 per cent of SOx, NOx and particulate matter and 30 per cent of CO2 emissions in total compared to a conventional harbour tug over the whole employment cycle. The 60 tonne bollard pull tug is fitted with fuel cells and hydrogen tanks, where hydrogen is stored under a pressure of 430 bar.

Fuel cells

The fuel cells, in combination with batteries, are able to provide sufficient power to operate the tug during standby and mobilisation/demobilisation periods. Only when substantial bollard pull is required to actually perform a berthing operation are the diesel generator sets used. Eighty-five per cent of the time, the tug is powered by the fuel cells and achieves zero emission. The Proton Exchange Membrane (PEM) fuel cells, developed by NedStack Fuel Cell Technology B.V. of the Netherlands, deliver well-to-propulsion efficiency of 34 per cent, substantially better than the efficiency of conventional diesel direct drive installations.