MAY 23, 2016 — IJMuiden, Netherlands, based Offshore Ship Designers (OSD) has added a powerful, low-emission compact e-tug to its Azistern series of vessels.
"The Azistern-e has the typical low resistance stable hull and all-round visibility that is associated with all Azistern designs," says OSD managing director Michiel Wijsmuller. "What makes this particular Azistern tug different is that it is driven by a revolutionary podded drive and that it has a flexible and green electro/diesel-electric configuration."
The hybrid power of the 22 m Azistern-e is generated by two 970 kW variable speed gensets and is supported by two 400 kWh lithium battery packs.
The low-emission tug can be delivered compliant with IMO Tier 3 requirements with an after-treatment system suitable for ECA areas, and is also equipped with an innovative energy management system.
According to OSD, "the uniform and perfectly optimized loading of the propulsion system ensures low maintenance and fuel costs. Transient sailing and manoeuvring can be performed using the batteries with zero emissions.
The Azistern-e is highly maneuverable, says OSD, and its power train has a remarkably short reaction time. By using the batteries as a booster, maximum bollard pull can be achieved within seconds. The relatively small size of the engines and the shaftless configuration frees up more space below deck, providing optimum flexibility in respect of the division of space and piping.
As a result of its podded drive and the double elastic mounting of its gensets, says OSD, the MLC-compliant vessel will also provide the highest comfort level for its four-man crew.