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Wartsila has introduced a new portfolio of tug designs named the Wartsila HYTug series, where the emphasis is on environmental sustainability.

Since they typically operate in or close to harbours and populated areas, tugs are particularly affected by environmental considerations, and the need for regulatory compliance is an increasing concern for tug owners and operators worldwide.

Wartsila has already introduced tug designs featuring liquefied natural gas (LNG) fuel technology as a means for complying with environmental legislation. Only last month, Bunker Index reported that the first Europe-built dual-fuel tug incorporates Wartsila LNGPac fuel systems with 30-cubic-metre horizontally mounted Type C LNG fuel tanks, and the company has been at the forefront in developing technologies for LNG-fuelled vessels for some time.

Wartsila says the HYTug series designs have been developed utilising its knowledge in hybrid propulsion technology, along with its experience with more than 1,000 tugs built based on Wartsila's ship designs.

The recently introduced Wartsila HY hybrid propulsion solution forms the basis of the new designs, the benefits of which include the flexibility and efficiency provided by the technology. Notably, the enhanced efficiency enables the total installed main engine power to be less than with conventional designs. Using less engine power also decreases exhaust emission levels and, therefore, the environmental impact. It also reduces the fuel bill and lessens the amount of engine maintenance needed, which again adds to the cost savings.

The designs are said to provide the power and manoeuvrability for practical tug operations, with the HYTug being optimised for low hull resistance, high towing / escort performance, sea-keeping, crew safety and comfort, as well as for easy maintenance. Each design has the option to select either diesel mechanical hybrid, or diesel electric hybrid propulsion, and the designs cover a 40 to 90 ton bollard pull range with the appropriate Wartsila equipment.

The new tugs are designed with thrusters from the Wartsila WST series featuring large propeller diameters for efficient and high performance propulsion. In addition to their excellent hydrodynamics and reliability, these thrusters are also easy to install, operate, and maintain.

"We believe that new tugs will in future rely more and more on battery and hybrid propulsion, which very well complements today's operational requirements. As a total solutions provider with unmatched in-house capabilities combining ship design, engine technology, propulsion, and electrical and automation systems, Wartsila is uniquely qualified to produce tug designs that fully meet the needs of the industry, and this we have now done," said Riku-Pekka Hagg, Vice President, Ship Design, Wartsila Marine Solutions.

The development work has been carried out in close cooperation with the ABS, BV and Lloyds Register classification societies, and the designs have received Approval-in-Principle (AiP) certification. This certification means that the design complies with class safety regulations and will be class approved in actual projects. The Wartsila HY solution has itself received AiP certification from the Lloyds Register classification society.

The new designs are being launched this week at the Asian Tug Technology and Salvage conference in Singapore on September 18 and 19.