First European hybrid will be a Rotor Tug

KOTUG’s ‘Rotor Tug’ RT Adriaan, currently operating in the Port of Rotterdam, will be retrofitted with a XeroPoint Hybrid Propulsion System. The conversion will be completed in the fourth quarter of 2011 and the first ‘EKOTUG’ will then rejoin the KOTUG fleet.

On announcing the new project at Tugnology in Antwerp on 17 May, Ard-Jan Kooren, President and CEO of KOTUG said, “We are very happy to be working with AKA on this exciting project. Like AKA, KOTUG has established a reputation as an innovator in the workboat industry. Our ‘Rotor Tug’ concept is an example of our ability to turn a good idea into reality. We believe that introducing AKA’s hybrid technology into our fleet is the next step in demonstrating our ongoing commitment to the environment.”

The XeroPoint hybrid system combines diesel and electric power on the same shaft line. A motor/generator (a single machine that can act as either a shaft motor or shaft generator) and a diesel engine are able to drive the shaft independently or in unison. The latter is made possible by a clutch positioned between the diesel engine and motor/generator. Auxiliary diesel generators meet the requirements of hotel and drive shaft motor loads. An identical drive train arrangement will be installed to power each of the three propulsion units.

When the tug is ‘standing-by’ or on very low power operations, electrical energy stored in batteries provides power, with no diesel machinery running.

At low power, the unique XeroPoint Hybrid arrangement enables the tug to operate as a conventional diesel-electric vessel. Propulsion and hotel loads are met by a combination of diesel generator sets and battery power.

When the vessel’s power requirements are within the efficient operating range of the main propulsion diesels, the tug operates as a conventional diesel only system. The shaft generators support the hotel loads, using modern power management technology to provide a constant voltage regardless of shaft speed.

At high power, the diesel main engines and shaft motors work together to provide propulsion. The shaft motors augment diesel power while simultaneously increasing system responsiveness with their superior low-end torque characteristics.

Aspin Kemp & Associates (AKA) is a systems integration company specializing in developing, implementing, supporting and maintaining engineering solutions in the marine and offshore oil and gas industries. Established in 1996 with headquarters in Owen Sound, Ontario, Canada, AKA operates internationally with offices in Dartmouth, Nova Scotia; Stratford, Prince Edward Island; Houston, Texas and Singapore.

AKA worked with Foss Maritime to develop the world’s first ‘hybrid’ ASD tug Carolyn Dorothy, now operating successfully at Long Beach and San Francisco, and their award winning XeroPoint Hybrid system has proven successful in reducing emissions and creating significant fuel and maintenance cost savings.

Jason Aspin, AKA’s CEO remarked, “AKA is pleased to be working with KOTUG in the continued deployment of practical hybrid solutions in the workboat industry. We are fortunate to have clients like KOTUG that recognise technology’s role in improving their environmental performance. AKA is committed to incorporating innovative advances in energy storage technologies as evidenced by the use of Corvus Energy’s advanced lithium polymer batteries for this project.”

KOTUG is well known as a European maritime service provider with its head office in Rotterdam. The company has a modern fleet of 30 tugs with bollard pulls ranging from 30 to 90 tons. Services include harbour towage, coastal and deep sea towage, tug management, chartering, brokerage, salvage, offshore services, and assistance to marine dredging operations. With almost a century of experience, KOTUG has built its reputation as a competitive and innovative player in the maritime industry. KOTUG recently won the Dutch Fuel Reduction Competition Award and the company’s commitment to the environment includes the use of sulphur free fuels and other initiatives.

The RT Adriaan is a 32m LOA tug with 80 tons bollard pull, built to the RT80-32 design and completed in 2009. It is understood that preliminary work aboard the tug will be carried out whilst the vessel is still in service. Once that work is done the tug will be withdrawn from service to allow the major components such as the motor/generators to be installed in the shortest possible time.