Innovation and Diversity

in Marine Design

Tugs with Alternative/Hybrid Energy Sources

The worldwide demand for lower emissions from industrial operations, especially in large commercial ports, has led to a significant interest in the development of tugs with better fuel efficiency and significantly lower emissions than can be offered by conventional diesel power plants.

Robert Allan Ltd. has been at the forefront of developments in this area, designing the world’s first hybrid-powered tug (and several more since), and with numerous new designs developed for tugs burning LNG alone or as part of a dual-fuel system.

The company has also developed a powerful analytical tool, the RAptures program (Robert Allan Ltd. Powering Tugs for Real Energy Savings) to enable a thorough analysis of the relative merits and efficiency of a variety of hybrid or conventional powering options, whether diesel-mechanical, diesel-electric or any combination thereof.

The space and weight challenges associated with any of these systems, especially in compact vessels like tugs, are very real and new ideas are required in order to realize the true potential of LNG in this size of vessel. Dual fuel tugs offer more service flexibility and are a more viable option in many instances

The RANGLer series of LNG (or dual fuel) powered escort and ship-handling tugs take maximum advantage of the space available for LNG systems, and look at tug design configurations with fresh eyes.

RANGLer 3600

Almost any of our design types such as the RAstar, RAmparts and RAmpage tugs are also candidates for adaptation to gas fuels, although larger-sized tugs (> 37 metres) are most suitable. Three RAstar 4000-DF class dual fuel tugs, the world’s most powerful LNG-powered escort tugs, are currently building for Ostensjo Rederi AS of Norway for delivery in 2016.

RAstar 4000-DF