Caterpillar Marine is developing a proprietary propulsion system for marine applications that will be suitable for tugs and offshore vessels.

The Cat Marine Advanced Variable Drive (AVD) is a patented system that leverages Caterpillar’s extensive experience with heavy duty continuously variable transmission (CVT) technology, advanced controls and power system integration knowledge.

In a joint development, Caterpillar is working with its Innovation & Technology Development Division (ITDD) on what it describes as a “cross-functional effort to develop and validate a fully integrated marine propulsion system, from bridge interface to propellers.”

“Thanks to the flexibility enabled by the innovative Caterpillar AVD technology, the speed of the vessel’s engines can be modulated and optimised independently from the speed of the fixed pitch propellers,” said Igor Strashny, Caterpillar ITDD engineering manager with responsibility for the concept.

“The speed of the propellers can be varied continuously throughout their full speed range. In addition, the power of the main and auxiliary engines can be channelled independently or jointly to propel the vessel.”

“These features provide superior vessel performance and manoeuvrability while facilitating significant improvements in fuel and operational efficiency.”

He described the Caterpillar AVD as “a cost-effective and fully integrated hybrid propulsion solution that reduces maintenance costs and has conventional service requirements.

“The system is scalable to meet requirements of a wide range of vessel types, applications, power levels and enables effective downsizing of engines without the loss of performance,” Mr Strashny said.

Caterpillar Marine product definition engineer Nathan Kelly, told OSJ “We are planning to introduce the new concept for tugs first in 2018, but the technology will be applicable to other markets as well in the future.”