Caterpillar Marine To Develop Innovative Hybrid Tug With Sanmar Shipyards

Hamburg, Germany - Caterpillar Marine is pleased to announce a collaboration with Sanmar Shipyards in Istanbul, Turkey to build an innovative tugboat with a hydraulic hybrid propulsion system.  The Cat Marine Advanced Variable Drive™ (AVD™) is a patented system leveraging Caterpillar’s extensive experience with integrated power systems technology.  Sanmar is the largest tug builder in Turkey with over 40 years of experience and known as a market leader at the forefront of the tug building industry.  

The AVD™ system provides significant improvements in both fuel efficiency and vessel performance through a fully integrated hydro-mechanical propulsion system.

“Different from a typical Power Take In (PTI) solution, the AVD™ incorporates a planetary gear set allowing seamless clutch engagement of main engines, auxiliary engines, or both to provide a scalable power installation to meet any customer need in terms of maximum vessel speed, power, or bollard pull,” said Nathan Kelly, Caterpillar Marine Product Definition Engineer.  “This also allows propeller speed independent of engine speed so optimal engine efficiency can be achieved leading to fuel savings of fifteen to twenty percent.  Basically, all the benefits of a variable speed Diesel Electric Propulsion (DEP) system at a fraction of the cost and size,” said Kelly. 

The AVD™ system is also flexible and can accommodate multiple configurations.  Auxiliary engines can be utilized to accommodate low load or transit operations greatly extending time to overhaul and reducing service costs on main engines.  Electric motors can also be used instead of hydraulics if required.  

“AVD™ enables straight forward integration of either diesel, natural gas or gas turbine engines or any combination of these as prime movers, accommodating various levels of engine load acceptance capability and engine speed regimes,” said Igor Strashny, Caterpillar Innovation and Technology Development Engineering Manager with responsibility for Advanced Marine Propulsion.  “Main engines can be downsized in most applications with supplemental power provided by auxiliary engines.  The system provides inherently high levels of propulsion redundancy. It is fully scalable to meet requirements of a wide range of vessel types, applications, and power levels”, said Igor.

“This strategic development between Sanmar and Caterpillar will provide a highly optimized, lower cost alternative to conventional electric hybrid systems with similar benefits regarding improved performance, lower noise, and lower emissions,” said Ali Gurun, Director of Projects, Sanmar Shipyards.

The Sanmar hydraulic hybrid tug will be a Robert Allan Ltd. designed RAmparts 2400SX harbor tug incorporating an integrated Caterpillar AVD™ system of 3512 main engines, a C32 auxiliary engine, Caterpillar MTA 627 fixed pitch tug thrusters, and bridge controls.  It will carry Fifi 1 designation with 70T metric bollard pull and will be supported by Turkish Caterpillar dealer Borusan Makina.  The AVD™ system will also include a fully integrated controls system with customizable operating modes and display panels at the bridge.  Compared to a conventional tug with equivalent bollard pull, the Return on Investment (ROI) is estimated at 3 years or less based on projected fuel and operating cost savings.

Cat® marine power and propulsion solutions are backed by the worldwide Cat® dealer network with trained technicians to ensure service support is never out of reach. For more information on Caterpillar Marine, visit  Follow us on Facebook: and Twitter @catmarineglobal

About Sanmar A.S.

Sanmar is in the business of operating tugboats, providing pilotage services and building tugs and workboats. With up-to-date equipment and well-trained and experienced crew, Sanmar provides a huge variety of services in various ports and around the coastline of Turkey.  The tugs and workboats that Sanmar operates are constructed by the company’s own ship building department at two custom-built yards.  Sanmar also supports its customers by providing technical consultancy services in advising the most appropriate tug and workboat design and equipment that will meet their operational needs.

About Caterpillar

For over 90 years, Caterpillar Inc. has been making sustainable progress possible and driving positive change on every continent.  Customers turn to Caterpillar to help them develop infrastructure, energy and natural resource assets. With 2016 sales and revenues of $38.5 billion, Caterpillar is the world’s leading manufacturer of construction and mining equipment, diesel and natural gas engines, industrial gas turbines and diesel-electric locomotives.  The company principally operates through its three product segments - Construction Industries, Resource Industries and Energy & Transportation - and also provides financing and related services through its Financial Products segment.  For more information, visit  To connect with us on social media, visit


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