First Reverse Stern Drive Compressed Natural Gas-Fueled Tug Planned

What do you get when put a world-class shipyard, a leading propulsion expert, and an international tug and towing specialist, together into one room?

The first ever reverse stern drive compressed natural gas-fueled tug with up to 90t bollard pull.

On Friday, Damen Shipyards, Rolls-Royce Power Systems’ MTU brand and Svitzer announced the launch of the new Reverse Stern Drive (RSD)® Compressed Natural Gas (CNG) series of eco-friendly tugs. The first RSD CNG tug prototype, which is planned for 201, will combine high power with lower fuel costs and reduced emissions.

Damen Shipyards, who will build the prototype, explains that the Reverse Stern Drive is essentially an ASD and tractor tug in one, with the ability to sail ahead and astern and with the same bow height forward and aft.

“With the MTU 4000 engine, this vessel is excellent for ship handling, with very quick acceleration,” says Martijn Smit, Damen Sales Manager Europe. “Maneuverability is combined with the vessel being green, clean and efficient.”

The new 16-cylinder pure gas engine being developed by MTU, pictured above, is based on its proven workboat Series 4000 M63 diesel engine, but complemented with a multipoint gas injection system, a dynamic engine control and an optimized safety concept.

“We are developing our new gas Series in order to meet the extreme load profile of the tugboat. The acceleration will be comparable to the level of our diesel engines. Due to the clean combustion concept, compliance with IMO Tier 3 emission legislation will be ensured without the need of additional exhaust gas after treatment. The 2,000 kW MTU gas engine is characterized by high power density combined with low fuel consumption,” says Dr. Ulrich Dohle, CEO of Rolls-Royce Power Systems AG, which owns the MTU brand.

Commenting on the reasons why SVITZER has decided to invest in such a unique vessel, CTO, Kristian Brauner, said “As a major harbour towage operator an important consideration is also that this tug will realize a considerable reduction in fuel costs and obviously fuel is a major cost concern for all operators. And crucially, as a market leader it is important for us to stay innovative with regards to performing safe and eco-friendly operations and to reduce emissions. Through the years we have already developed one version of the ECOtug and with this in mind, the choice to develop the new CNG tug is a natural step towards remaining an eco-conscious towage company.”

Damen says that the series will be comprises of three versions; the RSD 2210 with 50t BP, the RSD 2512 with a 70t BP and the RSD 2914 with 90t BP.

Illustration and photo courtesy Damen Shipyards Group and MTU