Schottel thrusters for LNG hybrid tug

The vessel is first in a series of 12 LNG-fuelled tugs stated as being suitable for Singapore’s operating profile which like many similar operations demands a highly variable power range, the project also part of Sembcorp’s plan to replace its existing diesel-powered tugs. The vessel is designed by LMG Marin, a wholly-owned Sembcorp Marine subsidiary based in Bergen, Norway.

Main engines and electric motors are coupled to the Sydrive system, either or both together able to be selected depending on the required operating mode and power requirement. Each thruster’s upper gearbox has two power inputs with an offset angle of +/- 90’ for two power sources and an option for a +/-135’ offset allowing greater design flexibility. The type SRP 430 RudderPropellers will each have a power intake capacity of around 2,000kW originating from zero-emission electric motors and/or the LNG-fuelled main engines offering a notable reduction in fuel consumption and emissions.

The Sydrive-E thrusters are manufactured in Germany and commissioning and after-sales will be provided by Schottel Far East, Singapore with the client’s tug fleet operated by Sembcorp Marine subsidiary Jurong Marine Services. Operations are scheduled to commence late in 2021.

Separately, Schottel has reported on its new LE-Drive (embedded L-Drive) system which is compatible with electric motors of all types and manufacturers and available for Schottel’s RudderPropellers (as above) and its EcoPeller (SRE).

Schottel state the installation height of the LE-Drive including the electric motor on top is comparable to that of a Z-Drive and that due to this ‘extremely low installation height’ is suitable for every common vessel design. The omission of the upper gearbox further increases mechanical efficiency by approximately three per cent while at the same time reducing fuel consumption and providing a reduction in operating costs. The omission of the upper gearbox has the additional advantage of reduced vibration and noise levels noticeably improving comfort on board for the crew.

The EcoPeller SRE range is optimised for open sea conditions and described as ‘suitable for medium to high speeds’ and the first azimuth drive that has been consistently developed for an electric drive source. The EcoPeller is particularly referenced in double-ended ferries with design options including ice-class vessels.

By Peter Barker