MAN L27/38 Propulsion Package for ‘Cattleya-trawler’

Esbjerg-based Danish owner Flemming Pedersen has ordered a replacement for his 2006-trawler - scheduled for 2012 delivery, but now larger, more advanced and again powered by MAN Diesel & Turbo’s L27/38 propulsion package.
The complete main propulsion package concept has earned over several decades its favourable position in a number of ship segments – amongst others for medium to large-size fishing vessels. As a matter of fact the original 4 hp Alpha CP Propeller based propulsion package concept materialized for a fishing vessel as early as in 1903. Today’s about 4,000 hp propulsion package for the new ‘Cattleya’ will include main engine and box coolers, reduction gear with hydraulic shaft brake and a 1,800 kW PTO and shaft alternator, propeller shaft line, sterntube, propeller and propeller nozzle – together with a complete propulsion control and safety system with manever stations for four bridge positions. The newbuilding number from Karstensens Shipyard is 420 and the number for the current ‘Cattleya’ was 399. The name ‘Cattleya’ will be continued from Flemming Pedersens current vessel and a quick comparison of the vessel specifications show a radical capacity step-up. The length oa grows from 62.6 to 69.9 m, and with 1.4 m additional width the tonnage increases from 1,337 to 1,750.

Propulsion Optimisation
The MAN L27/38 powered propulsion package might be seen as a direct repeat from the current vessel, but the 9-cylinder 2,999 kW Tier-II engine will be coupled to an (Alpha Module Gear) AMG55 gearbox with a large speed reduction ratio of 800:119 rpm for an even larger and more efficient 4.2 metre ducted CP Propeller. The new high-efficient (Alpha High Thrust) AHT propeller nozzle has been specified in this case for ‘headbox’ mounting. The optimization and adaptation of the large propeller and nozzle into the vessel’s aft ship design has been carried out in close cooperation with Karstensens’ naval architects and engineers. A propeller and propulsion-optimised aft ship solution equals energy optimization, resulting in fuel consumption savings and less exhaust gas emission.
As a result of the vessel’s floating frequency system (from 60 to 50 Hz), the propulsion system is also able to operate in ‘shaft alternator mode’ with reduced engine and propeller speed. With this part-load optimisation feature, offering up to 16.7% lower engine/propeller speed, the fuel consumption is further reduced. Additionally, the vessel’s electrically-driven retractable 800 kW azimuth thruster propeller can be deployed for low power propulsion, standby, take-home and maneuvering modes.