April 25, 2007
MAN Diesel propulsion packages for Stena super ferries
MAN Diesel is to supply complete propulsion packages based on its latest common rail engine, the medium speed 48/60 CR, for the world's largest RO/PAX ferries.
To be built by Aker Yards, Germany, the two 240 m, 62,000 gt newbuildings feature a record-breaking 5,500 meters of trailer lanes, 700 meters of car lanes and facilities for 1,200 passengers.
They are due to be delivered in the first and third quarters of 2010.
Under MAN Diesel's program of progressively introducing common rail fuel injection technology onto its four stroke medium speed engines, the common rail version of the well-established 48/60 engine closely follows the September 2006 launch of the all-new 560 kW per cylinder 32/44 CR engine.
The 48/60 CR engines for the new ROPAX ferries deliver 1,200 kW per cylinder at 500 rpm and are attanged in a four engine, twin propulsion train diesel mechanical system.
Each train consists of a "father and son" arrangement of one inline eight cylinder 8L48/60 CR and one six cylinder 6L48/60 CR connected by a twin input shaft, single output shaft type NDSHL-3400 double reduction gear from the Rheine works of MAN Diesel's sister company Renk AG.
The gears also feature shaft alternators driven from 3,000 kW PTO's.
Completing the MAN Diesel propulsion packages are twin 5.2 meter type VBS1560, Controllable Pitch Propellers from its Frederikshavn works, 41 meter shaft lines and ODF servo systems, together with the Alphatronic 2000 Propulsion Control and Management System for engine control room, main bridge and bridge wing consoles.
The overall machinery package of each vessel is completed by MAN Diesel gensets. Each vessel features four generator sets based on one 7L21/31 and three 6L21/31 engines. The generating sets and main engines are all resiliently mounted for the highest levels of onboard comfort for passengers and crew.
Stena selected the new common rail versions of the well-established type 48/60 engine because of their wide operational flexibility and their combination of favorable fuel efficiency, low emissions levels and invisible smoke under part-load operation.
With flexible control of injection pressure, timing and rate shaping, common rail fuel injection allows emissions and fuel consumption to be optimized over the entire load range. In the MAN Diesel common rail system, these advantages are complemented by modular design and suitability for retrofitting on engines already in the field. For example, the high pressure pumps of the MAN Diesel common rail system are installed in the same bores used for the conventional unit pumps in a conventional injection system and the pressure accumulators (common rails) are segmented to make best use of available space on the engine between the injection pumps and the injectors. In addition, the injectors used are standard, pressure controlled units controlled by solenoid valves mounted at the accumulator outlets.