MAN Introduces L27/38 Propulsion Package

MAN B&W has introduced a new generation propulsion package based on the L27/38 diesel engine. The package is designed to fulfill many current and future market needs, while minimizing the life-cycle costs. In particular, the L27/38 is a proven unit which offers a high stroke to bore ratio of 1.4 and a high compression ratio of 16.5 — values which will ensure that emission values are kept well below new limits, which are valid at the beginning of the coming year, without negative influence on the specific fuel oil consumption. The new propulsion package is, of course, centered around the popular MAN B&W L27/38 diesel engine. But the complete unit features engineering advances throughout, from the incorporation of the new MGS37 reduction gearbox range, to the new VBS CP propellers and the new Alphatronic 2000 monitoring, safety and control systems. L27/38 The central figure of the new unit is the L27/38 diesel engine, which offers end-users a host of benefits and operational advantages. First, the engine's above-mentioned ability to comply with ever-tightening emissions rules and regulations while not significantly altering performance and consumption numbers is a much sought-after trait by any vessel owner. The cylinder head offers a cross flow and inlet swirl, designed to provide optimal combustion and gas exchange over the whole load range. In addition, the cylinder unit — cylinder head, water jacket, cylinder liner and connecting rod — can be replaced as one complete unit … but it is also possible to take the individual components apart, while the marine head bearing remains on the crankshaft. The company has pointed out that previous problems with ovalization of the big-end bore, resulting in fretting between bearing shell and bearing bore with consequential damage, are completely eliminated. In terms of controlling engine size, to better conserve precious onboard space and weight, the company has introduced the Front-End-Box which reportedly contributes substantially to the shortening the overall length of the unit as much as possible. All external pipe connections are positioned on the sides of the Front-End-Box, and space is only required for exchange of the plug-in type oil and water pumps, etc. The Front-End-Box also has cast ducts for cooling water and lube oil, which means a minimum of piping on the engine. Standing Watch Following the trend toward increasingly sophisticated electronic monitoring and control, the L27/38 package integrates a fully electronic and redundant local instrumentation concept for both the engine and the gearbox, providing extensive monitoring and excellent overview for the operator. The operator panel for the engine is placed next to the governor in order to give the operator the best possible condition for controlling and monitoring the complete engine from one position only. Also, the operator panel for the gearbox and propeller is found next to the operator panel for the engine. Local monitoring and control are divided into two systems, one for the engine and one for the gearbox and propeller. The computer units — dubbed Alphacomm units — are all acting as data collection devices, interconnected via a redundant bus. Additionally, one Alphacomm unit serves the engine-related controls and one Alphacomm unit acts as a redundant safety system. The local monitoring systems and the safety system are based on three identical computer units mounted on engine and gearbox. Only one unit will thus be required as a spare part. If a unit needs to be replaced, the programming of the new unit is done automatically by transferring a copy of the program from one of the other two units on the network, a fully automatic programming feature, which was patented by MAN B&W.