MAN Diesel has enhanced its 50 cm-bore, low-speed engine programme with the launch of a series of MAN B&W S50ME-B type engines. These add to the existing, small-bore MAN B&W S35ME-B and S40ME-B engines that were introduced in mid-2006.
The new S50ME-B engines, available in three variants (Marks 7, 8 and 9), strengthen the proven and popular 50-bore range that also includes the S50 ME-C/MC-C/MC engine series, and which have a combined total of over 3,000 engines in service.
MAN Diesel is using the ME-B series to broaden the application of the ME concept in its small-bore and medium-sized, two-stroke engines using the electronic, fuel-injection control already introduced in its large-bore engines.
The S50ME-B7/8 variants have clear cost benefits in their power bracket. This makes it possible for existing ship designs with the S50MC-C to benefit where application of the advanced S50ME-C type is considered less feasible.
The S50ME-B7/8 will have the same output and installation data as the corresponding S50MC-C/ME-C versions.
With the introduction of the higher-powered MAN B&W S50ME-B9, engine output increases by 12.6% per cylinder, compared with the Mark 7. Furthermore, the Mark 9 is designed to suit continuously evolving hull designs, based on more efficient propellers with a lower optimum speed. The engine will adopt the design features introduced with the smaller ME-B engines, and will be introduced with 117 rpm.
All the new S50ME-B engines are available in five- to nine-cylinder variants. This means that the entire ME-B programme now boasts a total output range from 2,975 kW to 16,020 kW.
The ME-B7/8 design is based on that of the existing, mechanical MC-C range – the most popular two-stroke engines available on today’s market.
It upgrades some of the market’s leading engines with electronic controls that provide improved, operational economy and flexibility, and manoeuvrability.
As the production cost of small, two-stroke engines is of paramount importance, the ME-B9 will feature a higher MEP and stroke-to-bore ratio, and a higher mean piston speed to increase power concentration. A number of innovative, manufacturing, cost-saving features have also been introduced. The exhaust valve of all S50ME-B types is operated by a smaller camshaft than normal when compared with its MC-C counterpart.
The S50ME-B series can be optionally delivered with TCA turbochargers with variable nozzle rings technology (VTA), which compensate for the absence of variable, exhaust-gas valve timing in terms of part-load fuel consumption. These are expected to be released for sale in January 2008.
|Mean Piston Speed
||163 - 170
||163 - 170
||162 - 169|
The advanced, fuel-injection control is an efficient way of managing current and future environmental-emission requirements, with a fuel economy that is second to none in its class. As with the larger MAN B&W ME-engines, the Alpha Lubricator comes as standard, ensuring a very low, cylinder lubricating-oil consumption as the advanced, electronic, user-friendly interface allows precise adjustment.
In summary, based on well-proven diesel technology, the ME-B series provides engines geared to market requirements for:
- electronic fuel-injection control
- fuel economy
- higher power
- longer time between overhauls
- lower propeller speed
- better vessel manoeuvrability
- very low life-cycle costs
The Mark version number, which identifies the specific version of an engine type, has now been added to the engine type designation.
For example, the designation S50ME-B9 is the identification for a Super-long stroke (stroke/bore ratio) 50-cm bore, Electronically controlled, Compact engine, Mark version 9.
Until now, the Mark version has largely followed the mean effective pressure (MEP) of the engine, i.e., 18 bar = Mark 6, 19 bar = Mark 7, and 20 bar = Mark 8.
However, the new Mark 9 engines represent a breach with this principle in that they, irrespective of MEP, have a longer stroke, thereby achieving a higher output. Hence, the new, integrated Mark number is from now on a necessary part for a marine-engine’s identification.
You can download the graphics here.