In such a competitive field, regular releases of new models are essential to keep pace although it can be two or three years following the launch of a new engine before orders begin to be placed. This year (2018) has been rather quiet on the new engine front for commercial ships probably because the previous few years saw several new models released.
At SMM in 2014 and Nor-Shipping in 2015, two new engines were unveiled. These were the Rolls-Royce Bergen B33:45 and the Wärtsilä 31 respectively. The bore sizes of the two engines placed them in one of the most competitive segments of the four-stroke market where they will be competing against models from MaK and MAN Energy Solutions. Rolls-Royce is almost unique in not offering a dual-fuel engine preferring instead to produce its engines in either pure diesel or pure spark ignited gas variants; the B33:45 is no exception but the Wärtsilä 31 is offered in three versions diesel, dual-fuel (DF) and spark-ignited gas (SG).
The Rolls-Royce engine was described at the time as having world-class fuel efficiency and offering 600kW per cylinder in a compact engine design. In response to customer enquiries, Rolls-Royce focused on five main areas when designing the engine – achieving the lowest fuel consumption and emissions; highest power per cylinder in this engine class; increased power within the same footprint, and potential for fewer cylinders with lower weight and cost
a compact modular design and a base engine suitable for liquid or gas fueland dynamic and extended service intervals.
The Bergen B33:45 runs at 450-750rpm as a marine propulsion engine on propeller law, or 720/750rpm for 60/50Hz generator set drive. In line engines were the first to be produced, with 6, 7, 8 and 9 cylinders spanning a power range from 3,600kW to 5,400kW. At Nor-Shipping in 2017, Rolls-Royce announced a V12 version and said more vee engines will follow. The V12 version allows for 20% more power over the B32:40 predecessor while maintaining the same footprint.
Power and fuel consumption figures are much boasted about by manufacturers but there is often very little between the engines on paper and in practice the running parameters selected by the operators will likely affect the claimed figures to some extent. The 600kW per cylinder of the B33:45 is the same as for MAN Energy Solutions’ 32/44CR but the SFOC at 100% is said to be 176g/kWh for the Bergen and 174g/kWh for the MAN engine. Wärtsilä has outdone both in the claims for its new 31 type quoting 610kW per cylinder and a SFOC of just 170.6g/kWh for the diesel version. The Wärtsilä 31 is available in 8 to 16 cylinder configurations and has a power output ranging from 4.2 to 9.8 MW, at 720 and 750 rpm.
Most makers have opted for a modular design for new engines as a means of both reducing production costs and facilitating maintenance. On the 31 engine Wärtsilä has taken this to a new level by shifting from single parts to exchange units. For example, the powerpack unit now consists of a connecting rod, piston, cylinder liner and cylinder head with related pipes combined in one single exchange unit. Standardisation also makes conversion of the engine from one version to another a simple matter of swapping components without the need for machining.
In September 2017, MAN Energy Solutions unveiled a new engine range based on its earlier 48/60CR. Compared to its predecessor, the new 45/60CR engine achieves a sizeable increase in power per cylinder as well as a substantial SFOC reduction. Featuring the engine maker’s proven common-rail technology, the engine is fully geared to the its next generation of innovative ECOMAP function. The 45/60CR, along with its brand-new safety and control system, is designed for operation in combination with MAN Energy Solutions’ SCR system to fully comply with the IMO Tier III emission regulations.
At 1300kW per cylinder and with a SFOC of 166g/kWh, the new engine out performs rivals in the segments that the engine is targetted at. It achieves this partly by running at 600rpm rather than the 500-514rpm of competing models. MAN Energy Solutions plans to introduce a dual-fuel version at a future date.