When the ‘Marco Polo’ entered service in November 2012, it became the largest container ship in the world measured by capacity. It has a maximum TEU capacity in excess of 16,000, in other words, 97 km of containers in line. It is 396 metres long and nearly 54 metres wide. Just to give an idea of what these dimensions mean in day-to-day terms, the ship is larger than a US Navy aircraft carrier, and longer than four football pitches.
The ‘Marco Polo’ is owned by CMA CGM, a French container transportation and shipping company,and was built at the Daewoo shipyard in Okpo, Korea. It is the first of a series of three based on an extrapolated design slightly larger than that used for CMA CGM’s Christopher Columbus class. All of these giants are powered by the 14-cylinder, Wärtsilä RT-flex96C low speed diesel engine, the proven solution for large and ultra large container ships.
The development of these mammoth sized vessels is a fairly recent phenomenon. For instance, 30 years ago container ships were typically in the order of 4000 TEU in size. Ten years ago, they had grown to around 10,000 TEU and more, and today we are exceeding even that capacity by 60 per cent. The reason behind this rapidly evolving trend is simply that of economies of scale. Global trade expansion has occurred simultaneously with a hefty jump in fuel and other operating costs; a development that has caused owners and operators to reach the logical conclusion that one very big ship makes more economic sense than two or more smaller ships.
Efficiency, economy, environment
There are also environmental benefits to this trend, since the fuel consumption per TEU is somewhat lower than for smaller container vessels. But the greater sustainability benefits are brought about by the choice of the Wärtsilä RT-flex96C engine. This electronically controlled, 2-stroke diesel engine has particularly high efficiency, which naturally results in less fuel being burned and correspondingly fewer exhaust emissions. Furthermore, the engine provides different tuning capabilities to achieve the optimal fuel consumption at different load profiles, such as part and low load.
This retention of fuel efficiency at different speeds is a huge advantage in today’s container shipping sector. Driven by over capacity in the market, and by the necessity to reduce fuel costs, owners and charterers have had to adjust not only their services, but also the speeds at which the ships are operated. Lower speeds reduce fuel consumption and, therefore, costs, and this is likely to be a continuing trend in this sector. However, the engine must be capable of the flexibility needed to retain efficiency while adapting to running at slower speeds, which is why the RT-flex96C engine is Ideal.
Currently, more than 220 RT-flex96C engines are in service or on order, which is in itself a clear indication of the trust that owners and operators have in the reliability and technological advantages of this propulsion solution. The operating excellence and lifecycle cost efficiencies that it offers, are among the key reasons for it being the engine of preference for this shipping sector.
Martin Wernli, Managing Director of Wärtsilä Switzerland and Vice President, Ship Power 2-stroke, explains as follows: “The RT-flex96C is today the most powerful diesel engine in the world. It has proven to be the most efficient and flexible main propulsion engine for large and very large container vessels, and the experience gained from its operational success has formed the design basis for the new Wärtsilä X92 engine, which will be available from mid-2014.”
The launching of the ‘Marco Polo’ did indeed set a new benchmark in the size of modern day container ships. The widening of the Panama Canal, which is scheduled for completion in 2014, allows access to bigger vessels. The maximum breadth of ship that the widened canal will be able to accommodate is increased from 32.3 metres to 48.8 metres, and this triggered a new class of vessels known as the ‘New Panamax’ class. The ‘Marco Polo’ exceeds even this. But it is clear that the move towards these ultra large ships is likely to continue, and it is only a question of time before a new benchmark in container vessel size is set.
Environmental legislation, such as the Energy Efficient Design Index (EEDI) which is now mandatory for new ships, together with high fuel prices and fluctuating market conditions, has created the need for highly efficient solutions that offer the added value of operational flexibility. The new Wärtsilä X92, the soon-to-be successor to the RT-flex96C engine, will be delivered as from mid 2014 and is designed to provide optimum propulsion power to this new generation of large and ultra large container vessels. Savings in fuel consumption will be in the order of 10 per cent compared to previous solutions.
Image Credits: cma-cgm-blog