^ Expanding Sizes of Container Ships (Source: container-transportation.com) (Retrieved From: http://www.vox.com/2015/1/8/7513317/container-ship-msc-oscar)
To Cut a Long Queue Short
Malcolm McLean was one frustrated man in 1937. The owner of a North Carolina trucking company, he had to wait for hours as dock workers manually (and obviously slowly) loaded goods on ships at the New York harbor. Most fairy tales usually start with our hero in adversity. Right?
Once again, necessity became the mother of invention as McLean pondered over the idea of directly loading truck trailers onto ships with cranes. It took a while for his ideas to materialize. A whole 19 years lapsed before he made the world’s first container ship in 1956, the Ideal X that could carry only 58 containers.
In 1957, he came up with the Gateway City with the capacity to carry 226 containers. By the 1960s, his company Pan American was building larger and larger container ships. The fairy tale had come true.
The race to build larger container ships continues to this day because larger ships are more fuel efficient and less polluting. Presently the MSC Oscar is the largest container ship (in terms of capacity) with a 19,224TEU capacity. By 2017, the largest container vessel will be of 24,000TEU capacity.
And this capacity expansion will come without increase in size. Most probably, engineers will not boost the size of their engines. The extra power is most likely to come from turbochargers.
ABB A100L Turbocharger
ABB developed the A100L Turbochargers after exhaustive feedback from customers. The approach has borne fruit and the company has installed these on two container ships with the largest container capacity viz. the MSC Oscar (19,224TEU) and the CSCL Globe (19,000TEU).
ABB’s turbocharger assists these giants cut fuel costs while complying with progressively more demanding environmental regulations. Come January 1, 2016 and the more stringent IMO Tier III emission norms will come into force.
Said to be four times more exacting than current laws, IMO Tier III norms will apply to ships plying in the North American Sea and the United States Caribbean Sea with engines built on or after the first day of 2016.
ABB’s turbochargers comply with IMO Tier III regulations and have cut MSC Oscar’s fuel use by 35%. The A100L employs exhaust gas recirculation (EGR). When combined with other green technologies, the A100L will discharge 50%-60% less NOX. Owners of the MSC Oscar claim it is the ‘most efficient ship’ on the planet.
Kuwait-based UASC’s Barzan however is the first vessel to receive DNV GL’s Gas Ready notation. This notation ensures that a future, LNG-fueled version of a vessel (not currently powered by LNG) is in accordance with the necessary operational and safety norms. UASC claims the Barzan is the ‘world’s greenest ultra-large container vessel’.
Based on the feedback from the customers of over 200,000 of its turbochargers around the world, the A100L series of turbochargers endow low-speed, two-stroke marine engines with exceptional levels of fuel efficiency, emission compliance, reduced total cost of ownership (TCO), application adaptability, and appropriate operational safety.
|Pressure Ratio (Max)||5 bar|
|Mean Effective Pressure||23bar|
High levels of pressure ratio and combined with extremely wide compressor maps provide operational flexibility and record levels of fuel efficiency. The extensive feedback process has ensured tremendous availability and reliability of the A100L while ensuring long durations between maintenance, inspections, and overhauls for low TCO.
Wide compressor maps enable cost-effective switchover to slow steaming. These wide maps match air supply with demand through flexible features such as high-pressure tuning (HPT). HPT lowers fuel consumption at all loads. Air outlet silencer lowers noise for better ergonomics.
Engine exhaust gases drive turbochargers. These consist of two turbines mounted on the same shaft, one each at the exhaust and intake end of the engine. The exhaust turbine rotates only after the engine acquires a certain speed. The input turbine rotates concurrently and pumps air into the engine at more than atmospheric pressure.
Because greater amount or air at higher pressure is pumped into the engine, you can pump in more fuel. This improves the combustion in the engine as well as its power output and efficiency.
Larger Ships: Economies of Scale
These days, container ship operators de-rate their engines and practice slow steaming. De-rating is the lowering of engine power output to prolong its life. Slow Steaming is the deliberate cut-down of a vessel’s speed in order to cut fuel consumption.
Operators do this to minimize fuel costs. The container ship segment is plagued by overcapacity and any cuts in cost are more-than-welcome. Currently, container ships clock average speeds of 21-25knots only.
Slowdowns introduce unnecessary delays in transportation. More importantly, they frustrate the development of faster and larger container vessels, a phenomenon vital for overall human progress.
Larger ships carry greater load and emit lesser pollutants while consuming the same quantity of fuel because:
- Large ships are more stable and need to hold less ballast water. This reduces weight and transforms into lower fuel consumption
- One single large ship of cargo capacity equal to that of two smaller ships will weigh less than two smaller ships and have lesser hull area in contact with water
This means, the large ship needs less fuel and emits less pollutants to carry the same quantity of cargo
According to ABB, the cost of transporting one TEU for one day via sea:
- is about $12 for a 12,500TEU ship
- is around $10 for a 18,000TEU vessel
- will be $9.57 for a 24,000TEU ship
While it is possible to build ships of progressively larger capacities, certain practical constraints limit these sizes:
- capacities of crucial maritime transit channels such as the Panama Canal and the Suez Canal
- harbor depth
- capacity of cargo handling equipment at ports
To further slash emissions and fuel consumption, we need technological innovations such as ingenious hull coatings, more streamlined hull designs, use of a larger number of smaller marine diesel engines that perform better than a small number of large engines, and turbochargers.
Container ships have revolutionized international trade and commerce. Along with free trade policies, these ships are a major agent of globalization. We cannot expect such a groundbreaking force to be static.
To know more on developments that affect the efficiency of marine engines, visit our blog. Contact Kemplon Engineering for stellar marine fabrication services, marine pipe fitting, and large scale custom metal fabrication.