Oil consumption of containerships
Preface. Since 90% of international goods move by ships, I was curious about how much fuel they burned. It’s a lot: The very large container ship CMA CGM Benjamin Franklin above, which can carry 18,000 20-foot containers, carries approximately 4.5 million gallons of fuel oil, which takes up 16,000 cubic meters (FW 2020). As much fuel as 300,000 15-gallon tank cars.
But these ships can carry 200,000 tons of goods, so they end up being more energy efficient than 300,000 cars (Stopford 2010, UNCTAD 2012).
Pound for pound and mile for mile, today’s ships are the most energy-efficient way to move freight. Table 1 shows the energy efficiency of different modes of transport by kilojoules of energy used to carry one ton of cargo a kilometer (KJ/tkm). As you can see, water and rail are literally tons and tons—orders of magnitude—more energy efficient than trucks and air transportation.
Table 1 Energy efficiency of transportation in kilojoules/ton/kilometer (Smil 2013), Ashby 2015)
(A) ……………Transportation mode
50……………. Oil tankers and bulk cargo ships
100–150….. Smaller cargo ships
250–600….. Trains
360………….. Barge
2000–4000 Trucks
30,000…….. Air freight
55,000…….. Helicopter
(A) Kilojoules of energy used to carry one ton of cargo one kilometer Transportation mode
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Further details
Fuel consumption by a container ship is mostly a function of ship size and cruising speed, which follows an exponential function above 14 knots. So an 8,000 TEU container ship consumes 225 tons of bunker fuel per day at 24 knots, but at 21 knots consumption drops to 150 tons per day, a 33% decline. While shipping lines would prefer consuming the least amount of fuel by adopting lower speeds, this advantage must be mitigated with longer shipping times as well as assigning more ships on a pendulum service to maintain the same port call frequency. The main ship speed classes are (Notteboom 2009):
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