Emma Maersk, part 2

A day after leaving the Malaysian port of Tanjung Pelepas, the container ship Emma Maersk has already left landfall behind and entered the open waters of the Indian Ocean. We've already completed a night passage up through the Strait of Malacca and rounded northern Indonesia's state of Bandah Aceh. Sunrise finds us at 6 13 N/090 19 E, with nothing much to see but empty seas. Indeed, we'll see few other vessels as the Emma makes her way across the ocean towards the Red Sea at 21.2 knots.

As one of the largest working vessel's afloat, Emma Maersk's size can be difficult to imagine if you've never seen her. She's 397 metres long (1302 feet), 56 metres wide (183 feet) and rises as tall as a 16 storey building from her waterline to her wheelhouse. She joined the Maersk Line in January 2007, the first of new class of container ships that now number eight vessels. Known formally as "PS-Class" ships, Emma and her sister ships each have a carrying capacity of 11,000 TEUs, the somewhat arcane means by which container vessels are categorized. A TEU - or "twenty-foot equivalent unit" - was the size of the original steel boxes that container ships began carrying. Today, most containers are actually double that size (forty feet long) though they do still carry the shorter ones, as well as some even longer units.

After the frenetic activity of loading the Emma in various Asian ports, her crew can now relax a bit as we sail westward. Though she's an immense vessel, the ship is operated by a crew numbering 22, plus four Thai painters doing some touch-ups on the voyage. Mid-morning I find the Second Officer on the bridge updating our course. He's a young Romanian named Irinel Neamtu, a somewhat shy man who takes his seafaring profession quite seriously.

Second Officer Irinel Neamtu at the chart table

As the Second Officer finishes plotting out our route, we're joined in the wheelhouse by Chief Officer Niels Larsen and the Chief Engineer, Michael Sort. The two Danish officers are discussing work schedules for the crew and the need for some routine maintenance in the engine room. Chief Sort has one of the most enviable positions for a marine engineer, the care of the largest engine plant created for a seagoing vessel.

Chief Officer Niels Larsen in conversation with Chief Engineer Michael Sort

The Emma Maersk is powered by the world's largest single diesel engine unit, a 14-cylinder Wartsila-Sulzer power plant that can produce 109,000 horsepower, the same as 1,156 family cars. It stands about nine storeys high and is one of the more energy-efficient propulsion plants currently in use on a merchant vessel. Though it consumes some 1,660 gallons of fuel every hour she's at sea, the Emma has a unique waste heat recovery system that recycles the exhaust - mixed with fresh air - back into the engine for re-use, saving something like ten percent percent of the main engine's power. This saving is the equivalent to to energy consumption of 5,000 typical European households. The power plant allows the Emma Maersk to travel 66 kilometres using just 1 kWh of energy per ton of cargo. By way of comparison, a jumbo jet can travel barely half a kilometre at the same rate.

14-cylinder Wartsila-Sulzer main diesel engine

The Emma Maersk is propelled by a single screw, turning at up to 102 rpms. The shaft driving the propeller runs from the engine room beneath the aft eight cargo holds. There are two stern thrusters, as well as a couple more forward, to aid in berthing the vessel. the ship is also equiped with two pairs of active stabilizing fins located amidship, which can be deployed to combat the effect of rolling in high seas.

Shaft tunnel on Emma Maersk