Taking a cab from central London to Heathrow airport calls for judgement. To catch a “crack of dawn” flight at 5 AM, three quarters of an hour should be fine. But at 5 PM on a wet Friday, three quarters of an hour would hardly get you to Hammersmith. It’s a nightmare. The cab can do 80 miles an hour, but on Friday in the rain, 10 miles an hour’s a much better bet.
Flat Out on the High Seas
These are problems which the ship-ping industry, mercifully, rarely has to deal with. The high seas are wide open spaces and, once out of port, the master can order full ahead and the ship proceeds at full speed. “Full speed” is the only speed reported in, for example Clarkson’s World Fleet Register, usually based on 85% of the engine’s maximum continuous rating (MCR). So when analysts calculate how many ships will be “needed” to carry world trade, this is the speed they use and so do voyage estimators. Of course, port congestion and heavy weather slows things down, so a “sea margin” is deducted. But for years, “full speed” has been the norm.
Bin the Full Speed Focus, Bosun
Does that make “full speed” the right speed for today? Two recent developments suggest that it might not be and that the “85% MCR” norm should be consigned to the dustbin. The first is the fuel price revolution which has been creeping up on shipping for a decade. In the past, bunkers at $200/t were cheap enough to make full speed ahead the obvious strategy. Now fuel costs $600/t and earnings are lower. Full speed has become a high cost strategy (see SIW 1089). Also, environmental pressures are strangling performance, as SOX, NOX and carbon emissions all increase with speed.
Look, No Layup…
All this suggests that ships should be regarded as a flexible resource, whose performance can be adjusted within a wide spectrum to meet commercial and environmental goals. In a way this is already happening, as the Graph of the Week shows. Trade, shown by the line (left axis) is compared with the bulk carrier fleet (the bars). At 14.5 knots the mid 2013 “full speed” fleet of 700m dwt is 150m dwt more than is needed. But at an (estimated) speed of 11 knots, this 150m dwt surplus is soaked up.
And there’s a little-appreciated bonus. As well as saving about 50% on bunkers, slowing-down cuts carbon, SOX, NOX and particulate emissions, way ahead of IMO regulations. It’s magic! Tinkering with today’s engine room technology can achieve only a fraction of these savings.
“Right” Speed Ahead, Skipper
So there you have it. The way ship-ping views speed is changing. In a business driven by big fuel costs and small emissions, the “right” speed is a vital tool, demanding at least as much forethought as booking the “right” time to get to the airport. Confusingly, slow speed is also mixed up with market economics and is seen as an alternative to layup. The focus is on trading “full speed” for “right speed” and persuading charterers it makes sense. Have a nice day.