Change of topic off the maritime catastrophe of the day. The Antipodean Mariner has been studying devices to reduce the fuel consumption on the Capesize vessels under construction. With heavy fuel oil north of $700 a tonne, bunker consumption on a Capesize bulk carrier is around $50,000 a day while steaming, compared with break-even operating costs of about $25,000 a day.
Capesize charter rates are much lower than this opex breakeven, presenting a 'perfect storm' scenario of low hire rates and high fuel costs. The economies of scale of large ships are astounding. A slow speed, turbocharged 2-stroke diesel main engine will move one tonne of iron ore one nautical mile on one gramme of heavy fuel. However, in the tonnages moved and quantities of bunkers consumed savings are investigated in every part of the process of turning bunkers into forward motion. It is a sad fact that the new IMO Tier 2 emissions standards requires engines to consume more fuel, and emit more CO2, than the Tier 1 standard in order to meet nitrogen and sulphur limits. The California-inspired obsession with smog controls has lead to this anomaly.
There are two main areas of focus for naval architects and engineers when aproaching bluff, high block co-efficient bulk carriers and tankers. The first is the bow area, and the reduction of the wave form. Bulbous bows are falling out of fashion - great for fine-lined container and passenger ships but not for hulls experiencing up to 13 metres difference in draft between laden and ballast condition. The straight stem bow with the hint of a bulb is returning to a shipyard near you.
The second area is flow around the propellor. A number of proprietary systems make claims of 5-9% reduction in power requirements through harnessing the forward motion of the ship to improve flow into or behind the propellor. Even 5% translates to 3.5 tonnes, or $2,500 a day in operating costs.
Unfortunately, many of the Capesize ordered and built as a consequence of the 2007 freight rates orgy have little or no thought put into fuel economy. The Japanese Yards, with Government R&D assistance, have achieved some spectacular success in recovering energy and reapplying to power the ship on daily consumptions of ships half their deadweight.
Some pictures of hot technology in the market - an Oshima Seaworthy Bow on a forest products carrier, MOL's finned propeller boss and Becker's Mewis Duct.
The Antipodean Mariner