Ocean-going ships, presently in an excess for the amount of cargo to be lifted, increasingly steam at slower speeds in order to save expensive fuel oil bunker costs; better that than to be laid up reckon shipowners.
Photo courtesy of Maersk Line
The problem is that large marine diesel engines are not designed to operate below 85% power for long periods without harmful effects; effects best ameliorated by getting lubricating oil of the right specs. After a quick look at lubricating oil solutions, a handy little device to check cylinder performance is spotlighted.Marine Diesel Engines & Slow SteamingExperts at Castrol Marine drew on OEM reports and their own engine performance tests to analyse the effects of slow steaming on engine performance, finding that the oil-feed rate as well as a lower engine operating temperature had a bearing on the amount of corrosion caused on piston rings and cylinder liners.At lower loads, the cylinder oil’s feed rate is reduced, making ... [More]
Energy saving, fuel economy of 15%, by reducing frictional drag on the immersed hull by means of injected streams of air bubbles has been proven effective by recently concluded practical tests. Two years of trials of a technology known as ‘Air Chamber Energy Saving’ (ACES) installed in a working Dutch inland waterway tanker back up this claim.
Damen Shipyards in Holland commissioned the exercise in the Dutch inland waterway tanker Till Deymann provided by subsidiary company Bodewes Binnenvaart back in 2009 on the heels of detailed analysis of tank-testing and computer modelling (at the Dutch Institute MARIN in Wageningen and DST laboratories in Duisberg, Germany), that indicated the time was right for putting ACES to the test under operational conditions.
Till Deymann, chosen for conversion in order to test out the ACES system, was a standard 'River Liner' type 11.45e product from the Damen yard, of 2858 dwt, with a LOA of 110 m, moulded breadth of 11.45 m, and a d... [More]
Projects running with NYK Line ships under the Japanese Ministry of Land, Infrastructure, Transport and Tourism are investigating technological developments to curtail CO2 emissions from marine vessels. In the main project, two NYK ships, are equipped with an air blower to supply air to the vessel's bottom to reduce frictional resistance. Mitsubishi Heavy Industries supplied the engines and is also participating in the experiment. It was decided that, a module carrier, would be best type of vessel for this experiment. she has a wide, shallow-draft hull minimizing the energy required by the electrically blower supplying air to the vessel's bottom and should better retain the supplied air under the vessel's bottom. [More]