What to do when the tanker markets are depressed? Maersk Tankers has taken a hard look at bunker fuel consumption, which on their Very Large Crude Carriers (VLCC) makes up about 85% of the voyage costs. They found that the key to improve earnings is super slow steaming, which they’ve taken to a whole new low with giant VLCC’s ambling over the oceans at speeds as slow as 8.5 knots.Super slow steaming requires engine load to be decreased down to 10%, which is equivalent to 50% speed, but the company recently decided to further economise on fuel consumption (and not by reducing the speed of its ships yet more) with the retrofit of a Variable Turbine Inlet system (VTI) onboard the 318,000 dwt crude oil carrier Maersk Ingrid. Manufacturers, Mitsubishi Heavy Industries Marine Machinery & Engine (MHI-MME) say that their VTI turbocharger system has been been fitted to more than ten new buildings, but never before retrofitted to an existing unit, a job that took just four days d... [More]
Variable Turbine Area (VTA) geometry for the largest exhaust-gas turbochargers, introduced by MAN Diesel & Turbo about four years ago, recently topped the hundred sales mark according to the manufacturers, as the technology gradually proved itself effective in reducing fuel-oil consumption in medium and low-speed marine diesel engines.The VTA is designed for fitting on supercharged large-bore diesel engines with varying load profiles. Due to its adjustability, the VTA efficiently adapts to a wide range of engine operations, making it particularly useful for the present-day trend to slow-steam bulkers, tankers and container ships.MAN say that the first VTA unit delivered has so far accumulated over 20,000 operating hours running on engines using heavy fuel oil (HFO) to give fuel consumption savings of up to 5 g/kWh.VTA Turbocharging
VTA technology enables the quantity of charge air to be more precisely matched to the quantity of fuel injected, encouraging reduced specific fuel co... [More]
Turbocharger parts destined for scrap can now be repaired using a new laser cladding technology, called ‘Laser Aided Additive Manufacturing’ (LAAM) introduced recently by Singapore-based turbocharger specialists TruMarine. In essence this works by focusing a laser beam on a metallurgical additive composition, bonding it to the component needing repair. Classification society Det Norske Veritas has already recognised that LAAM technology is more than a temporary repair of damaged or worn turbocharger parts by giving the process their approval.
The cladding of turbochargers with particularly thin shafts, easily deformed by high temperature thermal repair, has been impossible up to now, but by means of LAAM technology they need not necessarily be replaced and discarded, but can be restored to the original quality of manufacture.The essential turbocharger has down to it the delivery of higher engine output, lower specific fuel consumption and cleaner exhaust gases, boosting th... [More]