The Mitsubishi Air Lubrication System (MALS) was the first air lubrication system in the world to be applied to a newly built ship, and resulted in a substantial reduction in the ship’s resistance. Therefore, a performance estimation method using computational fluid dynamics (CFD) needs to be established as soon as possible to apply the MALS to general commercial ships.
Wired – Grain conglomerate Archer Daniels Midland has ordered three dry bulk carriers that blow bubbles to improve fuel efficiency. The boats, to be completed by 2014, rely on Mitsubishi Heavy Industries’ proprietary Mitsubishi Air Lubrication System (MALS). Mitsubishi claims that MALS can reduce CO2 emissions by a quarter compared with conventional dry bulk carriers. Considering the ships will carry about 100,000 tons including cargo, fuel and crew, that’s a significant reduction. The three ships ordered by ADM will be 131 feet wide and 777 feet long and will be built by Oshima Shipbuilding.
Bubbles under the vessel bottom of the new bulk carrier with MALS.
Japan put Mitsubishi Air Lubrication System on module carriers — ships that bring heavy equipment to industrial development sites
GreenCarCongress – Mitsubishi Heavy Industries, Ltd. (MHI) has designed a new bulk carrier equipped with the proprietary Mitsubishi Air Lubrication System (MALS), which reduces frictional resistance between the vessel hull and seawater using air bubbles produced at the vessel bottom, along with high-efficiency hull form and enhanced propulsion system. The new MALS carriers will enable reductions in CO2 emissions by about 25% compared with conventional averaged bulk carriers.
The three bulk carriers, which mark the first new shipbuilding order placed by ADM, are designed to accommodate new post-Panamax needs.
Post-Panamax” class refers to the ships that are unable to travel through the Panama Canal and “new post-Panamax” refers to the size limit of ships that will be able to travel through the Panama Canal after its planned expansion is completed in 2014: 366m in length overall (LOA), 49m in width and 15.2m in tropical freshwater (TFW) draft. Panamax parameters are 295.0 m in LOA, 32.2 m in width and 12.0 m in draft.
A simplified piping diagram of MALS. In this design, presented in a paper on a MALS application in the Yamatai, air discharged from two sets of blowers is collected in a large-diameter pipe and then is distributed to fifteen branch pipes to be delivered to air chambers mounted on the bottom of the hull
The Great Lakes shipping industry could adopt the new bubble blower ships to increase fuel efficiency by 5 percent to 20 percent. Great Lakes ships tend to have large, flat bottoms – an ideal shape for the technology because air stays underneath the ship instead of bubbling to the surface. Costs of adding a blower depend on the ship. Ceccio said retrofitting old ships with the technology would often be more costly than building it on new ships.
So far no ships in the Great Lakes use air lubrication technology. “Over the past several years there’s been a great deal of progress,” Ceccio said. “Now in Europe and Japan they’re deploying large ships that use air lubrication to reduce energy use.”
The european partners are investigating using this type of bottom on a seagoing vessel, (up to a 360 m container feeder), and then they will also look at its potential for tankers. Seagoing trials are being carried out with the same model used for the inland waterways. If the outcome of the trials is positive the partners will construct a model of a seagoing vessel.
The next step is further research into the tanker business. But there are several challenges to be addressed when it comes to the tanker market, such as the ADN regulations and the fact that the ACES would be a double-double bottom construction.
Damen River Liner 11.45e