MARINE

TANKER TRIO STREAMLINES THE WATERLINE

TEXT: PATRICK REILLY ILLUSTRATION: WÄRTSILÄ

HEADING BELOW THE WATERLINE allowed Wärtsilä engineers to redesign its Aframax hull, increasing flow to the propeller and improving efficiency. Several green-tech touches completed the makeover, which created a splash at the tanker launch at Posidonia.

utting a new spin on the Aframax concept THE PROCESS INVOLVED EXTENSIVE USE of CFD (com- P is no easy feat. After all, the AFRA (Average putational fluid dynamics), a proven and widely used Freight Rate Assessment) system has been method in the ship design business, and tank testing around since the 1950s and remains the standard with the Forbes Institute in Copenhagen to further bearer for medium-sized crude tankers. evaluate the merits of all three designs. DUE TO ITS DIMENSIONS But that is exactly what Wärtsilä is aiming to do “Getting the optimum flow to the propeller is vital, AN AFRAMAX SHIP IS with its latest Aframax tanker design, available in so to do that we lifted the stern significantly. Com- not one, not two, but three different configurations; pared to the first design in 2011 the underwater pro- IDEAL FOR SERVING basic, environmental and dual-fuel. Going green is file of the ship now is quite different. As a result we ROUTES THAT DON’T the motivating force behind the trio of ships with improved the efficiency level by more than 25% com- the caveat that efficiency gains shouldn’t compro- pared to the first one,” Thygesen adds. HAVE LARGE PORTS. mise performance. Established in 1954 by Shell, the Aframax is one Plans for the new breed of ships were on the draw- of the most iconic oil tankers. Not to be confused ing board as long ago as 2011. Growing pains were with a supertanker, an Aframax vessel is smaller than inevitable as the challenges of creating a modern 120,000 tonnes with a maximum width of the Pan- Aframax prompted the designers to have a rethink, ama Canal – 32.2 metres. but the perseverance has paid off with interest already Due to its dimensions an Aframax ship is ideal for high in the fleet. serving routes that don’t have large ports. Which is “Our initial concept was not really competitive in just what these lengthy vessels have been doing for terms of efficiency so we went back to the drawing the past six decades; the average transport capacity board and focused more on the underwater structure is 700,000 barrels of crude oil in cargo. of these ships. Our efforts to improve the hull lines on The global demand for oil is as strong as ever, but this specific design are unparalleled compared with any- recent environmental legislation means the transport thing we have done before,” says Jacob Høgh Thygesen , of black gold has to be greener and cleaner. What Head of Merchant Ship Design Solutions with Wärtsilä. was de rigueur 10, or even five years ago is no longer

64 Twentyfour7. 3.14 lines are extremely important for any gains. efficiency water the hullbeneath the loaded, it linewhen isfully cient, that large sense inthe there isavery surface attention devoted to ship’s the hull. ers,” says Thygesen. dual-fuelthe version iseven more attractive to buy- ferent that class itso when means comes to efficiency roughly oil 10%.Ourfuel version isalready inadif- theremodel isareduction consumption inenergy by you compare conventional the version to green the engines.fuel lyst reduction, the green while version runs on dual- oftrio tankers. Wärtsilä executives revealed the much-anticipated Posidonia exhibition 2014 inGreece summer, this AT THELAUNCH OFTHENEWAFRAMAX pronged strategy to its fleet. new acceptable, which prompted Wärtsilä to take athree- sions cleaned using a scrubber and cata-sions selective cleaned using ascrubber the environmentalthe exhaust hasthe model emis- “For allintents it and same isthe ship. purposes If “When you have ships block with coeffi- ahigh rigorous gains the Key hasbeen energy to those basic configurationThe runs fuel heavy oil, on design at the per dayper inimproved efficiency.” tion profile and yieldedmore gains. tested using CFD, improved which accommoda- the to how perform it does.” successful way of applying to get amethod ship the After acomplicated and lengthy process we found a lion. Wärtsilä offering isalso shipyards integration willcost Aframax region inthe new of $50–$55 mil- and Mediterranean. the North South and Blackthe ChinaSeas Sea, East Sea, to come onstream inlate 2016 and largely operate in rates throughout Thefirst 2014. vessels are expected aspike AFRAmarket asthe time in hasseen good vided by atwo-stroke Wärtsilä 6X62 main engine. estimated 35.2 to be tonnes day per with power pro- ating of knots. at Fuel 14.5 aspeed oil consumption is (approximately 6,000miles) and iscapable of oper- tonnesmetric an endurance days of seven at sea THE NEWAFRAMAXHAS ADEADWEIGHT talks” with anumber of serious owners. Abrand Thygesensays that close isin Wärtsilä “very Wärtsilä’s addition new to sector comes the at a Thygesen adds; “By doing this gaveit us0.3 tonnes Furthermore, aerodynamics the of vessel the were of 111,000 chant fleet gets onboard also,” concludes Thygesen. mer- the before time of matter a only is it and forward have most the fuel-efficient the design.Thisis way aroused inshipowners. ing by amount the has Aframax of new the curiosity the right approach.” frombelieve an and ethical moral point of it view is of Wärtsilä. That comes acost,at course,of but we remaining to Wärtsilä’s true core principles els,” Thygesen adds. year, we needto know market their drivers and mod- ing 10ships over 365days running a25-year a period face it may insignificant seem but they if are operat- potential operational barriers and on. so Onthe sur- ownersthe are facedwith, such optimum asthe size, giant Clarksons inLondon. byeasier teaming shipping up closely with global ers to get active specialist market. inthis packages inorder to it make for possible more build- “In we sector Aframax are the extremely proud to “That provided uswith a huge know-how whatof An approach that to pay set looks dividends, judg- “We have significant a very obligation theto brand same standardsThe high applywhen comesit to Knowing needsof the shipowners the wasmade

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