Page 68: of Marine News Magazine (November 2011)

68MNNovember 2011Markey Advances Hawser Winch Technology With their recent shipment of the second, all new above deck hawser winch (DESDF-48-200HP) to Trinity Yachts? shipyard for the Colle/Signet joint venture in sup- port of Chevron?s LNG facility in Pascagoula, Mississippi, Markey has introduced yet another successful repackaging of its Asymmetric Render/Recover Escort winch technol- ogy. Markey has taken a series of proven ?below deck? winch solutions, and incorporated everything that has been learned into an ?all above deck? configuration for Signet?s new ?Constellation? and ?Stars and Stripes?. Launched just last month at the Trinity Shipyard in Gulfport, MS., Signet?s new state-of-the-art tugs will see demanding service in one of the most challenging envi- ronments: the escort of large LNG carriers (tankers) in and out of the facility in restricted waters. These units and the newly developed DESF-48-SD-100HP (a below-deck version) represent significant advances in Hawser winch technology. The Markey winch units offer exceptional rendering brake control through a large water-cooled slip-braking system, coupled with a heavy fairlead system to absorbgreater loads. Electric variable-frequency drives operate vector-duty motors connected to water-cooled clutches and custom gearing. This allows for a wide range of low speed-high speed performance. The combination makes it a winner for tugs performing Escort and Ship-Assist of LNG carriers. While the design does focus on a ?below- deck? profile, repackaging has reduced the impact on below-deck area directly beneath the winch. ?Additionally, it allows us to offer a wider range of performance, based on what the application needs? said Blaine Dempke, President of Markey Machinery. ?Our first preference will always be under-deck configurations? he added, ?We have learned that it?s almost a requirement for tugs that need to maintain position, such as during channel operations.?Since a number of LNG terminals are accessed by nar- row channels, while being subjected to a wider range of wave heights and wind, maintaining position requires higher horsepower for both tug and winch. ?It?s easier to accommodate larger drives in that configuration, and it?s easier to maintain a ?positive pressure? explosion-proof environment, critical for operation in close proximity to Markey personnel test the above deck DESDF-48-200HP hawser winch.MN#11 (66-81):MN 2011 Layouts 10/28/2011 10:54 AM Page 68