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A great deal has been written about the capabilities of the AT/B, or Articu- lated Tug/Barge? unit in recent years. Without a doubt, though, the concept is ? rmly established as a viable ocean and coastwise transportation system in North America. But like any trans- portation asset, the concept has to not only expand its capabilities, but also conform over time to ever-changing rules and regulations. It must also be able to embrace and adapt to changes in technology that hold the promise of reduced emissions as well as savings in fuel and protection of the environment. AT/Bs recently placed in service as well as those on the drawing boards to- day, are indeed being designed around these principles and future AT/Bs promise higher speeds per HP, lower fuel consumption and the application of all manner of green? technologies in their construction. EARLY ONThe United States and Canada both built their modern coastwise transpor-tation networks around self-propelled vessels. Once the age of powered ves- sels was born, the development of non- powered barges, towed by powered tugboats, began in earnest. The earliest barges were created from sailing ves- sels, and indeed, some even retained their sails, to assist in the movement of the tow. In fact, non-self-propelled vessels pulled by mules, or free-drift- ing in the current, had been common along North Americas rivers and ca- nals for many years. When it came to offshore and coastal operations, towed barges had a lot of issues when held up to the light of both fuel consumption and sched-ule reliability. There was also a desire to increase the safety factor in tug and barge operations by exerting better control over a barge than to have it on a long towing hawser. Looking at the entire situation, the solution was ob- vious enough. Create a tug and barge that could operate with the crew of a traditional tug and barge, yet could be weather-reliable and safer to oper- ate in heavy seas, with increased speed where that speed would be useful. Pushing a barge yields better speed than towing it. By its very nature, towing involves adding enough resis- tance to a barge stern that it will fol- low? the tug. If you are pushing, then you want that this resistance penalty is removed. So, various patents to con- nect a tug and a barge with a secure mechanical connection, were ? led - all the way back into the 1800s. In the late 1960s, Edwin Fletcher with ARTUBAR, and the Bludworth fam- ily of ? exible pushing systems, were pioneering efforts to marry the econ- omies of pushing, with the safety/seakeeping inherent in mechanically linking the tug and barge at sea. Oth- er systems were developed and tried; not all were successful. The AT/B owes its current state of the art, in large part to the progres- sion in development of ARTUBAR, and BLUDWORTH in the U.S., and then the landmark ARTICOUPLE system in Japan, followed by the IN- TERCON system in 1986. The 21st century has now also seen the wide application of the JAK system on small to mid size AT/Bs. SAFETY : SECOND TO NONEThe safety record of the AT/B has been excellent. No double-hulled AT/B has ever been involved in a cargo spill incident and only one AT/B has been involved in a collision that resulted in a spill and that was judged to be human error on the part of the bridge crew of all three vessels involved in the collision ? which in- cluded a ship. There has been no loss of life on an AT/B. Centofanti Marine SystemsDon?t settle for cheap imitations. Get the originalMark IV Air Clutch Control Panel Gear Mate Panel, Throttle Interlock, Governor Actuator, Chrome ?T? Handle Control Head And remember, just because you have installed electronic engines and gears doesn?t mean you have to give up the reliability of pneumatic controls. Contact us for more information on our PNELC System We are American Owned and American Made from Start to Finish Formerly Schrader Bellows Marine P.O. Box 1050 Uniontown, PA 15401 (724) 438-7666 louie@cmsgroup.net AT/B design specialist Robert Hill, Ocean Tug & Barge Engineering Corp. MN 105www.marinelink.com MN Sept2013 Layout 96-111.indd 1058/29/2013 4:42:28 PM