450-foot long “unique” machine used in Arrowhead Inland Feeder project is at auction site for preview by interested bidders LOS ANGELES, April 24 /PRNewswire-FirstCall/ – Ritchie Bros. Auctioneers (NYSE and TSX: RBA), the world’s largest industrial auctioneer, is selling a single shield 450-foot long, 820-ton, self-propelling, hard rock tunnel boring machine (TBM) with trailing gear at an upcoming three-day unreserved auction in Los Angeles from May 20 to 22, 2009….more at PR Newswire