When it comes to the subject of trains, Wally Ely has few equals.

Since his father worked on trains, he had the train bug early in life.Ely retired from the banking industry and is now a volunteer and past president of WK&S Railroad, Kempton, Berks County, which offers seasonal weekend excursions on what is known as its Hawk Mountain Line."Officially, Amtrak claims the train is three-quarter-mile long, made up of 18 passenger cars and 33 auto carriers, plus two engines," Wally Ely says of the Auto Train, the subject of his book, Images of Rail Auto-Train."These numbers qualify it for the 'longest passenger train in the world,' Ely continues. "Auto Train carries about 650 passengers plus 330 automobiles on a full trip."The book from Arcadia Publishing ($21.95, 128 pp., 200 photographs) is a long-time train lover's account of the origins of Auto-Train Corp., from 1971 until filing for bankruptcy in 1981, and Amtrak's Auto Train 1983 to the present day."Subjects I write about all come to me because I know a lot about a topic," Ely says.Image of Rail Auto-Train is available through Barnes and Noble, Amazon and

www.arcadiapublishing.com.Auto Train, running daily between Lorton, Va., just south of Washington, D.C., and Sanford, near Orlando, Fla., is the only train operating in the United States that ferries both passengers and their automobiles.It crosses through five states in just 16 hours, sparing its riders the challenge of 1,000 miles of interstate driving, numerous roadside meals and rest stops, and at least one-night's stay in a motel.Ely got the inspiration to write his book while he was traveling about four or five years ago."I went into the gift shop at the terminal, looked at the magazine and book rack, and there wasn't anything.," he adds. "Nothing about railroads. I thought there should be something. If nobody has written it, then I'm going to."I went to Arcadia Publishing. I told them, 'I have an idea for a book that would fit into your train series.'"Ely, 73, collaborated with the late Robert Ott on a book about Dorney Park for Arcadia Publishing's "Images of America" series."That book is now in its eighth printing," says Ely.