SAUGUS – Author Tom Sheehan has been writing books for the past 39 years with his 18th work, “The Nations,” currently in production – and he does it all for free.”I do it because of the love for the game,” he said.Sheehan’s passion for writing can be traced back to the second grade, when he wrote his first story about the 100-car freight trains trundling through Saugus.”I loved to watch the freight trains go through,” he said.However, he always wondered where they had come from before passing through the North Shore communities.Sheehan explained that his grandfather would routinely read to him the works of novelist Richard Yates while his grandmother, an employee at a Boston publishing company, would always bring home “reject” books that could not be sold as they did not have covers.”I was a reader at 6 years of age,” he said.In addition to writing, Sheehan explained that he played football and baseball at Saugus High School until he graduated in 1947. From there, he served in the Korean War from 1950 to 1952 as an Army staff sergeant in the 31st Infantry Regiment, also known as the Polar Bears. After leaving the Army, Sheehan attended Boston College until 1956 and ultimately accepted a position at Raytheon, where he worked until 1991. In his spare time, Sheehan added that he would walk 12 miles a day around town.”I had a lot of energy,” he said.The day after he retired, Sheehan’s family took him up to New Hampshire and bought him his first computer “with a screen the size of a postage stamp” to use instead of the five typewriters in his house.With an average length of 254 pages, some of Sheehan’s most notable works include “Epic Cures,” “Brief Cases,” “Short Spans,” “Collection of Friends” and “From the Quickening.”He has also published six collections of short stories, four e-books and was nominated 24 times for The Pushcart Prize honoring literary prose.Sheehan publishes a new book “every couple of years” and tries to write 1,000 words a day.”I very often hit that,” he said. “It keeps me busy. You’ve got to do something with your life other than just sitting around.”