A proposed rail trail in Swampscott moved a step closer when the Board of Selectmen recently chose a firm to design and do the engineering work for the project. Stantec Consulting Services , a Canadian firm based in Edmonton, Alberta, with offices in Boston and Burlington, was selected from among nine companies that submitted responses to a request for qualifications, according to Pete Kane, Swampscott’s director of community development. The rail trail would run along the existing National Grid utility corridor for about 2 miles, starting at Stetson Avenue east through the middle of Swampscott to the Marblehead town line, where it would connect to the Marblehead Rail Trail. The planned stone dust Swampscott Rail Trail would be built within a 10-foot wide easement along the corridor. Town Meeting last spring authorized $850,000 to design and engineer the project, and for acquisition of easement rights.John Laidler can be reached at firstname.lastname@example.org.