"I'm pleased to welcome Jim Daley as our special-teams co-ordinator," Cortez said in a statement. "I was always impressed by Jim's work ethic, thorough preparation and drive for success during our time together in Ottawa and Calgary.
"His skills and experience make him a fine addition to our staff.''
Martin becomes a full-time coach in Hamilton after spending last year as a guest coach with the CFL club. He has previous experience coaching defensive backs with Saskatchewan and also worked as a special-teams assistant with the Ottawa Renegades.
Martin also spent seven seasons in the CFL as a safety with the B.C. Lions.
Sheahan spent the last four years as an offensive assistant at Queen's University. He was the team's assistant offensive co-ordinator and quarterbacks coach in 2011 and also served as a guest coach with the B.C. Lions at the club's training camp.