The nation's largest railroad union wants federal regulators to do more to ensure conductors are properly trained in the wake of two recent trainee deaths. The Transportation Division of the International Association of Sheet Metal, Air, Rail and Transportation Workers union that represents conductors wants the Federal Railroad Administration to establish clear standards for how long new employees are trained and who mentors them to teach them the craft after they finish their formal training. The union said the recent deaths of two CSX trainees on different occasions in Maryland over the past two months highlight the need for better training.