It's midnight on the Cumberland Subdivision as workers chisel away at the lining of the famous Harper's Ferry tunnel. An all night curfew on the weekends is providing eight hours of work each night to raise the tunnel lining to accommodate double stack container trains. Harper's Ferry is the last tunnel on the Cumberland Subdivision to receive this work, being held up for months as CSX dickered with the U.S. Park Service over maintaining the historic appearance of the tunnel portal.