Changes to the rules about central door locking could mean the end of heritage trains on Network Rail infrastructure, a major operator has warned. West Coast Railway Company, which runs many steam-hauled specials on National Rail lines as well as the scheduled ‘Jacobite’ service between Fort William and Mallaig, is challenging a decision by the Office of Rail and Road to revoke an exemption which allows heritage trains on the main network even though they are not fitted with full central locking for their swing doors. West Coast has warned that converting its coaching fleet to full central locking would cost ?7 million. This would take almost 10 years to repay, and the business would cease to be a going concern.