A rail-based transportation apparatus is used in transporting automated equipments for performing different tasks with respect to heat insulators attached to inner wall surfaces of a ship cargo compartment. The apparatus includes a pair of rails removably secured to the heat insulators, a carriage frame for carrying the automated equipments, the carriage frame detachably mountable to and movable along the rails, a driving unit fixed to the carriage frame, the driving unit including a travel wheel adapted to make rolling contact with the rails when the carriage frame is mounted to the rails, and a support wheel assembly attached to the carriage frame.