RAIL DEVICE ON INNER FORMWORK

PROBLEM TO BE SOLVED: To provide a rail device on an inner formwork which enables formwork pieces without a rail to be stacked on the inner bottom surface of an inner formwork with an even stack height of the formwork pieces, thereby preventing an incident that formwork pieces to be transferred are obstructed by a high point in a stack due to a rail attached to a formwork piece and cannot be transferred forward.SOLUTION: A rail device comprises: a rail 51, which is attached to the inner face of a cylindrical inner formwork that is installed along the inner peripheral surface of a tunnel void made of a hole bored under ground in order to form a lining part between the inner formwork and the inner peripheral surface of the tunnel, and extends along the central axis of the inner formwork cylinder to form a track for a carriage to move along the central axis of the inner formwork cylinder; an attachment part 52 provided on the inner wall surface of the inner formwork; and attachment means 53 to attach the rail to the attachment part in a detachable way.