 The initial tunnel from Umeda to Shinsaibashi, dug entirely by hand, opened in 1933 after being initially plagued by cave-ins and water leakage caused by the poor composition of the earth below northern Osaka and the equally poor engineering skills of the work crew.The first cars were hauled onto the line by manpower and pack animals from the National Railway tracks near Umeda.Although the line only operated with single cars at first, its stations were designed from the outset to handle trains of up to eight cars.