The Miyako Harbor Line was a short freight spur line off the Yamada line in Miyako to service ships. Built during the Pacific war, it was abandoned in 1984 just before JNR was privatized. Here is an old map fragment that shows the old line in red.
Old hand drawn maps have a warmth that is beguiling. The 3D effect created by the contour lines is amazing. Cartography really is an art.