The calculated distance (air line) between T’ongch’ŏn-ŭp and Hŭngnam is approximately 63 miles respectively 101 kilometers.
By car or train, the actual journey to Hŭngnam is certainly longer, as only the direct route (as the crow flies) between T’ongch’ŏn-ŭp and Hŭngnam has been calculated here.
Air line (approximately)
101 kilometers
55 nautical miles