The calculated distance (air line) between Alpen and Bochum-Hordel is approximately 29 miles respectively 46 kilometers.
By car or train, the actual journey to Bochum-Hordel is certainly longer, as only the direct route (as the crow flies) between Alpen and Bochum-Hordel has been calculated here.
Air line (approximately)
46 kilometers
25 nautical miles