The calculated distance (air line) between Fortress Hill and Tin Shui Wai is approximately 17 miles respectively 27 kilometers.
By car or train, the actual journey to Tin Shui Wai is certainly longer, as only the direct route (as the crow flies) between Fortress Hill and Tin Shui Wai has been calculated here.
Air line (approximately)
27 kilometers
15 nautical miles