The calculated distance (air line) between Qaşr Lībiyā and Tobruk is approximately 153 miles respectively 246 kilometers.
By car or train, the actual journey to Tobruk is certainly longer, as only the direct route (as the crow flies) between Qaşr Lībiyā and Tobruk has been calculated here.
Air line (approximately)
246 kilometers
133 nautical miles