It would be one heck of a ride for the passengers if the coupling let loose, eh? Note everyone is facing in reverse for the better view of downhill too?
Or are they just watching the engine?
Many incline railways worked with the locomotive on the downhill end, for safety's sake.
I got to ride the "Wilderness Railway" in Tasmania some years ago. The rack line was miraculously rebuilt and operates with original vintage locomotives, after having been abandoned for decades. The maximum grade is 6.67% which maybe could have been worked by adhesion except for the wet climate?
I watched the locomotive being serviced after a day's work. The operating crew were talking about the three operating locos all of the same type, with the final comment "they're all different" - apparently with regard to their quirky operating characteristics. They had separate throttles and valve gear for the drive wheels and the rack gear. They are small locos by American standards, rated for 60 ton trains, just two cars of ore !