This narrow-gauge “Schienenwolf” (“rail wolf”) hook for destroying railway tracks is on display at the fortress in the Kalemegdan park in the Serbian capital Belgrade.
Also known as a “Schwellenpflug” (“sleeper plough”), the hook would have been lowered into the trackbed, then the wagon dragged behind a locomotive, tearing the sleepers in half and generally making a mess to render the line unusable by the enemy.
I didn’t measure it, but presumably it is 760 mm gauge, as Yugoslavia once had an extensive rail network at that gauge.
The hook is now part of the collection of the Belgrade military museum (Vojni muzej Beograd), where I photographed it in October 2008. Although the museum itself isn’t all that exciting — especially if, like me, you don’t read Serbian — there is quite an impressive line-up of various tanks, guns and other old hardware parked up outside.
A similar Schienenwolf survives at a closed museum at Sarajevo in Bosnia, where I photographed it in 2007. The now-defunct Museum of Army Transport at Beverley in the UK also used to have one — hopefully it has been found a new home somewhere.