Having made a living hauling scrap... I can tell you that a scrapyard will use whatever they can get at a cheap price...
I have seen truck mounted cranes to old rail cranes mounted on flat cars sitting on stacked ties.
a rubber tire crane is not really out of place. They could be the old solid rubber tires or the newer soft solid tires. Or even an old nasty set of pneumatic tires with a pile of patches and plugs in them, a junk yard would run whatever they had or could get inexpensively.
