Oh James They're AAR style locos for the North American loading gauge and track standards (32+ tonnes on axle, most over 3m wide). As I understand it, any Alcos left are broken up for parts which are in demand keeping Alcos going on Class 2s and short lines. BTW, I did see a bunch of cabs dumped in a field/paddock just off the Tonkin (I think it was ) Hwy in Perth. They looked to be ex-Pilbara. DW