O M G ,,,,,,I worked on one of those!!!
,,,,it's a machine for smashing up conglomerated lumps of burnt limestone.
After the lime is burnt is has to be crushed very fine and your little beauty is part of the process
Inside is a fast rotating shaft with chains attached,,, the stone is dropped down,, gets smashed and is taken away from below on a rubber conveyor belt.. I don't know why the shaft is driven from both sides.
The interior of the chamber is protected from wear by very hard plates which are attached by rivets or bolts which you can see peppering the casing.
My work in 1973 was as a contract fitter/turner,, I got to work in Aberthaw cement works now and then. Filty job but the canteen did magnificent sausage and bacon baps and there was that slim girl from the office that used to wear next to nothing and ,,,,,,,,, sorry,,,,my mind was wandering,,,,,,,you don't want to hear about that!!!!
Mostly we worked on the conveyors and cement packaging machinery but a lot of our time seemed to be spent hiding or sleeping,,,
,,,filthy job