Razgruzchik hopper wagons / Wagon unloader, Vinnytsia region.

Mobile unloader wagons (HOPPER-type wagon unloading station) is intended for unloading hopper-type railway wagons without the use of a pit. These unloaders are used for unloading dry bulk materials, such as cement, sand, grain, lime, granulatedудобрения etc. from railway carriages.

Bulk materials can be unloaded from wagons using the unloading station both directly into vehicles (cement trucks, bag trucks,dump trucks), and into the receiving hoppers of screw and belt conveyors when it is necessary to transport materials over long distances.
(//tractor-service.com)
The main advantage of the screw unloader is its low price, as well as the possibility of its use in conditions where it is impossible to build specialized structures (pits) for unloading wagons.

Complete set and principle of operation:

The screw unloader of wagons includes a receiving hopper into which two augers are installed. An inclined screw conveyor of a larger diameter is installed in the end part of the receiving hopper. Two screws installed in the receiving hopper rotate in one direction, due to which the unloaded material moves to the side of theinclined screw conveyor, which, in turn, picks up the material and moves it to an unloading height of 1200 mm.