A four-axle 440S Uacs tank railcar is designed for transport of powdered materials with bulk density of 0.5-1.4 t/m3 (e.g. cement, lime, fly ash). It is equipped with one two-chamber tank with total capacity of 55.2 m3 (2 x 27.6 m3). The railcar is loaded by means of gravity via two charge manholes located on top of the tank and unloaded pneumatically at maximum working pressure of 0.25 MPa. The railcar unloading system is designed so to allow for unloading of each tank chamber individually or both chambers at once.