The processes of loading trucks and railway wagons are similar: they are often filled with materials from bunkers or silos. While bunkers of various sizes are used to store bulk materials only for a short time, large silos serve to store these materials over longer periods.
Bunkers are often required as buffers between continuous and discontinuous conveying systems. The fastest and easiest way of loading is by gravity when the bulk material just falls into the vehicle cargo hold through the opened bunker gate. However, this is only possible in the case of easy-flowing materials such as grain, lump coal or certain building materials.