A material transfer system including a first vehicle and a second vehicle. The first vehicle has a pressurized compartment maintaining a first air pressure therein. The ambient air outside of the pressurized compartment is at a second air pressure, with the first air pressure being different than the second air pressure thereby defining a pressure differential. The second vehicle has a material discharge device. The material discharge device is capable of delivering material to the first vehicle. The second vehicle having a reservoir for receiving the material. The material passing from the reservoir into the pressurized compartment without substantial loss of the pressure differential.
