Applications of Pneumatic tube In postal service

Pneumatic tube tare systems that propel cylindrical containers through networks of tubes by compressed air or by partial vacuum. They are used for transporting solid objects, as opposed to conventional pipelines, which transport fluids. Pneumatic tube networks gained acceptance in the late 19th and early 20th centuries for offices that needed to transport small, urgent packages (such as mail, paperwork, or money) over relatively short distances (within a building, or, at most within a city). Some installations grew to great complexity, but were mostly superseded. In some settings, such as hospitals, they remain widespread and have been further extended and developed in recent decades.
A small number of pneumatic transportation systems(Performance Shock Absorbers) were also built for larger cargo, to compete with more standard train and subway systems. However, these never gained popularity.