Which statement about pneumatically unloaded hopper cars is true?

Which statement about pneumatically unloaded hopper cars is true?

• A. They typically carry powdered materials
• B. They are used for gases
• C. They never operate
• D. They carry pesticides

Answer: (A)

Pneumatically unloaded hopper cars are designed to move dry bulk powders and use air pressure to unload the material. The key idea is that these cars are built to handle powders and granular goods that can be blown or blown through discharge lines rather than poured out by gravity alone. Using pneumatic unloading helps prevent bridging and sticking of fine powders, making the unloading process efficient and reliable for materials like cement, fly ash, and other dry powders. Because they rely on air to move the material out, they are specifically intended for dry bulk powders, not for transporting gases, which require dedicated tank cars or pressure vessels. These cars do operate in service, so the statement that they never operate doesn’t fit. While pesticides can be shipped in various forms, the defining and most common use of pneumatically unloaded hopper cars is carrying powdered materials, making that option the best description of their typical purpose.

Pneumatically unloaded hopper cars are designed to move dry bulk powders and use air pressure to unload the material. The key idea is that these cars are built to handle powders and granular goods that can be blown or blown through discharge lines rather than poured out by gravity alone. Using pneumatic unloading helps prevent bridging and sticking of fine powders, making the unloading process efficient and reliable for materials like cement, fly ash, and other dry powders.

Because they rely on air to move the material out, they are specifically intended for dry bulk powders, not for transporting gases, which require dedicated tank cars or pressure vessels. These cars do operate in service, so the statement that they never operate doesn’t fit. While pesticides can be shipped in various forms, the defining and most common use of pneumatically unloaded hopper cars is carrying powdered materials, making that option the best description of their typical purpose.