Non-pressure / low pressure tank car - Answers For flammable liquids (e.g., Petroleum crude oil,
ethanol) with protective housing separate from manway and bottom outlet valve; pressures usually
below 25 psi.
Box car - Answers For general freight that carry bulk or non-bulk packages; may transport hazardous
materials/dangerous goods in small packages or 'tote bins'; features single or double sliding door.
Hopper car - Answers For bulk commodities and bulk cargo (e.g., coal, ore, cement and solid granular
materials); bulk lading discharged by gravity through the hopper bottom doors when doors opened.
Pressure tank car - Answers For flammable, non-flammable toxic and/or liquefied compressed gases;
protective housing with no bottom fittings; pressures usually above 40 psi.
General service tank car - Answers For a variety of hazardous and non-hazardous materials; fittings and
valves normally visible at the top of the tank; some may have bottom outlet valve; pressures usually
below 25 psi.
MAWP - Answers Maximum Allowable Working Pressure, which can vary by tank type; for example,
MC331, TC331, SCT331 has a design pressure between 100-500 psi.
Refrigerated liquefied gases tank car - Answers For refrigerated liquefied gases (cryogenic liquids);
similar to a 'giant thermo-bottle' with fitting compartments located in a cabinet at the rear of the tank;
MAWP between 25-500 psi.
Flammable liquids tank car - Answers For flammable liquids (e.g., gasoline, diesel); features elliptical
cross-section, rollover protection at the top, bottom outlet valves; MAWP between 3-15 psi.
Toxic, corrosive, and flammable liquids road trailer - Answers Circular cross-section with possible
external ring stiffeners; MAWP of at least 25 psi.
Corrosive liquids road trailer - Answers Usually for corrosive liquids; circular cross-section with external
ring stiffeners; tank diameter is relatively small; MAWP of at least 15 psi.
Emulsion and water-gel explosives trailer - Answers Hopper-style configuration; MAWP between 5-15
psi.
Compressed Gas/Tube Trailer - Answers Used for transporting compressed gases.
Dry Bulk Cargo Trailer - Answers Designed for transporting dry bulk materials.
Vacuum Tanker - Answers Used for transporting liquids under vacuum.
Mixed Cargo - Answers Designed for transporting a mix of cargo types.