Tank car
A tank car carries liquid or gas in a tank. The specification stencil describes the tank. The placard describes the load.
The tank is the car
A tank car is a horizontal tank on trucks. On many modern cars the tank itself is the structure, with a short stub sill at each end. Older cars sit the tank on a full center sill, so you see more frame. Either way, there is no box and no hopper bay. Domes, manways, and outlet valves are the fittings along the top and bottom.
The car-type code starts with T. The specification stencil, often a DOT or AAR code such as a 111 or a 117 class, identifies the standard the tank was built to. It describes the tank. It does not name the commodity.
The load is a separate statement
When a tank is carrying a hazardous material, the placard is the diamond that says so. Class number in the corner, identification number in the middle or on an orange panel. A placard can change from trip to trip. The specification stencil stays with the tank.
Leave the valves alone. If a car is leaking, smoking, or in a wreck, this page is the wrong tool. Move away and call the local emergency number. The placard guide on this site is for recognition, not for response.
Common questions
- Does the DOT specification say what is in the tank?
- No. The specification identifies the tank standard. The placard, when the car is placarded, identifies the hazard of the material on that move.
- Where is the reporting mark on a tank car?
- On the tank or the end sill, repeated so it can be read from the ground. It is the owner of the car, not the name of the product.