| Owner: | Martin Marietta Materials Incorporated |
| Type: | Open Hopper |
| AAR Class: | HT: Open top self-clearing car, having fixed sides and ends and bottom consisting of three or more divided hoppers with doors hinged crosswise of car and dumping between rails. |
| AAR Type: | H350 |
| Detail Info: | Unequipped Hopper, Load Limit: 185,000 and greater, Non-rotary couplers |
| Plate: | B |
| Dry Capacity: | 2400 |
