| Owner: | Union Pacific Railroad Company |
| Type: | Flat Car |
| AAR Class: | FMS: Specialty Ordinary flat car for general service. This car has flooring laid over sills and without sides or ends. |
| AAR Type: | F421 |
| Detail Info: | Flat Car, Load Limit: 200,000lb and greater, Equipped with cushioned draft gear/underframe, Inside length: less than 53ft |
| User Notes: | Rocket Booster car |
