If you add more than one block of cars enroute, which test must be performed on the added cars only?

• A. Class I Initial Terminal Air Brake Test
• B. Application and release test
• C. Full service brake test
• D. No test required

Answer: (A)

When you couple additional cars onto a train that’s already en route, you test only the added cars with the Class I Initial Terminal Air Brake Test. The reason is simple: the rest of the train has already been through required braking tests, so you focus on the new cars to confirm their air brake system is functioning properly and will respond to brake commands without leaking or misadjustment. This targeted test checks that the brake pipe can be charged and discharged correctly on those cars and that the brakes apply and release as they should, keeping the entire train safe once the cars are integrated. Full-service testing of the whole train isn’t necessary in this situation, and other tests would not be the standard method for verifying just the added cars.