CDL · Doubles and triples
Which of these steps do you carry out first when uncoupling standard doubles?
Correct answer: Lowering the second semitrailer's landing gear.
Answer options
- AUnlatching the first semitrailer's pintle hook.
- BLowering the second semitrailer's landing gear. Correct
- CLowering the converter dolly's landing gear.
Why
With the rig parked and braked, you lower the second semitrailer's landing gear enough to take some weight off the dolly, before closing the air shut-offs and pulling the dolly out. Releasing the pintle hook and lowering the dolly's own landing gear come later, when you uncouple the dolly itself.
About this question
Topic: Doubles and triples License: CDL
Part of these practice sets:
Where it applies: Asked in every state.
Practice the whole set
This question is part of Coupling Doubles and Converter Dollies (28 questions). Take the full set and check your score.
Practice Coupling Doubles and Converter DolliesMore questions from Coupling Doubles and Converter Dollies
- Which statement about a converter dolly is true?
- You are getting ready to hook a second trailer to your rig. What can you use to hold that trailer in place?
- You are about to uncouple the rear trailer. What do you do first?
- When you uncouple twin trailers, which of these is the final step?
- When hooking a converter dolly to the second or third trailer, how can you tell that the trailer is at the right height?
- When you drop the rear trailer from a double combination, what should you do with the air shut-off valve at the back of the front trailer?
- Which description best fits a converter dolly?
- In the official CDL manual, the section on doubles and triples generally explains coupling and uncoupling for which combinations?
Practice on your phone.
Practice here in your browser, or use the app with the same questions and explanations. It's free on the App Store.