Home › Practice › Doubles & Triples › Question 20

Doubles & Triples Practice Question 20

TDoubles & Triples · Question 20

A safety pawl or 'jaw lock' on the fifth wheel of a converter dolly:

• ALocks the dolly's wheels
• BPrevents the kingpin from disengaging unintentionally
• CHolds glad hands
• DActivates ABS

Correct answer: B. Prevents the kingpin from disengaging unintentionally

Why: Just like a tractor's fifth wheel, the dolly's fifth wheel includes a locking mechanism that must engage and secure around the kingpin.

How this question fits the Doubles/Triples test

Each additional articulation point multiplies rearward amplification. A driver pulling triples must steer earlier, brake sooner, and inspect twice as much equipment as a single-trailer driver.

Study technique for this topic

Learn the correct trailer placement order by weight, the procedure for converting a single to a double, and the special inspection items unique to converter dollies and pintle hook assemblies.

Related Doubles/Triples practice questions

• Q39. When uncoupling, the proper position for the trailer landing gear/dolly support is:
• Q52. When triples are not allowed on a route:
• Q5. The pintle hook is:
• Q18. When backing doubles, drivers typically:
• Q32. A driver of doubles/triples should keep a minimum following distance of:

Continue your CDL preparation

The Doubles & Triples portion of the CDL knowledge exam covers more than this single question. Use this site's full Doubles & Triples bank to drill every topic, then test yourself with one of our state-specific practice sets to confirm you are ready for the actual DMV exam in your state. Always check your state's CDL handbook for any local addenda before the test day.

If you are still building your overall CDL foundation, start with the General Knowledge bank — every CDL applicant must pass it — and then work outward to the endorsements you plan to add.