Skip to content

Inspecting Doubles and Triples

Inspecting Doubles and Triples covers the assembly and hookup inspection specific to pulling more than one trailer, drawn from 49 CFR 383.115(a), plus the general vehicle-inspection duties at 383.111(a)(17)(iii) and (iv) that apply to any CMV.

Practice Inspecting Doubles and Triples

5 Questions

  1. During the extra walk-around checks for a combination with a sliding fifth wheel, what two things does a driver verify?
  2. Among the extra walk-around items when inspecting doubles or triples, what does a driver check about the connection between the converter dolly and the trailer ahead of it?
  3. During the additional walk-around checks on a set of doubles, what position should the converter dolly's air tank drain valve be in?
  4. Beyond checking that they are connected and not leaking, what does a driver verify about the air lines running to the trailers of a double or triple?
  5. How do the doubles and triples inspection checks relate to the inspection a driver already performs on any vehicle?