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?

Explanation

The check is that the pintle-eye of the dolly is in place in the pintle hook, that the pintle hook is latched, and that the safety chains are secured to the trailer. Each of those is a separate point of failure within the one connection, which is why they are treated as three checks rather than one glance at the hitch: the eye can be out of position, the hook can be unlatched with the eye seated, and the chains can be unattached with the hook correctly latched. 49 CFR 383.111(a)(17)(iii) names coupling system defects as a required inspection knowledge area without listing these items, so they are attributed to the manual, while 49 CFR 393.70(d) separately makes the safety device itself a legal requirement rather than a matter of practice. The wrong options each describe a condition that would be a defect rather than a confirmation: a hook free to spin, an eye greased to pull free, and chains long enough to drag the ground are all failures of the connection.

Source: 49 CFR 383.111(a)(17)(iii)