Under 49 CFR 393.70(c), a full trailer must be equipped with a tow-bar and a means of attaching it. What does that paragraph require of the tow-bar and its attachment?

Explanation

49 CFR 393.70(c) requires the tow-bar and its means of attachment to be structurally adequate for the weight being drawn, properly and securely mounted, to provide adequate articulation at the connection without excessive slack at that location, and to have a locking device that prevents accidental separation of the towed and towing vehicles. Adequate articulation without excessive slack is the pairing worth understanding: the connection has to be free enough to let the units turn relative to one another, yet tight enough that the slack does not become play the driver feels as surge or snatch. The same paragraph requires the trailer hitch mounting on the towing vehicle to include reinforcement or bracing of the frame sufficient to prevent undue distortion. The wrong options invent figures and procedures that appear nowhere in the section: there is no doubled weight rating, no five-year replacement interval and no annual weighmaster stamp, and a welded connection would defeat the articulation the paragraph requires.

Source: 49 CFR 393.70(c)