Note: Your are not logged in. We can not keep your scores or track your progress unless you Register and Log In
Knowing how to couple and uncouple correctly is basic to the safe operation of doubles and triples. Wrong coupling and uncoupling can be very dangerous. Coupling and uncoupling steps for doubles and triples are listed below.
Secure Second (Rear) Trailer
If the second trailer does not have spring brakes, drive the tractor close to the trailer, connect the emergency line, charge the trailer air tank and disconnect the emergency line. This will set the trailer emergency brakes (if the slack adjusters are correctly adjusted). Chock the wheels if you have any doubt about the brakes.
For the safest handling on the road, the more heavily loaded semitrailer should be in first position behind the tractor. The lighter trailer should be in the rear.
A converter gear on a dolly is a coupling device of one or two axles and a fifth wheel by which a semitrailer can be coupled to the rear of a tractor-trailer combination forming a double bottom rig.
Position Converter Dolly in Front of Second (Rear) Trailer
Release dolly brakes by opening the air tank petcock (if the dolly has spring brakes, use the dolly parking brake control). If the distance is not too great, wheel the dolly into position by hand so it is in line with the kingpin. Or, use the tractor and first semitrailer to pick up the converter dolly:
Connect Converter Dolly to Front Trailer
Connect Converter Dolly to Rear Trailer
When pulling doubles or triples, what is important to know about the order of the trailers?
You can Return To The Table Of Contents