DTT HGV Coupling and Uncoupling Trailers

Question 1

Before reversing a tractor unit under a semi-trailer for coupling, the fifth wheel should be:

Accepted Answer

Clean, greased and in the unlocked (open) position

Answer

Locked in the fully closed position

Answer

Raised above the trailer height

Answer

Secured with a safety chain

Question 2

The kingpin on a semi-trailer connects with which part of the tractor unit?

Accepted Answer

The fifth wheel coupling plate

Answer

The drawbar hitch

Answer

The rear chassis bumper

Answer

The air brake connector

Question 3

After coupling a trailer, how should you test that the coupling is secure?

Accepted Answer

Attempt to move forward with the trailer parking brake applied

Answer

Drive forward 50 metres and check for movement

Answer

Visually inspect the coupling from outside the cab

Answer

Check the tachograph for any irregularities

Question 4

When uncoupling a semi-trailer, which sequence of steps is correct?

Accepted Answer

Apply trailer brake, lower landing gear, disconnect airlines, release fifth wheel, drive away

Answer

Disconnect airlines, lower landing gear, release fifth wheel, drive away

Answer

Release fifth wheel, lower landing gear, disconnect airlines, drive away

Answer

Lower landing gear, apply trailer brake, release fifth wheel, drive away

Question 5

After connecting the airlines to a trailer, what should you do before departure?

Accepted Answer

Allow air pressure to build and check for air leaks

Answer

Immediately proceed on your journey

Answer

Connect the electrical cable before anything else

Answer

Release all brakes and check for free movement

Question 6

The red (emergency) airline on a truck-trailer combination controls:

Accepted Answer

The spring (parking/emergency) brakes on the trailer

Answer

The service (foot) brakes on the trailer

Answer

The trailer's air suspension system

Answer

The landing gear electric motor

Question 7

The landing legs of a semi-trailer must be fully raised:

Accepted Answer

Before the vehicle combination moves off

Answer

After the airlines have been connected

Answer

Only when travelling on motorways

Answer

After the destination has been reached