DTT HGV Coupling and Uncoupling Trailers 2

Question 1

What is a 'fifth wheel' coupling on a heavy goods vehicle?

Accepted Answer

The coupling device on the tractor that locks onto the trailer kingpin

Answer

A spare wheel mounted at the rear of the tractor unit

Answer

The fifth wheel of the steering axle assembly

Answer

An additional support axle fitted under the trailer

Question 2

Before uncoupling a trailer on a public road, you must ensure:

Accepted Answer

The trailer is on level, firm ground with the brakes applied

Answer

Only the electrical cable has been disconnected

Answer

All cargo has been removed from the trailer

Answer

The RSA has been notified of the uncoupling

Question 3

What is the purpose of the landing gear (dolly legs) on a semi-trailer?

Accepted Answer

To support the front of the trailer when uncoupled from the tractor

Answer

To provide additional braking force when loaded

Answer

To lower the trailer bed for easier loading

Answer

To stabilise the trailer during sharp cornering

Question 4

Which of the following would indicate a faulty fifth wheel coupling?

Accepted Answer

The locking jaws do not fully close around the kingpin

Answer

The trailer sways slightly at motorway speeds

Answer

The trailer lights flicker when braking

Answer

The air pressure takes longer than usual to build up

Question 5

When coupling a trailer in poor visibility conditions such as at night, what is recommended?

Accepted Answer

Use a banksman or spotter to guide the reversing driver

Answer

Proceed quickly to minimise time exposed in the dark

Answer

Avoid coupling trailers entirely in poor visibility

Answer

Rely solely on the vehicle's reversing camera

Question 6

Before driving away after coupling a trailer, what must you confirm about the trailer brakes?

Accepted Answer

That the trailer brakes function correctly and are released for travel

Answer

That the brakes make a hissing sound when applied

Answer

That the trailer brakes remain permanently applied during driving

Answer

That the brake warning light on the dash is extinguished

Question 7

At what point should you stop reversing the tractor unit when coupling to a trailer?

Accepted Answer

When you hear or feel the fifth wheel jaws lock onto the kingpin

Answer

When the trailer is approximately 1 metre behind the tractor cab

Answer

When the tractor unit's rear bumper makes contact with the trailer

Answer

When the trailer's reversing lights illuminate