How to Couple and Uncouple Semi-Trailers to the Prime Movers

A semi-trailer comes without a front axle and front wheels. It can be connected to a truck and used to transfer goods. When disconnected, it doesn’t rest on the ground due to the absence of a front axle.

Unlike a full trailer, a semi-trailer relies on the fifth wheel coupling located on the back of the tractor to connect and distribute the weight between the tractor and the trailer. The process of connecting and disconnecting is called coupling and uncoupling the semi-trailers.

The process is quite simple but requires detailed attention. A single mistake can injure the person who is coupling or uncoupling. Therefore, here is a step-by-step process to couple and uncouple semi-trailers without causing harm to oneself.

Ways to Couple and Uncouple Semi-Trailers

semi-trailer coupling to the trucks — Inspect the mechanism of the semi-trailer when connected to the truck to ensure proper working

The first and foremost check is that the semi-trailer and prime mover truck mechanisms work together. The best way to ensure that is by learning a safe procedure to couple and uncouple the semi-trailers. However, performing these tasks incorrectly can damage equipment and increase the risk of injury.

Therefore, learning how to couple the trailers and the ways to control heavy vehicles is important. Here is how to couple and uncouple semi-trailers safely.

How to Couple a Semi-Trailer

It is essential to inspect the area and clear any obstacles. Ensure that there is enough lighting. Besides, stop the wheels from moving with a wedge but chocking the wheels isn’t required if the semi-trailer has spring-loaded brakes.

Here are steps to couple a semi-trailer:

Steps to couple the semi-trailers — Ensure that the semi-trailer aligns with the truck and that the connections have a proper lock

Examine the coupling devices’ functioning and find out if they fit together. Connect the prime mover and semi-trailer.
Use the mirrors to see if the edges align.
Check the semi-trailer height. The prime mover truck lifts the semi-trailer slightly.
Align the kingpin and turntable.
Avoid going under the semi-trailer to see its support with the prime mover since you can injure yourself if the landing gear collapses.
Reverse the prime mover and avoid clashing it with the semi-trailer. Stop the truck when the turntable top plate touches the semi-trailer’s apron plate.
Apply the parking brakes in the prime mover truck to take a look at the coupling of a semi-trailer.
Now perform a safety check all over again. You must ensure that nothing is missing and all parts are fixed properly.

Whether coupling or uncoupling the semi-trailers, safety check holds the utmost importance. For coupling, ensure that there is no space between the upper and lower portions of the turntable. Also, it is an essential inspection tip for truck drivers to check that the locking lever is in the locked position. Placing a safety catch over the locking lever or manually positioning it can prevent any opening while moving the truck.

Follow these steps to complete the connection after performing the inspection and placing the safety check:

Connect the air brake lines of the prime mover to the semi-trailer and ensure that they have safe support.
Inspect the connection by taking the weight off the trailer legs and disengaging the clutch. Repeat this step until a proper connection is made.
Engage the locking device with the help of an electric cable and check all the lights of the semi-trailers.
Remove the wheel chocks once you couple the prime-mover to the semi-trailer.

How to Uncouple a Semi-Trailer

Disengaging or removing the connection between the prime mover and the semi-trailer is known as uncoupling. When you couple and uncouple the semi-trailer, ensure the place is safe and secure with no fluids around to cause slipping. The following steps will help you uncouple the semi-trailer safely:

Ways to uncouple the semi-trailer from prime movers — Check the area and secure the wirings and cables while disconnecting the semi-trailer from the prime movers

Position the semi-trailer and put sporting plates or boards under the landing gear of the trailer.
Apply the brakes or chocks to hold the semi-trailer and release the kingpin lock lever.
Lower the landing gear using a handle that will make firm contact with the support plates or boards. Landing gear will support the semi-trailer and remove the weight off the prime mover, which will stop rising.
Disconnect air lines and electric cables. Secure the cables and lines to avoid any damage to them.
Raise the handle lock pin and release the turntable latch.
Now pull the prime mover and apply the parking brakes.
Check the semi-trailer support and ensure its safety. Slowly pull the semi-trailer by releasing the parking brake.

These were all the necessary steps to safely couple and uncouple the semi-trailers. Semir-trailers are essential for transporting goods within the city. When you buy a new or used truck for sale in the UAE, be mindful of all the safety and maintenance checks. Moreover, always make sure to follow RTA laws for heavy vehicles. You can learn safety tips for truck drivers to prevent any major accidents or injuries.

Keep reading the dubizzle cars blog as we feature more tips and tricks for heavy-duty vehicle owners and drivers.