LGV Coupling & Uncoupling

At Drive Personnel we take safety extremely seriously and it is important that all articulated lorry (C+E) drivers understand the critical importance of parking, coupling and uncoupling correctly.  Not following the correct procedures for the relevant vehicle can lead to potentially serious and fatal accidents and costly repairs.  Even if you are an experienced driver it is always wise to refresh your memory and skills to stop complacency creeping in and to avoid any accidents and keep yourself and other people safe.

Below is a link to the Health and Safety Executive website which has full information on this subject.  Please take some time to refresh your understanding.  There is also a handy booklet that can be downloaded that provides safe systems of work for all vehicles.  The booklet “Code of practice: Coupling or Uncoupling & Parking of Large Goods Vehicle Trailers” was published by the Institute of Road Traffic Engineers (IRTE) and HSE in March 2006.

If you are a HGV driver current working for Drive Personnel and need more information, help or advice then please contact us.


A summary of the recommended Coupling and Uncoupling procedure is as follows but please note that these instructions are only for use when there is room to operate safely between the back of the tractor unit and the front of the trailer. When this is not the case (close trailer coupling or for example on refrigerated trailers where the front mounted condenser restricts space) then please refer to separate ‘close coupling’ instructions:

Coupling Procedure

  • Slowly reverse the tractor unit in a straight line towards the front of the trailer.
  • Apply the tractor unit parking brake, turn off the engine and remove the keys.
  • Check that the trailer parking brake is applied.
  • Make any necessary adjustments to the trailer coupling height and slowly reverse the tractor unit under the trailer until the 5th wheel jaws engage.
  • Apply the tractor unit parking brake, stop the engine and remove the keys.
  • Carry out a visual check that the 5th wheel jaws have engaged correctly and fit the security “dog clip” or other safety device.
  • Carry out a second test that the 5th wheel jaws have engaged by selecting a low forward gear and with the trailer brakes still applied slowly pulling forward.
  • Apply the tractor unit parking brake, stop the engine and remove the keys.
  • Connect the service airline (yellow) and electrical connections.
  • Connect the emergency airline (red) and watch for any unexpected movement. (If the trailer moves, immediately disconnect the emergency airline (red) and check that the trailer parking brake has been applied.
  • Wind up the landing legs and secure the handle.
  • Fit the number plates and check that the lights work.
  • Carry out visual and functional vehicle checks on the tractor unit and trailer, and release the trailer handbrake before setting off.

Uncoupling Procedure

  • Park the combination in a straight line.
  • Apply the tractor unit parking brake, stop the engine and remove the keys.
  • Apply the trailer parking brake.
  • Remove and stow the trailer number plate and lower the landing legs.
  • Disconnect all of the air and electrical services and stow safely.
  • Remove the security “dog clip” and pull the release handle to disengage the 5th wheel jaws.
  • Slowly draw the tractor unit away from the trailer. If the tractor unit has mechanical suspension stop when the trailer is clear of the fifth wheel.
  • Apply the tractor unit parking brake, stop the engine and remove the keys.
  • Before leaving the trailer, walk round it to check that it has been left in a safe condition.

You may find it useful to memorise an acronym in order to remember the safe order. One such example is P-BLACK for uncoupling (remove number Plate and then engage parking Brake, lower Legs, disconnect Airlines, remove Clip and release Kingpin handle. You then use the reverse for coupling.