Where does your luggage go?

Discover the journey taken by your bags while you pass through security and browse the duty free

You don’t just wave goodbye to your friends or family at the airport – you also say farewell to your luggage. After you’ve had it weighed and the tag has been attached, the last you see of your possessions is your bag disappearing from sight on a conveyor belt into the labyrinth of the baggage handling system. You won’t be reunited with it until you reach your destination (hopefully). 

But how does your bag navigate the hidden network of bags, travelling at high speed along thousands of rollers and motors? It all comes down to that tag that you wrap around the handle. Your baggage is placed in a tray, which is loaded on a tray chassis. Each of these components have a unique code and the computer system pairs the two different numbers together. 

In the same way a railway track has movable points that can manually change the train’s course, an airport baggage system has a central computer that tracks the baggage and can change points in the track to move it to the correct destination.

However, the job of the baggage handling system isn’t just to get suitcases onto the correct flights – it is the responsibility of these systems and the staff that run them to screen each bag to make sure they do not contain anything that might compromise flight safety. Each piece of luggage will pass through several stages of imaging, including X-rays, as it travels through the airport to the gate to be manually loaded by staff, before – hours later – it’s unloaded at the destination airport and placed on a carousel waiting for you to come and pick it up.

Baggage handling steps

A sticker is generated with a barcode when the passenger checks in their baggage. It codes the origin of the bag, the destination and passenger details, plus the flight and airline code.

If the bag is cleared after passing through the automated X-ray it is directed towards the sorting area.

If the bag is not cleared, it is directed to a CTX screening machine, which slices pictures of the bag into multiple pieces to give a better view. If it’s cleared at this point, it joins the destination carousel.

A fully automated detection system, including high-tech tomography and X-rays, is involved in the next stage at the level-three screening. The images are analysed by an operator – if it is determined the bag is suspicious, the
passengers are called and the bags are opened.

The bags that leave the scanners are moved onto a tray and join the conveyor system.

Fully automated machines and sensors receive and release bags to change their route to the correct destinations.

A 270° infrared sensor reads the bag tag and sends a signal to the  processors, which determine which part of the carousel it needs to go to.

Officials read the codes with barcode scanners and load the bags on trolleys so they can be taken to the plane for loading.

This article was originally published in How It Works issue 118, written by Charlie Evans

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