Airports are in the business of ensuring their passengers reach their destination on time, safely, comfortably and with all their baggage. The need for a reliable Baggage Handling Systems (BHS) is therefore paramount to the functionality of an airport, which is why many are choosing a modern Individual Carrier System (ICS) to optimise their baggage operations.
The airport must consider many key factors before it chooses an ICS. Cost, reliability, efficiency and speed are all important, but ultimately the surroundings could outweigh them all.
After all, no two airports are identical, and the same is true of a modern ICS. Every system is tweaked to best fit the surroundings of the buildings that the airport inhabits.
Climatic considerations, such as humidity, can influence the choice. And so too can the building: ground-level airports simply can’t incorporate certain ICS systems due to necessary vertical height requirements.
Let’s for a moment compare the baggage sorting system of an airport to one you might find at a parcel distribution centre (DC).
Both play key roles, receiving thousands of items an hour, sorting them into various chutes so they arrive at their correct destinations.
But while the DC is designed to solely house the parcel sorter system, an airport has many other priorities: passenger comfort, retail, security, to name but a few. BHSs are accordingly designed to fit in with their surroundings.
The fallout of the systems breaking down couldn’t be more different. At the DC, the result is delayed deliveries – it’s unfortunate, but rarely critical. But at the airport, the fallout can be severe and far-reaching.
It won’t just cause delays that inconvenience airlines and passengers, but also affect arrival times at other airports, and consequently flight times over the rest of the day across an ever-widening geographical area.
That’s why an optimal ICS is so important, and why airports need to make the right selection – the wrong choice could adversely affect their performance.
So what qualities should an airport be seeking in its new ICS?
The tracking of bags (# 2 and 3) is not too dissimilar to the times a Tour de France race leader might be expected to clock at specific points during a time trial (the finish line being the bottom of the chute).
When the photo cell/tag reader does not detect the bag as anticipated at specific points, the bag falls out of sync with its virtual window, the system is warned there is a problem, security protocol is activated, and the bag will need to be re-identified and screened again – a drain on resources.
Many airports opt for a standard ICS belt option, but is this the best choice? The cross-belt system, for example, places the bag onto a completely flat, un-enclosed conveyor, which means there are no borders to stop it falling off.
This is a problem for soft round bags that can potentially roll, or top-heavy bags that can easily fall and tumble. Additionally, bags with big handles pose a risk they might get snagged on a corner.
When a bag falls off, or is even held back for 1-2 seconds, it loses its virtual window, along with crucial data, and it does not perform as anticipated – which is a problem, as 100 percent tracking is vital to the whole system functioning.
The bag might first recirculate around the loop, and then manual intervention is normally required, which involves re-identification and a revisit to security. This is time-consuming, costly and reduces capacity.
Placing the bag in an enclosed area eradicates all of the problems encountered on a cross-belt system. It could be a tray (tote) or an individual carrier, and borders and/or a more concave setting will prevent the bag from sliding out of place.
To discharge the baggage into the chute, cross-belt systems require increased acceleration, sourced from the motor in the conveyor the bag is sitting on.
If it’s too fast the bag might topple first and get misdirected or simply circulate on the spot; if it’s too slow it might miss the chute.
To counteract the problem, cross-belt system operators can slow down the speed, and/or make the chute bigger, but this reduces capacity as there will be fewer bags entering the sorter and fewer discharge points, so fewer flights can be catered to.
The typical cross-belt system can sort 4,000 to 4,500 bags during a period of peak demand – a long way short of the 5,000 to 6,000 the tilt-tray system, for example, is capable of.
Push the cross-belt system to the limit and the cracks will begin to show. In such an event, more labour resources are also required, driving up the cost.
The wooden tote used by a tilt-tray system is one of several ICSs generally preferred to cross-belt systems for their greater reliability.
Others include CrisBag®, which uses plastic totes, and ones that uses carts.
When the bag approaches the chute on a tilt-tray, the tote is simply tilted, at which point a kick effect is activated in case the bag is sticky, and gravity does the rest.
This means the chutes can be placed close to one another, so the maximum number of flights can be sorted.
Even at full capacity, the system has a sortation success rate of over 99.99 percent.
And what about the expense? The conveyor used by a cross-belt system might seem like an extra flat slab placed on the belt, but is in fact a complex piece of machinery.
As well as the motor, it is equipped with a number of other parts. This makes it heavier, which exerts more pressure on the wheels and the rail, making the whole system more prone to wear and tear.
So the cross-belt is much more susceptible to damage than the tilt-tray, for example, and more maintenance and spare parts are required – all at extra cost.
The lifecycle of the conveyor is also much shorter than other ICS options.
But there is one type of airport for which the cross-belt option is probably the best choice: when the loading, sorting and discharging all take place on the same level.
Many of the other ICS options use chutes that take the sorted baggage down a level below.
Tilt-tray systems, for example, require a certain amount of height to function – and in combination with makeup areas where tuck-and-dolly trains also have strict height specifications, they are not a good match.
In an airport where BHS is battling water pipes, fire systems and ventilation shafts for capacity, space is a precious commodity.
In such cases, the best fit will edge out the most reliable.
Cross-belt is a useful sortation technology – but a better fit for parcels than baggage. At airports, other ICS options are proving to be more reliable and less costly and labour-intensive as a result. However, sometimes the best choice of BHS is simply the one that fits the building. For single-level airports with limited vertical height, cross-belt is often their best option.
