How DHL makes heavy weights fly

Imagine an automotive production line brought to a standstill by one missing component. The part that can get it moving again weighs half a ton – and it's on another continent. How quickly can your component be shipped? And how can oversized goods that can weigh as much as a polar bear be moved quickly and safely through the delivery network?

The Heavy Weight Express (HWX) service was created to solve just that challenge, moving very heavy goods – from individual pieces of up to 1,000 kg to complete shipments of up to 3,000 kg – as quickly as typical express shipments. Delivering on that promise requires a complex set of services and capabilities, including a physical network that can get the job done.

And that’s where the Large Automated Conveyable System (LACS), a sorting system in Leipzig, Germany, comes in.

Leipzig/Halle Airport (LEJ), is the seat of DHL’s primary air hub, and over the years, the number of heavyweight shipments there has grown significantly.

Lars Gladisch, Vice President of Operations at the Leipzig Hub, recalls that when operations started in Leipzig in 2007, the hub handled only a few thousand heavy-weight shipments – items that were often shipped on pallets, and couldn’t travel through the conventional parcel sorting system due to their size, weight or both.

Today, the hub handles as many as 27,000 shipments per night weighing over 31.5 kilos per item – too heavy for the conventional sorting machines. That presented a fundamental problem – one that Lars and his colleague Mike Renoth, LEJ Operations Manager, set out to solve.

Heavy shipments used to be handled entirely manually, using pallet trucks or forklifts. “As heavyweight volumes increased, so did forklift traffic inside the hub, and that brought safety risks,” explains Mike. In addition, the speed of operations matters enormously in an express network. Every extra minute spent moving a shipment between its arriving aircraft or truck, and its outbound connection eats into the customer's transit time. Lars wondered: “How can we transport standard Euro pallets automatically and with shorter transit times?”

In 2014, as the Leipzig Hub prepared to expand, the project team received a deceptively simple challenge from Lars: "Make it conveyable." In other words, create a system where heavy items could be transported on an automated conveyor.

The first challenge? Create a conveyor that could do the job, since no comparable sorting machine existed on the open market.

The team found inspiration in an unlikely place: airport baggage systems. Major airports routinely move bulky suitcases long distances between terminals. Why couldn't a similar principle work for pallets and heavyweight shipments?

Working with baggage-handling systems specialist Vanderlande, a multidisciplinary DHL team of operations colleagues, process engineers and network, structural and sorting experts began developing what became the Large Automated Conveyable System, or LACS.

With floor space in the LEJ hub limited, they decided the best solution was to think vertically. Today, the LACS system sends shipments through different levels of the hub, at heights reaching 12.6 meters. The wider LACS infrastructure includes roughly 14 kilometers of conveyor track, 131 lifts, 161 loading and unloading workstations and 1,200 transport trays. Its maximum technical throughput is 5,096 items per hour.

Some of its innovations were distinctly low-tech at first.

During nighttime tests, the team used wooden blocks to work out how the trays could accommodate different pallet formats. Securing heavy loads as they traveled around curves and between levels posed another challenge. One team member stopped at a craft store on the way home and built a model of a possible solution. That idea eventually generated 13 options before the final design was chosen.

The result transformed the journey through the hub.

A heavy-weight shipment arriving by road or air is brought to a LACS workstation, where its weight, dimensions and packaging are checked before it starts its automated journey. Scanners and sorting logic determine its path through the system. The average internal journey now takes 9.5 minutes, compared with 35 minutes before LAC. That’s a reduction of about 71%.

For an express network, that is not simply an efficiency statistic, it helps make the service possible.

Emergency shipments are one part of the story of the riseof Heavy Weight Express (HWX) in heavyweight express, but they’re not the only factor. For example, a predictable express service can reduce the inventory companies need to hold as a buffer.

For technology, automotive, engineering, life sciences and energy companies, a delayed heavy-weight shipment can carry costs far greater than the price of transportation itself. 

That may ultimately be the simplest way of understanding HWX. A shipment might weigh 50 kg, 500 kg or several tons in total. To the customer waiting for it, however, its weight is secondary.

What matters is that it arrives when it is needed.