Aimetis helps improve health and safety for DHL / Tesco.

Tesco National Frozen Distribution centre in Daventry

A revolutionary CCTV site management system at the DHL operated Tesco National Frozen Distribution centre improves efficiency.

DHL Supply Chain Ltd employed integrator Piggott and Whitfield (P & W) to develop an IP CCTV system for monitoring frozen pallet placement and health and safety practice at its deep freeze, automated distribution warehouse. The CCTV system comprised Aimetis Symphony™ video management software (VMS) with Grundig IP CCTV dome cameras.

The Tesco National Frozen Distribution Centre is a 25,000 sq. m site and one of four similar facilities run by DHL Supply Chain Ltd for Tesco in the UK. It has 500 members of staff working 24/7. The coldstore warehouse is made up of 12 double deep aisles for pallets. It operates at -22°C, with Dematic Automated storage and retrieval cranes replenishing continuously. Aisles are 30m tall and 100m long, with five intermediate floors between aisle groups containing conveyors, where staff members pick goods for delivery to Tesco stores.

The challenge

Suppliers have scheduled delivery times for unloading their frozen cargos. The more efficient the turn around on doors the more effectively the coldstore environment is maintained.

The Dematic cranes will not place a pallet on a shelf if they sense an obstruction, which can be anything from loose packaging to a misplaced or damaged pallet. A member of staff then has to harness up in freezing conditions and climb as high as 30m above the ground to remove the obstruction manually to then return to the ground level and manually, by remote, put the pallet away. This can take 15 – 20 minutes and happens as often as 100 times a week, delaying the unloading and stacking process. Additionally, if the person should fall, although the safety ropes will hold them, they can experience suspension trauma. In the freezing conditions, this can mean they will only survive for 15 minutes. Clearly, strict adherence to Health and Safety procedures is critical in mitigating risk of accidents.

The solution

P & W installed tough, vandal-resistant, low temperature, infra-red Grundig IP CCTV dome cameras, supplied by The Security Buying Group. The cameras, which are heated, operate at extremely low temperatures, in the dark and are powered by PoE (Power over Ethernet) for minimal temperature impact. The cameras are installed on each side of the cranes looking towards the pallet locations in the aisles.

An Aimetis Symphony™ VMS system processes and records the camera video streams, allowing operators to view images from the cranes using wireless, tough notebooks (portable HMI screens). If a crane stops for any reason, they can identify the obstruction and in most cases, manually operate the crane from the ground to store the pallet.

Billy Currie
Billy Currie

“P&W was able to create a bespoke, wireless network solution that kept the CCTV security data within the DHL network and totally separate from Tesco’s own data network,” explained Billy Currie, Campus Automation and Facility Manager at DHL Supply Chain Ltd. “Other companies had tried to offer a solution, but failed.”

Chris Riesen, Intelligent Solutions Manager at P&W stated, “P&W’s specialist network and data communications expertise provided a bespoke solution to a difficult challenge. We tested our solution in one aisle, before implementing the system across the entire warehouse. There were a lot of demanding criteria to meet, including low temperatures; wireless operation because of crane movement; low light operation; and a robust, network solution that was totally separate from the wider Tesco distribution network.”

Grundig heated camera on Dematic crane.
Grundig heated camera on Dematic crane.

The results

“We could not have predicted the effectiveness of the system,” said Billy Currie. “In 96 – 99% of cases, my staff can safely recover the crane from the ground without having to climb to continue operation. Before the installation, we would have around 100 stoppages a week, so efficiency has been dramatically improved through reduced downtime!

“Site Health and Safety has also been improved as staff members rarely have to climb cranes to check for obstructions. We have also been able to ensure staff members adhere to our strict Health and Safety whilst working at height and in coldstore conditions, reducing risk to themselves and the business. DHL has been able to reduce risk and improve staff performance.

“Many of the genuine sensor alerts were caused by loose packaging or debris from pallets affected by the deep freeze environment. We have worked with suppliers to resolve this problem, which has improved efficiency further.”

P&W has provided a system that no other integrator could offer. They have installed a live, proactive IP CCTV system in a challenging environment, which works alongside crane sensors in an intelligent manner. Most significantly they have provided a wireless solution that operates solely on the DHL network, without interfering with the Tesco network and risking supply chain down-time.

DHL Supply Chain Ltd is now adding IP CCTV to other areas of the site, to ensure Health and Safety compliance and to dramatically improve efficiency and safety. The entire warehouse and external security cameras will be incorporated into the same Aimetis system, totalling around 80 cameras on a single server. A roll out to the other frozen distribution centres in the UK is also planned.