Newcastle upon Tyne, UK: Last year Greggs built a new deep-freeze high-bay warehouse at its factory near Newcastle Upon Tyne.
The 90,530 cubic metre warehouse has fire protection systems supplied by Wagner.
Automated warehouse carry a higher risk of fire that traditional warehouses due to the large amount of electrical equipment in the warehouse.
- The risk assessed at Gregg’s warehouse were:
- Electrical installations
- Extremely dry atmosphere that is created by low temperatures help spread a fire outbreak
- Height of the warehouse favours the chimney effect and accelerates the spread of a fire in the event of a fire
- High fire loads as a result of tightly packed goods
The high bay warehouse was difficult to protect by traditional methods due to the combination of its height, densely packed stored goods and deep-freeze operating temperature
The automated high-bay warehouse stands at 23 metres tall and has a storage capacity with upwards of 14,000 pallet bays.
The warehouse is operated at -20°, where savoury baked goods will be stored frozen packaged in plastic trays or cardboard boxes, in both cases on wooden pallets. Something else, that had to be kept in mind: the warehouse is directly connected to the factory. If a fire occurs, it must not spread.
- Gregg’s goals were:
- The odour-sensitive baked goods must be protected by the best possible means from damage by a fire or contamination by smoke and soot
- Functionality of the automated warehouse must be maintained under all circumstances
- The supply chain must not be interrupted
- Fire-related consequences must be mitigated to preserve customer loyalty and brand reputation
Greggs opted an active fire prevention system in combination with an oxygen reduction system. A fire testing protocol was developed In consultation with Greggs’ insurer and fire tests were carried out by Wagner.
Tests conducted at Wagner’s freezer test site, at its headquarters in Langenhagen, Germany, determined the ignition threshold of the products.
Gregg’s fire prevention system uses OxyReduct, that builds a protective atmosphere in the protected area with a permanently reduced oxygen level through the controlled introduction of nitrogen. This reduces the oxygen levels to prevent the spread of fires, taking the individual ignition thresholds of the most critical materials found in the warehouse into consideration. Sensors continuously measure the oxygen concentration in the protected area, working with the OxyControl system to maintain a constant oxygen operation concentration.
As a smouldering fire can still result despite oxygen reduction, the active fire prevention strategy also includes an early smoke detection system with air sampling smoke detectors.
