Fire safety tests are taking place in the new production and distribution centre of Coop in Schafisheim, which goes into service in 2016. Involved in these tests is "Izar" – the real fire test system from Basler & Hofmann. We take a close look on site.
The flames ignite, flare up in an orange colour and gradually change to a vibrant, almost neon-coloured blue. The air above the flickering flames shimmers. White "smoke" pours out of the silver-coloured tubes, which protrude to the right and left of the burner which is the size of a table. It rises rapidly and spreads out under the ceiling of the 17 metre high warehouse building. 18 pairs of eyes are transfixed by the burner and blanket of artificial smoke, mobile phones are held up in the air. The layer of smoke slowly sinks lower. After 15 minutes, Juan Blond, fire engineering expert at Basler & Hofmann, turns off the gas supply to the burner and the smoke machines. The system falls silent. The smoke extraction system has obviously passed the test: a perfect layer of smoke could be seen that was quickly sucked out into the fresh air – which is precisely how events should unfold in the case of a real fire. The system must also ensure that a 2.5 metre high layer with little smoke is guaranteed for at least 15 minutes – enough time to get all persons present to safety. Satisfied murmurings were heard coming from those attending the test, which included experts from the buildings insurance company, the in-house fire brigade, occupational health & safety officers and the specialist planners responsible for the project. Izar is dismantled and transported to the next test location, the railway hall.
Hot smoke test in cold store
The Izar real fire test system is deployed in the new distribution and production centre a number of times. The cold store with a prevailing ambient temperature of 3°C came first. For obvious reasons, the original aim was to manage without a hot smoke test. However, no smoke layer was formed during the warm smoke test. The artificial smoke spread all over the whole room, which meant it was not possible to test the efficiency of the smoke extraction system. It was only during a hot smoke test with Izar that it became evident that the smoke extraction system was operating correctly, leaving adequate time for evacuation.
The extensive fire safety tests show that safety is of the utmost importance here. And with good reason: from 2017 almost 2,000 people will be working in the new Coop production and distribution centre. Every year, around 60,000 tonnes of bakery products will be produced in the largest bakery in Switzerland. The whole of the country will be supplied from the neighbouring high bay freezer warehouse (in effect a freezer high-rise building), which extends 25 metres underground and 25 metres above ground. The complex also has an automated high bay warehouse with the capacity for 4,000 pallets, a railway hall, a cold store and a heating system – and the list is still not complete. Everything is interconnected – after all, a logistics centre must guarantee production and distribution chains that are as interruption-free as possible. And it is precisely this that presents the greatest challenges in terms of fire safety.
A steady stream of goods
The complex is connected by approximately 75 conveyor systems. In the high bay warehouse, the entire stock is turned around 1.5 to 2 times a day. This means a constant stream of goods – and therefore a medium with the potential to spread a fire. However, the entire facility cannot come to a standstill because of the smallest incident, because at the end of the day, Coop branches covering a third of Switzerland depend on this logistics centre for their supplies. "Personal safety has top priority. Then secondly, we must find a good balance between protection of material assets and maintaining a high level of system availability," says Alex Funk, Fire Engineering Team Leader at Basler & Hofmann, explaining the challenge.
In the railway hall
In the meantime, the test team has arrived in the railway hall. Here the Izar system is only allowed to heat up to a maximum of 50°C at ceiling level – in other words, the test set-up corresponds to a warm smoke test. Above all here, the intention is to test the requirement for the air to be changed eight times. The ventilation springs to life very noisily and drives the artificial smoke outdoors. After 20 minutes, visibility is returned and the whole palaver is a thing of the past. Yet another test has been passed.