Are we reaching the limit of what can be reasonably protected?

14 March 2019

Dr Jim Glockling asks, after the Ocado warehouse fire, whether we are reaching the limit of what can be reasonably protected

The Ocado warehouse fire is a stark reminder of the instantaneous impact that fire can have on a major business, its operations, and share price. Automated warehousing facilities present significant fire protection challenges as a result of very high storage densities, limited access, electronic conveyancing systems, high racking and cold storage requirements.

With (unconfirmed) information emerging that the Ocado warehouse was sprinkler protected, this sad event will no doubt prompt a thorough investigation as to the circumstances that might have led to the protection system being overwhelmed. Sprinkler system failures are very rare events; they are specifically designed to offer levels of resilience far in excess of any other suppression technology, and millions are spent every year around the world ensuring that installation and design rules keep abreast with modern day challenges and storage methods.

Although the majority of sprinkler actuations result in the extinguishment of the fire, their design remit is to stop the development of a fire, hold it at a manageable size, and support fire and rescue service (FRS) intervention - ensuring structural integrity of the building and supporting tenable conditions - for a predefined period of time until it is manually extinguished by the firefighters.

With the increasing size of buildings, complexity of internal structures limiting access within the building, and the potential for fire seats to be at some height, there may need to be a need to review just how effective FRSs can be expected to be within the sprinkler system design time frame.

That said, the design of any sprinkler system needs to be accompanied by strict control of the environment it is designed to protect. Any holistic design requires a passive envelope to work within, and control over key parameters that might act to form sustained ignition sources or spread fire, requiring isolation of power, heat, energy systems and conveyancing systems to name but a few. Failure of any one of these supporting systems could contribute to creating conditions that the sprinkler system was never designed to cope with.

It is the FPA’s belief that this isolated event should not detract from the unrivalled reputation sprinkler systems have for performance, and for the enormous contribution they make to the protection of the UK’s business economy; and that we learn from whatever this teaches us to make future systems better still. The UK has the laxest mandated requirements for the protection of the commercial estate from fire in Europe – allowing enormous unprotected compartment sizes.

Subject to the findings of any investigation, perhaps now might be the time to review this, so that FRS response and installed protection systems can be designed with knowledge of an upper limit - by the constraining of building proportions and compartment size - to a level that assures protection performance and FRS response can work in harmony, as design demands. Might it be that we are finding the limit of what can be reasonably protected?

 *Note: all comments made without specific knowledge of the circumstances surrounding the Ocado fire

Are we reaching the limit of what can be reasonably protected?