How Zurich is protecting 234 years of historyPreserving buildings of rare historical significance requires careful planning and sensitivity.
Traditional fire safety measures such as installing new fire doors can risk undermining the historical integrity and aesthetics of heritage buildings.
Zurich’s senior fire protection engineer, Gary Howe, has a wealth of experience in developing fire protection and risk management solutions. He was part of a team along with Phyllis Bayley from the National Trust which led Zurich’s fire safety upgrade at the mill at Quarry Bank, in Wilmslow, Cheshire, which became the first major National Trust site to be equipped with modern fire safety sprinklers.
Quarry Bank is a popular local landmark, and visitor numbers have increased since a Channel 4 drama, ‘The Mill,’ was filmed there. In 2015, the National Trust began a major conservation project to tell Quarry Bank’s story.
Finding a fire safety solution
A fire safety solution was needed that would preserve the look and feel of the mill, but also protect the property and the 200,000 visitors who come each year.
One key question for Gary and the National Trust to consider was whether sprinklers would be suitable for a building of such historical significance. Due to its age, layout and the building type, there were deficiencies in the fire compartmentation of the building. Sprinklers were proposed by Zurich as a compensatory measure, however there were concerns that sprinklers would be intrusive and expensive.
The National Trust eventually came around to the idea and agreed that because the mill is an industrial site, the sprinkler system would not look out of place in the historic building. The National Trust also recognised the crucial role sprinklers could play in suppressing and controlling a fire. The use of a modern-day sprinkler system was important as it facilitated, for the first time, full access to people who might need more time to evacuate, including those with disabilities.
The fitting of the sprinkler system alleviated the need to upgrade fire doors and compartment walls which would have significantly altered the historic appearance of the building. Furthermore, the installation of the sprinkler system removed the need for expensive upgrades to the glazing of the fire escape routes.
To ensure the sprinkler system matched the structure, Zurich recommended that the pipework was matched to that of the immediate background. The system was fitted with care and consideration and sympathetically embedded into the historic building.
There was still the matter of how to conceal the minibus-sized diesel engine that was needed to pump water at a rate of 2,000 litres-per-minute through the sprinkler system, as well as the 140,000-litre water tank itself.
Gary and Phyllis were able to find a solution to suit everyone. A red-brick coal shed next to the mill proved the ideal location to conceal the pump and tank, keeping all of the vital fire safety equipment dry, safe and easily accessible.
Testing the sprinkler system
Testing is a crucial part of the process of installing a fire safety sprinkler system.
Testing involves a fire alarm specialist holding a canister of artificial smoke up to a ceiling detector. Two puffs are enough to activate a red light on a single smoke detector, which switches the system to ‘alert’ mode and sends an audible warning to the site’s management. It also sends a text message to the managers’ mobile phones, telling them the location of the activated smoke detector.
With so-called ‘double-knock’ (two-alarm) fire detection systems, smoke must be detected in two separate zones to trigger the system’s warning to evacuate. The specialist will move to a second room and complete the same process, at which point two red lights will trigger on a second detector. An alarm will sound, all fire alarms will ring, and this will prompt the pump to fill all the sprinkler pipes with water.
Challenging misconceptions about sprinklers
Gary and his fellow fire protection engineers are keen to correct misconceptions about how fire sprinklers work.
“In the movies, activation of a single sprinkler head triggers a building-wide deluge,” he says. “But usually, only one or two sprinklers are activated and that’s enough to suppress and control a fire. Many people don’t understand this, and it gives sprinklers a bad reputation.”
Gary notes that sprinklers, properly installed and maintained, have been proven to help save lives, protect properties and minimise business interruption, over many, many years. Indeed, the first automatic sprinkler was patented as far back as 1874. Sprinklers can also help to protect the environment, by reducing airborne pollution emanating out of a fire.