High rise fires

High rise fires

Reflections of Bettina McDowell, General Manager of the International Water Mist Association (IWMA)

When I was nine years old, I happened to watch the news one evening and watched a high-rise office block in flames. I remember the reporter saying that the firefghters could not reach the upper floors as the fire ladders could not be extended to the height of the building which was the 25 storey Joelma Building in Sao Paolo, Brazil. An overheated air-conditioning unit had started the fire early on 1st February 1974. The gruesome outcome was that 179 people lost their lives.

I was in a hotel in London once when the fire alarm went off… Apparently, two boys in a room down the corridor had played arsonist and fireman. I grabbed my son, still a toddler at the time, and made my way to the only staircase. Many people were already trying to escape the building. Quite a few of them seemed to have had the time to pack whatever they could get hold of into their suitcases. And they were carrying them down the stairs while I had left even my handbag behind.

There are many issues which need to be looked at when it comes to fire safety, but there are also many solutions. Not every solution fits every issue though – for whatever reason. Will social housing estates ever be equipped with the latest technology network of fire protection and safety systems, with IP-enabled devices communicating which each other? Surely not! But then again, this may first of all be about the basics and about combining them, i.e. active fire protection, passive fire protection, building regulations, training and common sense. Everything beyond that point may remain the cherry on the cake.

When it comes to active fire protection, the use of a water-based fire suppression or extinguishing systems makes the most sense. Any system must be released as quickly as possible. Especially in a high-rise building time is of the essence. An additional fear factor provoked by the safety system itself should be avoided. The people inside the offices, hotel rooms, residential dwellings should not be exposed to an even higher level of stress in an already extreme situation knowing that a gaseous system has been or will be activated.

Bob Whiteley, chairman of the BAFSA/FIA Watermist Working Group, says: “The benefit […] is that for each litre of water discharged, the surface area of water exposed to the heat of a fire is greatly enhanced. This results in the rapid cooling of flames, the combustion gases, and the surrounding air, thereby sustaining a tenable atmosphere in which people can survive and firefighters operate.”

Obviously, the first water-based systems which come to mind are sprinkler systems because they have been around for a long time. On the other hand, why use a sprinkler system when you can use a water-mist system? This is always based on a real life fire test which confirms that the specific water mist system will fit the specific application. Water is a precious resource! Not only in the Middle East. Why waste it? Why pump a huge amount of water up a high-rise building if smaller droplets can suppress or extinguish the fire? There are reports that fire brigades only had to carry out a final check after having reached the scene, because the water mist system had already extinguished the flames.

Bob Whiteley continues: “The small droplets, being light in weight, remain airborne in the thermal air currents for extended periods, which enable them to optimize their heat absorption. This also enables them to be drawn by combustion air streams into the seat of a fire where they can vaporize to steam.” He concludes: “When water turns to steam, within the flame front, it expands 1,620 times and pushes air away from the fire”.

This really puts it in a nutshell. The water droplets take away the heat plus the oxygen from the fire. The fire suffocates.  It can burn no longer. What’s more: water-mist systems are easy to retrofit. And how many high-rise buildings exist, which are not at all protected by any kind of fire protection system? Like the 36-storey Marco Polo Apartments in Honolulu where a fire began in July 2017 and where luckily the noncombustible exterior limited the spread of the flames.

What is important is that existing buildings as well as buildings in the planning stage must be scrutinized. The obvious questions are: Are there enough means of egress? Are the escape routes well marked? Are there fire doors or luminous path markers? What building materials were used to erect the office block, the hotel or the block of flats in the first place? And if there have been any refurbishments, what need reviewing? Furthermore:  Do fire safety regulations keep up with increasing skills and design aspirations?  And can fire services respond efficiently if buildings heights are driven to more extremes? Will they be able to cope in case of an emergency in one of the seven London high-rise residential towers which are currently in the planning stage and which each will contain a single exit staircase only? The 67-storey Spire London amongst them will provide a single staircase only from the 55th floor upwards. Who would like to live in the penthouse?

Another important aspect is that we must always look at the fact that we have a variety of people in different buildings pursuing all kinds of activities. There are those sleeping, people engrossed in a book, dozing off in front of the television, arguing couples. We have the elderly, the impaired, the handicapped, pregnant women, children. Will they all be able to react quickly? Will they all be able to make their own way out?

Once a fire has started, the fire services as well as the persons inside the building have to deal with it. One of the most crucial questions is of course whether the people should wait for help or try to get out by themselves. If they decide to do the latter they should of course leave everything behind. They may understand how important this is if they have trained for the case of an emergency regularly and from an early age onwards. How often do schools test the fire alarm and practice an orderly escape? How often do people, living or staying in high-rise buildings, exercise an evacuation to train the procedure? Most probably not often enough! People may realize how counterproductive it is to bring suitcases along once they have practiced an escape and have received a warning by a fire officer.

There were more severe fires at the beginning of the 20th century like the Iroquoise Theatre fire in Chicago which in 1903 killed more than 600 people and the Triangle Shirtwaist Factory fire in New York which in 1911 killed 146 people. After the fire of the Joelma Building some new fire safety regulations were enacted. But how far have we come if in 2017 the tremendously high number of 71 people die in a fire? At the Grenfell Tower no fire safety system was in place and it seems that the cladding which had originally been proposed was replaced with a less fire resistant aluminium type.