Thursday, 15 June 2017

Fire Risk and Tall Towers













In 2005 JEP READERS voted emphatically against plans for high-rise developments on the St Helier waterfront in a telephone poll. The proposed development was set to be more than just new residential apartments and offices, the developers said it would also feature a boutique, media retailers, restaurants, cafes, coffee shops and other amenities. There would be three "iconic" towers of 20 storeys high.

One of the few supporters of the scheme said: “Three towers create perspective, contrast and balance…..The most important thing now is to make a decision. I hope this will be for tasteful high rise up to 20 storeys.” Another said: “A slender and elegant 20 storey building would be better than a lumpy and bulky 15 storey one.” In 2006 architect Peter Sandover's came up with suggestions for buildings of four, six, eight, nine, ten, 11 and 15 storeys on the Waterfront. The developers were still after at least one building of 20-storeys. There the scheme dropped off the radar.

The issue of fire safety seemed pertinent to me, especially as the Jersey fire service had limited resources – since reduced in numbers under Kristina Moore, just as the London one had been by the UK authorities, and I did some research at the time on fire in tall towers.

The fire in the Grenfell Tower – 24 storeys, only 4 more than the original Jersey proposal highlights the need for a proper understanding of the risk to life of fire in tall buildings.

The investigation into the cause of the blaze is likely to focus on whether cladding panels fixed to the outside of the building contributed to the pace of the fire spreading. While complying with building fire and safety regulations, this is about as much comfort as those on the Titanic being told that lifeboard provision exceeded that of the Board of Trade regulations. Clearly - as they appear to have been implicated elsewhere - an urgent re-appraisal is needed immediately.

There was also a lack of sprinklers to dampen the blaze, and it should be noted that water sprinklers also help to take smoke out of the air. A source who works for Grenfell Tower’s fire maintenance system says that: “There are no sprinklers in the building. I know that because we would manage them if there were. Regulations were different in the 1970s. Even now it’s only a recommendation. Sprinklers are expensive. They cost about £3,500 per dwelling — a lot for a high-rise building. But you should never put a limit on the price of safety of people’s lives.”

Here are some snippets which illustrate both the complexity and problems facing tackling and preventing a fire in tall buildings.

Research Notes:

OPERATIONAL ASPECTS OF HIGH-RISE FIREFIGHTING
A REVIEW OF MAJOR INCIDENTS and SOPs


UK Fire Officer Paul Grimwood has researched firefighting experience in high-rise buildings since 1975 and his 28 page report in FOG ATTACK (1991) demonstrates that many incident command systems and Standard Operating Procedures (SOPs) for tall structures are based on out-of-date policies.

The author worked on detachment with ten big city fire departments in the USA in 1990 and attended fires in five of the world's tallest buildings including the World Trade Center, New York City and the Sears Tower in Chicago. He also visited the scenes of past conflagrations at the Interstate Bank in Los Angeles and the Churchill Plaza in the UK where he discussed firefighting operations with firefighters and chiefs who attended these incidents. Using several case histories he explains how incident command systems, a detailed pre-plan 
(SOP), manpower and equipment logistics are key factors in any successful operation.

Fires in high-rise buildings everywhere have the potential to be one of the most challenging incidents to which we respond. The potential for loss of life is high. Fires can burn for extended periods of time before operations can begin. The reflex time involved is extended due to the additional time required to reach the fire area. It is not uncommon for 15 or 20 minutes to elapse after the arrival of the first unit before fire attack can actually commence.

A fire in a high-rise building requires a high level of coordination. Members should anticipate a large commitment of resources. High-rise fires have historically proven to be some of the most demanding a department can face. Members must realize that the majority of high-rise buildings in Northern Virginia have built-in fire protection systems. 

These systems include sprinkler systems, standpipes, fire detection systems, and fixed fire suppression systems. Only with proper preplanning, will familiarity with the response district be possible. 

There are still a significant number of high-rise buildings, both residential and commercial, that have nothing more in terms of fire protection than a standpipe. Northern Virginia alone has several thousand high-rise buildings, and many more are under construction or in the planning stage. Each of these presents its own set of problems and challenges in the event of a fire.

An event that will most certainly take firefighters by surprise is the negative pressure that often exists BEHIND them as they advance into a fire involved floor of a high-rise structure causing the fire to be 'sucked' out of the apartment or floor to head directly into the stair-shaft. This negative pressure may be substantial and is a by-product of natural stack effects in the stairway itself. On occasions this effect can cause a negative pressure in the fire area itself to cause outside windows to break inwards, allowing exterior winds to intensify fire conditions.

At a high-rise apartment fire in Houston, Texas where a Fire Captain was killed in 2001, it was reported -

'They exited the apartment and headed down the hall, but a nasty thing happened when they opened the stairwell door, sources say. The stairwell acted like a ferocious maw, sucking heat and smoke down from the burning apartment. For Jahnke and Green the effect was overwhelming. The smoke grew thick as a blindfold; a torrent of hot air whirred past. The captains reportedly tried to beat a retreat by following their hose out of the apartment and down the hallway, a task made brutally complicated by the coiled, irregular pathway of their lifeline.

The violent shift in the air current created high confusion by sucking the heat away from the fire. To Jahnke it seemed as if they were headed toward the fire, not away from it, as they followed the path of the hose, Hauck says'.........

20 Storey Buildings

UK Fire Officer Paul Grimwood has researched firefighting experience in high-rise buildings and his 28 page report in FOG ATTACK demonstrates that many incident command systems and Standard Operating Procedures (SOPs) for tall structures are based on out-of-date policies. 

The author worked with ten big city fire departments in the USA and attended fires in the World Trade Center, New York City and the Sears Tower in Chicago. He also visited the scenes of past conflagrations at the Interstate Bank in Los Angeles and the Churchill Plaza in the UK where he discussed firefighting operations with firefighters and chiefs who attended these incidents. Using several case histories he explains how incident command systems, a detailed pre-plan (SOP), manpower and equipment logistics are key factors in any successful operation.

A 12,000 Cu.Metre fire located high up within the confines of a downtown office high-rise structure is a lot different to the same fire located on the second floor! The logistical demands placed on firefighters have demonstrated that Incident Command needs to function well in advance of actual needs for as a plan is initiated there is a lengthy time delay prior to actioning! 

 At two fires in 1988 (Interstate Bank) and 1991(Churchill Plaza), US and UK firefighters were faced with office fires on upper levels that demanded a fresh 30 minute SCBA cylinder every 33 seconds for the entire duration of the Interstate fire and similar requirements for a fresh 45 minute cylinder every 80 seconds in the Plaza fire! Similarly in both fires, hundreds of firefighters were required to undertake a wide range of duties, estimated at both incidents as one firefighter for every 60 Cu.m of fire involvement.

It was in FOG ATTACK that he researched and initiated debate on reaction times - the time taken by firefighters to respond to an incident and get water flowing onto the fire on the upper levels of a high-rise. His research demonstrated 'reaction times' ranging from 9 to 40 minutes for fires located between the 10th and 33rd levels!

Air and smoke movement influenced by internal stack effects and exterior wind movements constantly catch firefighters out and negative pressure differences caused by internal fire towers or stairshafts have resulted in firefighter fatalaties both in the UK and the USA. 

The effects on water flows and fire streams in tall structures present unique challenges for the firefighting force and the difficulties of laying interior hose-lines are all discussed in the report, as are communication problems - "which stairway are we in guys - they wanna know".......! From 'lobby control' to 'staging' to 'search and rescue'........

Fire Ravages London High Rise - 2003
The most serious high-rise fire to hit the UK for many years took over 100 London firefighters several hours to control as flames ravaged the top five floors of the twelve storey Telstar House on Wednesday night.

GARLEY FIRE - HONG KONG 1996 - 39 KILLED
During welding work in an elevator shaft in the 16-storey Garley Building in Hong Kong district on 21st November 1996, a fire broke out which killed 39 people and seriously injured around 80 others. More than 90 people were rescued, some of them in daring scenes in which a helicopter pilot risked his own life.

Maintenance and repair work was in progress in the office and business tower when highly flammable material caught fire during welding work in the basement. The fire made its way up through the elevator shafts and spread like lightning through the top three floors of the building. 

The immense heat and smoke made these floors a death trap for the people working there: the windows could not be opened to let the heat and smoke out, and escape routes were filled with smoke or impassable on account of the fire. As a result, 22 charred bodies were subsequently found in a single office on the 15th floor.

ATLANTA HIGH-RISE FIRE - 1989
At 1029, June 30, 1989, in Atlanta, Georgia an electrical fire originating on the sixth floor of a 10-story office building killed five people, and injured 23 civilians and six firefighters. One woman had jumped from a sixth floor window prior to the Fire Department's arrival and was seriously injured. 

Firefighters removed approximately 14 people over aerial ladders and rescued five others from the interior of the building. The electric closet where the fire started opened directly onto the exit corridor. When the fire erupted, it immediately blocked the corridor, keeping most victims away from the two exits serving the floor.

This fire was reported to be the first multiple death U.S. high-rise office building fire in over 10 years. The fire demonstrates the need for automatic sprinkler protection for high-rise buildings and illustrates the impact that occupant behavior can have on survival in fire situations. 

All of the trapped survivors broke windows to offices and waited for rescue. Four of the people who died were overcome by smoke and toxic gases in the corridor or in offices where windows weren't broken. The fifth fatality was an electrician who was seriously injured by the inital electrical arc, then died from the effects of the fire.

The lo-story fire resistive office building was constructed in 1968 and was not required to be equipped with automatic sprinklers. The building evacuation plan, which had been practiced regularly, was credited with the successful evacuation of occupants on floors other than the fire floor. The building was occupied by a large number of federal workers who were required to practice evacuations, and also several private firms who were not obligated to and only occasionally participated in these evacuation drills.

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