As the largest freestanding building in the UK and with its distinctive wave-form roof, Heathrow’s Terminal 5 opened for business this month. Baggage system problems apart, there’s no denying that T5’s fire safety systems are pushing the envelope of technology – whatever side of the frequent flying debate you are on.
Heathrow Airport’s Terminal Five is a GB pound 2.2 billion project consisting of a main terminal building (T5A) which, at 40m high, 396m long and 176m wide, is the largest freestanding building in the UK. The structure uses fully glazed facades containing 5500 glass panels leaning at 6.5 degrees which, when combined with the 18,500 tonne wave-form roof, give the building its distinctive shape and style. 30 million passengers a year are expected to use T5, which also has 60 extra aircraft stand, 14 of which are big enough to handle the new Airbus A380. The opening of T5 enables Heathrow as a whole to cater for some 90 million passengers a year, and allows BAA to put much needed investment into some of the airport’s other terminals.
The main terminal (T5A) has two satellite buildings, one of which was has been completed so far (T5B). The site also consists of number of different buildings, including an underground railway station located beneath T5A and an automated underground track transit railway system connecting T5A, T5B and the proposed T5C.
Warringtonfire Consulting were employed to develop a fire safety strategy for the entire site. The primary focus of the strategy was to ensure a high standard of fire safety for the occupants. But it was also necessary to minimise the risk of fire affecting the operation of the site, or of damaging the fabric and contents of the buildings.
Airports present particular challenges in relation to fire safety in a number of areas; one of these is the necessity to maintain security separation between the airside and landside areas. At T5 it was also necessary to separate arriving and departing airside passengers. Also, in most other buildings the stairs would lead to the outside at ground level. In airside areas of a terminal building, however, this would mean evacuating passengers onto the tarmac, which would introduce a host of safety issues relating to aircraft movement and security.
Conventional ‘code compliant’ fire safety design would not address these issues, as codes are developed by committees based on past practice and, by definition, would assume a typical building design. They are generally focussed primarily on life safety of the occupants. This approach was not considered appropriate for the Terminal 5 project because:
– the building is highly complex and so codes that are designed for a standard design would not be appropriate
– code compliance would not cover the need for protection of operational continuity and limitation of property risk that was required by BAA
– code compliance requires a rigid enforcement of standard rules, whether or not they are appropriate for that particular building.
So at an early stage in the design process, Warringtonfire Consulting decided to use a risk based, engineering approach to fire safety throughout the design.
Shared responsibility
The basis of the fire safety approach was to introduce qualitative design reviews throughout the project, attended by all relevant parties, including the client, architect, engineers, fire brigade, building control and fire consultant. Each review went through every part of the relevant area, assessing the fire risk within the area, the fire safety facilities that were proposed, assessing the overall risk in terms of life safety, the financial risk to the building operation and property damage. Each area was categorised in relation to its operational criticality, allowing the analysis of the impact on the airport operation of a fire in each area of the building.
The probability of each fire scenario and its consequence were assessed and compared using a matrix such as shown in Table 1, so that the overall fire risk in each area could be determined. If the risk was found to be unacceptably high, additional fire safety precautions were introduced until the risk was reduced to an acceptable level.
As airport operators, BAA have a high standard of management within their terminal buildings. An important aspect of this management is related to fire safety, covering issues such as supervision of evacuations and maintenance of the fire safety systems, so this was an integral part of the strategies for the various areas of the building. The process ensured that the strategy could be implemented effectively by BAA and that the client accepted all the related management issues.
Using the risk assessment approach ensured that the fire safety facilities provided for each area of the building were those necessary to achieve the required level of life safety and property protection. The statutory authorities were involved throughout the process, and were therefore fully supportive of the strategy that was developed. The risk assessment approach ensured that the fire risk within the building was reduced as far as was practical, without wasting resources in areas where the risk was low enough that additional measures were not needed. For example, sprinklers are provided but only in areas where there is a fire risk. A large proportion of the building consists of circulation areas where the fire risk is extremely low and and where there is no need for sprinklers.
The fire strategy also ensured that the design included flexibility so that if, in future, additional fire risk elements were to be introduced in certain areas (such as retail kiosks) these would be allowed for in the design.
Smoke lessons
Smoke ventilation was provided in areas where it was necessary for life safety reasons and also to ensure that if a fire did occur, the smoke could be cleared rapidly after the fire had been extinguished, and the airport returned to normal operation as soon as possible.
Detailed fire engineering analyses were carried out in certain aspects of the building design. These included:
– smoke ventilation within retail units
– smoke flow in the main concourse areas
– structural fire protection to analyse the impact of a fire on certain critical elements of structure in the underground station
– evacuation from all areas of the building
The smoke ventilation is designed to ensure that if a fire occurs in a retail unit, the smoke will be contained within that unit and not spread into the main concourse area. This has benefits in terms of life safety and would also reduce the amount of operational disruption that would occur. Additional smoke flow modelling of a fire within the main concourse areas was carried out. This showed that even if smoke did spread into these parts of the building, there would be no life safety risk.
Structural protection
Fire protection analysis of the structure within the underground station areas was carried out. The main risk in the station areas is from the trains themselves, while the risk within the circulation areas is very low. Train fires were analysed and it was found that the structure close to the trains needed higher levels of protection, but that further away the need for protection was much lower.
Analysing the evacuation policy showed that occupants could vacate all areas of the building horizontally into other parts of the building, rather than into staircases. This has particular benefits for passengers and staff who would have difficulty using stairs (such as those who use wheelchairs). The full evacuation, which results in occupants being taken outside the building onto the tarmac, would therefore only be needed in extreme circumstances.
The Heathrow Terminal 5 project is a highly complex design incorporating a large number of different areas. The fire safety strategy that was developed was based on a risk assessment process that involved all interested parties. This ensured that the design that was developed was the most appropriate for the specific building and provided a high standard of life safety at the same time as reducing the potential disruption to the operation of the building.
BARRIER PROTECTION
To help protect the vast terminal from the effects of spreading fire, Promat’s Durasteel fire barrier and other fire protection systems are being installed across T5, in some areas forming barriers 14m high.
Durasteel is a sheet material made from a core of composite fibre cement, sandwiched between mechanically-bonded steel facings. It is described as impact resistant, light, and durable, and can cope with up to 360 minutes exposure to fire. While subjected to fire conditions, it will withstand spray from firefighters hoses or sprinklers.
At T5, Promat supplied 80,000m2 of Durasteel in 9.5mm sheet for insulated fire barriers. It features prominently below apron level, lining the tunnel-like service corridors, the cavernous baggage handling areas, lift pits, workshops and plant rooms. Indeed, continuous barriers of silver Durasteel – punctuated by apertures for doors and services – provide a visible presence in these areas.
The fire barrier met the specification for 120 minutes’ fire resistance. But that’s not the only reason it was chosen. The system was installed well before the dry envelope stage, so it had to be exceptionally tough and durable. “Before the roof went on, rain water was running down the Durasteel walls for months on end without any detrimental effect on the integrity of the product,” said Peter Sandals, site agent for Essex-based R&S Fire & Security, the specialist sub-contractor responsible for its installation.
The fire barrier’s high impact resistance was another key factor, as it has to withstand the impact of trolleys and baggage systems. In typical applications at T5, two layers of Durasteel are set on steel channel tracks, sandwiching mineral wool between them. Steel studs located at 1.2m centres are used to fix the sheets to fillets and horizontal framing members. The barriers have movement joints to accommodate movement of +30mm and -100mm.
Alongside Durasteel, significant quantities of other Promat products are being used at T5. They include Vermiculux, Supalux, Monolux and Promatect 250 high performance fire protection boards – as well as Durasteel doors. Applications range from protecting structural steelwork in the satellite building to providing ceilings to airside cores, and cavity barriers inside the new control tower.
the integrity of the product,” said Peter Sandals, site agent for Essex-based R&S Fire & Security, the specialist sub-contractor responsible for its installation.
The fire barrier’s high impact resistance was another key factor, as it has to withstand the impact of trolleys and baggage systems. In typical applications at T5, two layers of Durasteel are set on steel channel tracks, sandwiching mineral wool between them. Steel studs located at 1.2m centres are used to fix the sheets to fillets and horizontal framing members. The barriers have movement joints to accommodate movement of +30mm and -100mm.
Alongside Durasteel, significant quantities of other Promat products are being used at T5. They include Vermiculux, Supalux, Monolux and Promatect 250 high performance fire protection boards – as well as Durasteel doors. Applications range from protecting structural steelwork in the satellite building to providing ceilings to airside cores, and cavity barriers inside the new control tower.
As the largest freestanding building in the UK and with its distinctive wave-form roof, Heathrow’s Terminal 5 opened for business this month. Baggage system problems apart, there’s no denying that T5’s fire safety systems are pushing the envelope of technology – whatever side of the frequent flying debate you are on.
Heathrow Airport’s Terminal Five is a £2.2 billion project consisting of a main terminal building (T5A) which, at 40m high, 396m long and 176m wide, is the largest freestanding building in the UK. The structure uses fully glazed facades containing 5500 glass panels leaning at 6.5 degrees which, when combined with the 18,500 tonne wave-form roof, give the building its distinctive shape and style. 30 million passengers a year are expected to use T5, which also has 60 extra aircraft stand, 14 of which are big enough to handle the new Airbus A380. The opening of T5 enables Heathrow as a whole to cater for some 90 million passengers a year, and allows BAA to put much needed investment into some of the airport’s other terminals.
The main terminal (T5A) has two satellite buildings, one of which was has been completed so far (T5B). The site also consists of number of different buildings, including an underground railway station located beneath T5A and an automated underground track transit railway system connecting T5A, T5B and the proposed T5C.
Warringtonfire Consulting were employed to develop a fire safety strategy for the entire site. The primary focus of the strategy was to ensure a high standard of fire safety for the occupants. But it was also necessary to minimise the risk of fire affecting the operation of the site, or of damaging the fabric and contents of the buildings.
Airports present particular challenges in relation to fire safety in a number of areas; one of these is the necessity to maintain security separation between the airside and landside areas. At T5 it was also necessary to separate arriving and departing airside passengers. Also, in most other buildings the stairs would lead to the outside at ground level. In airside areas of a terminal building, however, this would mean evacuating passengers onto the tarmac, which would introduce a host of safety issues relating to aircraft movement and security.
Conventional ‘code compliant’ fire safety design would not address these issues, as codes are developed by committees based on past practice and, by definition, would assume a typical building design. They are generally focussed primarily on life safety of the occupants. This approach was not considered appropriate for the Terminal 5 project because:
• the building is highly complex and so codes that are designed for a standard design would not be appropriate
• code compliance would not cover the need for protection of operational continuity and limitation of property risk that was required by BAA
• code compliance requires a rigid enforcement of standard rules, whether or not they are appropriate for that particular building.
So at an early stage in the design process, Warringtonfire Consulting decided to use a risk based, engineering approach to fire safety throughout the design.
Shared responsibility
The basis of the fire safety approach was to introduce qualitative design reviews throughout the project, attended by all relevant parties, including the client, architect, engineers, fire brigade, building control and fire consultant. Each review went through every part of the relevant area, assessing the fire risk within the area, the fire safety facilities that were proposed, assessing the overall risk in terms of life safety, the financial risk to the building operation and property damage. Each area was categorised in relation to its operational criticality, allowing the analysis of the impact on the airport operation of a fire in each area of the building.
The probability of each fire scenario and its consequence were assessed and compared using a matrix such as shown in Table 1, so that the overall fire risk in each area could be determined. If the risk was found to be unacceptably high, additional fire safety precautions were introduced until the risk was reduced to an acceptable level.
As airport operators, BAA have a high standard of management within their terminal buildings. An important aspect of this management is related to fire safety, covering issues such as supervision of evacuations and maintenance of the fire safety systems, so this was an integral part of the strategies for the various areas of the building. The process ensured that the strategy could be implemented effectively by BAA and that the client accepted all the related management issues.
Using the risk assessment approach ensured that the fire safety facilities provided for each area of the building were those necessary to achieve the required level of life safety and property protection. The statutory authorities were involved throughout the process, and were therefore fully supportive of the strategy that was developed. The risk assessment approach ensured that the fire risk within the building was reduced as far as was practical, without wasting resources in areas where the risk was low enough that additional measures were not needed. For example, sprinklers are provided but only in areas where there is a fire risk. A large proportion of the building consists of circulation areas where the fire risk is extremely low and and where there is no need for sprinklers.
The fire strategy also ensured that the design included flexibility so that if, in future, additional fire risk elements were to be introduced in certain areas (such as retail kiosks) these would be allowed for in the design.
Smoke lessons
Smoke ventilation was provided in areas where it was necessary for life safety reasons and also to ensure that if a fire did occur, the smoke could be cleared rapidly after the fire had been extinguished, and the airport returned to normal operation as soon as possible.
Detailed fire engineering analyses were carried out in certain aspects of the building design. These included:
• smoke ventilation within retail units
• smoke flow in the main concourse areas
• structural fire protection to analyse the impact of a fire on certain critical elements of structure in the underground station
• evacuation from all areas of the building
The smoke ventilation is designed to ensure that if a fire occurs in a retail unit, the smoke will be contained within that unit and not spread into the main concourse area. This has benefits in terms of life safety and would also reduce the amount of operational disruption that would occur. Additional smoke flow modelling of a fire within the main concourse areas was carried out. This showed that even if smoke did spread into these parts of the building, there would be no life safety risk.
Structural protection
Fire protection analysis of the structure within the underground station areas was carried out. The main risk in the station areas is from the trains themselves, while the risk within the circulation areas is very low. Train fires were analysed and it was found that the structure close to the trains needed higher levels of protection, but that further away the need for protection was much lower.
Analysing the evacuation policy showed that occupants could vacate all areas of the building horizontally into other parts of the building, rather than into staircases. This has particular benefits for passengers and staff who would have difficulty using stairs (such as those who use wheelchairs). The full evacuation, which results in occupants being taken outside the building onto the tarmac, would therefore only be needed in extreme circumstances.
The Heathrow Terminal 5 project is a highly complex design incorporating a large number of different areas. The fire safety strategy that was developed was based on a risk assessment process that involved all interested parties. This ensured that the design that was developed was the most appropriate for the specific building and provided a high standard of life safety at the same time as reducing the potential disruption to the operation of the building.
BARRIER PROTECTION
To help protect the vast terminal from the effects of spreading fire, Promat’s Durasteel fire barrier and other fire protection systems are being installed across T5, in some areas forming barriers 14m high.
Durasteel is a sheet material made from a core of composite fibre cement, sandwiched between mechanically-bonded steel facings. It is described as impact resistant, light, and durable, and can cope with up to 360 minutes exposure to fire. While subjected to fire conditions, it will withstand spray from firefighters hoses or sprinklers.
At T5, Promat supplied 80,000m2 of Durasteel in 9.5mm sheet for insulated fire barriers. It features prominently below apron level, lining the tunnel-like service corridors, the cavernous baggage handling areas, lift pits, workshops and plant rooms. Indeed, continuous barriers of silver Durasteel – punctuated by apertures for doors and services – provide a visible presence in these areas.
The fire barrier met the specification for 120 minutes’ fire resistance. But that’s not the only reason it was chosen. The system was installed well before the dry envelope stage, so it had to be exceptionally tough and durable. "Before the roof went on, rain water was running down the Durasteel walls for months on end without any detrimental effect on the integrity of the product," said Peter Sandals, site agent for Essex-based R&S Fire & Security, the specialist sub-contractor responsible for its installation.
The fire barrier’s high impact resistance was another key factor, as it has to withstand the impact of trolleys and baggage systems. In typical applications at T5, two layers of Durasteel are set on steel channel tracks, sandwiching mineral wool between them. Steel studs located at 1.2m centres are used to fix the sheets to fillets and horizontal framing members. The barriers have movement joints to accommodate movement of +30mm and -100mm.
Alongside Durasteel, significant quantities of other Promat products are being used at T5. They include Vermiculux, Supalux, Monolux and Promatect 250 high performance fire protection boards – as well as Durasteel doors. Applications range from protecting structural steelwork in the satellite building to providing ceilings to airside cores, and cavity barriers inside the new control tower.
the integrity of the product," said Peter Sandals, site agent for Essex-based R&S Fire & Security, the specialist sub-contractor responsible for its installation.
The fire barrier’s high impact resistance was another key factor, as it has to withstand the impact of trolleys and baggage systems. In typical applications at T5, two layers of Durasteel are set on steel channel tracks, sandwiching mineral wool between them. Steel studs located at 1.2m centres are used to fix the sheets to fillets and horizontal framing members. The barriers have movement joints to accommodate movement of +30mm and -100mm.
Alongside Durasteel, significant quantities of other Promat products are being used at T5. They include Vermiculux, Supalux, Monolux and Promatect 250 high performance fire protection boards – as well as Durasteel doors. Applications range from protecting structural steelwork in the satellite building to providing ceilings to airside cores, and cavity barriers inside the new control tower.
