Fire Safety Engineering - Assignment Example

Week 1 1 Describe fire safety engineering Safety engineering refers to an engineering discipline involving mechanical, chemical, civil and electrical concepts in studying the fire effects and phenomenon through the study of human behaviour, proper design and arrangement of spaces in buildings to mitigate fire, save lives and property. It also involves the analysis of preventive, protective systems that can be installed within a building to limit the effects of fires. 2 Differentiate fire services engineering from fire safety engineering Fire services engineering refers to the design of features that are used in fire suppression while fire safety engineering refers to the application of engineering principles in the control of fires in buildings. 3 Outline the individuals involved in a project, the design team members or other stakeholders Many projects in the world involve setting up huge infrastructure and buildings which involves large groups of people, professionals and the public at large. Professionals are involved in the design of the project and at times some of them are involved in implementation. The design team is outlined below: Architect Structural engineer Mechanical Engineer Services engineer Quantity surveyors Specialist designers Other stakeholders include: Government Government agencies e.g. environment agency Community 4 Describe the VIC fire safety engineering regulatory framework These are regulations made to amend and prescribe standards which are used for the control of design, construction of buildings and entertainment places. It also prescribes the use of buildings and the seating arrangement thereof. 5 Describe the NSW fire safety engineering regulatory framework These are regulations stipulated for fire control through inspections of various premises and outlining of an emergency plan in the event of a fire. It advocates for the installation of hydrants, sprinkler systems, hose reels, etc. 6 Define an alternative solution Alternative solution refers to a building solution that complies with BCA section one part one performance requirements and the deemed to satisfy provisions. It enables practitioners to embrace flexibility in their work. 7 Roles of Relevant building surveyors (RBS) and their qualifications according to the VIC building regulations for assessing the alternative solutions RBS issue building permits after assessing the building work and the building permit for compliance with the building regulations as stipulated by the VIC building Regulations 2006 and the BCA 1993. This is outlined in section 24(1) of the BCA and Reg. 113A of the VIC regulations. They are required to have held a graduate certificate in building surveying from a university registered by the Tertiary Education Act of 1993. They are also required to have had three years practical experience to the satisfaction of the building practitioner’s board. 8 Using a flow chart show the permit process for the various stages of construction as per the regulations of the Act and the Vic building Reg. 2006 The following chart illustrates the various permits processes 9 Who is a chief officer? Regulation 309 requirements and associated process are described. A chief officer is an officer in charge of a metropolitan fire and emergency services according to the Metropolitan Act of 1958 or the officer in charge of a county fire authority. The report and consent of the chief officer containing fire safety matters should be obtained as outlined in regulation 309. Consent must be given for buildings which do not meet the deemed to satisfy criteria. For example, provision of a static water supply or allotment on which a building is located is subject to bushfire overlay and a permit is not required for the building. Regulation 309 requires that the deemed to satisfy provisions of the BCA must be met before any permit is approved. The provisions are as listed Fire hydrants Fire hose reels Fire mains Control valves Booster assemblies Emergency vehicle access Fire services control in passenger lifts Fire precautions 10 What is ‘Form 5’? Describe its purpose and who uses it. When is it done in buildings? It is an application for occupancy permit form; It is filled and addressed to the relevant building surveyor seeking approval for occupancy of a permit. It is done after the construction works on a building have been completed and it’s ready for occupancy. The form is filled by the owner or his agent and addressed to the relevant building surveyor. (Building Act, 1993), Schedule 2. 11 Who are the building appeals board (BAB) and what’s their role? Building appeals board is an institution tasked with listening to appeals as regards to any building dispute arising between individuals or if the building regulations have such a provision (Building Act, 1993), Part 10 Division 1 The board listens to appeals on: Building and occupancy permits (Building Act, 1993), section 138(10)- Protection work Temporary occupation of buildings Private building surveyors Building notices and orders Directions to fix building work 12 Outline the different sections in the BCA, of them which are relevant to fire safety. Which performance requirements relate to fire safety? Section A- General provisions which explain application and interpretation of the other sections Section B- Structure, deals with the structural integrity of the building Section C- Fire resistance Section D- Access and Egress Section E- Services and equipment Section F- Health and Amenity Section G- Ancillary provisions Section H- Special use buildings Section C, Section D & Section E easily related to fire safety Section 2(1) of the BCA outlines performance provisions of the Act. It is subdivided into other five sub-section (Structure, dampness, fire safety, health and amenity and safe movement and access). The section outlines the objectives, and performance requirements to be achieved by the building in resisting fire. The subsection requires the provision of facilities such as sprinkler systems in residential buildings, installation of warning systems such as smoke alarm technology and holistic reviews on fire safety. 13 Who are Registered Building Practitioners, which organisation do they register with? Different classifications of RBP and the criteria for a fire safety engineer to gain BRPP status are described. This are persons who are registered under Part 11 of the BCA as professionals. The individuals are required to register with the Building Practitioners Board for a certain category Categories of building practitioners are: Building surveyors Quantity surveyors Engineers- prior to registration with the BPB they are required to have registered with the National Professional Engineers Register (NPER). There are different classifications of engineers (civil, electrical or a mechanical engineer) and they are to register in their respective classes in the NPER. Draftsman who prepares plans for building work Builders Other categories include: building inspectors, draftspersons and supervisor. Fire safety engineers are required to have a degree in fire safety from a university established by the Tertiary Education act of 1993. Three years practical experience to the satisfaction of the board and a current certificate of registration as a fire safety engineer with the NPER is also a requirement. [Vic06] 14 Describe IFEG and outline the information it provides for firing engineers. Explain a trial design. IFEG is the international fire engineering guidelines, developed in 2005 by Canadian, Australian and American agencies, provides the processes for developing fire engineering solutions. It is used in the development of alternative solutions by engineers. Trial design refers to the use of fire engineering techniques to assess a fire safety system.[Int05] Week 2 1 Describe FEB FEB stands for Fire Engineering Brief, and it is a process that defines the scope of work for the fire engineering analysis. Its purpose is to set down the basis, as agreed by the relevant stakeholders, on which the fire safety analysis will be undertaken. 2 Describe FER FER stands for Fire Engineering Report, and it is a major and significant output of a fire safety evaluation and should be a self-explanatory document. The information contained in the final report may find use during construction, commissioning, management, use, maintenance, audits, alteration/extension or change of use of the building. 3 Differentiate Fire engineering brief and the Fire Engineering Report Fire safety engineering brief is conducted at the preliminary stage of the design phase. It involves communicating with stakeholders and authorities on the strategy and objectives to be incorporated in fire safety analysis. Whereas fire engineering report details the fire safety design solution which are formulated and analyzed against the objectives set out in the fire engineering brief Fire engineering brief, therefore, is conducted first before the fire engineering reports. 4 IFEG subsystems are described below Fire suppression and extinguishing services: those systems involve the use of either manual or automatic systems such as sprinkler systems, water mist systems, gas intervention systems and the use of the fire brigades as a manual system to intervene, control and extinguish fires. Smoke control systems: those are systems which aim at controlling the smoke levels in a structure that have caught fire to avoid choking of occupants. However, the additional air provided may increase the burning rate. They are used in tandem with sprinkler systems where the former is first activated. Commonly applied in tunnels Building elements failure: materials used in buildings may fail when in the event of a fire a certain time/heat level is achieved. These materials may be used on window frames and doors; this provides extra ventilation to the building. It is effective for ventilation controlled fires. However, the fire may be fanned by the addition of extra fuel in the case of breaking doors. 5 Risks and safety measures associate with each subsystem Smoke control systems when not well integrated can result in a higher heat release rate since it results in the supply of air into the fire plume. It requires integration with the fire suppression systems especially the automatic ones. Building elements failure can result in elevated fire levels by providing more fuel in the case of wooden doors. Fire suppression systems are risky when they use water as the coolant since water is a good conductor of electricity, electrocution becomes inherent. 6 Explain the different methodologies types of fire engineering assessment This refers to the various sub-systems used thereof: Fire initiation, development and control Smoke development, spread and control Fire impact, spread and control Fire detection, warning and suppression Occupant evacuation Fire services intervention 7 Briefly explained are the sensitivity, uncertainty and redundancy studies This are assessments of input, processes and outputs by fire engineers in the evaluation of outcomes after achieving high levels of confidence. Sensitivity studies change one input while redundancy studies examine the redundant measures and uncertainty studies show how uncertainties are inherent are reflected in the results. 8 AS2419 – Fire brigade fire suppression activities – fire brigade appliance, hoses, hydrants, boosting, booster assembly, etc. Fire hydrants are installed and designed as specified by the AS241 standard. The system comprises the following: Water supply and storage- water can be obtained from the street mains, dams or water tanks in the vicinity of the building. Fire brigade boosters- this are installed to provide extra water to the hydrants. They should be available to firefighters, therefore their location is of concern in the design. Pump Hydrants- they should be strategically located within the building as specified by the standard. The hose connection should also be as required by the local fire brigade. Fire hose. A hydraulic tests should be performed to ensure that there is sufficient water and pressure in all hydrants. WEEK 3 1 The fire triangle is as explained with examples on how it can be used to mitigate fire Fire triangle refers to a model used to show the three elements of fire which when combined in various proportions a fire occurs. The three elements are as follows: Oxygen Fires need oxygen for them to start and continue. Oxygen is air’s component that is essential for combustion to take place, oxidation, this is why fire extinguishers use dirt, soil and blankets to smother the fire to cut the oxygen supply to the fire. Using carbon dioxide also puts out fires. Fuel A fuel source is needed for a fire to burn. Fuel is anything that is flammable; examples include wood, papers, chemicals, Liquids. Once the fuel is depleted or removed the fire will go out. Forest fires are allowed to burn without any attempt to extinguish them, other than in creating a buffer, by cutting trees/ bushes a given safe distance from the fire. The fire then goes out on its own when the fuel, bushes, are depleted. Heat This is an essential fire element of the fire elements. Fires cannot start unless a certain heat amount is achieved. Firefighters apply coolants such as water to extinguish fires or other chemical retarders. Turning off electricity removes a source of heat in buildings, firefighters priority action when extinguishing fires. Wood embers can also be used to scrape embers of a fire source resulting in diffused heat, another heat control used to put off fires 2 Behaviour of solid timber in fire and charring definition and impact on the combustion process explained. How does laminated timber behave? Timber is a combustible material, though when altered and properly designed it can be effective in resisting fires. When timber is exposed to fire its exposed surface is almost equal to the fire temperature, it burns when the surrounding fire reaches its burning point. A char develops over the burned wood which acts as an insulating layer thus preventing excessive temperature being conducted to its core. However, the inner experiences a loss in strength, stiffness attributed to moisture loss through evaporation. Char refers to a charcoal like a layer that develops over a burning timber surface. This layer as stated earlier insulates inner core of timber. Thus it burns slowly since the temperature of the core remains low. Char makes timber remain intact and able to carry the structures load in the event of a fire.[Mal67] Charring rate increases initially but when the char depth increases slowing the combustion rate because of the stronger protective layer. The laminated timber consists of timber panels glued together to form a larger section. It behaves just as solid timber when exposed to fire by becoming charred, however, it takes more time for the whole section to fail since the majority of the panels have to be charred/ fail by fire. Therefore, laminated timber takes more time to fail compared to normal timber. [Mal67] 3 Systems available for automatic fire suppression, their applications and scenarios where they are used Sprinkler systems: these systems are widely used and specifications over their incorporation into buildings stipulated by authorities. Applied in residential buildings and shared accommodation buildings classified as class 3 by the Act. Water mist systems: water is applied at high pressures as fine spray droplets. They have better cooling effects, no water wastage and no use of extinguishing retarders. Stadiums rooms, tunnels (Singapore), large and high floor to floor heights buildings/display rooms. Gas intervention systems: gas is supplied to areas where there are fires upon detection through conduits from the cylinders where it is stored. Carbon dioxide is commonly used. It is used in server rooms, data centres and rooms with MRI equipment. Week 4 1 Define Standard fire test, describe how it is conducted. Which AS documents this test? Explain FRL determination for structural adequacy, integrity and insulation. This refers to a test conducted on materials to determine their fire resistance when exposed to heat under controlled conditions. The materials representative specimen is placed in a furnace synchronized and operated to satisfy a standard time vs temperature curve. The specimen can then be subjected to either or both of thermal and physical loading if conditions allow. Observations are then made on the tests and the various times at which the specimens fail recorded. FRL, refers to the fire resistance level, is determined by subjecting building material specimens to the standard time against temperature curve outlined by the standard fire test.[Aus05], earlier references are the BCA AS1530.4-1997 2 Described the ASET and RSET analysis differences. ASET, Available safe egress time, refers to the time elapsed between the development of hazardous conditions for human occupancy after a fire starts/ ignites. While RSET, Required Safe Egress Time, refers to the time required for owners/ a building’s occupant to wholly evacuate from it. ASET as defined is the time taken for conditions in a burning building to become unfavorable for humans while RSET is the time taken by the occupants to evacuate when a fire ignites. ASET needs to be greater than RSET for any building to be termed as having met the fire safety conditions with safe evacuation possible. ASET and RSET calculations ASET can only be calculated theoretically. Hand calculations are possible for ASET, however, computer programs are also used. Where a- ASET t- Evacuation time r- Environment factor A1- acceptable risk for occupants RSET contains various components which are used in its calculation. They are: pre-movement time (time before occupants react to a fire alarm after it has been raised), detection time (time that a fire takes from when it ignites to when it is sensed) and movement time (time an occupant takes to the exits of the building.) The following formulas are used Where td- ta- detection time to- pre-movement time ti- time awaiting evacuation te- time from start of evacuation to its completion. Ways in which ASET can be calculated Modelling is widely used to calculate the ASET by engineers other than mathematical computations. There are two models which can be used, Zone model: smoke layers’ heights are predicted using this model using simple geometries. Computational fluid dynamics (CFD) model: used for complex areas for assessing. They consider issues such as fire growth, flame spread and suppression. What is the determination of ASET (acceptance criteria)? ASET can be defined by the conditions which include smoke toxicity levels and temperatures. Research findings have been published to advice on the acceptable figures (minimum and maximum) for the conditions, for instance: Visibility to remain above 10m. Temperature to remain below 65oc. Carbon monoxide levels to remain below 1400 ppm. Week 5 1 Fire safety hazard review. The features of buildings addressed, their importance and impact on the fire safety of a building. Fire safety review refers to reports prepared on the fire safety levels of buildings annually, they involve inspection of the premises through walk-throughs and studying of its documentations after which a report is filed. The following features are considered: Existing openings- examples include atriums. They serve as conduits of smoke in buildings to upper sections where fire has not yet ignited. The openings when well engineered can increase the ASET of the building, increasing the chance of evacuation of the occupants. Vertical shafts such as staircases, elevator shafts- often fire spreads to other parts of the building through staircases, which also act as access/ evacuation paths in case of fire. Concealed spaces such as ceiling voids- The materials making up the ceilings should have a high fire resistance level to limit spreading of fire to other parts of the building. Ceilings should not span over large sections of the building. The spaces should also contain non-flammable materials to control fires. Walls- external walls must be incombustible according to Australian standards. Materials making them up should also be incombustible. This is to limit amount of air in the building and the fanning effect of wind. This also limits the spread of fire to other parts of the building. 2 Hazards of the following buildings relating to fire safety are explained. a 20-storey office buildings Tall buildings are exposed to high wind velocities, given there are no or little barriers at such heights. Wind fans fires by supplying extra oxygen to the fire leading to further spread within the building and high heat release rates. Fire load density-papers and furniture may increase the fuel available for fires in offices Firefighting capability- evacuation of people from such heights is a quagmire for most city fire fighters. b 20-storey residential building Evacuation- Massive efforts needed to evacuate everyone in the building given that the population density is high. At times some occupants may be asleep making it even harder for evacuation services. Staircase reliability- staircases accommodating the high influx of people and being fire free Stampede since reaction time is almost similar for most of the occupants. High Fire load due to gas and electricity lines in the building for cooking and lighting, increased fuel. c 3-storey aged care building Evacuation- the reaction time of aged people is low compared to those of young generations. Guidance to exits is also required for almost all occupants by workers leading to a strain on the evacuation team. d 2-storey shopping center Arson attack- shopping centers are a target by terrorists the world over, Fire load density- most items sold in malls are flammable, this increases the fuel available for fires to act on crowded areas which can easily lead to stampedes if not sufficiently spaced. Read More

FER stands for Fire Engineering Report, and it is a major and significant output of a fire safety evaluation and should be a self-explanatory document. The information contained in the final report may find useful during construction, commissioning, management, use, maintenance, audits, alteration/extension, or change of use of the building.

• A fire safety engineering brief is conducted at the preliminary stage of the design phase. It involves communicating with stakeholders and authorities on the strategy and objectives to be incorporated in the fire safety analysis. Whereas fire engineering report details the fire safety design solution which is formulated and analyzed against the objectives set out in the fire engineering brief
• The fire engineering brief, therefore, is conducted first before the fire engineering reports.
• Fire suppression and extinguishing services: those systems involve the use of either manual or automatic systems such as sprinkler systems, water mist systems, gas intervention systems, and the use of the fire brigades as a manual system to intervene, control, and extinguish fires.
• Smoke control systems: those are systems that aim at controlling the smoke levels in a structure that have caught fire to avoid choking of occupants. However, the additional air provided may increase the burning rate. They are used in tandem with sprinkler systems where the former is first activated. Commonly applied in tunnels
• Building elements failure: materials used in buildings may fail when in the event of a fire a certain time/heat level is achieved. These materials may be used on window frames and doors; this provides extra ventilation to the building.
  
  Risks and safety measures associate with each subsystem:

• Smoke control systems when not well integrated can result in a higher heat release rate since it results in the supply of air into the fire plume. It requires integration with the fire suppression systems especially the automatic ones.
• Building element failure can result in elevated fire levels by providing more fuel in the case of wooden doors.
• Fire suppression systems are risky when they use water as the coolant since water is a good conductor of electricity, electrocution becomes inherent.

 Fire triangle refers to a model used to show the three elements of fire which when combined in various proportions a fire occurs. The three elements are as follows:

• Oxygen

Fires need oxygen for them to start and continue. Oxygen is the air’s component that is essential for combustion to take place, oxidation, this is why fire extinguishers use dirt, soil, and blankets to smother the fire to cut the oxygen supply to the fire. Using carbon dioxide also puts out fires.

• Fuel

A fuel source is needed for a fire to burn. Fuel is anything flammable; examples include wood, papers, chemicals, Liquids. Once the fuel is depleted or removed the fire will go out. Forest fires are allowed to burn without any attempt to extinguish them, other than in creating a buffer, by cutting trees/ bushes a given safe distance from the fire. The fire then goes out on its own when the fuel, bushes, are depleted.

• Heat

This is an essential fire element of the fire elements. Fires cannot start unless a certain heat amount is achieved. Firefighters apply coolants such as water to extinguish fires or other chemical retarders. Turning off electricity removes a source of heat in buildings, firefighters prioritize action when extinguishing fires. Wood embers can also be used to scrape embers of a fire source resulting in diffused heat, another heat control used to put off fires.

Timber is a combustible material, though when altered and properly designed it can be effective in resisting fires. When timber is exposed to fire its exposed surface is almost equal to the fire temperature, it burns when the surrounding fire reaches its burning point. A char develops over the burned wood which acts as an insulating layer thus preventing the excessive temperature from being conducted to its core. However, the inner experiences a loss in strength, stiffness attributed to moisture loss through evaporation.

Char refers to charcoal as a layer that develops over a burning timber surface. This layer as stated earlier insulates the inner core of timber. Thus it burns slowly since the temperature of the core remains low. Char makes timber remain intact and able to carry the load of the structure in the event of a fire. (Malhotra, 1967)

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