Principles of means of escape Flashcards
Define means of escape
the routes of travel by which an occupant can make good their escape from fire to a place of total safety
The objectives of a MOE are to reach a place of safety and gather at a recognised assembly point.
How are these objectives facilitated ?
prompt fire detection fire action wall signs fire resisting separation directional signage direct escape routes more than one escape route where poss exits wide enough employee fire safety training
What differentiates routes in and out from escape routes
Escape routes are purpose built or modified for escape
Define protected route
An escape route that has adequate fire resisting construction from the remainder of the building along its route
Define unprotected route
A route that is not protected with fire resisting construction
What are the 3 stages of escape
- From a point in a room to the exit from that room
- From the exit from that room to the access into a stairway or if at ground floor the final exit
- From the access to the stairway to the final exit
Travel speed depend on ….
age, abilitity,
Travel distance definition is …
the actual distance covered between any point and the nearest
a) final exit
b) door to a stairway which is a protected route
c) door used for in a compartment wall
In an office building what is the aggregate travel distance, that is the traversing of all stages of escape ?
45m where there is an escape in more than one direction
18m escape in only one direction
Travel distance across a room no more than 12m if
a) only one exit from room
b) more than one exit but angle between the two is less than 45 degrees
In an shop building what is the aggregate travel distance, that is the traversing of all stages of escape ?
45m where there is an escape in more than one direction
18m escape in only one direction
No more than 12m of the total across a room
Travel distance across a room no more than 12m if
a) only one exit from room
b) more than one exit but angle between the two is less than 45 degrees
Define ultimate or total safety
The exterior of the affected building. Far enough away to be out of danger.
Define relative or reasonable safety
To the far side of a fire resisting door or wall where persons are protected from products of fire as they make their way to total safety.
State 7 general facts that relate to Fire routes and fire exits
- No combustible rubbish en route
- Corridor and under-stairs must be fire sterile; no cylinders, spare beds, electrically operated appliances
- No breaches in fire resisting walls
- Fire doors must not be wedged open
- fire exit doors open outwards
- If security requires a door to be locked it must be readily opened from inside. Panic bolt, break glass. Not needing a key
- No obstruction on either side of exit door. Weatherproof clear sign on outside
define direct travel distance
shortest distance to be travelled within a room or compartment achieved if room is empty of furniture
define indirect travel distance
Actual distance travelled within a room or compartment achieved if room if necessary to travel around furniture
State the measures that ensure that MOE can be safely and effectively used
Emergency lighting Fire exit signage Escape signage Fire door signage Emergency action signage Ventilation outlets Fire resisting construction
When calculating the time for escape in MOE , the following factors should be taken into
account
(i) Occupant characteristics;
(ii) Hazard assessment and probable fire growth rate;
(iii) The evacuation strategy of the building;
(iv) The probable time between ignition and alarm;
(v) Average movement speed of people along designated escape routes;
(vi) Probable total time of escape;
(vii) Probable total time where a person may be particularly at risk;
(viii) Psychological effects on escapees particularly those who may have sight
of fire or its effects;
(ix) Management input into evacuation process
When calculating escape times in MOE , OCCUPANT CHARACTERISTIC should identify the class of person who might be in the building and what they may be doing at the time of a fire, thus they should consider ? List them
(i) Occupants’ familiarity with the building.
(ii) Occupant commitment at the time of alarm.
(iii) Occupant commitment after alarm but before commencing escape,
e.g. helping others, fire-fighting etc.
(iv) Physical effort required to use escape routes e.g. stairs, upward escape
routes.
(v) Psychological effects on escapees particularly those who may have sight
of fire or its effects or who may have to wait before commencing their
escape.
(vi) The physical capabilities of the occupants, i.e. wheelchair users or others
with physical disabilities or compromised hearing and sight.
When calculating escape times in MOE what should you be aware of regarding HAZARD ASSESSMENT ?
A hazard assessment will have been carried out to determine the extent and
viability of the fire engineering installed. This should also identify where fires
are more probable or where rapid-fire growth rates might be expected. The
hazard assessment should also identify sources of heat, particularly those in
contact with combustible materials
When calculating escape times in MOE what should you be aware of regarding evacuation strategy ?
The evacuation strategy for the building will depend on its use, size and
height; the characteristics of the occupants and the degree of fire resisting
compartmentation, as agreed with the enforcing authorities.
regarding travel times calculations in MOE list the factors that determine the EVACUATION STRATEGY for the building ?
The evacuation strategy for the building will determine:
(i) The capacity of escape routes.
(ii) The configuration and type of the fire alarm system.
(iii) The configuration of the smoke control system.
(iv) The compartmentation of the building.
(v) The management requirements for the building.
(vi) Time between ignition and alarm.
Regarding the calculation of travel time in MOE what should you be aware of re the TIME BETWEEN IGNITION AND ALARM ?
The probable time between ignition and alarm will depend on the type of detection
employed. No building provided with engineered fire safety should rely only on
discovery of fire by people. All should be fitted with some form of reliable
automatic detection system programmed to keep unwanted calls to a minimum.
Detection should be at the point first involved in fire, thus ensuring that an
early alarm of fire is given. The signal from the first point of detection need not
activate the smoke control or other active systems but may prime those systems
where ‘double knock’ detection is used for activation
Regarding the calculation of travel times, list the factors the PROBABLE TIME OF ESCAPE depends on
Distance to travel
Speed
Physical capabilities
Number of people. The greater the number the slower
Flat surface/slope/stairs
Width
Queuing/routes merging/movement thru doors all slow
Regarding the calculation of travel times in MOE list the PEOPLE AT PARTICULAR RISK
People will be particularly at risk from fire, heat or smoke when:
(i) They are within the enclosure in which the fire first starts;
(ii) They are passing under smoke flowing towards or held in a smoke
reservoir;
(iii) They are at a higher level and thus closer to smoke held in a smoke
reservoir;
(iv) Their primary escape route is blocked causing them to travel a longer
distance to a suitable, alternative exit;
(v) They are required to carry out specific duties such as helping others or
carry out fire-fighting duties before they can themselves escape
Regarding the calculation of travel times in MOE what are the PHYSIOLOGICAL effects taken into account ? In particular those that have sight of the fire.
May have sight of fire so keep it to a min
Staff to help those with a disability
Stop people watching fire by repeated announcements
Exit routes well lit best is natural light
discuss refuge areas for disabled
refuges, i.e. places of relative safety
where people may wait for assistance in making their escape.
Refuges are relative safe waiting areas for short periods only
They are not areas
where people with disabilities should be left alone indefinitely until they are
rescued by the fire brigade, or until the fire is extinguished
The means of escape form those parts of the building protected by fire safety
engineering (protected area) should be within the design parameters of the
engineering and ensure that:
(i) Every part of the protected area has realistic alternative escape routes.
(ii) Any person entering a protected area should be able to find their way to
safety without the assistance of other persons.
(iii) No persons should be required to move in smoke for more than
15 seconds.
(iv) No person should be required to move under smoke for more than
3 minutes.
(v) The maximum time a person should be in the same part of the building as
the fire, other than in a protected route, should not exceed 7 minutes.
