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National Research Conseil national
I
Council Canada de recherches CanadaMANAGEMENT AND MOVEMENT OF
BUILDING OCCUPANTS IN EMERGENCIES
by J.L. ,../ Pauls
Reprinted, with permission, from Proceedings of the Second Conference on Designing to Survive Severe Hazards,
ZIT Research Institute, Chicago, 1 3 November 1977, p. 103
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BUltDf NG RESEARCH-
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DBR Paper No. 788
Division of Building Research
Price 50 cents OTTAWA
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PREFACE
The following i s a r e p r i n t of a paper t h a t f i r s t appeared i n proceedings of t h e Second Conference on Designing t o Survive Severe Hazards t h a t was held i n Chicago i n November 1977 a t t h e IIT Research I n s t i t u t e . Minor e d i t o r i a l r e v i s i o n s , including s i m p l i f i c a t i o n of Figure 1, have been made i n t h e r e p r i n t .
Excerpts from t h e s e c t i o n on evacuation of h i g h - r i s e o f f i c e buildings-were published s e p a r a t e l y i n May 1978 i n Canadian Architect
and i n B u i l d i n g s .
For d e t a i l e d information on evacuation and r e l a t e d t o p i c s
mentioned i n t h e paper r e a d e r s a r e r e f e r r e d t o a forthcoming book on behaviour and f i r e s , e d i t e d by David Canter and t o b e published by John Wiley and Sons.
Ottawa ~ u l y 1978
CONTENTS
ABSTRACT INTRODUCTION
MOVEMENT OF PEOPLE IN BUILDINGS Canadian S t u d i e s
Flow on e x i t s t a i r s Public assembly e g r e s s
Grandstand and a r e n a evacuation time EVACUATION OF HIGH-RISE OFFICE BUILDINGS
T o t a l Evacuation v i a S t a i r s : Example S e l e c t i v e Evacuation v i a S t a i r s : Example
Staged Evacuation v i a S t a i r s and Elevators: Example General Evacuation Time P r e d i c t i o n
SAFETY OF ELEVATOR AND STAIR USE
B e n e f i t s o f Normal Use of Exit S t a i r s EMERGENCY PROCEDURES IN OTHER OCCUPANCIES
Limited U t i l i t y o f t h e "Hydraulic Model" Health-care F a c i l i t i e s
EMERGENCY PLANS
Noteworthy Developments CONCLUD ING REMARKS
REFERENCES P age 105 105 107 107 107 109 109 111 11 1 114 115 118 118 120 121 121 122 12 2 123 124 124
MANAGEMENT AND MOVEMENT OF BUILDING OCCUPANTS IN EMERGENCIES J. L. Pauls
Research Officer Building Design and Use Division of Building Research National Research Council of Canada
Ottawa, Canada
ABSTRACT
Evacuation of endangered occupants of buildings may be necessary in a variety of intra-building and larger-scale emergencies. The effectiveness of building facilities and management procedures needed for evacuation has not been well understood until recently. To predict emergency performance more accurately and to assist building designers, managers, and safety authorities, research has begun on the movement of people in buildings and their behavior in emergencies.
In addition, examples are given of key findings and
predictive models developed in Canadian studies of evacuation of tall buildings and large public assembly buildings.
This paper suggests necessary areas of research and the need for change in a range of disaster mitigation measures,
including building design.
INTRODUCTION
A pre-Mao Chinese proverb recommends that "Of the thirty-six ways to escape danger, running away is bestM (1,Z). A better reaction to danger might be to remove the hazard. This is the position of many participating in conferences such as this one, and much technological effort is devoted to mitigating hazards. The reaction recommended by the Chinese proverb,
stressing escape, may be more conventional, but the conditions provoking the wish to escape may be real or they may be imagined threats. The place to which one tries to escape may actually be more hazardous and the act of escaping create other hazards.
Consider, for example, the experiences of someone in a well-engineered building during an cartl~quakc. There may bc a distinct fccling of
disconlfort, possibly cven loss of balance (3). l'here may be perceived and perhaps real danger of injury from falling furnishings and building fixtures. There may be views of terrible destruction outside as other structures
collapse. There may well be a strong feeling that the building may collapse, start burning, or that means of escape may be cut off. The individual may attempt immediate escape, unaware of attendant risks of elevator malfunction or of falls while rushing down stairs. If escape is successful the
environment outside the building may be far more hazardous than that left behind. Finally, the escape route will almost certainly be shared by others
who may not necessarily be travelling at the same speed or even in the samc direction (people may be re-entering the building for a variety of reasons).
This introduction suggests the complex nature of the subject.
Evacuation is both a design and a management problem. Controlling movement of people, facilitating safe, perhaps large-scale movement, and making
building occupants aware of emergency conditions and procedures are problems for all, including engineers, architects, building owners and managers, public-safety authorities, and researchers, plus those in the behavioral and social disciplines.
How well have these tasks been carried out? What basic knowledge and technology is available regarding evacuation in particular or building safety measures in general? To what extent can the performance of exits even be predicted? What evacuation or refuge procedures are appropriate and are they within the competence of typical occupants of buildings or those with management responsibilities?
Although evacuation has been a major concern of building codes for over half a century, the scientific and technological basis for exits is poorly " developed and often contains errors that have gone unrecognized. Recent research, much of it still not widely reported, has pointed out, for example, errors in current code rules governing the width of exit stairs and riser- tread geometry (4-7). The latter is often based on a simple design rule developed over three hundred years ago when body dimensions, stride length, and even the unit measurement were different from those used today
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important differences that are not sufficiently recognized. (Exit stair treads, for example, designed according to such rules, are about 2 inches too shallow, a deficiency with greater consequences for descent than for ascent.) Some general reviews as well as detailed reports are available (1-22).
Directed toward eventual application to a range of design and management problems, this recent research is developing a very different and more
realistic model of man than has been available to,date for preparing and implementing safety measures in buildings.
This paper attempts to provide basic information about various forms of evacuation in buildings and to model some using empirically-derived
relations. There will naturally be unanswered questions, including those about management roles, training, drills, cost-benefit, risk-acceptance. It reflects the author's main research interests in high-rise office buildings and large-scale public assembly buildings
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considering fire, crowd-generated mishaps, and individual accidents as well as several aspects of normal occupancy. Several other hazards leading to evacuation andmanagement problems are acknowledged, including earthquake, severe weather disturbances, bombings and bomb threats, and power failures.
One additional bias should be mentioned. This is the author's
preference for simple, "people-basedff solutions for many of the problems of evacuation and management. This occupant-reliant approach means that normal occupancy and emergency measures will be less affected by interruption of building systems such as power failure and breaches of security, and that those using buildings will be better able to cope in emergencies.
MOVEMENT OF PEOPLE IN BUILDINGS
Early studies bearing directly on movement aspects of evacuation were conducted first some sixty years ago, and frequently-mentioned, influential (to codes) reports from the United States and Britain are dated 1935 and 1952, respectively (23,24). Early work in other countries has been reported as well (25-31). In the English-speaking world, largely during the last decade, there have been a variety of studies (4,5,7,17-21,32-43). Many have dealt with capacity considerations for exit stairs, doors, and passageways; some have dealt with riser-tread details; a few have been particularly concerned with the difficulties disabled people experience in much of the built environment. ~esearchers aware of these studies note inadequacies in both quantity and quality. For designers of buildings, information sources are extremely limited, and to make matters worse the best book on design of pedestrian facilities appears to'be unknown bymost architects (20). Canadian Studies
The author's research began in the late 1960's at the Division of
Building Research of Canada's National Research Council. This was a time of 'growing concern about the problem of fire in high-rise buildings. Evacuation,
particularly the time required to clear a tall office building, was one of several major concerns. Others included internal communications, smoke movement, fire department access, fire suppression, and internal
communication (44-52).
Largely through the cooperation of Canada's Dominion Fire Commissioner small teams from the Division of Building Research carried out observations of forty evacuation drills in office buildings ranging from 8 to 29 storeys in height. Various evacuation procedures were used, some interpreted by the evacuees as actual emergencies (from both fire and bombings). Quantity and quality of a wide variety of data surpassed any reported to that time, but to date only preliminary analyses of these data have been reported
(4,5,53,54). Those that are available have dealt largely with density, speed, flow, time, and population characteristics of high-rise evacuations via stairs.
Flow on exit stairs. Major misconceptions have been discovered regarding the commonly used "unit exit width1' basis for determining stair width. More realistic flow capacities for exit stairs have been proposed. Figure 1 shows the linear proportional relation between mean flow in total evacuations and effective stair width (the measured stair width minus 12 in., or 300 mm). This is compared with the unit exit width concept (the step function plotted
in Figure I), which is assumed in drawing up building codes following National Fire Protection Association standards (52,55).
The unit exit width concept is based on an over-simplified model of how crowds move along passageways, ramps, and stairs. On the assumption that people will walk two abreast down a 44-in. (1120 mm) exit stair, code writers have long adopted this width as a standard minimum. Although the rationale has recently been found faulty, this width is retained in the simulations described below because it is a common stair width in existing buildings and is thus familiar.
EFFECTIVE STAIR WIDTH, inches (measured width minus 12 inches)
EFFECTIVE STAIR WIDTH, mm (measured width minus MO mm) 0 O
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Figure 1
E f f e c t i v e s t a i r width and mean flow i n t o t a l evacuations o f o f f i c e b u i l d i n g s 10 2 0 3 0 40 50 6 0 7 0 I I I 1 I I I 1 1
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FLOW INFLUENCED BY-
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POPULATION PER METRE OFEFFECTIVE STAIR WIDTH (PI
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1Study findings relating stair width and crowd use illustrate their potential application to building codes and design manuals. Other examples
of application are described in greater detail below (evacuation of tall office buildings), following a brief account of other studies of movement evolving from the drill observations.
Public assembly egress. Since 1972, in response to requests from designers and code officials for design information on crowd flow in multi-deck
grandstands, the Division of Building Research has extended its interest in evacuation to include the normal access and egress of crowds in theaters, arenas, grandstands, and transit facilities. Extensive studies were carried out during 1974 and 1975 in newly constructed grandstands in Calgary and Ottawa.
Most notable among ensuing requests for information was one early in 1976 by the organizers of the Olympic Games in Montreal for assistance in preparing for the large-scale crowd conditions in the newly-constructed Olympic Park. In addition to providing assistance to those responsible for spectator facilities and crowd control, a ten-person research team
(including two from the U.S.) documented varied aspects of spectator
behavior and facility performance in Olympic Park and in the public transit facilities serving the Park. An unprecedented research record on video tape and film is one of the tangible results of several thousand man-hours of work connected with the Montreal study.
Grandstand and arena evacuation time. As was the case with the earlier study of office building evacuation, the study of crowd movement in assembly
occupancies provided data and models for predicting building and management performance affecting crowd movement. Figure 2 shows the range of total evacuation times (either measured directly or calculated from observed flow data) for assembly-type buildings studied in Canada. One striking feature of this graph is the wide range of exit loadings and resulting clearing times for capacity crowds. A range of actual exit loadings and resulting clearing times for each building illustrates the observed effects of various imbalances in exit use that can occur, sometimes because of faulty
distribution of means of egress and sometimes because of crowd-control procedures.
The set of arrows along the horizontal scale (for population per unit exit width
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a standard code approach) marks Canadian code requirements for total exit width: 60 persons/unit for enclosed arenas, 100 persons/unit for elevated open grandstands, and 500 persons/unit for open grandstands giving immediate access to the ground. (Upcoming code revisions may state the rule for grandstands as 300 or 225 persons/unit; but this is a compromise rule that does not necessarily reflect recent research (56) .) Although not strictly applicable to the total clearing times plotted, two arrows on the vertical time scale mark recent British requirements for clearing time for any one area of a grandstand, nominally 2+ minutes for low-quality grand- stands susceptible to rapid fire spread and nominally 8 minutes for high- quality grandstands (57). Disparities between requirements and actual performance raise questions that may not be settled for some time.ACTUAL POPULATION PER UNIT EX I T WIDTH, persons per 22 inches measured width 35 30 25 20 15 10 5 0 0 Figure 2 1 I 1 1
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100 200 300 400 5 0 0 600 700 800 900Evacuation t i m e i n r e l a t i o n t o population using e x i t s i n some Canadian grandstands and arenas
Within t h e c o n t e x t o f t h e p r e s e n t conference, r e l e v a n t q u e s t i o n s i n c l u d e what kind o f hazards n e c e s s i t a t e r a p i d c l e a r i n g and what a r e t h e l i m i t i n g times f o r v a r i o u s s i z e s and forms o f b u i l d i n g s ? For example, a sudden change i n weather, b r i n g i n g high winds, r a i n o r h a i l , could prompt a r a p i d c l e a r i n g o f an o p e n - a i r grandstand (an example of t h i s , with
r e s u l t i n g crowd crush f a t a l t o some s p e c t a t o r s was r e p o r t e d r e c e n t l y i n Kingston, Jamaica). I n o t h e r words, t h e t y p e of grandstand assumed t o be l e s s s u s c e p t i b l e t o t h e hazards o f f i r e , r o o f c o l l a p s e , e t c . ( i . e . ,
t r a d i t i o n a l code concerns) may prove t o be one needing more e x i t f a c i l i t i e s and n o t fewer, a s i s u s u a l l y allowed i n b u i l d i n g codes.
Aside from hazards o f e a r t h , a i r , f i r e , and w a t e r , t h e r e a r e a l s o
crowd-generated hazards. A f t e r a t o t a l o f 125 d e a t h s and over 1000 i n j u r i e s i n e i g h t crowd-related i n c i d e n t s d u r i n g t h i s c e n t u r y i n B r i t a i n , r e g u l a t i o n s and s t a n d a r d s have been i n t r o d u c e d t h a t set o u t s t r i n g e n t requirements
applying t o new and e x i s t i n g s p o r t s grounds (57,58). Such measures a p p l i e d t o p h y s i c a l a s w e l l a s management f e a t u r e s should h e l p t o r e c t i f y s i t u a t i o n s t h a t v e r g e on t h e d e p l o r a b l e i n some s p o r t s grounds.
These comments a r e made t o broaden t h e d i s c u s s i o n o f movement of people i n b u i l d i n g s , a s u b j e c t t h a t technology h a s l a r g e l y n e g l e c t e d . A b i l i t y t o p r e d i c t performance and t o e v a l u a t e c o s t / b e n e f i t / r i s k i s inadequate d e s p i t e r e c e n t p r o g r e s s i n r e s e a r c h . P-hch of t h e i n f o r m a t i o n needed t o a s s e s s e x i t performance i s unpublished, s t i l l r e s i d i n g i n f i l e s . To t r a n s m i t some o f t h a t information t o o t h e r s t h e f o l l o w i n g s e c t i o n i n c l u d e s examples of e v a c u a t i o n systems i n h i g h - r i s e o f f i c e b u i l d i n g s .
EVACUATION OF HIGH-RISE OFFICE BUILDINGS
Thanks mainly t o technology (and t o some e x t e n t , good f o r t u n e ) t h e r i s k of d e a t h from a major f i r e i n North American h i g h - r i s e b u i l d i n g s remains low ( 4 6 ) . N e v e r t h e l e s s , t h e p o t e n t i a l f o r d i s a s t e r e x i s t s . Hazards o r p e r c e i v e d hazards o t h e r than f i r e may l e a d t o evacuation of p a r t o r a l l of a h i g h - r i s e b u i l d i n g . For example, r e c e n t l y i n New York some 100,000 people were c l e a r e d from o f f i c e b u i l d i n g s a s l a r g e a s t h o s e i n t h e World Trade Center owing t o bombings o r bomb t h r e a t s . These e v a c u a t i o n s were conducted by means of e l e v a t o r s , probably i n a manner n o t t o o d i f f e r e n t from normal end-of-day e g r e s s (59).
E l e v a t o r s may n o t be u s a b l e when d i s a s t e r t h r e a t e n s , depending on a
i v a r i e t y of f a c t o r s i n c l u d i n g t h e i r d e s i g n , t h e n a t u r e o f t h e hazard, and
I
o p e r a t i n g d e c i s i o n s . e x i t s t a i r u s e , b u t i n c l u d e t h e p o s s i b i l i t y o f e l e v a t o r u s e i n l a r g e The f o l l o w i n g modes o f evacuation a r e based l a r g e l y on b u i l d i n g s .T o t a l Evacuation v i a S t a i r s : Example
F i g u r e s 3 , 4, and 5 show i n g r a p h i c a l form t h r e e procedures t h a t might , be used i n e v a c u a t i n g some o r a l l occupants from a h i g h - r i s e o f f i c e b u i l d i n g o r o f moving endangered people t o a r e a s of r e f u g e . I n t h e s e c h a r t s t h e v e r t i c a l s c a l e i s t h e v e r t i c a l s p a t i a l dimension of a b u i l d i n g , with each
f l o o r i n d i c a t e d . The h o r i z o n t a l s c a l e i s t i m e , measured from t h e i n i t i a t i o n of t h e alarm. Each l i n e i s a movement t r a c e i n d i c a t i n g where ( i n h e i g h t ) a
15 E V A C U A T I O N OF L A S T P E R S O N F R O M STOREY DOWN E X I T S T A I R 10 > W a 0 C "l 5 C R O 0 5 10 T I M E , m l n u t e s Figure 3
Total evacuation v i a e x i t s t a i r s i n 15-storey building
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E V A C U A T I O N OF L A S T - P E R S O N FROM STOREY DOWN E X I T S T A I R - - E V A C U A T I O N - ORDER G I V E N - > W - E 0 C - "l - - - - - - GRO 1 1 1 I I I I 0 5 1 0 15 TIME. minutes Figure 4 S e l e c t i v e evacuation v i a s t a i r s i n 15-storey b u i l d i n gparticular evacuee is at any particular time. In presenting data from observed evacuations, such traces usually record, as well, the observerst movements down the stairs with the evacuees. In the present charts the traces represent the movement of the last individuals leaving each floor.
The slopes of the lines indicate speeds of movement (3.6 floors per minute in Figure 3). The vertical separations between the lines indicate the relative amounts of space available to the occupants of one floor as they queue or move through the exits (in Figure 3, 2.5 sq ft (0.23 m2) per
evacuee queuing on the stairs and nearly twice as much walking down the stairs). The horizontal separations of lines indicate flow (in Figure 3,
60 persons per minute down each standard 44-in. (1120 mm) exit stair). Assumed speeds, densities, and flows are based on the observed performance of nearly 15,000 persons in nearly thirty total evacuation drills (4,s). The chosen values reflect an optimistic judgement that would be justified with experienced occupants and high standards of exit facilities. Thus the predicted evacuation times should be considered lower limits. Upper limits could be 2 minutes longer (even more for evacuations held in cold weather when there may be delays in entering stairs and lower flows of descent because evacuees may retrieve and wear or carry bulkier outdoor clothing.
Figure 3 displays movement traces characteristic of total evacuation, the conventional procedure where all occupants attempt to leave the building at the same time. Illustrated is the total evacuation of a 15-storey office building with two 44-in. (1120 mrn) wide exit stairs. Each floor is assumed to contain 70 able-bodied persons when evacuation begins. This is a realis- tic expectation of the average number of occupants actually present for each 15,000 sq ft (1400 m2) of gross rentable area per storey (4,5,60)
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assuming about 200 sq ft (19 m2) per actual occupant, in contrast with the 100 sq ft figure usually suggested in building codes. Applying somewhat optimistic evacuation-initiation and flow assumptions it can be predicted that such a building will be cleared of 980 occupants by means of stairs in just under 9 minutes.A brief comment on the term "able-bodied persons" may be appropriate. If the office workers observed in Canadian office buildings are representa- tive, as they appear to be, it is estimated that about 3 per cent of those usually present in high-rise office buildings cannot or should not attempt to evacuate by means of crowded exit stairs. In addition to those with obvious physical disabilities, this minority includes people with heart disorders and convalescents from recent illness, surgery or accident. Movement of these individuals to a place of safety will require additional planning and assistance from other occupants. It could include their
desccnding stairs behind able-bodied persons (who would already be moving at
a fairly slow speed characteristic of high-density crowds); being carried; or having elevators operated by authorized personnel to take them to safety.
A building such as that depicted in Figure 3 could be expected to have approximately 25 persons who might descend the stairs behind the main crowd of evacuees and approximately five best evacuated by elevator, assuming one is available. Evacuation of the disabled is thus, in part, a problem of management, of first determining the abilities of persons in the building, planning for assistance and evacuation facilities, and finally making sure the appropriate procedures are carried out.
Although it has the virtue of simplicity, total evacuation has drawbacks. When everyone is evacuated indiscriminately, it entails considerable movement, totalling over 7,000 person-storeys in Figure 3. (A person-storey is a unit of measurement derived from multiplying the number of persons by the distance each moves on the stairs.) Evacuation times increase in a nearly-proportional relation with the number of people evacuated (Figure 6) and can quickly become too long. People on floors where danger may be greatest do not necessarily receive priority in using exit stairs. Priority in uncontrolled total evacuations was observed (in the drills studied) to go generally to those entering the exits rather than to those queuing in them.
Selective Evacuation via Stairs: Example -
In selective or phased evacuations (Figure 4 ) , exit stairs are generally reserved during initial stages of evacuation for people on the fire floor and adjacent floors (assuming for the moment that fire is the hazard). Ten
phased-evacuation drills observed in Ottawa included sequential evacuation of occupants on some or all other floors, starting from the top. Upper floors can become untenable before most of the lower floors because of smoke movement due to chimney effect during cold weather (48-52). In buildings having zoned air-handling systems for groups of floors the priority with which floors are to be cleared could differ.
Figure 4 shows movement traces characteristic of selective or phased partial evacuation in which both the need to evacuate and the priority of such evacuations are determined, partly in advance, by trained building staff and by fire department personnel. They use communications systems to
determine emergency conditions, make decisions on appropriate action, and give directions regarding evacuation. (It should be noted that the sharing of responsibilities and actions may differ from one city to another, particularly if people are directed not to evacuate but rather to stay in the building.)
The 15-storey building, similar in exit features and population to that depicted in Figure 3, is assumed to have a fire on the tenth floor. Only the top half of the building is to be evacuated (in a special sequence) and people from upper floors may seek refuge on certain lower floors or may evacuate to the exterior at ground level. In any event, because of the time required to control evacuation and because of reduced density and flow conditions, nearly 9 minutes are required merely to move half the building occupants to below the fire area (5). This would entail some 2,600 person-storeys of stair use by 490 persons.
From simulations (utilizing realistic input data) it can be seen that 15 storeys occupied by 1,000 persons could be taken as perhaps representing a limiting condition below which total evacuation might be used in preference to controlled selective evacuation, assuming that people facing the most immediate threat somehow get into the exits first. It must be stressed that selective evacuation entails functioning equipment for communications and personnel proficient in its operation
-
conditions that are not easily achieved (5,54,61).Staeed Evacuation v i a S t a i r s and E l e v a t o r s : E x a m ~ l e
A l i m i t i n g c o n d i t i o n f o r evacuation may be reached a s h e i g h t and p o p u l a t i o n i n c r e a s e . Evacuation procedures e n t a i l i n g l i m i t e d movement by s t a i r s t o r e f u g e o r muster f l o o r s , followed perhaps by f u r t h e r complete evacuation by p r o t e c t e d e l e v a t o r s , may then be worth c o n s i d e r i n g . One such procedure i s d e p i c t e d i n Figure 5. I t was p a r t l y i n s p i r e d b y f i r s t - h a n d knowledge o f t h e e f f i c i e n c y of t h e r e l a t i v e l y simple t o t a l evacuation movement by s t a i r s . I t i s a f u r t h e r development of t h e i d e a , promoted
r e c e n t l y , t h a t e l e v a t o r s should be p u t t o g r e a t e r u s e f o r evacuation (62-64). Perhaps most important, it i s an attempt t o s o l v e , o r a t l e a s t t o avoid, problems experienced a l r e a d y w i t h e l e v a t o r s exposed t o f i r e , earthquakes, o r even sabotage (52, 65-68). (Because of such problems, codes do n o t i n c l u d e e l e v a t o r s a s e x i t s (52,55,56)
.
)The h y p o t h e t i c a l b u i l d i n g modelled i n Figure 5 h a s 40 o f f i c e f l o o r s , two 44-in. (1120 mm) wide e x i t s t a i r s , and f o u r groups of f o u r e l e v a t o r s s e r v i n g t h e ground f l o o r and f l o o r s 2 t o 12, 12 t o 22, 22 t o 32, 32 t o 41. E l e v a t o r c a r s a r e 3,500-lb (1600 kg) s i z e ( l a r g e enough t q c a r r y s t a n d a r d ' s t r e t c h e r s ) , with speeds ranging from 800 t o 1200 f t / m i n (244 t o 366 m/min), t h o s e w i t h h i g h e r speeds s e r v i n g upper zones. Assumed b u i l d i n g p o p u l a t i o n s served by t h e f o u r groups o f e l e v a t o r s a r e ( s t a r t i n g w i t h f l o o r s 2 t o 11) 1200, 1200, 1100, and 1000 persons o r 4500 persons i n t o t a l . Such a b u i l d i n g might have 20,000 t o 25,000 s q f t (1860 t o 2326 m2) o f g r o s s r e n t a b l e a r e a p e r o f f i c e f l o o r .
The b u i l d i n g would have no s p e c i a l f i r e p r o t e c t i o n o r communication systems i n s t a l l e d o t h e r than on t h e e l e v a t o r t r a n s f e r f l o o r s , 12, 22, and 32, which were o r i g i n a l l y c o n s t r u c t e d o r r e t r o f i t t e d w i t h f i r e s u p p r e s s i o n , smoke c o n t r o l , compartmentation, and communication systems p e r m i t t i n g them t o be used a s r e f u g e f l o o r s i n t h e e v e n t o f f i r e . The e l e v a t o r systems and s h a f t s have no unusual s a f e t y f e a t u r e s ; t h e y can be r e a d i l y switched t o independent o r emergency s e r v i c e . (Measures p r o v i d i n g g r e a t e r s a f e t y i n e l e v a t o r s used by f i r e department p e r s o n n e l and p o s s i b l y f o r evacuation a r e d e s c r i b e d more completely i n t h e l i t e r a t u r e (49,52,56,65).)
Before d e s c r i b i n g t h e emergency c o n d i t i o n s under which s t a i r s and e l e v a t o r s a r e used s e q u e n t i a l l y t o evacuate such a b u i l d i n g t o t a l l y , b r i e f mention should be made o f one a l t e r n a t i v e , t h a t of u n c o n t r o l l e d t o t a l
evacuation v i a e x i t s t a i r s ( s i m i l a r i n form t o t h a t d e s c r i b e d f o r a s m a l l e r b u i l d i n g i n Figure 3 ) . Assuming t h a t 4500 able-bodied occupants a c t u a l l y s t a r t t o l e a v e when n o t i f i c a t i o n i s given, t h e t o t a l evacuation v i a 44-in. (1120 mm) s t a i r s would t a k e almost 40 minutes. The movement t r a c e f o r t h e l a s t person from t h e f o r t y - f i r s t f l o o r i s i n d i c a t e d by t h e dashed l i n e i n Figure 5. Note t h a t t h i s e n t a i l s a w a i t of n e a r l y 27 minutes, e i t h e r on t h e o f f i c e f l o o r o r i n t h e e x i t s t a i r b e f o r e t h e l a s t evacuee s t a r t s t o descend. With a l l 4500 i n t h e e x i t s simultaneously, t h e r e would o n l y be about
1 . 8 s q f t (0.17 m2) o f s t a i r a r e a , o r h a l f o f one t r e a d , p e r evacuee.
The evacuation procedure d e t a i l e d i n Figure 5 e n t a i l s u n c o n t r o l l e d evacua- t i o n down t h e s t a i r s t o r e f u g e o r muster f l o o r s ( t h e e l e v a t o r t r a n s f e r f l o o r s ) , a p r o c e s s i n i t i a t e d by t h e simple sounding of a g e n e r a l alarm c l e a r l y under- s t o o d by t h e occupants a s a d i r e c t i v e t o evacuate. (This assumption r a i s e s
G R D
0 5 10 15 2 0
25
3 0 35 4 0TIME, m i n u t e s
1
Figure 5
q u e s t i o n s i n t h e l i g h t o f r e p o r t e d , b u t n o t well documented, i g n o r i n g of f i r e alarms, p a r t i c u l a r l y i n occupancies where f a l s e alarms a r e f r e q u e n t and evacuation d r i l l s n o t h e l d .
S i m i l a r i t i e s between h i g h - r i s e b u i l d i n g s and l a r g e s h i p s a t s e a have been made p r e v i o u s l y i n p o i n t i n g o u t t h a t b o t h must cope w i t h emergencies by means o f s e l f - c o n t a i n e d r e s o u r c e s . I t i s u s e f u l t o extend t h i s analogy t o n o t e t h a t , j u s t a s i n s h i p s , evacuation i n t h i s h i g h - r i s e b u i l d i n g i s a two-stage p r o c e s s . On a s h i p , passengers and crew a r e mustered on l i f e - b o a t decks where optimum u s e i s made o f management r e s o u r c e s while d e c i s i o n s a r e made r e g a r d i n g f u r t h e r a c t i o n ; f i n a l l y , and i f n e c e s s a r y , l i f e b o a t s a r e used a s e f f e c t i v e l y a s p o s s i b l e . The procedure i n a b u i l d i n g i s s i m i l a r , w i t h muster f l o o r s and e l e v a t o r s .
Each person would have up t o 20 s q f t (1.9 m2) of f l o o r a r e a on t h e s e r e f u g e f l o o r s , which can be reached by a l l occupants (except t h e 1200 from f l o o r s 2 t o 11 proceeding d i r e c t l y by s t a i r t o t h e ground f l o o r ) w i t h i n a 10-minute p e r i o d . During t h i s time and f o r 5 minutes t h e r e a f t e r , a l l
e l e v a t o r s would be r e t u r n e d t o t h e ground f l o o r and switched t o emergency o r independent s e r v i c e , t h e system would be checked, and ( i f f u n c t i o n i n g
a d e q u a t e l y and approved by t h e commanding f i r e o f f i c e r , i f t h e emergency were f i r e , f o r example) p u t t o u s e t r a n s p o r t i n g d i s a b l e d persons from t h e o f f i c e f l o o r s t o t h e ground f l o o r . A p e r i o d o f 15 minutes h a s been assumed f o r completion o f t h i s c r i t i c a l phase e n t a i l i n g " e l e v a t o r c a p t u r e , " checking, a p p r o v a l , and d e d i c a t e d u s e f o r d i s a b l e d .
I f no f u r t h e r evacuation o f t h o s e on r e f u g e f l o o r s were warranted and a r e t u r n t o normal occupancy d e s i r a b l e , t h e occupants' could r e a d i l y move back t o t h e i r f l o o r s o f o r i g i n by e l e v a t o r s and s t a i r s w i t h i n a n o t h e r
15 minutes. On t h e o t h e r hand, i f t h e hazard r e q u i r e d complete e v a c u a t i o n , t h e e l e v a t o r s could be used i n t h e i r most e f f i c i e n t mode of o p e r a t i o n t o t r a n s p o r t organized groups from r e f u g e f l o o r s t o t h e ground f l o o r . Only t h e o p e r a t i o n of t h e t o p group of e l e v a t o r s i s shown i n Figure 5. Fourteen t r i p s p e r e l e v a t o r would be needed d u r i n g a 20-minute p e r i o d t o c l e a r 1000 people from t h e i r temporary r e f u g e on t h e t h i r t y - s e c o n d f l o o r . The o t h e r two r e f u g e f l o o r s could be c l e a r e d i n a somewhat s h o r t e r time.
( E l e v a t o r performance d a t a f o r t h i s s i m u l a t i o n a r e a s given by Strakosch (69) .)
I f s t a i r s a r e t o be used c o n c u r r e n t l y w i t h e l e v a t o r s t o move people from t h e t h r e e r e f u g e f l o o r s t o ground l e v e l , t h i s s t a g e of t h e evacuation could be shortened from 20 t o about 14 minutes, assuming t h a t o n e - t h i r d of t h e people on each of t h e t h r e e r e f u g e f l o o r s u s e t h e s t a i r s . The t o t a l time f o r t h e s t a g e d evacuation could t h u s be under 30 minutes, o f which 5 minutes would be marked by no mass movement.
T h i s extended d e s c r i p t i o n of t h e procedure i s intended t o i l l u s t r a t e problems a s w e l l a s p o s s i b i l i t i e s . S e v e r a l f a v o r a b l e f e a t u r e s have a l r e a d y been mentioned. A l l e l e v a t o r t r i p s from t h e r e f u g e f l o o r s a r e made through s e c t i o n s of t h e hoistways t h a t do n o t have f l o o r s t o p s and t h e r e f o r e lack doors, t h e r e b y p r o v i d i n g a measure of p r o t e c t i o n a g a i n s t f i r e . T h i s f e a t u r e could be d i s c a r d e d i f f o r some r e a s o n one o f t h e groups of e l e v a t o r s proved t o be i n o p e r a b l e o r was needed f o r f i r e department o p e r a t i o n s . I n t h i s c a s e
all four groups of elevators would be used, including those serving lower floors (the earlier procedure leaves the lowest group of elevators unused); evacuees would board the elevators usually serving floors below the transfer
(refuge) floor rather than those serving floors above. Another feature of the evacuation depicted in Figure 5 is the emphasis that can be placed on quality rather than quantity of communication channels and supervisory personnel, there being only three refuge floors to deal with.
An additional feature should be mentioned, for it mitigates a common difficulty. The sudden discharge of 4500 building occupants would not take place until some 15 minutes into the emergency, permitting traffic control procedures to be set up at street level. A very real problem in evacuations
(or in any normal end-of-the-day egress) is the provision and management of adequate pedestrian facilities for large groups of people at street level
(20,21,70,71).
Finally, it must be stressed that no general recommendation for use of elevators in emergencies is implied. In view of the problems that have occurred with elevators in building fires their use requires careful consideration and approval by authorities. This hypothetical examvle is given only to illustrate some of the problems and some of the potential solutions.
General Evacuation Time Prediction
A more comprehensive graph showing evacuation time as a function of actual evacuation population is given in Figure 6. Here is plotted the generally-useful relation between time of evacuation by stairs and actual evacuation population in office buildings. Also plotted are time require- ments for completion of both the first and second stages of the stair/ elevator procedure depicted in Figure 5. This permits prediction for a range of population and building heights. The effect of one procedural change is shown, entailing mass evacuation by elevator from the refuge floors after 5 rather than 15 minutes. Although not recommended such a procedure could be attempted.
Similarly, a relatively uncontrolled procedure using only elevators operating in normal down-peak, automatic mode is problematic. In view of the number of things that can go wrong with such elevator use in emergencies
it is not possible here to predict related evacuation times (assuming I I
evacuation can be successfully completed). At best the evacuation times might be similar to those predicted by line C2 in Figure 6, at worst in
excess of those predicted by line C1.
1
1
SAFETY OF ELEVATOR AND STAIR USE 1
One final comment, albeit a tentative one, should be made regarding the I relative merits of elevator use and stair use. This pertains to risk. One I
source, using elevator company statistics, notes that fewer than 1000 accidents were reported in 1973 for an estimated use of 350,000 elevators totalling I 40 billion rides in the U.S. (72). By comparison, annual stair use roughly
estimated to total some 2,000 billion person-flights in the U.S. results in accidents requiring hospital treatment for 465,000 persons (for a rate of
A, E V A C U A T I O N T O G R O U N D L E V E L B Y W A Y O F T W O 4 4 - i n . W I D E E X l T S T A I R S B1, E V A C U A T I O N O F L O W E S T 1 0 F L O O R S T O G R O U N D L E V E L B Y W A Y O F T W O 4 4 - i n . W l D E E X l T S T A I R S
-
B 2 , R E F U G E E V E R Y 1 0 F L O O R S , R E A C H E D B Y W A Y O F T W O 4 4 - i n . W l D E E X l T S T A I R S C, E V A C U A T I O N T O G R O U N D L E V E L B Y E X P R E S S E L E V A T O R S ( I* F R O M R E F U G E F L O O R S : 1, B E G I N N I N G A T 1 5 m i n u t e s 2, B E G I N N I N G A T 5 m i n u t e s ( I*, 3 5 0 0 P O U N D E L E V A T O R S W l T H S P E E D S 8 0 0 T O 1 2 0 0 f p m , I N C R E A S I N G W l T H H E I G H T [ 1 9 P E R S O N S I C A R ] O F O F F I C E S A C T U A L T O T A L P O P U L A T I O N Figure 6Times needed f o r v a r i o u s r e f u g e and evacuation procedures u s i n g s t a i r s and e l e v a t o r s i n t a l l o f f i c e b u i l d i n g s
1/4,200,000) (19). These f i g u r e s a r c f o r normal use and, f o r s t a i r s , covcr a c o n s i d e r a b l e range i n q u a l i t y o f f a c i l i t i e s .
With r e g a r d t o p o s s i b l e r i s k of i n j u r y due t o f a l l s experienced i n evacuation s i t u a t i o n s , p r e l i m i n a r y Canadian s t u d i e s of o f f i c e b u i l d i n g evacuation and normal crowd e g r e s s i n p u b l i c assembly occupancies suggest t h a t one i n j u r y r e q u i r i n g h o s p i t a l t r e a t m e n t may occur f o r s t a i r u s e
(during evacuation) ranging from one m i l l i o n t o t e n m i l l i o n p e r s o n - f l i g h t s . Total-evacuation d r i l l s s t u d i e d i n Ottawa e n t a i l e d about 200,000 o r more p e r s o n - f l i g h t s and no i n j u r i e s were r e p o r t e d .
Such f i g u r e s a r e p r e l i m i n a r y and u n o f f i c i a l . What can be r e p o r t e d , based on f i r s t - h a n d o b s e r v a t i o n , i s t h a t dense crowd movement ( i n h e r e n t l y slow) may p r e s e n t lower r i s k o f f a l l i n g t h a n i s t h e c a s e f o r i n d i v i d u a l s moving a l o n e o r i n small groups.
Based on t h e s t u d y d i r e c t e d by Canada's D i v i s i o n of Building Research a t t h e 1976 Olympic Games i n Montreal, and from a r e a d i n g o f r e c e n t r e p o r t s on s t a i r d e s i g n and s a f e t y , t h e r e i s c o n s i d e r a b l e evidence t h a t f a u l t y s t a i r d e s i g n , c o n s t r u c t i o n , and maintenance (sometimes s t i l l i n compliance w i t h e x i s t i n g b u i l d i n g codes) i s a major f a c t o r i n s t a i r a c c i d e n t s ( 7 , 1 9 , 2 1 , 2 2 ) . A t one of t h e stadiums r e c e n t l y s t u d i e d i n Canada, a s e r i o u s d e f e c t of r i s e r - t r e a d dimensional i r r e g u l a r i t y n o t e d on one p a r t i c u l a r s t a i r was l i n k e d t o an i n c i d e n t r a t e some f i f t y times l a r g e r t h a n t h e i n c i d e n t r a t e observed on t h e same s t a i r a f t e r dimensional i r r e g u l a r i t i e s were c o r r e c t e d .
(The r a t e o f t h e s i m p l e s t observable i n c i d e n t o r n o t i c e a b l e m i s s t e p i s
l i n k e d t o t h e r a t e of i n j u r y e s t i m a t e d f o r s t a i r u s e , t h e r e being about a thousand n o t i c e a b l e m i s s t e p s f o r each i n j u r y r e q u i r i n g h o s p i t a l t r e a t m e n t (19) .)
The s u b j e c t of s t a i r s a f e t y , p a r t i c u l a r l y i n evacuation s i t u a t i o n s ,
i s one r e q u i r i n g f u r t h e r r e s e a r c h , both s t a t i s t i c a l and e t i o l o g i c a l .
T h i s being t h e c a s e , it i s impossible t o s u g g e s t i n any comprehensive manner what d e s i g n and r e t r o f i t t i n g requirements a r e j u s t i f i e d . Research t o d a t e h a s , however, provided an improved t e c h n i c a l b a s i s f o r s a f e t y r e g u l a t i o n s and d e s i g n r u l e s f o r s t a i r s (5,6,7,19,21,22,34,35,40).
B e n e f i t s of Normal Use o f E x i t S t a i r s
- Perhaps a problem o f p o l i c y and p r a c t i c e i s t h e d e l i b e r a t e de-emphasis
of normal u s e of e x i t f a c i l i t i e s a r i s i n g o u t of a concern f o r s e c u r i t y . In h i g h - r i s e b u i l d i n g s occupants d i s s u a d e d , e i t h e r s u b t l y o r openly, from u s i n g e x i t s t a i r s f o r some o f t h e i r normal c i r c u l a t i o n may become t o o
dependent on e l e v a t o r s , even t o t h e p o i n t of n o t knowing where t h e e x i t I s t a i r s a r e l o c a t e d and what t h e experience of u s i n g them i s l i k e . T h i s i s
u n f o r t u n a t e i n view o f t h e overwhelming evidence t h a t lack o f f a m i l i a r i t y with more t h a n one means of a c c e s s and e g r e s s h a s l e d t o unnecessary d e a t h s i n b u i l d i n g f i r e s . I t f u r t h e r complicates t h e management of e v a c u a t i o n s where s t a i r s must be used.
Although t h e s e a r e reason enough f o r r e v e r s i n g t h e t r e n d towards
c u t t i n g o f f a c c e s s t o e x i t s t a i r s f o r o r d i n a r y u s e , t h e r e a r e o t h e r b e n e f i t s t o be gained from normal u s e of e x i t s t a i r s . During power f a i l u r e s ,
elevators are totally or severely disabled and such stairs must be used. Again, familiarity would be an advantage. Greater normal use of exit stairs also reduces the demand on elevators for a variety of intra-building and inter-building trips. Although this may be a minor factor in some buildings, depending on tenancy, in others it could be exploited and could result in , savings in capital and operating expenses.
In one 21-storey office building studied recently in Ottawa each
occupant used the building's exit stairs for an average of three trips each day. Although average stair-trip lengths were shorter than average
elevator-trip lengths the estimated cost of stair use compared with cost of elevator use is worth considering. The cost of stairs is estimated to be less than one cent per use; that of elevators can be at least three times as much per trip, assuming six trips per day by elevator. These costs do not include cost of employee time for the trip. In addition to documenting use of stairs and elevators by an accurately-determined building population, this study utilized questionnaires to gauge office workers1 attitudes and reasons for stair or elevator use. This pointed out further justification for choosing stairs rather than elevators: less delay in getting from one place to another, and the prospect of healthful benefits from the mild physical exertion in using stairs (40)
.
To make this digression directly relevant to the subjec't of designing for emergency, the normal use of exit facilities should encourage more conscientious design and maintenance. Such improvements can only increase their effectiveness when their use is crucial to life-safety.
EblERGENCY PROCEDURES IN OTHER OCCUPANCIES
The foregoing description of evacuation considerations has been based on studies largely carried out in office and public assembly occupancies. The examples have been for office building evacuation and refuge procedures, but these are not the only, nor even the most pressing, concerns in the field of life safety from fire and other hazards. They are merely the ones that have been accessible to the author over the last decade and lend
themselves to relatively simple modelling. Limited Utility of the "Hydraulic Model"
Models such as that illustrated in Figure 3 and those that have long been assumed in drafting code requirements for means of egress have been described by the term "Hydraulic Model1' (19). In simple form the model treats a building like a reservoir of water (or ball-bearings). Exit routes are pipes with valves controlling drainage through the bottom. Performance, or rate of discharge, is related to readily-measured orifice dimensions.
Treated with caution, such a model has much utility. Proof of this is the resulting ability to predict with reasonable accuracy the time required for total evacuation of able-bodied persons from office buildings, sports buildings and schools. The danger lies in inappropriate gcneralization to
include other occupancies or even to more realistic, complex situations in the occupancies studied. For example, the importance of realistic
out. Failure to model this initial stage of evacuation properly has bcen partly responsible for overly-optimistic predictions of total evacuation times reported in the literature.
Widespread acceptance of the model in code requirements has perhaps drawn attention away from what happens at the "threat end" of the
evacuation process as opposed to the "safe end" (the size of the exit orifices) (19). It is at the threat end that so many of the unsolved
problems of life safety lie, for it is here that the vast majority of people die, for example, in fires.
Fortunately, in recent years research attention has begun to concentrate more fully on the problems occurring at the threat end and mitigating measures are beginning to appear: obvious ones are detection units and systems,
emergency communications systems, and fire suppression systems. No less significant, but in fortunately not subject to the same commercial incentives for research and development, is the concern for normal occupancy activities, management capabilities, and emergency procedures in buildings.
Health-care Facilities
Concern about emergency procedures in health-care facilities is at the heart of recent major research programs in the U.S., Britain, and Canada. With funding largely from national health agencies this research is being conducted within national institutes for building and fire research as well as under contract to university and private research personnel (19, 73-77).
Empirical and theoretical studies within these research programs have included findings similar to that reported above regarding long delays in evacuation-initiation when controlled procedures are attempted in office evacuations. For example, the staff organization in a hospital requires time to asses the situation prior to a mass movement of patients. Even within the.confines of a hospital ward threatened by fire, considerable time may be required simply for staff to shift furniture and prepare patients to be moved. These tasks alone add significantly to-the time required for evacuation. In a recent British test evacuation of one ward of less than thirty patients, complete removal to the ground level two floors below took 23 to 30 minutes, of which as much as a third was taken up by preparation for movement (74). There is a great need for the development of workable, efficient emergency methods of moving patients and for making these methods familiar to staff in health-care facilities (78).
In addition to the normally recognized institutions such as hospitals and nursing homes there are also new occupancics such as large residential buildings occupied mainly by self-reliant elderly people. Aside from
physiological disabilities that may affect perception and decision-making, there are special social and psychological characteristics that must be taken into account in planning facilities and procedures, perhaps entailing evacuation, for use in emergency situations (79).
EMERGENCY PLANS
Responsibility is divided for making best use of emergency facilities and human resources among various authorities, emergency services, building
management personnel, and ultimately everyone using buildings. It is not surprising, therefore, that there is confusion regarding fire safety measures. This does not mean that people cannot cope with emergencies.
Contrary to what is often believed, they generally cope well with unexpected, life-threatening situations, whether fire or natural disaster. Panic is rare (1,2,11,12,18,80). There is, however, some evidence and a growing body of scientific documentation in support of the effectiveness of safety
education, drills, and other activities affecting awareness, as well as adequately prepared management resources. In short, coping ability is surprisingly good, but it can be made better.
Noteworthv Develo~ments
A few examples of fire safety may illustrate the state of the art. In view of the Canadian context in which this paper is prepared, mention should be made oF'the requirements, standards, and training programs of the Dominion Fire Commissioner. These apply to buildings occupied by Canadian federal employees (61,81). Significant attention to fire safety is also evident in the efforts of the U.S. General Services Administration, particularly during the early 19701s (45, 82-84). There has also been activity at state and local levels where authority often lies for the safety of the general public. The high-rise fire-safety requirements of New York Cityls Local Law 5, 1973, have drawn wide interest and some local opposition, the latter recently leading to a court ruling that some
requirements (e.g., for retrofitting) are void and unenforceable (85,86). In the context of this paper it is worth noting that the New York City requirements for fire safety planning, including occupant education and building-management fire-safety responsibility, were upheld by the Court.
Not necessarily in response to legal requirements, associations and individual building administrations also are becoming increasingly aware of fire safety. In many cases, however, the recommendations for fire-safety planning appear to be given only lip-service, particularly outside of institutional or government occupancies (87). Knowledgeable individuals and associations such as the National Fire Protection Association and the National Safety Council have prepared guidelines and standards to assist managers and others in setting up emergency plans (52,55, 88-90).
In making available such action-oriented literature there are dangers, on the one hand, of being superficial and not providing sufficient detailed guidance, on the other, of going into excessive detail, thus limiting
application to a variety of building and occupancy conditions. In either case, much of the literature is partly based on misconceptions about human behavior of the type mentioned above with reference to panic or is
excessively modelled on military-type organizations and procedures.
A quotation from an article titled "Disasters bring out the best in people," (although taken somewhat out of context) gives two generally-useful
suggestions (80) :
1. Don't overplan. "You can't think through cvery contingency," says Quarantelli, "and a massive disaster plan is no plan at all if no one knows what it says. The plan must state
2 . Plans should be tried out. The plan must be practiced to uncover minor but crucial flaws, says Dynes.
"...
such as stretchers in a hospital not fitting through the emergency exit stairway." Exercising the plan is more important than drawing it up, he emphasizes. Unless it is practicedpeople will do things in their own normal way.
To these recommendations might be added two others based on observations of office building evacuation drills. In holding drills distinguish between the goal of training and education and the goal of evaluation. For example, to make high-rise building occupants more aware of what happens and why, take the time in the course of pre-announced drills to communicate, over public address systems if available, general explanations in addition to specific directives. Other types of drills, given without advance notice (and only after sufficient information-giving drills), can be held to
evaluate occupant preparedness, determine evacuation times, etc. The second suggestion is that systematic observation, evaluation, and reporting should be done on the drills that are held. In such studies there is much to be learned that may alter the current conception of and approach to building safety measures. This will provide a better idea of how well safety dollars are being spent, and will improve awareness of the relative effectiveness of building design, equipment systems, and operating or management measures. CONCLUDING REMARKS
In the absence of measures for mitigating the physical impact of severe hazards, and perhaps even with such measures, evacuation may still be needed to preserve life safety. Properly understood, it can serve us well;
misunderstood, it may serve us badly.
Ideally, people using a building should be aware not only of its emergency features and appropriate procedures but also of the conditions they will face in carrying out such procedures; for example, the delays they may experience as other people are given the necessary priority in exit use. Unfortunately, as has been suggested here, this goal is several steps away. To achieve the goal, designers and managers need detailed knowledge of the appropriate procedures and resulting conditions. Researchers have only recently begun to assemble data and to build models, including models of human behavior related to emergencies in buildings. Only the first steps have been taken towards increased ability to predict, and eventually to control, emergency conditions.
This paper is a contribution from the Division of Building Rescarch, \
National Research Council of Canada, and is published with the approval of
the Director of the Division. 1
REFERENCES I
1. Quarantelli, E.L. Human behavior in disaster. Proceedings of Conference, Designing to Survive Disaster, IIT Research Institute, Chicago, Nov 1973, pp. 53-74.
2. Q u a r a n t e l l i , E . L . Panic behaviour: some e m p i r i c a l o b s e r v a t i o n s . I n
Human Response t o T a l l Buildings. Ed. by D. J . Conway. ~ t r o u d s b u r ~ 7 ~ a .
,
Dowden, Hutchinson & Ross, I n c . , 1977, pp. 336-350.3. Yamada, M. and T. Goto. Human response t o t a l l b u i l d i n g motion. I n
Human Response t o T a l l Buildings. Ed. by D. J . Conway. ~ t r o u d s b u r g , Pa. , Dowden, Hutchinson 6 Ross, I n c . , 1977, pp. 58-71.
4. P a u l s , J . L . Evacuation and o t h e r f i r e s a f e t y measures i n h i g h - r i s e b u i l d i n g s . ASHRAE TRANSACTIONS, Vol. 81, P a r t 1, 1975.
5. Pauls, J . L . blovement o f people i n b u i l d i n g e v a c u a t i o n s . I n Human Response t o T a l l Buildings. Ed. by D . J . Conway. s t r o u d s b G g , Pa., Dowden, ~ u t c h i n s o n ' & Ross, I n c . , 1977, pp. 281-292.
6 . F i t c h , J . M . , J . Templer and P. Corcoran. The dimensions o f s t a i r s . S c i e n t i f i c American, Vol. 231, No. 4 , Oct 1974, pp. 82-90.
7. Templer, J . A . S t a i r shape and human movement. Unpublished Doctoral D i s s e r t a t i o n , Columbia U n i v e r s i t y , N . Y . , 1974.
8. P a u l s , J . L . F i r e s a f e t y and r e l a t e d man-environment s t u d i e s . Man-Environment Systems, Vol. 5 , No. 6 , Nov 1975, pp. 386-394.
9. S t a h l , F . I . H i g h - r i s e f i r e s a f e t y : an a n n o t a t e d b i b l i o g r a p h y . Council of Planning L i b r a r i a n s , M o n t i c e l l o , I l l . , Exchange Bibliography 823, June 1975, 19p.
10. McDaniel, M. Bibliography o f human behavior and f i r e s . F i r e and Human Behavior Research C e n t e r , Applied S o c i a l Psychology Program, Loyola U n i v e r s i t y , Chicago, I l l . , Dec 1976, 7p.
11. Baker, G.W. and D.W. Chapman (Ed.). Man and S o c i e t y i n D i s a s t e r . New York, Basic Books, 1962.
12. Haas, J . E . S o c i o l o g i c a l a s p e c t s o f n a t u r a l d i s a s t e r s . I n Human Response t o T a l l Buildings. Ed. by D . J . Conway. ~ t r o u d z u r ~ , Pa., Dowden, Hutchinson
G
Ross, I n c . , 1977, pp. 329-335.13. Canter, D. and R . Matthews. The behaviour of people i n f i r e s i t u a t i o n s : p o s s i b i l i t i e s f o r r e s e a r c h . U . K . , Building Research Establishment,
F i r e Research S t a t i o n , C u r r e n t Paper CP 11/1976, J a n 1976, 17p.
14. Breaux, J . , D. Canter and J . Sime. Psychological a s p e c t s of behaviour of people i n f i r e s i t u a t i o n s . U n i v e r s i t y of S u r r e y , F i r e Research U n i t , 1976.
15. Marchant, E.W. Human behaviour i n f i r e . F i r e , J u l y 1977, p. 76.
16. Rubin, A.I. and A. Cohen. Occupant behavior i n b u i l d i n g f i r e s .
National Bureau of S t a n d a r d s , U.S. Department o f Commerce, Washington, NBS Technical Note 818, Feb 1974.
17. Wood, P.G. The behaviour of people in fires. Great Britain, Fire Research Station, Fire Research Note No. 953, Nov 1972.
18. Bryan, J.L. Smoke as a determinant of human behavior in fire situations. Fire Protection Curriculum, College of Engineering, University of
Maryland, College Park, Maryland, June 1977, 288p.
19. Archea, J.C. Private communication. National Bureau of Standards, Center for Building Technology, Washington, D.C.
20. Fruin, J.J. Pedestrian planning and Design. New York, Metropolitan Association of Urban Designers and Environmental Planners, Inc., 1971. 21. Asher, J.K. Toward a safer design for stairs. Job Safety and Health,
Sept 1977, pp. 27-33.
22. Kvarnstrom, L. Trappor (Stairs, in Swedish). Stockholm, Statens r&d fbr byggnadsforskning, T3:1977, 85p. (Includes an English summary available separately as S2:1977.)
23. National Bureau of Standards, Design and construction of building exits, National Bureau of Standards, Department of Commerce, Washington, D.C., Miscellaneous Publication M 151, 1935.
24. Joint Committee on Fire Grading of Buildings, Post War Building Study
No. 29, Fire grading of buildings (Part 3, Personal safety). London,
Her Majesty's Stationery Office, 1952.
25. Togawa, K. Study of fire escapes basing on the observation of multiple
currents. Building Research Institute, Japan, Report No. 14, Feb 1955. 26. Malinski, A.I. Principles for regulating the evacuation of public
buildings. In Fire prevention and fire fighting: Symposium. (Translated from Russian by L. Herdan, Fire Research Station, Boreham Wood, Herts.), National Lending Library for Science and Technology, Boston Spa, Yorkshire, England, 1966, pp. 29-50.
27. Predtetschenski, W.M. und A.I. Milinski. Personenstrbme in gebauden. Rudolf Muller, Koln-Braunsfeld, 1971.
28. Roytman, M.Y. Principles of Fire Safety Standards for Building Construction. New Dclhi, Amcrind Publishing Co. Pvt. Ltd., 1975,
pp. 283-386. (Published for the Nat. Bureau of Standards, U.S. Dept.
Commerce, and Nat. Science Foundation, Washington, D.C.)
29. Peschl, I. Flow capacity of door openings in panic situations. BOUW,
No. 2, Jan 1971,pp. 62-67.
30. Ottel, Dip1.-Ing. Dr. Techn. Rupprecht. Private communication.
