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Evacuation Drill Held in the B.C. Hydro Building, 26 June 1969
Pauls, J. L.
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DIVISION OF BUILDING RESEARCH
'fE
C
1HlN
][
CAlL
NOTE
No.
543
PREPARED BY J. L. Pauls CHECKED BY G. O. H.
APPROVED BY N. B. H.
February 1970
PREPARED FOR Inquiry and Record Purposes
SUBJECT EVACUATION DRILL HELD IN THE B. C. HYDRO BUILDING,
26 JUNE 1969.
On 26 June 1969, a preannounced evacuation drill was conducted at the Head Office of the British Columbia Hydro and Power Authority in Vancouver. The 22-storey building was successfully evacuated within 14 minutes from the time the alarm was turned in. Employees were back at work within an hour.
The decisions on the need for such an evacuation drill and the procedures to be followed were made by B. C. Hydro. An independent observation committee was invited to supervise detailed observations and assist in assessing the exercise. (See Appendix I for a list of com-mittee members). As a member of this committee the author was re-quested to prepare a record of observations and related information.
This note serves as the detailed record of the drill. It is produced and distributed by the Division of Building Research with the approval of the British Columbia Hydro and Power Authority with the aim of bringing about a wider appreciation of life- safety measures in buildings. EVACUATION PLANNING AND ORGANIZATION
The planning of evacuation procedure was extensive. Emergen-cies for which such an evacuation might be considered necessary include fire, major earthquake, and explosion in the Vancouver harbour. The preparation for such emergencies is described in a bulletin given to the
2
-Head Office staff on 23 June 1969. This bulletin is reproduced in Appendix II. In addition to this bulletin, specific directives were
issued to five Evacuation Control Officers (E. C. O. 's), Floor Wardens, Assistant Floor Wardens and Searchers. This hierarchy of evacuation personnel is headed by a Chief Evacuation Control Officer.
With emergency procedures planned in great detail, the B. C. Hydro staff was better prepared than might normally be the case in high-rise buildings. In this evacuation drill the staff had the benefit of a thorough briefing and, on some floors, a trial run only a few days before the actual drill. In addition, some of the arrangements for the drill were in evidence on 25 June when the exercise was postponed because of threatening rain showers. On 26 June the drill was not unexpected nor were there many questions about procedure.
BUILDING COMMUNICATIONS
The effective functioning of the hierarchal organization of personnel responsible for evacuation of the B. C. Hydro Building is dependent on the building's communications systems. The se consist of a public address system, an emergency phone system in the exit stairwells, and elevator intercoms. These are all controlled from a service centre which also acts as a trouble centre for B. C. Hydro's power distribution network and is thus constantly manned by trained
staff. If a fire alarm is activated, the service centre staff confirm the need for evacuation by consulting evacuation personnel on the IIFire Floor". (This alarm is also connected with the B. C. District Telegraph office which notifie s the Fire Department).
The building is not equipped with a general fire gong system but it does have a public address system controlled from the service centre. When the appropriate announcements are made, the personnel responsible for evacuation take up duties ranging from control of the emergency communication system in the service centre to searching for other personnel. A siren signal is used on the public address system to introduce the evacuation order given to the occupants.
Building occupants move down the east stairwell if on an odd-numbered floor and down the we st stairwell if on an even -numbered floor. Floor wardens report their floors "clear" to the service centre using the emergency phones in the stairwells. The actual success of these procedures in the drill is discussed later in this Note.
DESCRIPTION OF THE BUILDING AND ITS OCCUPANCY
This air -conditioned office building was constructed in 1957. It has 21 floors above main, mezzanine, first and second basement levels. The floor plan of floors 3 to 21 is illustrated in Figure 1. These floors form a reinforced concrete slab-type tower above a
partial podium containing customer service, cafeteria, lounge, assembly, storage, workshop, computing, banking and trouble -service facilities. The last two of these are effectively separated from the other areas and thus were not evacuated during the drill.
A typical floor in the tower has a gros s area of about 11,500 sq ft of which 2, 000 sq ft is taken up by circulation routes and 6,800 sq ft is considered usable for offices. For floors 1 to 21, the total floor area served by the two exit stairs is about 188, 000 sq ft (gross area minus core area but including circulation area).
Using the National Building Code of Canada, 1965, formula for occupant load for this area on floors 1 to 21, one arrive s at a design population of 1,880 persons. As detailed later, only 1,365 work pla.ces were provided on these upper floors and only 945 persons were present
at the time of the drill.
About 200 work places were provided in the two basements and on the main and mezzanine levels. (The hundred or so occupants evacuated these areas within ten minutes).
The geometry of the exit stairs is shown in Figure 1. The width of each stair is
49t
in. minus2t
in. for the single handrail. Each stair thus provides two units exit width giving a total of fourunits for each floor. The usable area of stairs and landings is 150 sq ft for each exit or 300 sq ft for each floor. Travel path, from storey to
storey within each exit, is 40 ft, measured along the centre of stairs and landing s.
Travel distance to the exit on a typical floor is a maximum of 70 ft if both exits are available and up to 150 ft if only one is available on each floor (as was the case during the drill). Total travel distance from the farthest point on the twenty-first floor to the exit at ground level is 1030 ft. With a floor-to-floor height of 10 ft 6 in., the twenty-first floor is about 230 ft above the ground floor.
given in (2). The The last column These are expla.ined 4
-This building is occupied solely by the staff of the British Columbia ,Hydro and Power Authority (except in the banking area). In addition to a
wide range of ancillary activities (in the lower floor areas mentioned
earlier), there are general and executive activities carried out by a majority of the Head Office staff. The staff members engaged in these activities
are, with a few exceptions, capable of evacuating the building without as-'sistance. Arthritics and those having heart conditions or other disabilities · are assisted by evacuation personnel on each £loor and evacuate by manually-; controlled elevator. During the evacuation drill less than four per cent
· of the building population used the elevator. The remainder were perhaps in better physical condition than most office workers due to the frequent use of stairs for interfloor travel and normal access and egress (particu-larly below the sixth £loor). Factors encouraging this frequent use of · stairs range from the internal communications requiremehts of the single-· tenant occupancy, the relatively slow elevator service, the placement of
washrooms off the stairs, and environmental characteristics (discussed later in this Note).
PREDICTIONS OF EVACUATION TIMES AND TRAVEL RATES
Exit dimensions, occupant loads and rates of exit travel have been related in several studies carried out in the United States, Britain and Russia. Most of these have been reviewed in two publications by M. Galbreath of the Division of Building Research (1, 2). Using these rela-tions and some of the data for the B. C. Hydro building it is possible to make certain predictions.
Travel rates and evacuation times are given in Table I for three conditions of occupant load or population, which, for floors 1 to 21, are:
(a) 1880 persons, based on the National Building Code formula of 100 sq it per person in office buildings
(b) 1365 persons, based on the number of work places provided (c) 910 persons, the actual number evacuating by the two stairs.
Predictions in Table I are based on relations formula for evacuation time is given in Appendix Ill. "d" gives some features of the drill as carried out. later in this report.
It should be noted at this point that the actual population of the building was low, relative to the capacity of the exits. At the time of the drill, the population per floor was such that the number of persons
per unit of exit width ranged between 5 and 25. Moreover, each stair is wide enough to permit persons to walk side by side. These factors tend to make rapid evacuation of this building feasible (in terms of speed alone) in contrast to evacuation attempts in some high office buildings (1).
OUTLINE OF THE DRILL AS CARRIED OUT
The following log of events during the drill was derived from a tape recording of all conversations on the emergency telephone system and from notes made by a team of s=:'tvente.en observers(vvhose locations during the drill are listed in Appendix I). Times are given with
9:
30 a. m.=
0: 00: 00, the start of the drill. Other events during the drill are de-scribed in later sections of this Note.Log of Key Events (Times are given in minutes and seconds) 0: 00: 00 0:45 0: 50 1: 15 1: 45 2:30 2:35 4: 00 6:30 10: 35 11: 10 14: 00 14: 30 21: 30 22:45 23: 00 23:15 60: 00
Fir e alarm pulled on 7th floor
Call over P. A. for Evacuation Control Officers (Some floors appear to have begun their evacuation prematurely with this announcement)
7th floor (J. Flanagan) asked to investigate alarm 7th floor reports total evacuation required
Siren sounds over P. A. and evacuation announced First E. C. O. arrives at service centre
First people out of exit stairs
E. C. O. takes over phone in service centre,
Firemen enter building exits and proceed to 7th floor Firemen arrive at 7th floor
Last floor reports "clear" (floor 8)
Firemen on 7th floor report everything OK Last people out of exit stairs
Building reported "clear"
Elevator sent to 6th floor to bring down injured girl Re-entry of building approved by C. Sutton
Injured girl removed from 6th floor
Re-entry started. (Elevators were manually controlled and operated in express fashion to speed re-entry (approx.) Re-entry completed.
DETAILED ANALYSIS OF MOVEMENT DURING THE DRILL
This section should be read in conjunction with Figures 2 to 5 as well as Table 1. These describe the predicted and actual movement characteristics for the evacuation of floors 1 to 21. Because each exit served alternate floors two sets of graphs are provided.
6
-The ITleaning of Ilevacuation tiITle" ITlust be clarified if the results of this drill are to be cOITlpared with others. Evacuation tiITle, in this case, should be considered as 12 ITlinutes, the period between the order to evacuate and the egress of the last occupant. "Evacuation tiITle" ITlight also be used to describe the tiITle taken for organizing the evacuation as well as the actual tiITle spent in leaving. In the latter case, evacuation tiITle would be 14 ITlinutes. A proper cOITlparison of the results of this drill with others would require a careful study of procedures used. In SOITle situations for exaITlple, floor groups would enter the exits in ran-dOITl order while in others "fire floors" and adjacent floors or upper floors would leave fir st. In this drill, the floor groups wer e expected to evacuate in sequence, with the lower floors leaving the building first. In actual fact there were exceptions to this, the ITlost notable being floor 8 which was the last group out. If there had actually been a fire on floor 7, floor 8 should have been one of the first to evacuate. In SOITle high-rise buildings, places of refuge ITlay be available to perITlit a two-stage action leading either to eventual evacuation of the building or to resum.ption of norITla1 activity after eITlergencies have been assessed and brought under control. Thus the ITloveITlent to a place of safety ITlay or ITlay not require evacuation. Figure 5 cOITlpares ITloveITlent characteristics found in drills of total evacuation of other buildings.
Figures 4 and 5 and Table I indicate how well the results agree with the liITlited theory developed for ITloveITlent in buildings. The differ-ences appear to arise because of ITlinor organizational difficulties in carrying out this exercise. For exaITlp1e, as seen in Figures 2 and 3, entry into the stairwells was delayed and nioveITlent and density were not uniforITl. Travel rates ranging froITl lOO ft per ITlin to 160 ft per ITlin were not sustained Over the total evacuation route. Thus the average rate of 86i t per ITlin was ITluch lower than the predicted rate of 147 ft
per ITlin and the actual evacuation tiITle was nearly double the predicted 7 ITlinutes. Figure 4 illustrates how si'rnilar actual and predicted re-sults ITlight have been if there had been no delays.
The delays in initiating and in carrying out the egress ITlovement are discussed in later sections of this Note.
AN ASSESSMENT OF ENVIRONMENTAL CONDITIONS IN THE EXITS The asseSSITlent of environmental conditions poses difficulties not only because factors are not readily quantified but also because they are not related in a siITlple way to behavioural factors. Rather than set aside their study in the context of evacuation drills, however, an effort should
be made to build up an empirical basis for future analysis and interpre-tation. With this goal in mind, visual, acoustic and other environmental factors were noted in the course of this exercise.
The two exit stairways were well illuminated. No measurements were made during the drill, however, maintenance staff reported illumi-nation at about 20 footcandles (20 lumens per square foot). This was pro-vided by an unusual system of unshielded continuous-tube fluorescent
luminaires at the soffit. Wall surfaces were plaster and stair treads were terrazzo thus producing various degrees of spread and regular reflection. Emergency lighting was installed but not used during the drilL (All en-vironmental systems in the building were in normal operation. )
In terms of these visual features, the exits should function better than most found in office buildings (which often have inadequate or poorly distributed illumination). (This comment is based on a survey of Vancouver office buildings described in the author's unpublished graduation thesis,(3).) Except for a possible claustrophobic response to the spiraling enclosure geometry of the stairway, occupants appear to find the stairs "attractive" and suitable for frequent use.
Sound levels were measured in the west stairwell with an octave band noise analyzer set up on the fourth floor landing. The noise analysis is given in Figure 6. Sound levels in the stairwell before and during the evacuation fall under N. C. 45 and N. C. 70 respectively with most of the noise produced by speech and the impact of footsteps on the terrazzo floor.
Initially, there was some question about whether noise and ex-cessive reverberation would make the exit seem more crowded or if it would interfere with the use of the emergency phone in the exits. In the tape recording of emergency phone conversations there seemed to be little difficulty with speech interference. The results of a questionnaire given to evacuation staff after the drill indicate only a small number of people found the noise annoying while a dozen indicated it made the use of the emergency phone more difficult. (This could represent a majority of those personnel who had to use the phone.) Another difficulty with the emergency phone arose when floor wardens used it unnecessarily and thus jammed the control board in the service centre. (This may have influenced the replies to the questionnaire.) Conver sations inside the stairwell were clearly heard over several feet thus permitting people walking side by side to talk easily. In general, it appears that rever-beration' which was severe when the stairwell was unoccupied, became
- 8 "';"
minor when many people were present (thus increasing absorption). As mentioned earlier, there is no general fire bell system in the building. Emergency instructions (and the siren signal) were given over the public address system. With few exceptions, all floor groups heard the initial evacuation instructions clearly. In some cases, floor wardens, stationed at the emergency phones in the exits, did not hear subsequent announcements clearly. Their requests, by phone to the service ｣･ｮｴｲ･ｾ
for repeat announcements possibly caused some delays in the evacuation of their own and other floors. There were many suggestions made in the questionnaire that the public address system should also be installed in the exits, not only for the benefit of those using the emergency phone but to facilitate changes in evacuation procedure once people are in the stair-wells.
In general, it would be worthwhile to compare the public address system with the conventional alarm systems in terms of information con-tent and emotional influence as well as flexibility and reliability in a variety of emergency conditions. In this ､ｲｩｬｬｾ the use of an amplified
siren signal to introduce the evacuation instructions caused" some con-fusion among the building occupants.
Turning now to thermal conditions, there was some question ini-tially about stuffiness and overheating in the stairwells. Although the questionnaire given to observers and evacuation staff did not cover this point specifically there were several comments to the effect that the lower levels of the stairwells were too warm and stuffy. This was the case even in the east stairwell where doors on the ground, first- and twenty-first-floor levels were left propped open; in the west stairwell, only the tenth-floor door was propped open. No measurements were
taken of thermal conditions. Air conditioning was left in normal operation. There were no obvious upward drafts in the stairwell. (Any occurrence of chimney effect was asswned to be insignificant because indoor and out-door temperatures differed only by IO to 15 degrees. )
RESULTS OF A QUESTIONNAIRE GIVEN TO OBSERVERS AND EVACUA TION PERSONNEL
A questionnaire was given to evacuation personnel after the drill to assess employee reaction. This same questionnaire was also used by observers to record comments about the drill. The responses from 63 staff members and 17 observers are summarized below. The responses should be interpreted with some caution due to the selective nature of the survey population. Although the staff resp:mdents likely were more
attentive to events during the drill than were other building occupants, they might be biased because of their responsibility in this and future drills.
In the following summary of responses, the observers' comments are given, in parentheses, only if they are significantly different from those of the evacuation personnel.
(1) "What was your floor of origin?"
Responses here were the sole means of identification which was necessary to apply many of the comments to the detailing of Figures 2 and 3.
Responses were received from all floor s.
(2) "Comment on how well the initial alarm was heard and understood by yourself and others. Did some people need additional information before
they started evacuation?"
- almost everyone indicated alarm and initial instructions were clearly heard. Only one floor requested a repeat announcement - most said no further information was needed and some pointed out
that as the drill had been anticipated instructions were a bit re-dundant
- 7 people indicate d confusion as to whether the siren or the announce-ment was the cue to evacuate
- there were 6 reports of confusion about which exit to use or which of the two door s to use to enter the exit
- only one respondent mentioned giving extra instructions to visitors - (an observer commented that the siren sound could be confused
with one from an emergency vehicle on the street).
(3) "Did you initially interpret this as a real emergency or a drill?" - Everyone was sure it was a drill. This result is not surprising
because everyone in the building was briefed just two days before. In addition, many had seen preparations being made for the drill that morning or the previous morning. (By way of comparison, a similar question was put to students after a drill at the University of B. C. Although there had been no advance warning and students had not been in a fire drill for an average of
2t
years, only 4 per cent interpreted it as a real emergency while 91 per cent felt it was a drill or a flase alarm (3).)(4) "What caused delays in clearing the floor and in going down the stairs?"
Here it appears that many respondents did not consider some delays worth mentioning, perhaps because they might be expected to occur in
- 10
-- 14 blamed the emergency phone system which had to be used to - re-port floor s "clear"
- 13 reported delays at lower floors
7 mentioned mix-ups in evacuation sequence (lower floors were to clear first)
4 indicated searchers were slow in checking floor areas.
(5) "Describe difficulties experienced in having people stop in the stair.:. wells to wait for lower floor s to clear. "
- 65 reported no difficulties
- one suggested stops would be more troublesome if movement was faster
- one remarked that time passed more slowly when standing in the stairwell
- (instructions to stop were readily passed up the stairs). (6) "How did people go down the stairs?"
(a) Were they crowded
(b) Were they distributed uniformly (c) Did they walk side by side
(d) Were they staggered
ＨｾＩ Was travel rate uniform
Yes 3 65 58 19 63 ｾ
64
5 1029
7- (observers at the exit discharge on the ground floor reported gaps between floor groups)
- only a few reported single file movement
- one floor warden had women walk on the inner side of the stairwell where the handrail was located. Men went on the outside.
- there were no reports of difficulties when two firemen went up each stair to the seventh floor.
(7) "Where did congestion occur?" - 37 reported no congestion
- 15 indicated congestion due to lower floors entering stairs, pa1"ticularly around the thirteenth and fourteenth floors.
4 reported congestion on entering stairs (some floor groups lined up in the corridor before entering the exit).
- one, complained this occurred at an exit door that had been blocked open
- there were no reports of congestion as floor groups passed floor wardens standing at the emergency phones on the landings.
(a) Was it annoying
(8) "Describe the effect of noise in the stairwell. " Yes
12 12
should be no talking when using Yes No
(b) Did it ITlake us e of the phone difficult - there was one suggestion that there
the stairwell for evacuation.
(9) "COITlITlent on the effects of fatigue as you went down the stair sand outside, particularly if you were on the upper floors. Was it serious for anyone who used the stairs?
Did SOITle people have to stop for a rest or leave to continue by elevator? "
- alITlost all reported no difficulties
_ persons who anticipated difficulty with the stairs were able to go down by elevator. The 35 people in this category represented about 4 per cent of the building population
- two froITl upper floors cOITlITlented about dizziness during the descent
- there were signs that people were eager to lean against sOITlething or sit down after descending the stairs
- one girl froITl the ninth floor slipped and fell just below the seventh floor. (Observers in the iITlITlediate vicinity gave assistance and after about 15 ITlinutes on the sixth floor she was taken down by elevator to the teITlporary first aid station. The injury was ITlinor. This delay, caused by cOITlITlunication difficulties, ITlight not have been so great if evacuation personnel rather than observers had COITle to her assistance. )
- (soITle observers reported that travel rates could not have been ITluch faster. The observer ITloving with the group froITl the six-teenth floor reported the speed as "exceedingly fast". Figure 3 shows a travel rate of 160 it per ITlinute for this group. )
(10) "CoITlITlent generally on the instructions received during the drill itself." (It should be reITleITlbered that the respondents here were those who likely gave instructions during the drill or those who had detailed briefing about procedures before the drill. )
- only a few reported that instructions received during the drill were difficult to hear
- 17 indicated clearer directions should be given on the procedure once out of the building and when arranging for entry
- Many suggested loudspeaker s for the public addres s systeITl be in-stalled in the exits
- (observers felt that evacuation personnel ITlanaged very well con-sidering this was the first test of the evacuation plan).
(11) "EITlployee Reaction. "
12 -" impressed,-" -"very important-".
- many suggested such drills should be held again, perhaps on an annual basis
- many felt that the staff should not be warned before future drills - several indicated that some staff members left the building before
the drill to avoid it. GENERAL DISCUSSION
It is unusual to have an evacuation drill in a building as high as the B. C. Hydro building. There is hesitation on the part of management personnel to authorize such a disruption in businesss routines. Further-more, it is not always clear whether such a drill has a positive or a neg-ative effect on the occupants' attitudes toward safety and whether mass egress actually solves a life-safety problem without creating a more dif-ficult situation.
These issues will likely be partially resolved with some sort of cost-benefit analysis. This drill was quite successful in many ways. B. C. Hydro management personnel were able to assess a comprehensive plan without disrupting employees for too long. The experience of the B. C. Hydro staff should serve them well in future emergencies (if their reactions and observed behaviour are any guide). It was also successful in generating information which can be applied to life-safety planning in other buildings. This is particularly useful at this time as management, design, regulatory and fire protection agencies attempt to solve the problems of fire iIi high-rise buildings. (For example, as this report is being prepared, consideration is being given to new requirements in the 1970 edition of the National Building Code of Canada to make high-rise buildings safer.)
A difficult question to be answered is whether mass evacuation is necessary in case of fire and, if so, how it could be conducted without causing other problems such as increased smoke circulation and block-ing of access routes for fire department personnel. Features such as smoke-proof elevator lobbies and shaft pressurization might obviate the need for total evacuation in fire situations. In any case, such provisions should increase the critical time available to control fires and permit evacuation with less emphasis on speed alone.
The results of this drill suggest that this particular building and its occupancy would permit any of a number of solutions to emergency procedure. For example, the adequacy of exit area for the number of occupants permits a rapid evacuation by stairs. Also" the use of a
public address system rather than a general fire alarm system permits greater control of partial or staged evacuation procedures. Moreover, the building is well supplied with circuits and power sources so that elevators can be used for emergency access and egress. The floor plan would permit smoke-proof elevator lobbies with minor construction changes.
The value of findings from this exercj se should increase as similar exercises are held in other buildings and modified procedures are used in future drills held in the B. C. Hydro building. For example, the com-munications systems were not used effectively in this first exercise and changes have already been made to correct shortcomings (such as jam-ming of the emergency phone lines with the result that floor wardens were delayed in reporting to the service centre). The study of versatility, reliability and economics of existing communications systems in such buildings could assist in drawing up life-safety requirements for other buildings.
RECOMMENDA TIONS FOR FUTURE OBSER VA TIONS
The purpose of this section is to outline some ways (suggested by the author) Qf utilizing research possibilities in future evacuation ex-ercises. Recommendations about the need for such drills and the form they should take are left as a subject requiring broader study.
Future observations should relate movement characteristics with environmental characterisitcs in a more detailed manner than that achieved in this drilL For example, congestion patterns, travel rates and occupant loads should be more carefully plotted in space and time cOQrdinates and compared with geometric characteristics as well as with less tangible qualities of the physical and social environment. Under this latter heading would come observations of the information resources and communication channels available to building occupants in general and evacuation control personnel in particular. In addition to recording the readily observable movement characteristics one might also be able to assess such phenomena as distortions in the perception of space and time. Both of these were in evidence in the comments made by ob-servers and evacuation personneL Such distortions could be a problem in larger and more complex buildings where orientation is not clear or in situations requiring prolonged confinement in a place of refuge. Such an assessment could be made by comparing observations, questionnaires and analyses of circulation during future exercises.
The analysis of circulation was perhaps more thorough in this report than is normally the case. The methods of collecting the data,
- 14
-however, ITlay have introduced a good deal of error. Observers' written notes were difficult to incorporate into an over -all analysis of ITloveITlent. Space and tiITle coordinates are not easily recorded in the course of
ob-serving and participating in the evacuation. In future drills the use of inconspicuous portable tape recorders is recoITlITlended for recording events and conditions. In this way, space locations can be recorded on the tapes and later transferred to a tapescript with tiITle coordinates established froITl evacuation alarITls and announceITlents. The analysis of the exercise would then be greatly siITlplified and less subject to error. Such a procedure becoITles almost essential if evacuations are COITlpli-cated by delays in the exits, changes of travel paths in the course of egress, lighting, blackouts, etc. In this drill the recording of the con-versations on the eITlergency phone systeITl proved valuable to B. C.
Hydro personnel as well as to the author. This procedure is also reCOITl-ITlended for future drills.
Questionnaires can also be a useful source of certain data. It is recoITlITlended, however, that they be drawn up by persons in disciplines such as the behavioural and social sciences and that survey populations be carefully identified. This should ITlake theITl easier to interpret and ITlore valuable as an aid to understanding building use.
References
(1) Galbreath, M. A Survey of Exit Facilities in High Office Buildings. Building Research Note No. 64, Division of Building Research, National Research Council of Canada, Ottawa, October 1968. (2) Galbreath, M. TiITle of Evacuation by Stairs in High Buildings.
Fire Research Note No.8, Division of Building Research, National Research Council of Canada, Ottawa, May 1969.
(3) Pauls. J. L. Responses to EITlergencies in Buildings. Unpublished graduation thesis, University of British ColUITlbia, May 1969. AcknowledgITlents
The assistance given by the British ColUITlbia Hydro and Power Authority in the task of planning and conducting observations is gratefully acknowledged. The assistance given by Mr. C. Sutton. B. C. Hydro! s Chief Fire Prevention Officer. is especially appreciated. In addition. the author wishes to thank ITleITlbers of the observation teaITl for their assistance in collecting inforITlation and preparing this Note.
COMPARISON OF PREDICTED AND ACTUAL EVACUATION CHARACTERISTICS FOR VARIOUS CONDITIONS OF
OCCUPANT LOAD
Predicted Actual
a b c d
Total occupant load 1880 1365 910 910
Average load per floor 90 65 43 43
Average area of stair per person (sq ft) 3.3 4.6 7.0 7.0 Average discharge rate per stair 86 86 78 42
(persons per minute)
Travel rate in stairs (ft per minute) 80 110 147 86
*
94*:-:<
Evacuation time including 130 ± 30
***
O. 7 minutes on floor (minutes) 12.0*
(1 ) distance/travel rate 11.8 8.8 6.8(2 ) formula (Appendix 3) 12.7 9.4 7 . 1
*
based on time from beginning of evacuation to clearing of building**
based on average rates in the two stairs during the period after all floors enter exit/
18 RISERS AT 7" RUNS AT 10"
STAIR FINISH - TERRAZZO
SCALE: I. ful j i SCALE:;/1"ie!
.
,
o 6 18 o 16 STAIRWEll DETAil FIGURE IPLAN OF TYPICAL FLOOR IN THE B.C. HYDRO HEAD OFFICE BUILDING
ｾ･Ｋ
>-
1 7g;+
..,0 ｾｱ LLJ ｾｾＫ e:::: 131&.1<+
'p
ｾ 0 /v. I - 0"" Vl 9,
Fire ...ｾＮ Floor //} 5 1 GRD 0 5 1 0 15TI ME, MINUTES
Discharging Floor Group 3 1 7 5 8 11 13 15 17 19 21
Available Work Places
40 145 98 66 79 67 50 64 54 45 18 on Floor Actual Number of 19 61 72 58 62 49 55 35 31 27 15 Evacuees in Group Total Number of 19 80 152 210 272 321 376 411 442 469484
Evacuees Using Exit
:r: I-0 ｾ 100 I-LLJ
--I - X«
w z e:::: Vl-I-::E LLJ Ｍｾ Co=> ZVl 50 e:::: =>Z«
NO:::c
II Vl£>e: U w Vl £>e:o...--«
a
£::) I-Vl 0 5 10 15 £>e:TI ME, MINUTES
0 LL.FIGURE
2
GRAPHS AND A TABLE DESCRIBING THE EVACUATION OF
PERSONS ON ODD-NUMBERED FLOORS USING THE EAST
STAIRWELL
THE UPPER GRAPH SHOWS LOCATIONS OF LAST MEMBERS OF EACH FLOOR GROUP AS THEY LINE UP AND PROCEED DOWN THE STAIRS. THE TABLE GIVES POPULATION FIGURES FOR
THE FLOOR GROUPS. THE LOWER GRAPH PLOTS THE DISCHARGE RATE FOR THE STAIR AT THE GROUND FLOOR.
20
>-
16 I.LJc::::
12 0....
Vl 8 4 MEZZ. GRD. 0 5 10TI ME, MI NUTES
15 a::o
u.Discharging Floor Group 2 4 6 10 12 14 16 20 18 8 Available Work Places 99 51 64 63 70 72 49 44 48 81 on Floor
Actual Number of 54 ? ? 37 ? ? ? ? 25 99
Evacuees in Group ? ?
Tota I Number of 54 105 142 251 301 326 425
Evacuees Using Exit ? ? ? ?
0'----I._-'-_.L.-...L..J_-J-_.J....---J1.---I-_.J....--J_-J-_..J....---1._....L-J
o
5 10 15TIME, MINUTES
FI GURE
3
GRAPHS AND A TABLE DESCRIBING THE EVACUATION
OF PERSONS ON EVEN-NUMBERED FLOORS USING THE
WEST STA I RWELL.
THE UPPER GRAPH SHOWS LOCATIONS OF LAST MEMBERS OF EACH FLOOR GROUP AS THEY LINE UP AND PROCEED DOWN THE STAIRS. THE TABLE GIVES POPULATION FIGURES FOR
THE FLOOR GROUPS. THE LOWER GRAPH PLOTS THE DISCHARGE RATE FOR THE STAIR AT THE GROUND FLOOR. (THERE IS
GREATER UNCERTAINTY WITH THESE RESULTS THAN WITH THOSE FOR THE EAST STAIRWELL).
-2
0
5
10
5
3
1
19
17
15
- '13
ｾ
L.1.J11 -'
ｾ9
0o
- '7
u.. 140 Ft/Min and Discharge Rate of 20 Persons/Min Simplified Graph of Actual Egress Movement 7.1 Min ..I
Possible Evacuation Time With No Stops \ \ \
"
"
,
"
'"
200 Ft/Min" " " on Floor , " ' ' '.
\'
Average Wh lieｾＮＬＭＭＭｾＧｯＭＭＭ
...
ｾＢＢ｜
V
'
in Stairwell \ "' '"ＨｾＱＰＰ
F t / M i n ) ' ' " Overall AverageＭ｜ｾ｜ＭＭＭＭｾＮＮＮＮＮＮＮＬＮＮＮＬ
" (86 Ft/Min) \ ' " Prediction forＭＭＭＭＭＭＧｾｾ｜
" " Conditions of \ ' " " 7 Sq Ft/Person " '\. " and a Discharge \ , " Rate of 78 Persons/Min \ '\.." and 147 Ft/Min i n ' '\." Stairwell ',
,
Ｇｾｉ
- ' L.1.J>
«
ｾ I-o
X L.1.Jo
500
I -L.1.J U Z«
l -V>o
I -L.1.J <.::> ｾ«
:c
u
V> I -L.1.Jｾ
1000
FIGURE
4
COMPARISON OF PREDICTED AND ACTUAL EGRESS
MOVEMENT FOR PERSON WALKING THE MAXI MUM
DI STANCE FROM THE 21st FLOOR
I
I
I
I
I
f - - Predicted Maximum _ _ _ _ 1 6
A
-for7Sq Ft/Person
'+ ". ... \"
-21 ;' . Max imum Rate According to
I
/ 0 London Transport Board Study
;' f - - / ... 15
-I
e / 0 f West d 1"'0 East I 8 0•
•
0i
I g tｾ 0 f - - / c• Estimates of Av. Conditions in East and
-/0 0h
West Stairwells During Period After all Ob Floors Enter Exit
... Estimates of Max. Sustained Travel Rates 00 for Various Floor Groups
f-- AVERAGE CONDITION OVER
-EVACUATION PERIOD: • Result of Drill in B.C. Hydro Building
o
Results of Drills in Other BuildingsI
I
(see table below)o
o
4
8
12
16
20
24
AREA OF STAIRS AVAILABLE PER PERSON, SQ FT
200
160
z
ｾ I -u. ,120
- J LLJ>
«
c:::: I-80
u. 0 LLJ I-«
c::::40
Building: (a) having 11 storeys was cleared in 7! minutes (b) ... 12... 9 (c) . . . .. 11 ...•.. 6! (d)... 9 5! (e) . .. .. 9. . .. . . .. .. 4! (f) 18 7! (g) . .. .. 7. . . .. .. .. .. 5 (h) 13 7! * (i) 13 4 (j) 7 4!
*Repeat in building (h) when real emergency was suspected.
FIGURE
5
COMPARISON OF EVACUATION CONDITIONS IN THE
B.C. HYDRO DRILL WITH THOSE IN DRILLS REPORTED
BY GALBREATH
(1)RESULTS FOR THE B.C. HYDRO DRill ARE PLOTTED ON A GRAPH DERIVED FROM REF. (1). THE INFORMATION FOR THE TABLE COMES FROM HIS SURVEY AS WEll AND IS
GIVEN FOR COMPARISON WITH THE 12-MINUTE EVACUATION OF THE 22-STOREY B.C. HYDRO BUILDING.
Freq uenc ies for Footsteps and Speech
...
..
co
"'t:J , 70 --I L..W>
LLI --Ic
50z
«
CO L..W>
ｾ
30 Uo
N.C.70 is the background noise criterion for noisy factories.1 0
26.5 53 106 212 424 849 1700 3390 6790 13590
FREQUENCY, CPS
TEST TIME, MI NUTES NOISE ANALYZER RESPONSE SETTING
a
- 5 (Before Dri II ) Slowb
+ 4 (During Drill) SlowC
+ 6 (During Dri II) Fastd
+10 (During Drill) SlowFI GURE
6
STA I RWELL NO I SE ANALYS IS
NOISE MEASURED IN THE WEST STAIRWELL, FOU RTH FLOOR, WITH A GENERAL RADIO CO. TYPE 1558-A OCTAVE BAND NOISE ANALYZER WITH 1560 PET MICROPHONE ASSEMBLY THREE FEET ABOVE FLOOR LEVEL.
APPENDIX I
LIST OF OBSERVERS AND THEIR LOCATIONS DURING THE DRILL
P. Anhorn (DBR/NRC), West exit, ground-floor door
*G. Birnie (Chief, Vancouver Fire Warden), 6th floor, with radio T. Blackall (DBR/NRC), BaseITlent exit
A. W. J. Bridge (Burnaby Fire DepartITlent), West exit, 14th floor to ground level
H. ChapITlan (Burnaby Fire DepartITlent), West exit, 20th floor to ground level R. W. Davies (MacMillan Bloedel), East exit, 7th floor to ground level
H. Hogan (Burnaby Fire DepartITlent), West exit, 8th floor to ground level *H. Jenns (Deputy Provincial Fire Marshal), 6th floor, with radio
G. A. Laurie (MacMillan Bloedel), East exit, 15th floor to ground level D. McCluskie (Vancouver Fire DepartITlent), East exit, ground-floor door H. J. McColITl (Vancouver Fire DepartITlent), Service centre
R. Montador (City of Vancouver), West exit, 16th floor to ground level *J. Pauls (DBR/NRC), West exit, 4th floor, noise ITleasureITlent
M. Rangeley (Vancouver Fire DepartITlent), West exit, ground-floor door J. Robinson (City of Vancouver), East exit, 5th floor to ground level P. Schaerer (DBR/NRC), East exit, ground-floor door
*D. Watts (MacMillan Bloedel), East exit, 21 st floor to ground level
*MeITlbers of observation cOITlITlittee
The observation cOITlITlittee also included the following ITleITlbers who were un-able to attend the exercise, with the exception of Messrs Sutton and
Flanagan who did actively participate. (see p. 5 of this Note. ) C. W. Sutton, B. C. Hydro, Chief Fire Prevention Officer
J. Flanagan, B. C. Hydro
R. Chandler, Chief, West Vancouver Fire Dept. L. Auvache, Chief, Burnaby Fire Dept.
B. McLure, B. C. Telephone Co. W. Ball, DBR/NRC
STAFF BULLETIN FROM S. SIGMUNDSON, GENERAL MANAGER, B. C. HYDRO
For Your Information. Evacuation Drill Planned
JlA mass evacuation of Head Office - believed to be the first of its kind to be carried out in Canada in a high-rise building - is planned within the next few weeks to test building evacuation procedures under simulated emergency conditions.
The evacuation will be signalled by the sounding of an alarm through-out the building and will take the form of a carefully-planned drill. Those employees on mezzanine and main floors and 1st and 2nd basements, to-gether with those unable to use stairways, will go to the parking lot north of Head Office building. Other employees will file down stairways and out emergency exits to an assembly area on the Dawson School grounds on the south side of Nelson St.
Employees should note that the Medical Department will be evacuated and the 1st Aid Stations will be established at both assembly areas.
The purpose of the drill is:
(1) To familiarize H. O. employees with evacuation procedures to be followed in a real emergency;
(2) Serve as a model for future safety planning in this and other high-rise structures.
As a planning model, the Head Office evacuation Will draw observers from federal, provincial and municipal agencies and from. leading business corporations such as B. C. Tel. and MacMillan Bloedel.
Vanc ouver Fir e and Polic e departments will take part in the drill, and arrangements have been made to block off streets surrounding Head Office during the evacuation, as required.
During the test drill only manually controlled elevators will be in operation to pick up from designated floors those employees with disabilities who are unable to walk down stairways. If you are within this category, please submit your name to your Floor Warden.
Evacuation of each floor will be under the direction of a warden assisted by two searchers whose duties will include checking restrooms to warn anyone therein and assisting any personnel requiring help.
Procedure for the drill is simple. Personnel will assemble in the floor corridor under the direction of the floor warden, and will leave the building AT A WALK by the exit designated by the warden. All
AII-2
eITlployees MUST accept the authority of evacuation control personnel. NaITle of the warden for each floor will be found above the telephone iITl-ITlediately opposite each washrooITl door.
Only personnel reITlaining in the building during this test evacuation will be those required to ITlaintain essential services: telephone operators to inforITl callers a fire drill is in progress, service centre personnel and power dispatchers.
Planning for the drill has been carried out over several ITlonths by a special cOITlITlittee headed by C. W. Sutton, Hydro's Chief Fire Pre-vention Offic er.
The ultiITlate aiITl of the evacuation plan is to devise an effective procedure which will serve in any eITlergency. For the individual eITlployee the keynote is siITlplicity. Do as you are told and do not panic. Or, in this instance, please do not treat this drill lightly: it is a serious ITlatter.
Here are the siITlple DO NOTs for evacuation. DO NOT: (a) Run
(b) Lag behind
(c) Pass others on stairways (d) Try to use elevators (e) Return for clothing, etc.
EITlployees engaged in phone calls when the siren signals the start of the planned evacuation should terITlinate their phone calls politely but iITlITlediately as follows:
"I beg your pardon but a test evacuation of this building has begun and I ITlust leave iITlITlediately. I will call you back as
soon as possible."
Visitors in the building when the evacuation COITlITlences should be advised to leave the building either via the eITlergency stairway or the el-evators. 1£ they elect to use the elevators, the floor warden should be notified.
The siren that will be used in the event of a real eITlergency will be tested today at lOa. ITl. so you will be faITliliar with its sound and im-port. This signal also will be used to launch the test evacuation on the day it takes place. "
where
FORMULA FOR EVACUATION TIME This formula is derived from Reference 2. (p. 14).
T
=
(N+
n)/RT
=
time for evacuation by stairs (not including travel time before entering stairs)N
=
number of persons evacuated by each stairn
