Evacuation drill held in the B.C. Hydro Building 26 June 1969

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Evacuation drill held in the B.C. Hydro Building 26 June 1969

Pauls, J. L.

CANADA

I

i

Ser THI ANALYZED B92 no. 80 c . 2 /

EVACUATION DRILL

HELD IN THE

B. C. HYDRO BUILDING

26 J U N E

1969

.

J.

L. Pauls 5

1

OCT

25

1971

I

-

,??

LI7d_J3 D l Y l S l O N O F BUILDING R E S E A R C H H A T l O H A L R E S E A R C H C O U H C l L

-

O T T A W A C A N A D A

EVACUATION DRILL WELD IN THE

B.

C.

HYDRO BUILDING

26 J U N E

1969

J, L. Pauls

Over the last f e w years interest in emergency evacuation of buildings has grown considerably, as a r e s u l t of f i r e incidents in tall building6 and intensive study of the movement and c o n t r o l of

smoke (1, 2). A s part of a total a p p r o a c h to life safety in buildings there exists a need f o r information describing t h e context, proce -

dur s , and efficacy of building evacuation. A f e w publications a r e available that summarize s o m e pertinent operations research s t u d i e s , examine existing regulatory practices in exit design, or even analyse some of the f r a g m e n t a r y r e c o r d s of evacuations of l a r g e buildings ( 3 - 9 ) . These do not, however, meet the r e q u i r e - ment for d e t a i l e d descriptive and analytical information on

evacuation as it rnay be conducted in the context of newer, higher buildings that may have sophisticated f i r e protection, air handling, and communications systems.

T h i s Note r e p o r t s a major evacuation exercise initiated and conducted by the British Columbia Hydro and P o w e r Authority

in

Vancouver. At B. C. Hydro's request an independent observation committee (Appendix A) o r g a n i z e d observations a n d assisted B,

C.

H y d r o in evaluating the exercise.

As

a m e m b e r of the committee,

the author prepared an unpublished report that was d i s t r i b u t e d on

a l i m i t e d basis d u r i n g 1 9 7 0 by the D i v i s i o n of Building Res earcb.

Although DBR/NRC

is

publishing this Note (with the p e r m i s s i o n

o f the B.

C ,

H y d r o and P o w e r Authority), no endorsement of a

particular evacuation organization or procedure is intended.

BRIEF DESCRIPTION OF DRILL

O n 26 June 1969 a pre-announced evacuation d r i l l was conducted

at t h e H e a d Office of t h e B r i t i s h Columbia H y d r o and P o w e r Authority

in Vancouver. Over 1000 people w e r e successfully evacuated f r o m the

D u r i n g the f i r s t 2 min of t h e d r i l l a prearranged procedure w a s followed

to check the source of the alarm and organize key evacuation personnel.

When t o t a l evacuation w a s ordered over the building's public address system, floor wardens s u p e r v i s e d the clearing and checking of each

floor before reporting to

a

central c o n t r o l centre, using an emergency

telephone system.

It

took 12 min tu clear the building once the evacua-

tion was announced. Of a total of 945 p e o p l e from floors above t h e mezzanine level 910 l e f t by t w o 41-in. exit s t a i r w a y s and 35 u s e d a

supervised elevator.

DESCRIPTION O F THE BUILDING AND ITS OCCUPANCY

The air -conditioned office building was c o n s t r u c t e d in 1 9 5 7 .

It has 2 1 floors above main and mezzanine, and t w o basement levels.

The floor plan of floors 3 t o 2 1 is illustrated in F i g u r e 1. T h e s e f l o o r s farm a r e i n f o r c e d concrete slab-type t o w e r above

a

partial

podium containing customer service, cafeteria, lounge, assembly,

a t a r a g e , w o r k s h o p , corn?uting, banking a n d trouble-service facilities.

The last t w o are effectively separated f r o m the o t h e r areas and w e r e not evacuated during the d r i l l .

A typical f l o o r has a g r o s s area of about 1 1, 500 s q f t l of w h i c h about 6, 800 s q f t is c o n s i d e r e d usable f o r offices and about 2, 0 0 0 s q

f t is taken up by main circulation r o u t e s . F o r f l o o r s 1 t o 2 1 the total f l o o r area served by the two exit stairways is about 188, 000 s q R. In_{this area 1365 work places w e r e provided at t h e time of t h e d r i l l ,}

but only 945 persons were actually present. About Z O O w o r k places w e r e p r o v i d e d in t h e two basements and on t h e main and m e z z a n i n e l e v e l s .

At the t i m e of the d r i l l the b u i l d i n g was occupied s o l e l y b y t h e

staff of the British Columbia Hydro a n d P o w e r A u t h o r i t y (except in

the banking area). &I addition t o a w i d e range of ancillary a c t i v i t i e s

in

the podium a r e a s of t h e building t h e r e w e r e general and executive office activities c a r r i e d out b y a m a j o r i t y of Head Office staff. Staff members engaged in these activities w e r e , with a few exceptions,

capable of evacuating the building without assistance. D u r i n g the

d r i l l 35 people, including a r t h r i t i c s and those having heart conditions,

w e r e evacuated by elevator, representing about 4 p e r cent of the

total number on t h e upper floors, The r e m a i n d e r w e r e probably

fairly accustomed to using the stairways because of heavy i n t e r f l o o r

traffic in this s i n g l e -tenant occupancy, f a i r l y s l o w elevator s e r v i c e , the placement of w a s h r o o m s off the stairways ( s e e Figure 11, a n d t h e generally high standard of finish and illumination in t h e s t a i r w a y s .

The geometry of the two exit stairways is shown in F i g u r e I . They have

a

w i d t h of 47 in. at shoulder height, and each stairway

has an area of 1 5 5 sq f t per storey, of which about 140 s q f t is the effective area taken up by a 47-in.- w i d e s t r e a m of people. The length of the travel path per floor is 40 f t m e a s u r e d along the centreline of

a

47 -in. path down the stairs and landings.

EVACUATION PLANNING,

ORGANIZATION,

AND PROCEDURE

The planning for the evacuation d r i l l and f o r f u t u r e emergencies w a s extensive, and both planning and the procedures to b e f o l l o w e d

(as w e l l as w a r n i n g of

an

impending d r i l l ) w e r e outlined in a bulletin given t o B.

C.

Hydro Head O f f i c e staff a few days b e f o r e the d r i l l .

Tn

addition, detailed instructions (for total and partial evacuations) w e r e i s s u e d t o evacuation control personnel: evacuation control officers (five in the building)* floor wardens, assistant f l o o r wardens, a n d

s e a r c h e r s , all under the d i r e c t i o n of

a

Chief Evacuation Control

Officer.

Evacuation p r o c e d u r e s for the B.

C.

H y d r o H e a d Office building a r e d e s i g n e d to be simple to follow w h i l e permitting flexible control

by key evacuation personnel. Total evacuation, for example, is initiated by means of a siren signal and an announcement, both

transmitted over the building's public address system. (The building is not

-

equipped with a general fire gong system. ) Evacuation of each f l o o r occurs untier the direction of a floor w a r d e n or his alternate;

people line up in the c o r r i d o r area at the designated exit and

proceed down the exit stairway as the warden d i r e c t s . ( D u r i n g the d r i l l l o w e r floor6 w e r e to precede upper f l ~ o r s . ) The w e s t s t a i r w a y is the designated exit f o r even-numbered floors and the east stairway

the exit f o r odd-numbered floors, although a warden can order evacuation via the alternate exit stairway i f this is m o r e appropriate. People w h o cannot walk down the stairways are evacuated by elevators taken out of automatic s e x v i c e by maintenance staff. Once out s i d e t h e building, all personnel assemble in designated a - e a s away f r o m a c c e s s r o u t e s t o

t h e building.

The effective functioning of the hierarchical organization of

evacuation control personnel is dependent on the building's communica-

t i o n s systems (although each f l o o r warden can i n d e p e n d e n t l y evacuate his floor if necessary). These systems i n c l u d e a public address

network t h r o u g h o u t the building, an emergency telephone s y s t e m in

each exit at every floor level. and intercorns in the elevators. T h e s e systems a r e all c o n t r o l l e d from a s e r v i c e c e n t r e that n o r m a l l y a c t s as a t r o u b l e centre for

B.

C.

Hydro's power d i s t r i b u t i o n network and is thus constantly manned by t r a i n e d staff.

W i t h e m e r g e n c y procedures ~lanned in g r e a t d e t a i l , the B. C . H y d r o H e a d Office staff w a s probably better prepared f a r an evacuation t h a n might normally be the case in high-rise office buildings. W h e n

a d r i l l was held on 2 6 June it w a s not unexpected a n d there w e r e few

questions about procedure.

OUTLINE

OF

THE DRILL AS CARRIED OUT

The following l o g of events: during t h e d r i l l w a s d e r i v e d f r o m a

t a p e r e c o r d i n g of all conversatioas on the ern ergency telephone s y s t e m

a n d from notes made by a t e a m of seventeen o b s e r v e r s stationed

throughout the building (Appendix A). Times are given in m i n u t e s and seconds, starting at 9 : 30 a. m, (assumed a c c u r a c y is w i t h i n

*

1 5 sec).

0: 0 0 Manual f i r e alarm station activated on seventh f l o o r

0:45 C a l l aver public address for Evacuation C o n t r o l o f f i c e r s

to r e p o r t

0:50 Seventh floor asked to investigate alarm

1: 15 Seventh floor r e p o r t e d that total evacuation r e q u i r e d

1:45 Siren sounded for about 30 s e c over p u b l i c address s y s t e m

2: 15 Total evacuation announced over p u b l i c a d d r e s s s y s t e m

2:30 First Evacuation Control Officer a r r i v e s at service c e n t r e

2 : 3 5 First people out of e a s t exit stairway ( p r e m a t u r e evacuation)

3: 3 0 First people out of w e s t exit s t a i r w a y

41 00* Firemen entered building and walked up stairways

6 : 3 0 F i r e m e n arrived at seventh floor

1 0 : 35 Last floor reported clear (eighth floor).

11: 10 Firemen on seventh f l o o r reported everything @'OKu

14: 00 Last people out of exit stairways

14: 30 Building officially reported clear 22: 45 Re-entry of building approved.

+ T h e V a n c o u v e r F i r e Department responded to the alarm from a

distance of several blocks and checked t o s e e h o w e a s i l y f i r e m e n c o u l d ascendthe stairways against the descending stream of e v a c u e e s .

(fn

a real f i r e emergency the F i r e Department would be notified b y the B.

C .

District Telegraph Office, which acts as t h e c e n t r a l supervising s t a t i o n

ANALYSE

OF

MOVEMENT DURING THE DRILL

The charts and t a b l e s in F i g u r e s 2 and 3 p r o v i d e , in highly condensed a n d abstract f o r m , a description of movement d u r i n g the

d r i l l . In _{Figure 2 , f o r example, the movement characteristics of} occupants f r o m odd-numbered f l o o r s (all using the e a s t exit) a r e described on a t i m e -scale s t a r t i n g w i t h the initial activation of the f i r e a l a r m station on the seventh floor.

In

the upper chart the sloping lines trace the movement of groups of occupants as these floor groups f o r m and then follow each other down the e x i t stairways in n e a r l y r e g u l a r sequence. The information in the table immediately below the upper chart identifies the f l o o r groups, the number of working places on the f l o o r s , a n d the actual number of evacuees from the floors. Positions of data f o r each floor group l i n e up vertically

w i t h the lower end of the corresponding movement "trace" l the

upper chart.

h

addition, the flaw of evacuees from the stairways

is plotted in the l o w e r g ~ a p h , directly below the corresponding

population d a t a in the table.

This analysis of the evacuation movement w i l l be d i s c u s s e d kn t e r m s of the t h r e e key movement variables: speed, flow, a n d

stairway area per person (the r e c i p r o c a l of density).

The s l o p e s of the t r a c e s i n the upper charts of Figures 1 and 2

represent speed of movement down the stairs.

h

s a m e cases d a t a were available f o r caLculating t h e s e speeds, which a r e i n d i c a t e d as

r a n g i n g between 120 and 160 f t per min (equivalent to descending 3 to

4 storeys per min). Although this range is near or slightly above normal for movement down stairways (4,

51,

the longer travel path length per storey (40 ft _{versus 30 f t or less f o r s t a i r w a y s having a} m o r e conventional geometry w i t h less landing area) means that

descent f r o m upper floors takes longer.

In

addition, the frequent

change of d i r e c t i o n a n d stepping pattern f r o m t r e a d s to l a n d i n g s may

tend to reduce the density of a descending group of evacuees, thus

r e d u c i n g the flow down t h e stairways.

The d i s c h a r g e rate, or flaw of people from the exit stairways (plotted an the lower graphs i n F i g u r e s 2 a n d 31, w a s lower than might

be p r e d i c t e d f o r s t a i r w a y s 4 7 -in. w i d e . For example, the e a s t exit

stairway had a mean discharge rate of 33 persons p e r minute, w i t h a maximum sustained rate of about 7 0 persons per minute f o r about. a 2-min period. The literature on evacuation by stairs suggests a maximum flow of about 90 persons p e r minute in this w i d t h of stair

-

way, i. e . , 45 persons p e r minute far each 22-in. unit of exit width (3, 8, 9).

T h e area of s t a i r w a y available per p e r s o n [the reciprocal of density] d u r i n g the evacuation m3vement can b e calculated once t h e

s p e e d a n d flow are known(see Appendix B). F a r example, at a f l o w of about 70 persons per minute t h e speed of descent in _{the e a s t exit} s t a i r w a y c o u l d be assumed t o be about 120 ft p e r min. T h i s s u g g e s t s

that each person moving f r o m the stairway at t h i s point had about 6 sq ft of area available w h i l e still in the stairway. An over -all estimate of the average area available p e r person just b e f o r e leaving the exit is I 1 s q f t ( a s s u m i n g average speeds of 130 f t p e r m i n a n d

discharge rates of 42 p e r s o n s p e r minute). Observers r e p o r t e d that t h e r e w e r e g a p s in t h e f l a w f r o m the exits s o that this estimate of

1 1 s q ft average area p e r person s h o u l d be reduced to p e r h a p s 9 or 10 s q f t t o represent a typical condition in t h e d e s c e n d i n g g ~ o u p s of

occupants. These figures and t h e subjective evaluations of observers

suggest that the stairways w e r e not overcrowded. O b s e r v e r s a n d

evacuation personnel a l s o r e p o r t e d t h a t rntlvernent: w a s predominantly

two-abreast or in a s t a g g e r e d f i l e (as opposed to single file), as would be e x p e c t e d w i t h 47-in. s t a i r w a y width. This suggests that,

on the average, a spacing of five stair treads existed between one

person and the next immediately ahead in t h e stairway.

U n d e r these conditions, f e w difficulties w e r e e x p e r i e n c e d b y

those using t h e stairs. Only one minor mishap w a s observed when

a woman f r o m the ninth floor s l i p p e d and f e l l at about the seventh

flaor. She w a s assisted o u t of the exit at t h e sixth floor and w a s

taken down t o ground level by elevator. Apparently, there w a s little

difficulty when several firernen walked up each s t a i r w a y , against the downward flow of evacuees, to reach the seventh floor (the "fire floor''),

According t o observers and evacuation p e r s a n n e l , i n t e r r u p t i o n s

of uniform downward movement w e r e largely t h e result of l o w e r floor groups e n t e r i n g the stairs and t h u s stopping t h o s e from floors above

(this p r i o r evacuation of l o w e r f l o o r s being p a r t of the planned p r o c e - d u r e f o r the d r i l l ) . This is shown, in the top charts 05 Figures 2 and 3 ,

as p r o g r e s s i v e l y longer p e r i o d s of halted movement at t h e u p p e r , storeys. It s h o u l d be noted that the eighth - f l o o r grolrp w a s seriously

d e l a y e d in e n t e r i n g the stairway because upper floor groups w e r e

p e r m i t t e d to precede it. If t h e r e had been an actual f i r e an the s e v e n t h f l o o r , t h e eighth should have been one of the f i r s t t o be evactlated.

In comparing t h i s evacuation e x e r c i s e with other e v a c l ~ a t i o n e x e r c i s e s

it is i m p o r t a n t to keep in mind t h a t t h e B. C, H y d r o p r o c e d u r e c a l l e d f o r

the group f r o m each floor only left that floor w h e n all the occupants had gathered

in

the vicinity of the one exit designated f o r that floor. This p r o c e d u r e permits a great deal of control t o be exercised b y evacuation personnel (at the c o s t of increased evacuation t i m e ) .

Other evacuation procedures employ such c o n t r o l in varying d e g r e e s .

They i n c l u d e the traditional t y p e of unorganized egress of i n d i v i d ~ z a l s without specific directions ( o t h e r than an a l a r m signal) and a phased,

partial evacuation w h e r e complete f l o o r s i n t h e vicinity of a fire a r e evacuated before upper floors (starting at the t o p of the building and

c a r r y i n g on down to t h e f i r e area). F u r t h e r m o r e , evacuation m a y not

be from the b u i l d i n g to the outside but f r o m a f i r e c o m p a r t m e n t and

other threatened compartments to selat iveiy s a f e areas in the s a m e building.

EVACUATION TIME

Evacuation time, f o r total evacuation by stairways, is an a g g r e g a t e

of the t i m e s taken for occupants to p e r c e i v e the signal t o evacuate, d e c i d e

on appropriate behavior, move to the exit s t a i r w a y , a n d w a l k down the s t a i r w a y s t o the e x t e r i o r at ground l e v e l . The t i m e taken for all the peapleto move down the stairs can be considered as a function of the

speed of movement of the f i r s t p e r s o n from :he l o w e s t occupied f l o o r

to the exit discharge a n d also t h e d i s c h a r g e rate (itself a function of

s p e e d and density) for the stream of evacuees who follow.

If a prediction w e r e t o be m a d e for t h e fastest p o s s i b l e evacuation of 910 persons by t w o s t a i r w a y s f r o m f l o o r s 1 t o 21 of the B. C . H y d r o

building, the evacuation t i m e would include about

$

rnin for t h e f i r s t

1

persons t o reach the stairways, 2 _{min for travel by them f r o m the}

first floor t o the ground level (at a s p e e d of about 1 0 0 f t p e r min) and about 5 min f o r the remaining occupants t o f l o w out behind t h e s e f i r s t persons in a s t e a d y stream (at an average flow of 9 0 people p e r minute). This totals about 6 min. Keeping i n mind that the p r e d i c t i o n is f o r u n - c o n t r o l l e d evacuation, t h i s time m a y be compared w i t h t h e 12-min p e r i o d that ensued after occupants in the B.

C ,

H y d r o b u i l d i n g heard the evacua

-

t i o n announcement over the p u b l i c address s y s t e m and e v a c u a t e d in a

controlled manner.

It

should be noted that the t w o most important factors i n f l u e n c i n g evacuation time in the exercise w e r e the organization f o r e v a c u a t i o n

before t h e stairways w e r e entered and the actual rate of d i s c h a r g e f r o m the exits. T h i s rate only averaged about 42 persons per m i n r ~ t e (with

a s u s t a i n e d peak of about 7 0 persons p e r m i n u t e ) instead of a b o u t 9 0 persons per minute as the p r e d i c t i o n assumed. The l o n g e r a c t u a l time

apparently resulted because

a

l a r g e measure of control w a s exercised

in the evacuation p r o c e d u r e and the evacuees d e s i r e d comfort rather than m a x i m - ~ r n s p e e d and d e n s i t y in the stairways,

If another, s i m i l a r , evacuation w e r e attempted, with a comparable d e g r e e of procedural c o n t r o l and occupant comfort, it would be p o s s i b l e

to reduce evacuation t i m e t o about 10 min. This w o u l d require a m o r e

efficient u s e of t h e t i m e spent organizing occupants on each floor a n d t h e avoidance of gaps in the flow of evacuees, especially between floor groups.

Another improvement in p r o c e d u r e might b e t o m o d i f y or d e l e t e

the r e p o r t i n g by w a r d e n s to the s e r v i c e centre, by emergency telephone,

of clearance of each floor. T h e s e reports w e r e delayed b y as m u c h as

6 rnin (with a mean delay of 2 rnin L O o e c ) w h e n the telephone s y s t e m became jammed. Although these delayed r e p o r t s m a y have tended to

give evacuation c o n t r o l o f f i c e r s at the service centre a p o o r p i c t u r e of

the course of the evacuation, they w e r e apparently not a factor in e x t e n d i n g

the evacuation time since t h e longest reporting delays w e r e experienced by the wardens from the l o w e r floors, which w e r e the first t o be c l e a r e d .

ENVIRONMENTAL CONDITIONS

IN

_THE

_STAIRWELM

It has a l r e a d y b e e n noted that evacuees had adequate room t o walk

comfortably down the exit stairways.

h

addition, several o t h e r

environmental conditions w e r e noted to assist in establishing the context f a r evacuation movement:

The t w o exit stairways w e r e w e l l l i g h t e d . N o m e a s u r e m e n t s w e r e made during the d r i l l , but maintenance staff reported illumination a t a b o u t 2 0 footcandles (20 lumens per f t ) . This w a s p r o v i d e d by an u n u s u a l

system of unshislded continuous -tube fluorescent l u m i n a i r e s at the

soffit. W a l l surfaces w e r e p l a s t e r and s t a i r treads w e r e t e r r a z z o ,

various degrees of spread and r e g u l a r reflection, E m e r g e n c y lighting was installed but not u s e d during t h e d r i l l .

h

t e r m s of t h e s e visual features, t h e exits should function b e t t e r

than many found in office buildings (which often have inadequate or poorly d i s t r i b u t e d exit illumination). Except for a p o s s i b l e claczstrophobic

response t o the spiraling enclostlre g e o m e t r y of the s t a i r w a y , o c c ~ i p a n t s

appear to find the stairs "attractive" and suitable f o r frequent u s e .

Sound levels w e r e measured in the w e s t s t a i r w e l l with an octave

hand noise analyser installed on the f o u r t h floor landing.

The

noise

during the evacuation fall under W.C. 45 and N.C. 70, respectively, with m o s t sf the noise p r o d u c e d by speech and the impact of f o o t s t e p s on the terrazzo f l o o r .

Initially, there w a s some question of whether noise a n d excessive

reverberation w o u l d make the exit s e e m m o r e c r o w d e d o r interfere

with the use a£ the e m e r g e n c y telephone in the e x i t s . In the tape r e c o r d i n g of emergency telephone conversations there s e e m e d to be

little difficulty wfth speech interference. The r e s u l t s of a questionnaire

given t o evacuation staff after the drill indicate that only a s m a l l

number of people found the noise annoying including a dozen w h o indicated

that it m a d e the use of the e m e r g e n c y telephone m o r e d i f f i c u l t . ( T h i s

may represent a majority of those who h a d to u s e t h e telephone.

1

C u n v e r sations inside the stairwell w e r e clearly heard aver s everal feet, permitting people walking s i d e by s i d e to talk easily. In general,

it appears that reverberation, which w a s severe when t h e stairwell w a s unoccupied, w a s minor when people w e r e present awing t o increased absorption.

T h e r e w a s some question, initially, about stuffiness and o v e r -

heating in the stairwells. Although the questionnaire d i d not cover

this point specifically, there w e r e s e v e r a l comments that the l o w e r

levels of the stairwells w e r e t o o w a r m a n d stuffy, even in t h e east

s t a i r w e l l w h e r e d o o r s on the ground, first a n d t w e n t y - f i r s t l e v e l s w e r e left open. In the w e s t stairwell only the ground- and tenth-floor

d o o r s were propped open, No m e a s u r e m e n t s w e r e taken of t h e r m a l cond itions.

C OMMENTS FROM EVAGUATION P E R S O N N E L AND OBSERVERS

W i t h

a

few exceptions, t h e s i r e n and the initial announcement, both transmitted over the public address system, w e r e c l e a r l y heard

everywhere in the floor areas. W i t h no speakers in the exit s t a i r w a y s , however, there w a s s o m e confusion when s o m e of t h e wardens stationed at the emergency telephones did not hear subsequent announcements. (Provision of speakers in t h e exits could alleviate this difficulty a n d provide a convenient means of communicating wfth evacuees in the

exits should s o m e change in the evacuation procedure become necessary.

3

In t e r m s of their initial interpretation of t h e public address

announcern ents, all t h e evacuation personnel, and presumably most

of t h e other occupants, w e r e sure it w a s an exercise rather than a

W h e n asked to comment an t h e effects of f a t i g u e in d e s c e n d i n g the s t a i r w a y only

a

few of those questioned thought t h i s w o r t h mention-

ing. (A short questionnaire w a s given to 6 3 evacuation personnel and 1 7 observers to help in assessing the exercise. ) T h e r e w e r e t w o r e p o r t s of slight dizziness d u r i n g descent from upper f l o o r s and it is p r o b a b l e that many people's legs w e r e a b i t unsteady after the

u n a c c u s t o m e d long descent. An observer moving w i t h the group f r o m the sixteenth f l o o r reported the s p e e d as "exceedingly fast. I n In F i g u r e

3 this particular speed is estimated t o be 1 6 0 f t p e r min.

Employee reaction t o the exercise appeared to be favourable, and,

in s o m e c a s e s , enthusiastic. T h e r e w e r e some r e p o r t s of staff

members who arranged to be absent at the t i m e of the expected d r i l l , but the number of people actually participating p r o b a b l y r e p r e s e n t e d a

typical building p o p u l a t i o n . The prevailing f a v o u r a b l e a t t i t u d e of the

B.

C.

Hydro staff to the exercise w a s due in l a r g e part to the

approach taken by B.

C ,

H y d r a management in explainingJ endorsing, p a r t i c i p a t i n g in, and expressing appreciation f o r t h e successful

e x e r c i s e . In addition, the exercise w a s w e l l reported by n e w s m e d i a

in Vancouver so that

B.

_{C. Hydro personnel knew they had participated}

in an i m p o r t a n t exercise having implications beyond their o w n safety. SUMMARY

fi; i s not the purpose of this Note to present d e t a i l e d conclusions

o r to suggest a comprehensive list of improvements t o the organization, procedures, and communications s y s t e m s t e s t e d in the

B.

_C.

_{H y d r o}

exercise. T h e exercise is significant in that it w a s a t t e m p t e d ,

completed, and reported. The r e s u l t s answer s o m e questions and

p o s e others; f o r example, office w o r k e r s are, on the whole, capable of

descending 22 flights of stairs in a very short time, but it is q u e s t i o n a b l e

whether they a r e w i l l i n g t o sacrifice their "body b u f f e r zone" (space between themselves and other people o r environmental features) in order to u s e the stairways m o r e efficiently.

The a n s w e r i n g of questions such as these and p r o p o s i n g of optimum

solutions t o the evacuation problem, as one aspect of a total approach to life safety, depends on a s e r i e s of studies ranging f r o m d e s c r i p t i v e reporting through h i g h l y disciplined hypothesis f o r m a t i o n and t e s t i n g activities, This report forms a small p a r t of tne necessary f i r s t s t e p .

REFERENCES

1 . Tamura, G.T. and J.H. McGuire. Smoke movement in high-

r i s e buildings. N a t i o n a l R e s e a r c h Council of Canada, Division

of Building Research,

CBD

133, January 1931.

2. Tarnura,

G.

T. and

J.

H. McGoire. Smoke control in high-

r i s e buildings. N a t i o n a l Research Council of Canada,

Division of Building Research, CBD 134, F e b r u a r y 1 9 7 1 .

3 . Design and C o n s t r u c t i o n of Building Exits. U. S. D e p a r t m e n t

of Commerce, National Bureau of Standards, Miscellaneous

Publication M 1 5 1 . Washington, 1935.

4. S e c o n d r e p o r t o f t h e o p e r a t i o n a l r e s e a r c h t e a m o n t h e c a p a c i t y

of footways. London Transport Board, Research Report No. 95,

London, 1958. ( S e e also reference 5 f o r abridged report).

5. Hankin, B. D. and

R.

A. W r i g h t . P a s s e n g e r flow in subways.

Operational Research Quarterly, Vol.

4,

No.

2, 1959* p 81 -88.

6 .

Malinski, A.

I.

Principles for regulating the evacuation of

public buildings, Fire Prevention and Firefighting:

Symposium. (Translation of Russian book), National L e n d i n g

Library f o r Science and Technology, Boston Spa, Yorkshir e ,

England, 1966.

7. Galbreath, M. A survey of exit facilities in high office b u i l d i n g s . National Res earch Council of Canada, Division of Building

Research, Bnilding Research Note No. 6 4 , September 1968.

8. Stevens, R. E. Movement of people. Fire J o u r n a l , J a n u a r y 2969,

p. 27-29.

9. Galbreath, M. Time of evacuation by stairs in high office b u i l d i n g s . Fire Fighting in Canada, February 1969 ( E R N 8).

ACKNOWLEDGEMENTS

The assistance given by the British Columbia H y d r o and P o w e r

Authority in the task of planning and conducting observations is grate -

fully acknowledged. The assistance given by Mr.

C.

Sutton, B. C . ~ ~ d r o ' s Chief Fire P~evention O f f i c e r , is e s p e c i a l l y appreciated.

In

addition, the author w i s h e s to thank members of the observation t e a m

APPENDIX A

MEMBERS

OF

OBSERVATION

COMMITTEE

L.

Auvache, Chief, Burnaby Fire Dept.

W.H. B ~ I , DBR/NRC

G.

Birnie, Chief, Vancouver Fire Warden

R. Chandler, Chief, W e s t Vancouver Fire Dept.

J. Flanagan, B. G. H y d r o

H. Jems, Deputy Provincial Fire Marshal B. M c L u r e ,

B.

C.

Telephone Co.

J.

L. Pauls, DBR/NRC

C ,

W.

Suaon, Chief Fire Prevention O f f i c e r , B.C. Hydro D. W a t t s , MacMillan Bloedel Ltd.

LIST

OF

OBSERVERS AND LOCATIONS DURING DRILL P, Anhorn, DBRJNRC, ( W e s t exit, ground f l o o r )

G . Birnie, Chief, Vancouver F i r e W a r d e n , (6th floor, w i t h radio) T. N. Blackall, DBRJNRC, (Basement exit)

A . W. Bridge, Burnaby Fire Dept.

,

( W e s t exit, 14th f l o o r to ground) H. Chapman, Burnaby Fire D e p t . , ( W e s t exit, 20th floor to

R. W. D a v i e s , MacMillan Bloedel, {East exit, 7th floor ta ground)

H. Hogan, Burnaby Fire D e p a r t m e n t , ( W e s t exit, 8th Iloor t o p o u n d )

H. Jenns, Deputy Provincial Fire Marshal, (6th f l o o r , w i t h radio]

G.

A. Laurie, MacMillan Bloedel, ( E a s t e e t , 15th floor to ground)

D, McGluskie, Vancouver F i r e D e p t . , (East exit, ground floor) H. J. McColm, Vancouver F i r e D e p t . , (Service centre)

R.

Montador, City of Vancouver, ( W e s t exit, 16th floor to ground)

M. Rangcley, Vancouver Fire Dept., ( W e s t exit, ground floor) J. Robinson, City of Vancouver, (East exit, 5th floor t o ground) P . A . Schaerer, DBR/NRC, (East exit, ground floor)

APPENDIX

B

RELATION B E T W E E N SPEED, F L O W , AND DENSITY

OF MOVEMENT

DOWN STAIRWAYS

Flow is d i r e c t l y proportional to both s p e e d and density f o r movement down stairways

The constant of proportionality for this relation is d e t e r m i n e d by the geometry of the stairway

where

F is the f l o w inpersons/min

S

is

the speed in _ft/min

D is the density of persons on the stairway in persons/sq f t

a is the horizontal area of stairs and landings in sq f t / s t o r e y 1 is the travel path length in ft/storey.

The area of stairway available p e r p e r s o n {represented by A in the equation below) is s i m p l y the reciprocal of the d e n s i t y (D). The

concept of area per person is somewhat easier to visualize and f o r this reason is used in d i s c u s sing stairway movement characteristics.

A = a

.

s

-

1

F

It should be noted that as a refinement to this equation the area

a is considered to be the effective horizontal area that would be used by

a

d e s c e n d i n g stream of people and 1 the centreline distance of this s t r e a m taken along the slope of the s t a i r s . As a result, the area

a used in this Note is less than the area of the &air shaft (i. e . 1 4 0 s q ft rather than 1 5 5 sq ft). This refinement s i m p l y recognizes that a

moving stream of people d o e s not fill angular corners of the stairshaft. (The effective area f o r movement is shown as a shaded r i n g , 4 7 in.

SCALE: i n t t a t DUCTS : : I I L J

,'

I8 RISERS AT 7' RUNS AT 10" STAIR F I N I S H

-

TERRdfZO SCALE: b 0 8 IU I STAIRWELL DETAILS

FIGURE

I

1

G R D

-

Position of Lost Member

a

I 5 _{1 0}

₁

- 1.5 I

T I

ME,

M I N U T E S

I

t

+

I I Ac h a l Number of Evacuees in Grow

F I G U R E

2

19 61 72 58 6 2 49 55 35 31 27 15 Total Number o f

Evacuees Usina Exif

5 1 0

TIME,

MINUTES

Discharging Floor Group

Available Work Places

on F l m r 19 80 152 210272 321 3 7 6 4 1 1 4 4 2 4 6 9 4 8 4

G R A P H S

A N D

T A B L E

D E S C R l B I N G THE E V A C U A T I O N

O F

P E R S O N S

ON O D D - N U M B E R E D

F L O O R S

U S I N G THE

E A S T

STRI

R W E L L

3 1 7 5 8 11 13 15 17 19 21 40 145 98 66 79 67 50 44 54 45 18

-

P a i t i o n of Lmt Member af each Floor Group in

fhe Ex?t Stairway

I Actual Number of 154 3 3 3 7 ? ? ? ? 25 99 0 15 10 1 5 I 1

TIME, M I N U T E S

I ! f

+

Discharging Flmr Group Availuble Work Places on Floor

,,

.loo 4 % ELL- w

o n >

~ 5 ~ 5 0 u O ~

=,*

a

-

F-

a 4

0 0 5

:

0 15

T I ME,

MINUTES

2 4 6 10 12 14 16 20 18 8 99 51 64 63 70 72 49 44 48 01 Evacuees i n Group Total Number of

Evacuees Using Exit

G R A P H S

A N D

T A B L E D E S C R I E l N G T H E E V A C U A T I O N

O F P E R S O N S O N

EVEN-NUMBERED

F L O O R S U S I N G T H E

W E S T

S T A I R W E L L .

P ? 54 105 142 25 1 301 326 425 ? ? ? 7

.C -70 is the background noise criterion for noisy factories.

26.5 53 106 212 424 849 1700 3390 6790 13590

F R E Q U E N C Y , C P S

STAI

R'E'VELL

NO1

SE

A N A L Y S I

5

TEST

a

C

NOISE M E A S U R E D I N T H E W E S T S T A I R W E L L , F O U R T H

FLOOR, W I T H A G E N E R A L R A D I O C O . TYPE 15513-A O C T A V E B A N D NOISE . Q N A L Y S E R W I T H i 5 6 0 P E T M I C R O P H O N E A S S E M B L Y

? ? r

A B C V E F L 0 0 R LEV. 1 TIME, MINUTES

-

5 (Before Drill + 4 (During Drill) 6 (During Drill)

+I0 (During Drif I)

NOISE ANALYSER

'

RE-m~~E s E T ~ l ~ = Slow Slow Fast Slow