NBS

PUBLICATIONS

NBSIR 80-2049

Emergency Egress From Mobile

Homes: Anthropometric and

Ergonomic Considerations

i AlllDD TflflTbS

V. J. Pezoldt

Consumer Sciences Division

Center for Consumer Product Technology

National Bureau of Standards

U S. Department of Commerce

Washington, D C. 20234

February 1980

Final Report

Issued May 1 980

Sponsored by:

Office of Policy Development and Research

Department of Housing and Urban Development

Washington, D C. 20410

repared for: Environmental Design Research Division

Center for Building Technology

National Bureau of Standards

NBSIR 80-2049

EMERGENCY EGRESS FROM MOBILE

HOMES: ANTHROPOMETRIC AND

ERGONOMIC CONSIDERATIONS

WATIONAL BUBJEAC or standabdb

I.ihRABY

WAY I HO-t - C^rCQ^foo

V.J. Pezoldt

Consumer Sciences Division

Center for Consumer Product Technology

National Bureau of Standards

U.S. Department of Commerce

Washington, D.C. 20234

February 1980

Final Report

Issued May 1980

Sponsored by;

Office of Policy Development and Research

Department of Housing and Urban Development

Washington, D.C. 20410

Prepared for; Environmental Design Research Division

Center for Building Technology

National Bureau of Standards

U.S. DEPARTMENT OF COMMERCE, Philip M. Klutznick, Secretary

Luther H. Hodges, Jr., Deputy Secretary

Jordan J. Baruch, Assistant Secretary for Productivity. Technology, and Innovation

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
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Table of Contents

page

Acknowledgements ; , . . ii

List of Figures iii

List of Tables. . .

' iv

Abstract .

.’ i. v

1. Introduction 1

2. Anthropometric Considerations for the Design of

Emergency Egress Devices 2

2.1 Population at Risk 2

2 . 2 Review of Anthropometric Data 2

2.3 Conclusions from the Anthropometric

Literature 12

3. Opening Size Requirements for Emergency Egress

Devices 14

3.1 Background 14

3.2 Method 16

3.3 Results 20

3.4 Conclusions 28

4. References 32

Appendix: Regression Models for Predicting the

Acceptable Area of Egress Openings . . 34

i
Acknowledgements Several individuals deserve recognition for their

valuable contributions to the completion of this project.

Thanks are due to Peun Tyeryar and Mary Abbott for secretarial

support, Harry Appleby for construction of the test apparatus,

Louis Porter for initiating the review of anthropometry

and Addie Stei#art and George Lapinsky for assistance in

data collection. Special thanks also to Mr. Lapinsky

and Sanford Adler for substantive suggestions and support

throughout the inception and performance of the project.

ii
List of Figures

Figure page

1 Vertical Grip Reach as a Function of Age 5

2 Maximal Force Exerted by Male Adults . . 6

3 Three-Point Pinch Forces as a Function of

Age ‘ . 8

4 Lateral Pinch Forces as a Function of Age 9

5 Maximal Forces Exerted on a Vertical

Hand-Grip by Standing Male Adults ... 10

6 Two Egress Opening Configurations Employed

by Hunt Co. (1972) and the Present Study 15

7 Emergency Egress Test Device 18

iii
1

2

3

4

5

6

7

8

9

10

11

A1

A2

List of Tables

page,

Vertical Grip Reach as a Function of Age 4

Maximal Torque Applied to Cylindrical Knobs

by Male Adults 11

Estimated Maximal Torque Applied to

Cylindrical Knobs by Female Adults ...... 13

Anthropometric Measures of Experimental

Subjects 17

Mean Difficulty Ratings for Minimum Size

Egress Opening Allowed by HUD Standard ... 21

Smallest Acceptable Area of Egress Opening:

Female Subjects 23

Smallest Acceptable Area of Egress Opening:

Male Subjects 24

Analysis of Variance: Minimum Acceptable

Egress Opening Area for Females 25

Analysis of Variance: Minimum Acceptable

Egress Opening Area for Males 26

Experimental Data Compared with Minimum

Egress Opening Area Permitted by HUD

Standard 27

Experimental Data Compared with Minimum

Least Dimension of Egress Opening Permitted

by HUD Standard 29

Anthropometric Data for Males and Females

Compiled from the Anthropometric Source

Book, 1978 36

Predicting Area (cm ) of Acceptable Egress

Openings 37

I iv
Emergency Egress from Mobile Homes

Anthropometric and Ergonomic Considerations

Abstract

This report summarizes a two task effort which is

part of the National Bureau of Standards evaluation of

the Federal Mobile Home Construction and Safety Standard.

The first task consists of a review of relevant anthropometric data from which egress requirements might be drawn.

The second task is an empirical study of egress designed to

generate data which can assist HUD in evaluating the existing

size requirements for egress devices. The degree to which

the requirements in the current standard for location and

operating characteristics of egress device latches and other

operating mechanisms are acceptable varies for different

segments of the population at risk. The limited applicable

anthropometric data suggests that the requirements are

sufficient, for the most part, for average, healthy,

normally ambulatory adults. The minimum opening size

requirements were also shown to be acceptable for average

healthy adults under most conditions tested. However,

devices which meet the maximum sill height allowed by the

standard were shown to be extremely difficult to negotiate

or unusable by a significant portion of the experimental

test subjects. Implications of the present egress requirements for escape by handicapped or otherwise impaired

individuals are discussed.

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Emergency Egress from Mobile Homes:

Anthropometric and Ergonomic Considerations

1. INTRODUCTION

In accordance with congressional legislation which

mandated the development of a national mobile home standard,

the Department of Housing and Urban Development (HUD)

published in the Federal Register (40FR58754) the final

rules and regulations for the Federal Mobile Home

Construction and Safety Standard. The standard, dated

December 18, 1975, became effective June 15, 1976, and is in

substantial measure based on previously existing National

Fire Protection Association and American National Standards

Institute standards (NFPA-501B-1974 , ANSI A119 . 1-1975 ) . In

addition, parts of the HUD standard are derived from state

standards, enforcing agency standards, and the results of

mobile home research conducted at the National Bureau of

Standards (NBS) and elsewhere.

A previous study conducted by NBS (Adler, 1977) to

identify the technical bases of the emergency egress

provisions of the HUD standard and to assess the adequacy of

these provisions concluded that, in general, there is

neither readily available data that provides a technical

basis for the egress provisions of the standard nor are

these egress requirements adequate.

In light of the generally negative conclusions of the

earlier work, HUD requested that NBS pursue further

analytical and empirical efforts relative to emergency

egress from mobile homes. This report summarizes the

portion of that effort directed at further exploration of

the anthropometric and ergonomic considerations of the

egress problem, especially as they bear on recommendations

for egress requirements.^

Two tasks are reported on here: (1) a review of

existing anthropometric data from: which egress requirements

might be drawn and (2) an empirical study of egress designed

to generate data which can assist HUD in evaluating and/or

redefining the opening size requirements for egress devices.

Measurement data in this document are reported in both English

and SI units where practicable. Because the HUD standard uses

English units, they are given precedence. Where conversions from

one system to the other are necessary, the following equivalences

are used: 1 in = 2.54 cm, 1 Ibf = 4.45 N, 1 in-lbf = .113 N-m.
2. ANTHROPOMETRIC CONSIDERATIONS FOR THE DESIGN OF

EMERGENCY EGRESS DEVICES

2.1 Population at Risk

The design of emergency egress devices should take into

account the characteristics of the population which may have

the need to use such devices. Some evidence suggests that

there are differences between the demographic

characteristics of mobile home occupants in the U.S. and the

population of the U.S. as a whole. The 1975 Annual Housing

Survey (Bureau of the Census, 1975) indicates that the heads

of households living in mobile homes and trailers are

slightly younger than those in all occupied housing. Also,

households in mobile homes are more likely to include one or

more children under 6 years of age. Lacking more compelling

data, these minor differences between mobile home occupants

and the population at large do not warrant consideration of

the population at risk in mobile homes as being

significantly different from the general population in terms

of those anthropometric considerations which may influence

design options in the setting of standards for egress

devices.

2.2 Review of Anthropometric Data

The application of anthropometric data to the

specification of design and performance requirements for

emergency egress devices must be undertaken very cautiously.

Many theoretical and practical problems with existing data

preclude the direct translation of such data into exact

specifications. At best, the available data may be used to

suggest guidelines or boundary conditions and, in a general

sense, to evaluate the requirements of the existing standard

in terms of the likelihood that they will provide adequate

egress conditions for the population at risk.

I Among the more obvious problems associated with the

available data is that the vast majority of data is from

military populations, primarily healthy young male adults,

and is not generalizable to the whole U.S. population. As

one proceeds from physical dimensions to static and dynamic

forces, the already limited data become increasingly task

specific and are based on even smaller samples. In

addition, most anthropometric measurements are made under

"best case" laboratory conditions and not in "worst case"

real-life situations as may be encountered when an emergency

egress device is used. Notwithstanding the limitations of

- 2 -
applying the anthropometric data, the design requirements

currently specified in the standard have been reviewed with

respect to relevant anthropometric measurements.

2.2.1 Size of Egress Opening . For egress openings, the

dimensions and height above the floor have been considered

independently from other design features and are the subject

of an empirical effort described in Section 3 of this

report.

2.2.2 Location of Egress Device Control Mechanisms . The

current standard requires that all latches , operating

handles, tabs and any other device which needs to be

operated to exit through the egress device be located a

maximum of 60 inches (152 cm) above the. floor. , Table 1 and

Figure 1 show the mean, 5th and 95th percentile"^ vertical

grip reach of males and females as a function of age (Snyder

et al, 1977) . These data suggest that operating mechanisms

which meet the maximum height requirements of the standard

may be expected to be accessible to 95 percent of 10 year

old children. Virtually all healthy, normally ambulatory

people above the age of 11 years could reach control

mechanisms located at the highest point currently allowed

assuming that no obstacles prevent a direct vertical reach

to the device. Only a very small percentage of 7 year old

and younger children would be predicted to be capable of

reaching a 60 inch (152 cm) high control without assistance.

2.2.3 Force Requirements for Operation of Control

Mechanisms . The force required to operate control mechanisms

may not exceed 20 pounds (89 N) for, the primary window and 5

pounds (22 N) for appurtenances to comply with the standard.

Although there is a considerable body of anthropometric data

regarding applied forces , only a limited amount is

applicable to the present situation. The forces which can

be applied depend in large part on the type of device being

operated and the spatial orientation of the device with

respect to the operator.

Figure 2 shows the 5th percentile and mean maximum

static forces exerted by adult males for three types of

prehension (Taylor, 1954) . For all three types; palmer,

tip and lateral, the mean force exceeds 20 pounds (89 N)

The 5th percentile maximum forces range from 12.6-15.3

pounds (56 - 68 N) depending on the type of prehension. A

control mechanism which requires a pinching or squeezing

operation with the fingers which does not require in excess

of 12.6 pounds force (56 N) to operate should be suitable, for

about 95 percent of the adult male population. Although no

A percentile point is defined as a specific point in a

distribution which has a given percent of icases below it.

- 3 -
Table 1. Vertical Grip Reach As a Function of Age

(Snyder et al, 1977)

Grip Reach

Age Mean 5th Percentile 95th Percentile

cm in cm in cm in

2.0- 3.5 107.3 42.2 97.5 38.4 121.8 48.0

3.5- 4.5 116.6 45.9 107.0 42.1 128.5 50.6

4.5- 5.5 126.1 49.6 113.1 44.5 136.9 53.9

5.5- 6.5 135.6 53.4 124.1 48.8 147.2 58.0

6.5- 7.5 144.6 56.9 129.5 51.0 158.5 62.4

7.5- 8.5 152.2 59.9 138.7 54.6 163.2 64.2

8.5- 9.5 160.8 63.3 146.1 57.5 173.8 68.4

9.5-10.5 167.1 65.8 153.5 60.4 182.0 71.6 1 10.5-11.5 174.7 68.8 156.0 61.4 190.3 74.9

11.5-12.5 181.6 71.5 il65.4 65.1 198.5 78.1 1 12.5-13.5 190.5 75.0 174.3 68.6 208.4 82.0 j 13.5-14.5 195.3 76.9 175.8 69.2 211.3 83.2 1 14.5-15.5 199.8 78.7 183.2 72.1 215.4

1 84.8 ! 15.5-16.5 205.0 80.7 185.0 72.8 224.4 88.3

16.5-17.5 205.6 80.9 186.3 73.3 224.5 88.4

17.5-19.0 206.9 81.4 188.9 74.4 227.0

i_—

89.4

- 4 -
FIGURE

I

<

VERTICAL

GRIP

REACH

AS

A

FUNCTION

OF

AGE

G>

<0 S ? 3

OaHQ. ttUJ<OX HZ HZOZUJ(0

5

CAdapi«d

from

Snydor

el

a\,

19775
FIGURE

2:

MAXIMAL

FORCE

EXERTED

BY

MALE

ADULTS

8 10 (9

b-ooeobj MZ a.O3ZO(0

6

TYPE

OF

PREHENSION

CAdapl«d

from

Taylor^

1054)
comparable data are available for women, Laubach (1976)

suggests a procedure for estimating female strength

capabilities from male data. In this case, the 5th

percentile maximum force exerted by females is estimated at

67 percent of that for males shown in Figure 2, or about 8.4

pounds force (37 N) . The pinch forces which can be exerted

by 10 year old children do not differ markedly from those

estimated for 5th percentile female adults. Figures 3 and 4

show the mean, 10th and 90th percentile forces applied by 3

to 10 year old children with a three-point pinch and lateral

pinch respectively (Owings et al, 1975) . The three-point

pinch was performed using the thumb and first two fingers to

pinch together two plates 20 mm apart. The lateral pinch

employed the thumb and side of the first finger.

Figure 5 suggests the maximum forces which can be

applied to devices which require a vertical movement and

which can be gripped by the whole hand CRohmert, 1966)

.

Figure 5 provides data from standing male adults applying

force with the right hand on a vertical hand-grip in three

directions, to the right, up and down. The figure shows the

maximal forces exerted in these directions at 100 and 50

percent of the subjects' maximum grip distance. Maximum

grip distance occurs when the arm is fully extended away

from the body. The data are presented at both 0 degrees,

i.e. arm extended horizontally, and 30 degrees, i.e. arm

raised 30 degrees above the horizontal. Estimates of the

maximum forces of these types which could be exerted by

females are about 58 percent of that of males (Laubach,

1976). Thus, a reasonable maximum forceto allow for

mechanisms requring a vertical downward pull is about 19

pounds (85 N) . For mechanisms requiring movement upward or

to the right a maximum force of 11 and 12 pounds (49 and 54

N) respectively should be allowed. These estimates are very

conservative in the sense that they are based on a "worst

case" situation in which the required forces would be

applied in a manner least conducive to generating large

forces. That is, they are based on data taken with the arm

fully extended directly in front of the body.

Although the current standard permits operating

mechanisms which require rotary motion of up to .180 degrees,

the maximum torque allowed for the operation of such devices

is not specified. The magnitude of torque which can be

applied to turn knobs varies greatly as a function of knob

characteristics. In general, as shown in Table 2 (Roebuck,

1965) , greater torque can be applied when knobs are knurled

rather than smooth and, all else being equal, more torque

- 7 -
FIGURE

3:

THREE-POINT

PINCH

FORCES

AS

A

FUNCTION

OF

AGE

V

Q>

QO

<D

U)

CO

CM

(M — • CO ^ CM

IkOOCOId MZ Q.O3ZQC0

G>

8
FIGURE

4:

LATERAL

PINCH

FORCES

AS

A

FUNCTION

OF

AGE C9

0>

00

(O

Id

(D<

li)

<o

<0

00 <0 ^ CM

li.OaOUJ HZ 0.03Za(0

C

Adapted

from

Owings

et

al^

19755
FIGURE

5

MAXIMAL

FORCES

EXERTED

ON

A

VERTICAL

HAND-GRIP

BY

STANDING

MALE

ADULTS

8

%

8

8

O

CM

IcOOCOUJ HZ Q.O3ZO<0

DIRECTION

OF

FORCE

CAdapied

from

Rohmori^

1

966>
Tfedsle 2. MBDcinal Itxrque jelled to Cylindrical Khobs

By Male Adults (Roebuck, 1965)

Rx>b Configuration

Kiob Diameter Smooth Knurled Knurled

(inches) .5 in Thldc .5 in Thick .65 in Thick

s

5th . 5th 5th

Mean Percentile Mean Percentile Mean Percentile

.125 .255 .145 — — .749 .580

.5 2.61 1.87 — — — —

1.0 7.62 2.88 11.9 6.0 11.3 6.2

1.5 14.6 7.00 — — — —

2.0 18.7 9.67 26.5 18.3 27.3 18.4

2.5 26.5 18.52 — — — —

^1 torque values are in inch-pounds.

percentile values have been oonputed fran standard deviations.

i

-11-
can be applied as knob diameter increases . For females , the

magnitude of torque which can be applied is approximately 53

percent of the torque applied by males (Laubach, 1976) . The

computed estimates of mean and 5th percentile maximal torque

applied by female adults are presented in Table 3,

2.3 Conclusions from the Anthropometric Literature

The degree to which the requirements in the current

standard for location and operating characteristics of

egress device latches or other control mechanisms are

acceptable varies for different portions of the population

at risk. Based on the limited applicable anthropometric

data available the following conclusions can be drawn. . The maximum allowable height for operating devices, 60

inches, is acceptable for virtually all ^healthy "adults and

most children 10 years old and older. Most children less

than 7 years old and adults who are unable to fully raise

their arms likely will not be able to reach devices located

at the maximum height without assistance.

The maximum operating forces which can be exerted on

latches, knobs or other mechanisms is very task specific.

For control tasks which require relatively gross whole arm

forces, the current maximum allowable forces of 20 and 5

pounds for primary windows and appurtenances, respectively,

is within the capability of most healthy adults. For

devices which require greater dexterity and more precise

application of force , the force which can be exerted drops

significantly. Most adults will be able to operate

mechanisms that are pinched or squeezed which do not require

application of greater than eight pounds force. Depending

on the specific type of pinching force required, most lO

year old children will also be able to operate such

mechanisms. , - .

The torque which can be applied to knobs requiring

rotary motion, currently allowed only up to 180 degrees,

varies significantly with knob size and surface

characteristics. Knobs less than 1.5 inches in diameter

should require a torque of less than 5 inch-pounds.

It must be remembered that the data upon which these

conclusions are drawn were collected from healthy, normal

adults under laboratory conditions . To the extent that

egress devices are intended to be operable by the very

young, old, or handicapped without assistance, the forces

- 12 -

I
Table 3. Estimated^ Maximal Torque i^lied to Cylindrical

Knobs by Fennale Adults

Knob Oonfiguration

ii Knob Diameter Smooth Knurled Knurled

(inches) .5

Nean^

in Thick

5th

Percentile

.5

Mean

in Thidc

5th

Percentile

.65

Mean

in Thick

5th

Percentile

.125 .135 .077 — — .397 .31

.5 1.38 .99 — — — —

1.0 4.04 1.53 6.31 3.2 6.0 3.3

1.5 7.74 3.71 — — — —

2.0 9.91 5.13 14.04 9.7 14.5 9.8

2.5 14.04 9.82 — —

^Estimates are .53 of torque applied by male subjects.

^All torque values are in inch-pounds.

I

t

1

!

-13 -
which can be applied will be reduced, in some cases to

essentially zero. On the other hand, maximum forces

measured under laboratory conditions may be considerably

less than those exerted in actual emergencies during which

physiological changes associated with stress may serve to

temporarily enhance physical capacity. Also, motivational

levels attained in emergencies will likely be higher than in

the experimental environment.

3. OPENING SIZE REQUIREMENTS FOR EMERGENCY EGRESS DEVICES

3 . 1 Background

The HUD standard requires all egress devices to provide

a minimum opening of 720 in^ (4645 cm^) with a least

dimension of 22 in (56 cm) . The bottom of the opening may

be a maximum of 36 in (91 cm) above the floor. Although

these dimensions are compatible with the dimensions required

by previous voluntary standards for mobile homes (MHMA, 1973

and NFPA, 1975) and with design recommendations for crawlthrough openings (Woodson and Conover, 1964; Van Cott and

Kinkade, 1974; and McCormick, 1976) in military and

industrial settings, there is very little directly

applicable anthropometric or other empirical data to support

the current dimensional requirements.

A study by Robert Hunt Co. (1972) did directly address

the issue of opening size for emergency egress. This study

concluded that markedly smaller openings than those

permitted by the current standard provide comparable or

better egress efficiency. In the Hunt study, the mean time

required to egress from the "standard” opening (32.75" w x

22" h) was compared with the mean egress times for five

other opening configurations. Unfortunately several aspects

of this study limit its usefulness in assessing the adequacy

of the present standard.

The least dimension for each of the comparison openings

employed in this study was the width (16 or 18 in) , while

the only "standard" opening used had the height as its least

dimension. Thus, as shown in Figure 6, all comparison

openings were tested in configuration A while the minimum

size opening allowed by the standard was only tested in

configuration B. Also, since the inl^erior sill heights

ranged from 42-48 in above the floor, an 18 in high step was

used to afjsist subjects over the sill and a ladder was

placed adjacent to the exterior of the opening to assist in

- 14 -
FIGURE

6.

TWO

EGRESS

OPENING

CONFIGURATIONS

EMPLOYED

BY

HUNT

C0.CI072>

AND

THE

PRESENT

STUDY

—I

>

15
egress. These conditions cannot be assumed to exist at the

time of actual use of emergency egress openings. Finally,

although the ages of the 10 subjects (8 males, 2 females) in

this study ranged from 20-60 years, all but four subjects

were 31 years old or younger.

Given the inadequacy of existing data for determining

the appropriate dimensions for emergency egress openings in

mobile homes, an empirical study was performed. While this

study could not ameliorate all of the deficiencies of past

efforts, it does provide additional data under somewhat more

realistic conditions.

3 . 2 Method

3.2.1 Subjects . A total of 25 paid volunteers, 16 females

and 9 males, participated in the study. The only subject

selection criteria were that all subjects be between 40 and

65 years of age, and in general good health with no history

of chronic or acute heart, respiratory or back problems.

The female subjects ranged from 40-63 years old (mean = 48.8, s.d. = 6.5) and the males ranged from 42-64 years old

(mean = 57.4, s.d. = 6.8).

In addition to age, five other subject variables were

measured and subsequently used in the analysis of the

experimental data. These variables are: stature, weight,

bideltoid breadth, hip breadth, and sitting acromial height.

Also, a derived measure, the ratio of stature to weight, was

computed. All measurements were made with subjects fully

clothed with the exception of the height and weight

measurements which were taken without shoes. Subject

measurement data are summarized in Table 4.

3.2.2 Apparatus . The primary test apparatus (see Figure 7)

was a specially fabricated wooden fixture consisting of a

wall with an egress opening simultaneously adjustable in

both width and height, and an adjustable floor platform.

The bottom of the egress opening was 122 cm (48 in) above

the floor on the "exterior” side of the test wall. The

"interior" floor was a platform which could be adjusted to

provide interior sill heights of 15, 46 and 91 cm (6, 18 and

36 in) . The width of the egress opening was continuously

adjustable between 0 and 122 cm (0-48 in) . The height of

the opening could be adjusted in 2.54 cm increments from 41-

122 cm (16-48 in)

.

- 16 -
Table 4. Anthropometric Measures of

Experimental Subjects

Measure Mean S.D. Mean S.D.

Age years

Female 48.8 6.5

Male 57.4 6.8

Stature cm in

Female 163.6 8.2 64.4 3.2

Male 172.0 5.7 67.7 2.3

Weight kq lb

Female 68.4 15.7 150.7 34.6

Male 79.1 10.9 174.4 24.1

Bideltoid Breadth cm in

Female 41.9 3.7 16.5 1.4

Male 44.4 2.7 17.5 1.1

Hip Breadth cm in

Female 37.2 3.7 14.6 1.5

Male 36.4 2.3 14.4 1.9

Sitting Acromial

Height cm in

Female 58.5 3.7 23.0 1.4

Male 60.8 2.3 23.9 .9

Stature/Weight cm/kg in/lb

Female 2.58 . 63 .45 .11

Male 2.27 . 36 .39 .05

Stature Bideltoid

Breadth

Sitting Acromial

Height

- 17 -
- 18 -
The test apparatus differed from actual mobile home

egress openings in several ways due to features of the

apparatus designed to assure the safety of experimental

subjects. The "exterior" landing area to which subjects

egressed was covered with a 20 cm thick foam pad. All

exposed surfaces of the egress opening were smooth sanded

and the opening sill was covered with cloth tape to provide

a smooth surface. Clearly, this provided a smoother surface

for egress than that found in existing mobile home egress

devices. Also, the exterior sill height was less than that

likely to be encountered in mobile home installations.

3.2.3 Procedure . Subjects were informed that the purpose

of the study was to provide data which would assist HUD in

determining the appropriate size opening for escapes from

mobile homes in the event of fire or other emergencies.

Subjects were not told the current minimum dimensions until

all testing was completed. They were instructed that they

would make a series of simulated escapes though various size

openings with three different interior sill heights (15, 46,

and 91 cm) and that they would be free to egress in any

manner they desired with the restriction that they must land

on the exterior landing pad feet-first. No head-first dives

or tumbles were permitted. Also, it was suggested that

subjects imagine the exterior drop to be higher than it

actually was to discourage egress techniques in which the

sill was straddled and one foot placed on the landing mat

while the other was still on the sill. Such egress

strategies were only possible for the taller and more limber

subjects tested.

The order of presentation of the sill heights was

randomized across subjects. The first egress opening

presented was, for all subjects and at each sill height, the

minimum opening size currently permitted by the standard,

i.e. 4645 cm^ (720 in^)

.

Before any egresses were attempted, subjects were

instructed that they were to rate the ease/difficulty of

each escape immediately upon completion of the trial. The

rating was made on a 5 point scale where 1 = extremely easy

and 5 = extremely difficult. A rating of "3" was to fall

midway between the extremes of ease and difficulty. It is

this moderately easy/moderately difficult rating of "3"

which, for the purposes of this study, defines the

"acceptable" size egress opening. After the first trial the

height or the width of the opening was increased to 107 cm

(42 in) by the experimenter and the remaining dimension was

- 19 -
adjusted to that dimension which the subject predicted would

be the smallest he or she would rate a "3.” The subject

then made an egress. If the rating was less than 3, the

opening was decreased until the subject predicted a rating

of ”3" would be made. If the rating was greater than 3 the

opening was increased along the pertinent dimension. This

iterative process was then repeated for the second

dimension. The process was continued until the smallest

dimensions both in width and height for which the subject

gave a rating of "3" was determined. The process was

carried out in both configurations A and B (see Figure 6)

for each subject at each of the three interior sill heights.

Each series of trials always began with the "standard" size

opening.

The iterative testing procedure described above

resulted in approximately 5 test trials per sill height for

each of the 2 opening configurations. Thus, each subject

made a total of approximately 30 simulated emergency

egresses. The dimensions of the egress opening and the

associated rating were recorded for each trial.

Subjects were instructed to give their rating for each

egress immediately upon completing a trial. They were

further instructed not to make comparative ratings between

the various trials, but rather, to the extent possible, to

make independent ratings of each trial.

3.3 Results

The results of the present study are reported in

several parts. Presented first are data relating to ratings

of the minimum size opening currently permitted. These are

followed by results concerning the area of subject generated

egress openings and the least dimensions of these openings.

The results of an attempt to generate a multiple regression

model of the minimum acceptable area for egress openings are

described in the Appendix.

3.3.1 Ratings of Current Minimum Opening . All subjects

egressed through the minimum size opening now allowed by the

standard, 4645 cm^ (720 in^ ) , at each of the three sill

heights. The mean difficulty ratings for these egresses are

shown in Table 5. Sill height did not significantly

influence the ratings of the men egressing through the

standard opening (F = 1.54, df = 2/24, p

> .05). The mean

rating was "acceptable" i.e. 3 or less, for all £;ill

heights. The mean rating of the women was "acceptable" for

- 20 -
Table 5. Mean Difficulty Ratings for Minimum

Size Egress Opening Allowed by HUD

Standard—4645 cm2 (720 in^)

Females

Males

Sill Height in cm (in)

15 (6) 46 (18) 91 (36)

2.50 2.44 3.81

2.00 2.89 2.00

- 21 -
the 15 and 46 cm sill heights/ but significantly more

difficult for the 91 cm sill, which received a mean rating

of 3.81 (F = 6.54/ df = 2/45, p

< .01). Two of the women

were incapable of egress at the highest sill height allowed

by the standard.

3.3.2 Area of Subject Generated Openings . The raw data for

each subject was reduced to yield the smallest area of

egress opening which was rated "3" (i.e. defined as

"acceptable") for both of the two initial configurations at

each of the three sill heights. These data are shown in

Tables 6 and 7 for females and males respectively. Note

that no data are presented for female subjects 9 and 11 at

the 91 cm sill height, since these subjects could not egress

through any opening at this sill height because they could

not negotiate this sill height unassisted. The missing data

for female subject 6 at the 15 cm sill height is

attributable to experimenter error while testing this

subject. The empty cells produced by these missing data

were accounted for by using unequal number of subjects analyses

in all subsequent analyses.

These data were subjected to a two-way classification

analysis of variance and the associated simple contrasts to

identify any significant differences among the means as a

function of sill height and opening configuration.

Separate analyses were performed for males and females. The

results of these analyses, presented in Tables 8 and 9,

indicate that for females there was no statistically

significant difference in the egress opening as a function

of opening configuration. The opening size required for the

91 cm (36 in) sill was significantly greater than that

required for either the 15 or 46 cm sill height but no

difference between the size required for the 15 and 46 cm

heights was observed. For males, no difference in size was

detected as a function of sill height, however, opening

configuration did produce a difference in the minimum size

opening found acceptable. Configuration B (horizontal

orientation) resulted in a significantly larger opening size

than configuration A (vertical orientation) . The

interaction between sill height and opening configuration

was not significant for either females or males.

When the mean acceptable opening size data under the

various egress conditions of the present study are compared

with the currently allowed minimum opening size (Table 10)

the present areal dimension appears generous for all

conditions except for females egressing over a 91 cm (36 in)

sill and men egressing over a 46 cm (18 in) sill through a

- 22 -
Table 6. Smallest Acceptable Area of Egress Opening:

Female Subjects

Subject Sill Height 15 cm/

6

in 46 cm/ 18 in 91 cm/ 3 6 in

Configuration I A*

\ A B A B

1 cm^ 4064 5419 i 4969 4268 3606 4355

1 ^ in^ 630 840 1 770 662 559 675

o cm^ 3616 2400 2787 3523 3500 3484

in^ 560 372 432 546 542 540

*1 cm^ 5290 5400 6435 4723 6710 5403

in^ 820 837 998 732 1040 833

A cm^ 2710 3716 4771 5052 6000 4258

H in 2 420 576 740 783 930 660

cm^ 6774 5045 4361 4516 5110 5110

i j in^ 1050 782 676 700 792 792

cm* 4181 — 4529 5574 5161 5323

0

t in* 648 - 702 864 800 825

! 7 cm* 4297 4400 4023 4181 3774 3929

i f in* ; 666 682 624 648 585 609

cm* 3832 5661 3613 4826 5284 4971

3 in* 594 878 560 748 319 770

I Q cm* 2768 2323 3658 2613 - -

i in* 429 360 ; 567 405 - -

i 10 cm* 2806 3613 2800 4290 3193 4542

i in* 435 560 434 665 495 704

1 11 cm* 3071 3484 4658 3339 - - in* 476

) 540 722 518 - -

12 cm* i 3103 3116 2768 3716 4258 4658

in* : 481 434 429 576 660 722

11 cm* 3071 3432 5200 4529 4935 4839

in* , 476 532 806 702 765 750

1 14 cm* 4045 4897 4452 3800 . 5987 5252

i in* ‘ 627 759 690 589 923 814

i 15 cm* 3716 4722 3729 4723 4403 4955

1 in* 576 732 578 732 682 768

i

! 16 cm* 1 2890 4000 3071 4000 3290 4452

( in* 448

i

620

1

476 620 510 690

^ A = Vertical orientation

** B = Horizontal orientation
Table 7. Smallest Acceptable Area of Egress Opening:

Male Subjects

i

- -

( Subject Sill Height

1 15

.....

^

. cm/ 6 in 46 cm/18 in 91 cm/ 3 6 in

1 Configuration . B** A B A B

K ... . ) cm^ 3181 4697 4045 3434 4852 3793 * X

i in 2 493 728 627 540 752 538

I

(

i 2 cm 2 3432 5510 3613 6371 4606 5564

i in^ 532 354 560 988. 714 362

1 3

i

cm^

in^

3319

592

2468

38 3

2981

462

4064

6 30

3071

476

4606

714

4

cm^ 1548 1548 2323 2323 1355 1355

in^ 240 240 360 360 210 210

5 cm^ : 2200 2031 2600 3339 2864 3774

in 2 341 322 403 518 444 585

6 cm^ 3613 5510 4877 5748 4542 5193

in^ 560 854 756 891 704 805

7 cm^ , 3619 5148 5148 5535 4645 5961

, / in^ 561 798 798 8 58 720 924

1 ®

i

j

cm^ 4413 4413 4181 59 35 5332 5564

in^ ? 684 684 648 920 ; 326 86 2

9 cm^ 4064 4894 5555 5855 • 3274 4526

in^ 630 758 861 903 508 7 02

1

I ;

1

I * A = Vertical orientation

** B = Horizontal orientation

- 24 -
Table 8. Analysis of Variance;

Minimum Acceptable Egress Opening Area for Females

Source S'S df MS F P

Total 86052794 90

Sill Height 8153156 2 4076578 4.51 .014

Conf iguration 587581 1 587581 <1 >.05

Sill Height

& Configuration 27424 2 13712 <1 >.05

Error 76760121 85 903060

Simple Contrasts for Sill Height

Contrast SS F P

15 cm vs 46 cm 910197 1.01 >.05

15 cm vs 91 cm 8012779 8.87 .004

46 cm vs 91 cm 3697221 4.09 .046

SS = stun of squares

df = degrees of freedom

MS = mean square

F = F-ratio

p = probability of error

I

- 25 -
Table 9. Analysis of Variance:

Minimum Acceptable Egress Opening Area for Males

Source SS df MS F

Total 93342789 53

Sill Height 4172587 2 2086294 1.22

Configuration 7046001 1 7046001 4.12

Sill Height

Configuration 66776 2 33388 ’ .1

Error 32057425 43 1709530

SS = sum of r.quares

df = degrees of freedom

MS = mean square

F = F-ratio

p = probability of error

- 2G-
Id0) u<

tr> c

•Hc0) Q* O

U)m0) VhO' Me

•Hc

•HT

x:4J•H

*0

Id •oc

Id 4JtooD

VX 0) V4 Id9* g

>1

X3

OU

Id 4J

Id Q 0) +J4J •H

(U 04

Id 4Jc

(Ue

•H(1) aXu

(U rHXI

Id Eh

27 -
configuration B opening. In all other conditions, the mean

size opening required was considerably less than the 4645 cm^

(720 in ) now required. In the conditions cited under which

the mean opening size was greater than the current minimum,

the largest difference between the mean observefi size and

the standard is only 94 cm^ (15 in^) , or about 2%. Quite a

different picture emerges, however, if we look at the 95th

percentile data from the experimental subjects., These data

indicate that under only one egress condition, (i.e. males,

15 cm sill height, configuration A) , is the 95 percentile

area smaller than the minimum size now, permitted. For the

other egress conditions, the 95th percentile area of opening

required for acceptable egress ranged fom 11-34 percent

larger than the minimum now allowed by the standard.

3.3.3 Least Dimensions of Subject Generated Openings . The

mean and 95th percentile data for the least dimension of the

smallest acceptable openings generated by the subjects are

compared with the least dimension allowed by the standard in

Table 11. As was the case with the areal dimension, the

mean values for the least dimension of the openings

determined empirically fare quite well with respect to the

least dimension permitted by the standard. In only three of

the experimental conditions does the mean least dimension

exceed the 56 cm (22 in) minimum set by the standard. Under

these conditions, the mean least dimension exceeds the

standard by a maximum of 10 percent. When the 95th

percentile data are examined, however, the least dimension

observed was less than 56 cm under only two conditions for

the men. For females, none of the 95th percentile least

dimensions fall at or below the minimum allowed by the

standard. Overall, under those conditions in which the

least dimension was greater than allowed by the standard,

the least dimension ranged from 9.5 to 66 percent larger

than now permitted.

3.4 Conclusions

The results of the empirical study to determine an

acceptable opening size for emergency egress devices are,

unfortunately, equivocal. The major problem in interpreting

the experimental results lies with the concept of

"acceptable.

If the definition of acceptable adopted in this study,

i.e. a rating of 3 on a five point scale of difficulty, is

used, the results of this study indicate that the minimum

opening size now allowed is generous for the average.

- 28 -
Table

11.

Experimental

Data

Compared

with

Minimum

Least

Dimension

of

Egress

Opening

Permitted

by

HUD

Standard

<u (N in e\ iH iH iH

iH C • • • • • • •H •H VO VO VO VO ^

CM m CM CM CN CM

•H : x: CM 00 ^ fO <3* CM

i; 6 • • • • » « CM !1 in 0 <r» CM 00 VO VO iH

CM 1

1 O' VO O' VO VO VO VO

u

c

CM m

• • ^ o• • m "O'• • VO •H iH ^ iH CM CM O

in

Mean

CM CM CM CM CM CM

g

00 00

• • m O'

• • VO O'

• • m iH

in VO ^ in in in

VO iH

in m

t

>

J 0) O' to rH 00 to CM rH C • • • • • • •H ‘H in 00 VO o CM VO P CM rH CM CM to CM G

f

5 0)u 1 M

j 0)

i < C , 00 in CM 00 o

•H x: B • • • • • • c P 0 in VO VO CM CM VO

' 0 CM in VO VO in 00 VO -H CM O'

1 +J

(0 B

' p o , VO in in ^

O' c • • • • • • •H VO

i •H in O' r- CO 00

M-l in c rH rH rH rH CM iH C Id 0 0) u s O' m to 00 s • • • • • • O O' O' O' VO

to in ^

fd *0c

rd 4JCO s

0) Id >i rH

.Q Id rH rH

f Id Q rH rH rH

J TJ 4J rH •H •H

(1) D4>H •r| (0 (0

(U Id (0 0 O 4J C C

o c C 0) •H (1) •H 0) •H < 0) •H iH rH rH

« < = B 2 ID 00 Id 0) VO Id 0)

1 •H VO g rH rH c rH CO g H 1 g B U 0) Id 0) Id 0) Id

j 3 B m * fci S ^ fc S S

1 E 6 a B B B

•H •H X o 0 o

i c c: H

•H •H m VO rH

!

1 s rH O'

-I

-J

- 29 -
healthy adult in the 40-65 year age group. The mean

smallest acceptable area and least dimension generated by

the subjects in this study fall below or very close to the

minimums allowed by the standard under all of the

experimental conditions. The 95th percentile subject

generated openings, on the other hand, indicate that the

current minimum opening size is too small. In only one of

the experimental conditions was the 95th pecentile opening

size smaller than the current minimum size in both area and

least dimension. Further, an acceptable opening size could

not be determined for two of the women egressing through an

opening with a 91 cm (36 in) sill height since they were

incapable of any egress over a sill of this height.

If the concept of "acceptability" as defined in this

study is abandoned and replaced with the notion of

"possibility," the experimental results become somewhat

easier to interpret. With the exception of the two women

noted, all subjects did successfully egress through the

minimum size opening allowed by the standard at each of the

three sill heights tested. Many subjects egressed through

openings significantly smaller than the minimum currently

allowed. Clearly, emergency egress through openings which

meet the requirements of the current standard is possible

for healthy adults in the age range tested, except at the

greatest sill height permitted. The experimental data

indicate that the maximum sill height should be less than

the 91 cm (36 in) now allowed. Since no data were collected

with sill heights between 46 and 91 cm (18 and 36 in) , no

recommendation for the maximum height can be justified by

the data.

A final problem encountered in interpreting the present

data involves the population sampled. For ethical and

safety reasons, a condition of participation in the study

was that all subjects be in general good health and, more

specifically, have no history of heart, respiratory or back

problems. Along with more incapacitating handicaps, these

are the very conditions which would make egress the most

difficult. While the experimental data provide some

assurance that egress openings which meet the requirements

of the current standard will provide a means of escape that

is usable by healthy adults , no implications can be drawn

from the present data concerning the accessibility of such

devices to individuals who are in any way physically

impaired. If emergency egress devices are to be usable,

without assistance, by all mobile home occupants, the

devices must be designed to offer no greater obstacle to use

- 30 -
than the egress devices normally used by the occupants . In

practice this would mean that the minimum acceptable

emergency egress device would consist of an outside access

door located in each occupied area of mobile homes.

Ai>thor's Note: After subject testing was completed, the HUD

project officer requested information regarding the effect

on the required egress opening which would be realized if a

barrier, e.g. a table or chest, were situated in front of the

egress device. It was suggested that if such a barrier were

sufficiently wide and deep, it should have little effect

on the opening area required for egress. For egress devices

with high sill heights, a barrier could assist egress. Although

no formal testing of this hypothesis was performed, one male and

one female subject did egress through openings with a 36 in

(91 cm) sill both with and without a 29 in (74 cm) high,

18 X 22 in (46 x 56 cm) table in front of the opening. The

presence of the barrier did not result in a larger opening size

required for egress for either subject. For the male, the

barrier resulted in a significantly smaller size opening.

- 31 -
4. References

1. Adler, S.A., Evaluation of the egress provisions of the

HUD mobile home construction and safety standard . NBSIR 77-1246, May 1977, National Bureau of Standards,

Washington, D.C.

2 . Annual housing survey. United States and regions . Current housing reports; series H-150-75A, April 1977,

Bureau of the Census, Washington, D.C.

3 . Anthropometric source book. Volume II; A handbook of

anthropometric data . 1978, NASA Reference Publication 1024.

4. Federal mobile home construction and safety standards.

Federal Register , 1975, £0, 58754.

5. Green, P.E. and Tull, D.S. Research for marketing

decisions , 1970, Prentice-Hall: Englewood Cliffs, New

Jersey.

6. Kerlinger, F.N. and Pedhazur, E.J. Multiple regression

in behavioral research . 1973, Holt, Rinehart and Winston;

New York.

7. Laubach, L.L. Muscular strength of women and men: A

comparative study . AMRL-TR-75-32, 1976, Aerospace Medical

Research Laboratories, Wright-Patterson Air Force Base,

Ohio.

8. McCormick, E.J. Human factors in engineering and design , 4th edition, 1976, McGraw-Hill: New York.

9 . MHMA , Window specifications for utilization in mobile

home and factory built housing , 1974 , Mobile Home

Manufacturing Association.

10. NFPA, Mobile Homes , 501B-1974, National Fire Protection

Association (ANSI A119. 1-1975)

11. Owings, C.L., Chaffin, D.B., Snyder, R.G. and Norcutt,

R. H . Strength Characteristics of U.S. Children for Product

Saf ety Desig^ October 1975, contract FDA-"/ 3- 32, prepared

for Consumer Product Safety Commission, Washington, D.C.

12. Robert W. Hunt Co. Results of a study to evaluate various

size openings for use as emergency egress in residential

housing Report 6-179, August 19/2, Robert VJ. Hunt Co .7

Chicago, Illinois.

32
13 . Rohmert, W. Maximalkraf t von maennern im hewegungsraum

der arme und beine. 1966, Westdeulscher Verlaz: Koeln,

Germany. cited in H.P. Van Cott and R.G. Kinkade (eds.).

Human engineering guide to equipment design , 1972, Joint

Array-Navy-Air Force Steering Committee.

14. Snyder, R.G., Schreider, L.W., Owings, C.L., Reynolds,

H.M., Golomb, D.H., and Schork, M.A. Anthropometry of

infants, children and youth to age 18 for product safety

design . UM, HSRI-77-17, May 1977, Highway Safety Research

Institute, University of Michigan: Ann Arbor, Michigan.

15. Taylor, C.L. The biomechanics of the normal and of the

amputated upper extremity. In P.E. Klopsteg and P.D.

Wilson (eds.) Human limbs and their substitutes , 1954,

McGraw-Hill; New York.

16. Van Cott, H.P. and Kinkade, R.G. (eds.). Human engineering

guide to equipment design . 1972, Joint Army-Navy-Air Force

Steering Committee.

17. Woodson, W.E. and Conover, S.W. Human engineering guide

for equipment designers . 1966, University oY California^

Press: Berkeley, California.

33
APPENDIX

Regression Models for Predicting

the Acceptable Area of Egress Openings

It was noted in the text that seven subject variables

were computed for each experimental subject. These seven

variables: age, stature, weight, bideltoid breadth, hip

breadth, sitting acromial height and stature/weight ratio

were selected as potentially useful in predicting the

minimum acceptable opening size required for emergency

egress, A series of linear multiple regression models were

constructed using these variables as independent or

predictor variables and the area of the egress opening as

the dependent or criterion variable . A packaged computer

program designed for use with a Tektronix 4051 terminal

computer was employed in this analysis. This program

permits the calculation of the least squares regression of Y

on the set or any subset of the variables x^ ... xj^, where,

in the present case:

Y = acceptable egress opening area

XI = age

X2 = stature

X3 = weight

X4 = bideltoid breadth

X5 = hip breadth

xg = sitting acromial height

X7 = stature/weight

The general model is the least squares approximation of

opening size by a linear function of one or more of the

independent variables. Thus, the general equation:

y' = a + biX3 + b2X2 + •••

where Y' = predicted value, a = intercept constant, b], b2

. . . b^= regression coefficients associated with the

independent variables ... xj-. No curvilinear regression

analyses were carried out. That is, no statistical tests

34
were performed to determine if any predictability in the

present data is afforded by a nonlinear rule.

The present data were subjected to both forward and

backward stepwise regression analyses (Kerlinger and

Pedhazur, 1973) . The data from one male and two female

subjects were deleted from the analyses. Inclusion of their

data resulted in very low correlations between the criteria

and predictor variables. If these subjects represent a

significant part of the total population, use of the

regression models presented here becomes suspect on

statistical bases. Despite the deficiencies of the present

data, the models do shed additional light on the size of

emergency egress openings which are required to rate

"acceptable" as a function of anthropometric measures.

Because of the limited number of subjects and the lack of

any tests of model validity, the models presented cannot be

considered definitive.

Table A1 presents the coefficients for the

statistically significant regression equations resulting

from the analysis for those models in which > .50 and the

fewest number of variables are nece^ary. The square of the

multiple correlation coefficient, R“^, expresses the

proportion of variance of Y accounted for by the linear

combination o^ x-j^ ... • Xj,. In the present case an adjusted

value of R^, R^ has been used to decrease the likelihood of

overestimating R^ as occurs when a large nxamber of

independent variables are employed

subjects (Green and Tull, 1970).

formula

R^ = 1 - (1-r 2) Bzi

n-q

^relative to the number of

R"^ is determined by the

where n = number of subjects

q

= number of variables in the regression equation.

Given the appropriate coefficient for each variable, we

can predict the acceptable opening size for any individual

for whom we know the pertinent anthropometric data.

Anthropometric data on the variables of interest are

compiled in Table A2

.

As an example of the use of the regression

coefficients, we can predict the minimiam acceptable area for

a configuration A opening with a 91 cm sill height by

35
Table

Al.

Selected

Regression

Coefficients

for

Predicting

Area

(cm'^)

of

Acceptable

Egress

Openings

VD rH VO P- 0 VO 00 r-1 r- • • • • • 1-1 1 1 1 CV 1 1 rH ! 1 CM 1 1 1 CM

t-l 11 ! as 1 as 1 1 Os 1 1 CJV vr 1 i •H i I CO 1 1 CO 1 1 1 1 PI 1 1 rH

00 0 o^ 0 CJV <T\ 0 fH in CjS 00 0

KO • • • • • • • -H rH VO VO ! 1 1 CO 1 0 VO 1 1 1 0 in i 0 1 0 0 Ov 1 1 n ! rn (N 1 n I 1 1 CM 1 rH1 1 1 1 1 ' 1 1 1 1

cv as VO 0 r* in r- p' • • • • m 1 ! 1 1 1 11 in 1 1 1 iH m 1 wo 1 1 1 ov 1 1 1 CM 0 1 1 1 1 r-i1 1 1 1 1 rn1 1 1 1 CM 1 1

VO in in as CM 0 CM in in 00

'H iH CM VO fH rH VO 'ir in CO CO P' H • • • • • • • • • • • 0 • CM ! 00 ro 00 0 CM CM 00 0 in CM CO 'si' 1 > CD I ov as as 0 CJV 0 rH 0 in 1 iH 1 00 V CO rH CO CM CM CM ro ro CM 1 1 y 1 1 1 1 1 1 1 1 1 1 1 1 ow

CO VO in p'

VO CT« 'S’ VO VO

-P 1 1 • i1 1 1 1 • 1 1 • • 0 • 1 s j VO as 1 •M* 00 P4 n ! 1 1 CO 1 i I i 00 1 1 CM 00 m 1 •H 1 rH rr o

•HiH cr\ CN cs as ov rH as 0 (N

14-1 VO CD in

n CO 1 •sr 1 1 1 1 0 • • • • • • • 11 0 • 1 1 1 • 1 0 (N ni in CO rH r- rH 1 1 1 rH u OV 0 CO 'iS* CO 0 VO r-i rH rH CM CM rH CM CO CM 1

«4' CO VO in cr> tH • 1 • 1 11 1 1 1 i 11 • 0 I • 1 i CM { i 1 I 0 as CO 1 I CO 1 1 I 1 1 1 1 r- VO 1 CM1 1

+J •H 00 as 0 VO VO r> as CO as 0 VO 0 O4 • • • • • • • • 0 0 • • • t • <U rH 0 0 0 in CO CM cr> 0 p' CM 00 in ro rVO rH ov m in rH ro VO M* VD 0 CO H r- as PO CO rH LO 0 00 r>- P- r>- rH 0 in 1 CO in 00 CM 0 CM 00 CM CM 00 VO

•P 1 rH rH rH CM rH in CM 1 rH

.5 1 1 1 1 1

r' 0 as

m 0 CO CO in ro 00 0 VO ro

•K * H ov 00 as VO cr> CO r- as as 00 VO in p> VD '_o

•H

•a8 < < m

a < » < m CQm < < < cn

m P

x:

•S'

<u ^ in in

m in VO VO rH rH rH iH VO VO iH r-i 0 rH rH rH rH o> CJ> CfS as CTv as as

•H

iH•H

Sex S s X

a

aa s a

a

a

a Cm Cti Cm Cm Cm •

iH <N CO in VO 00 OV 0 rH P4 ro M* 10

r-l rH rH rH rH rH

36
Table A2

Anthroporaetric Data for Males and Females Compiled

from the Anthropometric Source Book ,* 1978

Percentile

5 th 50th 95th

Stature (cm)

Female 149.5 160.5 171.3

Male 161.8 173.6 184.4

Weight (kg)

Female 46.2 61.1 89.9

Male 56.2 74.0 97.1

Bideltoid Breadth

Female

(cm)

38.2 41.8 45.9

Male 42.3 46.2 50.8

Hip Breadth (cm)

Female 31.6 34.8 38.8

Male 30.9 33.9 37.9

Sitting Acromial

Height (cm)

Female 51.6 56.2 60.7

Male 56.5 61.0 65.9

*The original sources of the data in this table

are a number of surveys which sampled different

populations. These data represent, in the author's

opinion, the best approximations of the relevant

anthropometric measures for the U.S. population.

37
solving equations 7 and 13 in Table A1 for males and

females, respectively. For a male with 50th percentile

anthropometric measurements we have

:

Y' = -12172.6 + (187.31 x 173.6) + (-372.49 x 46.2)

Y' = 3135 cm^ (486 in^)

The opening area for a female exhibiting 50th

percentile body dimensions is predicted by the equation:

Y' = 2765+(44.65 x 61 . 1) + (-203 . 35 x 41.8)+(203.7 x 34.8)

Y' = 4082 cm^ (633 in^

)

In both of these cases, the predicted acceptable

opening area is smaller than the minimum currently allowed

by the HUD standard. Solving these equations using the same

coefficients, but 95th percentile anthropometric data yields

predicted acceptable opening areas of 3445 cm^ (534 in^) and

5349 cm2 (829 in^) for males and females, respectively. For

females, the predicted minimtim opening size is considerably

larger than the 4645 cm^ (720 in^) minimum area permitted by

the standard

.

It is important to note that while the regression

models generated from the present experimental data predict

minimum opening sizes acceptable to healthy 40-65 years old

individuals for whom the relevent anthropometric

measurements are known , the use of population anthropometric

data, as above, can lead to erroneous predictions. This is

due to the fact that there is only a very low probability

that any individuals exist whose anthropometric measures

equal any given percentile on all of the body measurements

required in the regression equations. Even if a given

individual does exist who exhibits for example 5th

percentile body dimensions on all relevant dimensions, it

does not follow that this represents a 5th percentile

person. The regression equations presented here, therefore,

are best used only in cases where the dimensions are known

for an actual individual.

38
NBS>114A (REV. 0>7«)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 80-2049

4. TITLE AND SUBTITLE

Emergency Egress from Mobile Homes:

Anthropometric and Ergonomic Considerations

5. Publication Date

1/

7. AUTHOR(S)

V. J. Pezoldt

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

11. Contract/Grant No.

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, st^te. ZIP)

Office of Policy Development and Research

Department of Housing and Urban Development

Washington, D. C. 20410

13. Type of Report & Period Covered Final

15. SUPPLEMENTARY NOTES

I »I Document — — describes a computer program; SF*185, FIPS . .. w Software mwwmm. Summary, is’ attached. ~ —

16. ABSTRACT (A 200-word or teas lactaal aumaiary ot moat aigniiteant inlormation. It document inetudea a aignificant bibliography or

literature atirvey, mention it here.) This report summarizes a two task effort vAiich is part of the National Bureau of

Standards evaluation of the Federal Mobile Home Construction and Safety Standard. The

first task consists of a review of relevant anthropometric data from vAiich egress requirements mi^t be drawn. The second task is an empirical study of egress designed

to generate data vMch can assist HUD in evaluating the existing size requirements for

egress devices. The degree to vM.cdi the requirements in the current standard for

location and operating ctosicteristics of egress device latches and other operating

ttjechanians are aooeptable,^vBrie3 ^for different segpU^ts, of the population at risk.

Bie limit^'appllcalsle antifkbpcmetric dj|& suggest' that the requirements are sufficient

for the mbst part, for average, healthy/ norfijally airbiilatory adiiLts. Ihe minirmin

opening size requirements were also shown^to be ^iigceptable for average healthy adults

under most conditions tested. Hov^ever, devices v^ch meet the maximum sill height

allowed by the standard were shown fto 1^.extremely diffica^ to ne^tiate or ijnusable

by a significant portion of the ej^jerimental test subjects. Implications of the

present egress requirements for escape by handicapped or otherwise iitpaired individuals

are discussed.

17. KEY WORDS (aix to twelve entriea; alphabetical order; capitalize only the iirat letter of the lirat key word unless a proper name;

raparated by aemicolona)

lUithropometry ; emergency egress; escape behavior; HUD; mobile home;

safety; standard; window

18. AVAILABILITY [^^4fnlimited

I I For Official Distribution. Do Not Release to NTIS

I I Order From Sup. of Doc., U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003-

IX~1 Order From National Technical Information Service (NTIS), Springfield,

VA. 22161

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22. Price

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