ISO 10542-1:2001

INTERNATIONAL ISO
STANDARD 10542-1
First edition
2001-07-15
Technical systems and aids for disabled or
handicapped persons — Wheelchair
tiedown and occupant-restraint systems —
Part 1:
Requirements and test methods for all
systems
Assistances et aides techniques pour les personnes invalides ou
handicapées — Systèmes d'attache du fauteuil roulant et de retenue de
l'occupant —
Partie 1: Exigences générales et méthodes d'essai pour tous les systèmes
Reference number
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be
edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file,
parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters
were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event
that a problem relating to it is found, please inform the Central Secretariat at the address given below.
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, elec-
tronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's mem-
ber body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.ch
Web www.iso.ch
Printed in Switzerland
©
ii ISO 2001 – All rights reserved

Contents Page
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Design requirements . 6
5 Identification, labelling, instruction and warning requirements . 8
6 Performance requirements . 13
7 Test reports . 16
Annexes
A Test method for frontal impact . 17
B Measurement of WTORS belt lengths and geometry . 22
C Test for webbing slippage at adjustment devices of wheelchair tiedown straps. 25
D Test method for partial engagement . 27
E Surrogate wheelchair specifications. 28
F Recommendations for design, performance and documentation. 33
G Information sources . 38
Bibliography. 40
©
ISO 2001 – All rights reserved iii

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this part of ISO 10542 may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 10542-1 was prepared by Technical Committee ISO/TC 173, Technical systems and aids
for disabled or handicapped persons, Subcommittee SC 1, Wheelchairs.
ISO 10542 consists of the following parts, under the general title Technical systems and aids for disabled or
handicapped persons — Wheelchair tiedown and occupant-restraint systems:
— Part 1: Requirements and test methods for all systems
— Part 2: Four-point strap-type tiedown systems
Annexes A, B, C, D and E form a normative part of this part of ISO 10542. Annexes F and G are for information only.
©
iv ISO 2001 – All rights reserved

Introduction
Providing effective protection for the wheelchair-seated occupant of a motor vehicle usually requires that equipment
be installed to secure the wheelchair and restrain the occupant of the wheelchair. ISO 10542 is applicable to this
motor-vehicle adaptive equipment, which is referred to as wheelchair tiedown and occupant restraint systems
(WTORS). The requirements and test methods of this part of ISO 10542 apply to all WTORS that use belt-type
occupant-restraint systems. Additional parts of ISO 10542 will address specific types of WTORS, or deal with
particular applications, and will supplement and/or modify the requirements of this part of ISO 10542. If an additional
part of ISO 10542 exists for a particular type of WTORS, this part of ISO 10542 is not to be used alone for that
WTORS.
This part of ISO 10542 places particular emphasis on design requirements, test procedures, and requirements with
regard to the performance of WTORS in a frontal impact. Performance of WTORS used with rear-facing wheelchairs
involved in frontal impacts, performance of WTORS in rear, side and rollover impacts, and performance of WTORS
used with wheelchair-seated children, may be addressed in future versions of this part of ISO 10542 and its
additional parts. Transportation-related requirements for wheelchairs that are suitable for occupant seating during
motor-vehicle transportation are specified in ISO 7176-19.
The use of only a pelvic belt as an occupant restraint is unlikely to provide adequate safety to a wheelchair user in
the event of a frontal impact. Therefore, this part of ISO 10542 only includes test set-ups and procedures for
occupant restraints that incorporate both a pelvic and an upper torso restraint.
©
ISO 2001 – All rights reserved v

INTERNATIONAL STANDARD ISO 10542-1:2001(E)
Technical systems and aids for disabled or handicapped persons —
Wheelchair tiedown and occupant-restraint systems —
Part 1:
Requirements and test methods for all systems
1 Scope
This part of ISO 10542 specifies test methods and requirements for design and performance, for instructions and
warnings to installers and users, and for product marking and labelling for wheelchair tiedown and occupant-restraint
systems (WTORS). It applies to all WTORS that use belt-type occupant restraints that are intended for adult-
occupied wheelchairs used as forward-facing seats by passengers and drivers of motor vehicles.
This part of ISO 10542 applies primarily to complete WTORS, but other parts of ISO 10542 can also be applied to
components and subassemblies sold separately and for replacement parts.
This part of ISO 10542 applies to WTORS intended for use with all types of manual and powered wheelchairs
intended for use by adults, including three- and four-wheeled scooters.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this part of ISO 10542. For dated references, subsequent amendments to, or revisions of, any of these publications
do not apply. However, parties to agreements based on this part of ISO 10542 are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below. For undated references,
the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of
currently valid International Standards.
ISO 3795, Road vehicles, and tractors and machinery for agriculture and forestry — Determination of burning
behaviour of interior materials.
ISO 6487, Road vehicles — Measurement techniques in impact tests — Instrumentation.
UN/ECE R 16, Uniform provisions concerning the approval of safety belts and restraint systems for adult occupants
of power-driven vehicles, Revision 3, Amendment 3, 27 February 1996.
FMVSS 209, Standard No. 209; Seat belt assemblies. Federal Motor Vehicle Safety Standards, 49 CFR
part 571.209, 1 October, 1992.
3 Terms and definitions
For the purposes of this part of ISO 10542, the following terms and definitions apply.
3.1
adult
person having a mass greater than 36 kg
©
ISO 2001 – All rights reserved 1

3.2
airbag
inflatable restraint system
supplementary restraint system
supplemental occupant-restraint system, consisting primarily of a sensor or sensors, diagnostics, inflator(s) and
module(s), which inflates a bag in certain vehicle crashes to assist in preventing the occupant(s) from impacting the
interior portions of the vehicle
3.3
anchor point
point (area) on a vehicle interior component, floor, or wall, wheelchair or wheelchair tiedown, to which an anchorage
is attached
3.4
anchorage
assembly of components and fittings by which loads are transferred directly from the wheelchair tiedown to the
vehicle, or from the occupant restraint to the vehicle, wheelchair, wheelchair tiedown or vehicle interior component
3.5
anthropomorphic test device
ATD
articulated physical analogue of a midsize male used to represent a wheelchair occupant in a test
3.6
automatic-locking retractor
belt retractor incorporating adjustment by means of a positive, self-locking mechanism which is capable of
withstanding occupant-restraint forces
3.7
back restraint
device or system intended to limit rearward movement of an occupant during an impact by providing support to the
back of the torso
3.8
belt
length of webbing material used as part of an occupant restraint or postural support
3.9
emergency-locking retractor
belt retractor incorporating a locking mechanism that is activated by vehicle acceleration, deceleration, or rate of
webbing movement relative to the vehicle, and that is capable, when locked, of withstanding occupant-restraint forces
3.10
end fitting
anchorage or securement hardware to which wheelchair-tiedown or occupant-restraint webbing is fastened, that
attaches directly to an anchor point or to the securement point on the wheelchair
3.11
excursion
horizontal movement of an ATD or wheelchair target relative to its initial position on an impact sled during a test
3.12
fastener
device used to physically secure hardware components and parts in place
NOTE These include, but are not limited to, bolts, nuts, screws, pins and rivets.
©
2 ISO 2001 – All rights reserved

3.13
forward-facing
orientation in which the wheelchair-seated occupant faces the front of the vehicle, with the wheelchair reference
�
plane within 10 of the longitudinal axis of the vehicle
3.14
four-point tiedown
wheelchair tiedown system that attaches to the wheelchair frame at four separate securement points and also
attaches to the vehicle at four separate anchor points
3.15
four-point strap-type tiedown
a four-point tiedown that uses four strap assemblies to secure the wheelchair in the vehicle
3.16
harness
occupant-restraint assembly consisting of at least one belt designed to provide pelvic restraint and two belts that
restrain the upper torso by applying forces to both shoulders
3.17
head restraint
device intended to limit rearward displacement of the occupant's head
3.18
impact simulator
device for decelerating, accelerating, or a combination of decelerating and accelerating a section of a vehicle or
assembly of simulated vehicle structures, including instrumentation for measuring data required by this part of
ISO 10542
3.19
impact sled
part of an impact simulator to which components can be mounted for impact testing
3.20
occupant restraint
system or device intended to restrain a motor-vehicle occupant during an impact in order to prevent ejection, and
prevent or minimize contact with the vehicle interior components and other occupants
3.21
pelvic restraint
pelvic belt
lap belt
lap restraint
lower torso restraint
belt-restraint assembly intended to limit movement of the pelvis
3.22
point P
reference point that lies at the cross-sectional centre of a cylinder of diameter 100 mm and length 200 mm,
positioned with the longitudinal axis perpendicular to the wheelchair reference plane such that the curved surface of
the cylinder contacts the backrest and the upper surface of the seat
SeeFigure1.
3.23
postural support
postural belt
component or belt used to support a person in a desired seated position, but not intended to provide occupant
restraint ina vehicleimpact
©
ISO 2001 – All rights reserved 3

Dimensions in millimetres
Key
1 Cylinder, diameter 100 mm
a
Wheelchair reference plane
b
Wheelchair ground plane
Figure 1 — Wheelchair reference point P and wheelchair reference plane
3.24
securement hardware
components of a wheelchair tiedown that attach to the wheelchair
3.25
securement points
points on the wheelchair to which wheelchair tiedowns are connected
NOTE Securement points may be located on hardware components that are permanently or temporarily fastened to the
wheelchair.
3.26
strap
length of webbing material used in a wheelchair tiedown
3.27
surrogate wheelchair
SWC
rigid, reusable device that conforms to the requirements of annex E and that is used to simulate a wheelchair for the
purpose of testing wheelchair-tiedown and occupant-restraint systems
3.28
three-point restraint
three-point belt
occupant-restraint assembly comprised of both a pelvic belt and a diagonal shoulder belt that connect together near
the hip of the user
SeeFigure2.
©
4 ISO 2001 – All rights reserved

Key
1 Diagonal shoulder restraint
2 Pelvic restraint
Figure 2 — Three-point belt
3.29
two-point restraint
two-point belt
belt-type occupant-restraint assembly comprised of a single length of webbing and related hardware that anchors at
both ends
SeeFigure3.
Figure 3 — Two versions of a two-point belt restraint: a two-point shoulder belt and a two-point pelvic belt
3.30
upper-torso restraint
shoulder belt
diagonal belt
diagonal restraint
chest harness
portion of an occupant restraint intended to limit movement of the chest and head by application of restraint forces to
the shoulders and chest
©
ISO 2001 – All rights reserved 5

3.31
webbing
woven material, usually made from nylon or polyester yarn, used in belt and strap assemblies of occupant restraints
and wheelchair tiedowns
3.32
webbing guide
hardware loop or ring anchored to a structural member in the vehicle or wheelchair back, through which an occupant-
restraint belt passes, and changes direction, along the path to the vehicle anchor point
3.33
wheelchair ground plane
plane representing the surface on which the wheelchair rests
SeeFigure1.
3.34
wheelchair reference plane
vertical plane in the longitudinal centreline of the wheelchair
SeeFigure1.
3.35
wheelchair-tiedown and occupant-restraint system
WTORS
complete restraint system for wheelchair-seated occupants comprised of equipment for wheelchair tiedown and a
belt-type occupant restraint
3.36
wheelchair tiedown
wheelchair securement
device or system designed to secure a forward-facing wheelchair in place in a motor vehicle
4 Design requirements
4.1 WTORS
WTORS shall
a) be for use with only one wheelchair and one occupant at a time, and
b) include a belt-type occupant restraint, either by specifying use of the belt restraint and anchorages provided with
the vehicle, or by providing a belt-type occupant restraint with the wheelchair tiedown as part of a complete
WTORS,
c) not require components of wheelchair tiedowns and occupant restraints to pass through the wheels of a
wheelchair,
d) not require removal of wheelchair frame material, drilling into the wheelchair frame, deformation of the
wheelchair, welding, or use of an adhesive process during installation,
e) once installed, be operable without tools,
f) incorporate features to prevent unintentional loosening of all fasteners,
g) have all small manually detachable hardware and fittings tethered to WTORS subassemblies, and
h) include a manual override in case of power failure for any power-operated tiedown or restraint.
Specification of a vehicle-equipped belt-restraint system is primarily for situations in which the WTORS is intended
for use by drivers but, even in this situation, it is recommended that the WTORS manufacturer provide a complete
system, including both wheelchair tiedown and occupant restraint, for after-market installation in the vehicle.
©
6 ISO 2001 – All rights reserved

4.2 Wheelchair tiedowns
Wheelchair tiedowns and tiedown components shall
a) not release if any wheelchair component deforms, or if one or more tyres deflate during a vehicle impact,
b) include a means to minimize vehicle-induced movement of the wheelchair that does not require the use of tools,
c) not depend on the wheelchair brakes, and
d) not utilize the occupant restraint to secure any portion of the wheelchair.
4.3 Belt-type occupant restraints provided by the WTORS manufacturer
4.3.1 Occupant restraints provided by the WTORS manufacturer shall
a) have both pelvic and upper torso belts designed to apply forces to the occupant's skeletal regions,
b) function independently of the wheelchair, such that the restraint belts anchor to either the vehicle or wheelchair
tiedown components so that occupant-restraint loads are not transmitted through the wheelchair,
c) have belt restraints that can be adjusted in length without the use of tools.
NOTE WTORS designed with occupant restraints that transfer occupant-restraint loads through the wheelchair require special
labelling and will be dealt with in a future part of ISO 10542.
4.3.2 When set up and measured in accordance with annex B, occupant restraints provided by the WTORS
manufacturer shall
a) produce rear-view projected angles of the pelvic belt within the zones shown in Figure 4,
� �
b) produce side-view projected angles of the pelvic belt between 30 and 75 to the horizontal, as shown in
Figure 4,
c) provide for a range of adjustment of the pelvic restraint that allows for increasing and decreasing the total belt
length by 200 mm from the nominal setup conditions, with at least 25 mm of webbing extending through any
fitting where adjustment takes place,
d) provide for a range of adjustment in the upper-torso restraint that allows for increasing the length by 200 mm, and
shortening the length by 300 mm, from the nominal setup conditions, with at least 25 mm of webbing extending
through any fitting where adjustment takes place, when tested in accordance with annex B, and
e) have the junction of the shoulder and pelvic belts of three-point belt restraints located not less than 150 mm from
the ATD centreline.
4.3.3 If occupant restraints include structural components for the attachment of upper anchorages or guides for
upper torso belts, locations for the upper anchor points shall be provided that are
a) adjustable in height so they can be positioned at or above the shoulder level of the intended user(s), or that are
b) located at least 1 100 mm above the wheelchair ground plane.
4.3.4 Occupant restraints shall
a) only use an airbag for supplementary restraint in conjunction with a wheelchair tiedown and belt-type occupant
restraint that conform with the requirements of this part of ISO 10542, and
b) not depend on an airbag in order to conform with the performance requirements of this part of ISO 10542.
©
ISO 2001 – All rights reserved 7

Dimensions in millimetres
NOTE Angles indicated are obtained by projecting the angle of the pelvic belt onto a vertical plane that is parallel to (side view)
or perpendicular to (rear view) the wheelchair reference plane.
a
Wheelchair reference plane
Figure 4 — Range of required angles for pelvic belts and locations of pelvic-belt anchor points
5 Identification, labelling, instruction and warning requirements
5.1 Identification and labelling
5.1.1 WTORS and replacement parts shall be permanently and legibly marked showing
a) manufacturer's name or trademark,
b) month and year of manufacture, and any other identification necessary to clearly identify a WTORS in the event
of a product recall, and
c) that it conforms with ISO 10542-1.
5.1.2 Primary WTORS components and subassemblies shall be accompanied by information that includes
a) manufacturer's model and part number or an equivalent identification code, and
b) the name and intended use of each detachable WTORS component (e.g. right-rear tiedown, shoulder belt, pelvic
belt, etc.).
5.2 Instructions for installers
5.2.1 Manufacturers of WTORS shall provide written instructions for the installer in the principal language(s) of the
country in which it is marketed.
5.2.2 The instructions shall include statements that
a) the WTORS should be installed for forward-facing wheelchairs,
b) identify the number of separate packages containing WTORS components,
©
8 ISO 2001 – All rights reserved

c) the WTORS conforms with ISO 10542-1,
d) indicate the minimum specifications for all wheelchair tiedown and occupant- restraint anchorage fasteners and
related components,
e) identify any components to be permanently fastened to the wheelchair, and
�
f) indicate that the pelvic-restraint anchor points should be positioned to achieve belt angles of or greater to the
� �
horizontal, and preferably between 45 and 75 to the horizontal, in order to fit low across the pelvis and/or over
the upper thighs and thereby reduce the possibility of the belt loading the abdomen.
5.2.3 The instructions shall include descriptions of
a) any wheelchair features that are required to allow correct fitting of WTORS components that are to be
permanently fastened to the wheelchair,
b) procedures for attaching any components to be permanently fastened to the wheelchair,
c) how the WTORS is to be used, so that the installer may be fully informed regarding the purpose and function of
all components and how they should be installed,
d) the location points of upper anchorages or webbing guides of shoulder and harness restraints, and an
explanation that these points should be selected so that the belt webbing fits near the midpoint of occupants'
shoulders and so that the height is at or above the shoulder heights of intended users, so as to minimise
downward loads on the spine, and
e) minimum vehicle-strength recommendations at all WTORS anchor point locations.
5.2.4 The instructions shall include diagrams and drawings that illustrate
a) acceptable methods for fastening WTORS anchorages to the vehicle, along with minimum strength requirements
forallWTORSanchorpoints,
b) an exploded-view drawing and a parts list for all components required in the installation,
c) the locations for anchor points of independent belt restraints relative to wheelchair tiedown anchor points, along
with the information in Figure 5,
d) distances between WTORS' anchor points and vehicle interior components, including the information in Figure 6.
5.2.5 The instructions shall include warnings that
a) the WTORS be installed by an experienced technician,
b) both pelvic and upper-torso restraints be installed to reduce the possibility of head and chest impacts with vehicle
interior components, and that
c) vehicle anchor points may require reinforcement,
d) additional vehicle interior padding should have a burning rate that does not exceed 100 mm/min when tested in
accordance with ISO 3795,
e) a vehicle-anchored back restraint be provided if a head restraint is anchored to the vehicle, in order to minimize
rearward deflection of the wheelchair seatback and the potential for neck injury,
f) the WTORS not be installed in a manner that may block deployment of an airbag,
g) an airbag be used only as a supplementary occupant restraint in conjunction with a wheelchair tiedown and belt-
type occupant restraint,
h) it is important to locate the wheelchair anchor points properly with respect to the anchor points of the upper and
lower torso belts to achieve good belt-fit geometry,
i) the WTORS manufacturer be consulted in case of questions as to the method of installation on the wheelchair
and/or in the vehicle,
j) alterations or substitutions to the WTORS components should not be made without consulting the WTORS
manufacturer,
k) webbing be protected from contacting sharp corners and edges, and potential corrosive liquids,
l) the extent of head and chest excursions also depends on the location of the upper-torso belt anchor points and
may increase as anchor-point distance above and behind the occupants shoulder increases.
©
ISO 2001 – All rights reserved 9

Dimensions in millimetres
a
Wheelchair reference plane
Figure 5 — Preferred and optional angles for pelvic restraints
5.3 User and maintenance instructions
5.3.1 Manufacturers shall provide written instructions for the use and maintenance of the WTORS in the principal
languages of the country in which it is marketed.
5.3.2 The instructions shall include statements that
a) the WTORS conforms with ISO 10542-1,
b) care should be taken to prevent contamination of the webbing with polishes, oils and chemicals, particularly
battery acid, along with procedures and materials to be used for cleaning parts of the WTORS,
c) frayed, contaminated or damaged webbing, and broken or worn parts should be replaced,
d) webbing should be protected from contacting sharp corners and edges, and
e) occupant restraints should be adjusted to fit the user, and that:
1) both pelvic and upper-torso restraints should be used to reduce the possibility of head and chest impacts with
vehicle components,
2) the extent of head and chest excursions also depends on the location of the upper-torso belt anchor points
and may increase as anchor-point distance above and behind the occupants shoulder increases,
3) the pelvic belt should be worn low across the front of the pelvis so as to bear upon the bony structure of the
body, with any junctions between the pelvic and shoulder restraints located near the wearer's hip,
� �
4) the angle of the pelvic belt should be within the preferred zone of 45 to 75 to the horizontal, or the optional
� �
zone of 30 to 45 to the horizontal, as shown in Figure 5,
5) belts should not be held away from the body by wheelchair components or parts such as the wheelchair
armrests or wheels, along with an illustration similar to that of Figures 7 and 8,
©
10 ISO 2001 – All rights reserved

6) occupant restraints belts should be adjusted as firmly as possible consistent with user comfort,
7) upper-torso restraints should fit over the shoulders,
8) upper-torso anchor or webbing guide points that are adjustable in height should be set at or above the
wheelchair occupant's shoulder so as not to impose downward loads on the spine in the event of an impact,
9) restraint webbing should not be worn twisted.
Dimensions in millimetres
Rigid vehicle components that are inside the clear zones should be covered with padding that conforms with the
impact performance requirements of FMVSS 201, EC 74/60 or UN/ECE 21.
NOTE 1 The rear clear zone is measured from the rearmost point on an occupant’s head. The front clear zone (FCZ) is meas-
ured from the frontmost point on an occupant’s head.
NOTE 2 Seated head height (HHT) ranges from about 1 200 mm for a small adult female to about 1 550 mm for a tall adult
male.
a
650 mm with upper torso restraint; 950 mm with only pelvic restraint. The FCZ may not be achievable with wheelchair -seated
drivers.
Figure 6 — Clear zones for wheelchair-seated occupants
©
ISO 2001 – All rights reserved 11

Figure 7 — Example of warning label illustrating improper positioning of occupant restraint belts
Figure 8 — Illustration of proper belt fit
©
12 ISO 2001 – All rights reserved

5.3.3 The instructions shall include descriptions of
a) how the WTORS is to be used,
b) the types of anchorage hardware that may be used with the vehicle-installed anchorage components,
c) the features required of a wheelchair for effective attachment of tiedown end fittings, and
d) how to inspect, clean, and maintain all WTORS webbing and components.
5.3.4 The instructions shall include warnings that
a) the use of occupant restraints other than those specified by, or included in, the WTORS system may compromise
the performance,
b) the WTORS be used only with forward-facing wheelchairs,
c) WTORS components, including anchorages, be replaced if they are suspected to have been in use during an
impact from which the vehicle must be towed,
d) the WTORS be used with only one wheelchair and one occupant at a time,
e) postural supports and belts not be used as occupant restraints,
f) auxiliary wheelchair equipment be effectively secured to the wheelchair or removed from the wheelchair and
secured in the vehicle during transport, so as not to break free and cause injury to vehicle occupants in an
impact, and that
g) items attached to the wheelchair in front of the wheelchair occupant, other than footrests, be removed whenever
possible and secured separately during transportation, in order to reduce the potential for injury to the wheelchair
occupant and others in the vehicle.
5.4 Instructions for WTORS components and subassemblies sold separately
Replacement parts for WTORS, and parts of WTORS sold separately, that conform to appropriate requirements of
this part of ISO 10542 shall:
a) be described in accompanying presale marketing literature as being part of a system or systems whose
performance meets the requirements of this part of ISO 10542, and
b) be supplied with installation, user and maintenance instructions that include details of the WTORS devices and
components with which they are compatible.
6 Performance requirements
6.1 WTORS components
6.1.1 All webbing, metal parts, buckles, release mechanisms and adjustment mechanisms of wheelchair tiedown
and occupant-restraint systems shall conform with applicable subclauses of one or both of the following documents,
as indicated in the applicable column of Table 1 and/or Table 2:
a) UN/ECE regulation No. 16;
b) FMVSS 209 seatbelt assemblies.
6.1.2 All webbing and padding used in WTORS shall have a burning rate not exceeding 100 mm/min when tested
as specified in ISO 3795.
©
ISO 2001 – All rights reserved 13

Table 1 — Applicable subclauses of UN/ECE regulation No. 16
UN/ECE No. 16 tests ref-
a
Subclause Component Subject Application
erenced
6.2.1.1 rigid parts sharp edges — OR + WTD
6.2.1.2 rigid parts corrosion
7.2 OR + WTD
6.2.1.4 rigid parts cold impact test
7.5.4 OR + WTD
6.2.2.1 buckles correct use and size
—OR
6.2.2.2 buckles closing/releasing
7.8.2 OR
6.2.2.3 buckles cold mating
7.5.3 OR
6.2.2.4 buckles repeated testing
7.7 OR
6.2.3.2 adjustment devices micro-slip
7.3 OR
6.2.3.4 belt adjusting device force
7.5.6 OR + WTD
6.2.5 various belt retractors performance
7.2, 7.6.1 thru 7.6.4 OR
6.2.6 preloading devices performance
7.2, 7.9.2 OR
6.3.1 belts general specs
—OR
6.3.2 belts strength
7.4.1.1, 7.4.2 OR + WTD
6.3.3 belts strength
7.4.1, 7.4.2 OR + WTD
6.4.2 belts strength
7.4.1.6, 7.4.2, 7.5 OR + WTD
a
OR = occupant restraint, WTD = wheelchair tiedown
Table 2 — Applicable subclauses of FMVSS 209
FMVSS 209 tests
a
Subclause Component Subject Application
referenced
S4.1 (d) hardware burrs and sharp edges — OR + WTD
S4.1 (e) release mechanism design — OR
S4.1 (h) webbing unravelling — OR + WTD
S4.2 (a) webbing belt width S5.1(a) OR
S4.2 (b) webbing breaking strength S5.1(b) OR + WTD
S4.2 (c) webbing elongation S5.1(c) OR + WTD
S4.2 (d) webbing abrasion resistance S5.1(d), S5.3(c) OR
S4.2 (d) webbing abrasion resistance S5.1(d) WTD
S4.2 (e) webbing light resistance S5.1(e) OR + WTD
S4.2 (h) webbing stain resistance S5.1(h) OR + WTD
S4.3 (a) hardware corrosion resistance S5.2(a) OR + WTD
S4.3 (b) hardware temperature resistance S5.2(b) OR + WTD
S4.3 (d) buckle release release force S5.2(d) OR
S4.3 (e) adjustment device adjustment force S5.2(e) OR
S4.3 (f) tilt-lock devices locking angles S5.2(f) OR
S4.3 (g) buckle latch separation force S5.2(g) OR
S4.3 (i) belt retractor performance S5.2(i) OR
S4.3 (j) belt retractor performance S5.2(j) OR
S4.3 (k) belt retractor performance S5.2(k), S4.4 OR
S4.4 (a) pelvic restraints performance S5.3(a) OR
S4.4 (b) 3-pt restraints performance S5.3(b) OR
a
OR = occupant restraint; WTD = wheelchair tiedown
©
14 ISO 2001 – All rights reserved

6.2 Dynamic performance requirements
6.2.1 Post-test acceptance criteria
When the WTORS is tested in accordance with annex A, the following requirements shall be met at the conclusion of
the test.
a) The ATD shall be retained in the seat of the SWC.
b) The SWC shall be in an upright position on the impact sled.
c) No WTORS anchorage components or securement end fittings shall be detached or separated.
d) Release of the SWC from the wheelchair tiedown shall not require the use of tools.
e) Release of the ATD from the occupant restraint shall not require the use of tools.
f) No part of the WTORS shall exhibit visible signs of tearing, fragmentation, fracture, or complete failure of any
load-bearing part, unless such parts are intended to fail in a manner that limits the forces on the occupant.
g) The WTORS shall exhibit no dangerous roughness, sharp edges, or protrusions likely to increase the risk of
injury to the occupant.
h) The force required to open the buckle of any tiedown or occupant restraint components shall not exceed 60 N
when tested as specified by 6.2.2.5 of ECE R 16:1996, in accordance with the procedures of 7.8.
6.2.2 Dynamic performance requirements during the test
When the WTORS is tested in accordance with annex A,
a) the horizontal excursions of the ATD and the SWC with respect to the impact sled shall not exceed the values
given in Table 3, and
b) the WTORS shall prevent the wheelchair from imposing forward loads on the occupant, as indicated by the ATD
knee excursion exceeding the wheelchair point P excursion by 10 % or more (x =x > 1,1).
knee wc
Table 3 — Horizontal excursion limits
Measurement point Excursion variable Pelvic and shoulder restraint
mm
Surrogate wheelchair x 200
wc
ATD Knee x 375
knee
ATD Head x 650
head
x is the horizontal distance relative to the sled platform between the point-P
wc
target on the SWC at timet , to the point-P target at the time of peak wheel-
chair excursion.
x is the horizontal distance relative to the sled platform between the ATD knee-
knee
joint target at timet , to the knee-joint target at the time of peak knee excur-
sion, and
x is the horizontal distance relative to the sled platform between the most for-
head
ward point on the ATD's head above the nose at timet , to the most forward
point on the ATD's head at the time of peak head excursion.
6.3 Webbing slippage at tiedown adjustment devices
When tested in accordance with annex C, strap-type adjustment mechanisms of the wheelchair-tiedown system shall
not show slippage greater than 25 mm.
©
ISO 2001 – All rights reserved 15

6.4 Partial engagement of anchorage and securement components
When WTORS anchorage and securement components are tested in accordance with annex D, all improper and
partial engagements shall separate with a force of less than 22 N.
7 Test reports
7.1 The following information shall be included in each test report resulting from one or more tests conducted in
accordance with this part of ISO 10542:
a) name and address of test institution;
b) date of test;
c) a unique test report number shown on each numbered page;
d) manufacturer, product, and serial number, if applicable;
e) product type and designation;
f) name and address of manufacturer;
g) a photograph of the WTORS test setup.
7.2 For the frontal impact test of annex A, the test report shall also include
a) the measured or calculated value of the test velocity change,
b) a photograph of the WTORS and wheelchair as set up prior to the test,
c) a graph of the impact sled deceleration plotted against time and superimposed on Figure A.1,
d) the test results as specified in 6.2.1 and 6.2.2,
e) a statement as to whether or not the WTORS met the requirements of the clauses listed in d) above, and
f) any other relevant observations.
7.3 For the tests of restraint-belt geometry and length adjustment of annex B, the report shall also include
a) a photograph of the WTORS and wheelchair set up for the test,
b) the test results as specified in B.5,
c) a statement as to whether or not the occupant restraint tested met the requirements of 4.3.2, and
d) any other relevant observations.
7.4 For the test for webbing slippage at adjustment devices of wheelchair tiedowns specified in annex C, the test
report shall also include:
a) a photograph of the test setup,
b) a photograph and description of each adjustment device tested,
c) the test results as specified in 6.3,
d) a statement as to whether or not the occupant restraint met the requirements of 6.3, and
e) any other relevant observations.
7.5 For the test for test for partial engagement of annex D, the test report shall also include
a) a photograph and description of the components involved in each test,
b) the test results as specified in 6.4,
c) a statement indicating whether the equipment met the requirements of 6.4, and
d) any other relevant observations.
©
16 ISO 2001 – All rights reserved

Annex A
(normative)
Test method for frontal impact
A.1 Principle
A surrogate wheelchair (SWC) constructed in accordance with annex E is mounted in a forward-facing configuration
on the impact sled of an impact simulator and is loaded with an anthropomorphic test device (ATD).
The WTORS is installed to secure the SWC and restrain the ATD. The sled platform is subjected to a defined

v
acceleration/deceleration-time pulse, in order to achieve a defined horizontal velocity change ( ). Observations
and measurements are made to determine if the WTORS conforms to the requirements of this part of ISO 10542.
A.2 Test sample
An unused WTORS, including upper and lower torso restraints, all fittings, anchorages, fasteners, and instructions for
installation and use, shall be provided for testing. If a WTORS is designed to use the vehicle original equipment
manufacturer (OEM) belt-type restraint system, the WTORS manufacturer shall provide a representative OEM
restraint system for testing. Documentation shall be included to indicate any components of the WTORS system that
are designed to provide controlled failure or deformation under dynamic loading.
A.3 Apparatus
A.3.1 An impact simulator shall be used that includes the following:
a) an impact sled with a flat, horizontal, structurally rigid platform on which the SWC can be mounted, and to which
the WTORS can be fastened;
b) a rigid structure attached to the impact sled to which the upper-torso restraint can be anchored in the manner,
and to the geometry, specified by the WTORS manufacturer;
+2
c) a means to drive the impact sled through a change in velocity of 48 km/h;
d) a means to accelerate and/or decelerate the impact sled and test setup such that the processed sled
acceleration- and/or deceleration-time pulse
1) falls within the shaded area of Figure A.1,
2) exceeds 20g for a cumulative time period of at least 15 ms,
3) exceeds 15g for a cumulative time period of at least 40 ms, and
4) has a duration of at least 75 ms fromt tot ;
0 f
e) aHybridIIorHybridIIIATDwithatotalmassof 76,3 kg�1kg;
f) a surrogate wheelchair that conforms with the specifications of annex E.
A.3.2 A means shall be provided to measure the ATD and surrogate wheelchair horizontal excursions specified
in 6.2.2 a) with an accuracy of�5mm.
NOTE A side-view high-speed camera or video system with a minimum frame rate of 500 frames per second can be used.
A.3.3 A means shall be used to measure the horizontal acceleration and/or deceleration of the impact sled in
the direction of travel at a sampling rate in accordance with ISO 6487, and with a precision of� 0,5g.
A.3.4 A means shall be provided to measure the horizontal velocity change (
v) of the impact sled during the
impact with a precision of� 0,5 km/h.
©
ISO 2001 – All rights reserved 17

The acceleration/deceleration of the impact sled shall stay within the shaded area and exceed the indicated levels
for the specified continuous (unbroken arrows) and cumulative (broken arrows) time periods.
Figure A.1 — Acceleration/deceleration requirements for the (48� 2 km/h) impact test
A.3.5 Provision shall be made to filter analog transducer signals using a low-pass filter in accordance with
ISO 6487, including
a) prefiltering of all transducer signals to Channel Class 1 000 (−4 dB at 1 650 Hz) prior to digitizing at 10 000 Hz,
and
b) filtering of the digitized accelerometer and load-cell signals to Channel Class 60 (− 4 dB at 100 Hz).
A.4 Test preparation and procedure
A.4.1 The procedures for setting up the test may be undertaken in any order.
A.4.2 Adjust the ATD to achieve a static resistance of 1g at each joint, as indicated by just-noticeable movement
from the mass of the distal body segment, as specified by the ATD manufacturer.
A.4.3 Place close-fitting cotton clothing on the pelvis, thighs and torso of the ATD.
A.4.4 Set up the test apparatus (see A.3).
A.4.5 Prepare the SWC as follows.
a) Modify the frame structure as needed to accommodate the tiedown system to be tested while maintaining the
SWC specifications within the tolerances specified in annex E.
b) Inflate the SWC tyres as specified in annex E, with the wheelchair unoccupied and resting on a horizontal
surface.
c) Inspect the tyres for cracks and replace if the weakness could cause the t
...