BRITISH STANDARD BS EN ISO

5353:1999
BS 6912-27:
1999
Incorporating
Corrigendum No. 1

Earth-moving
machinery, and
tractors and machinery
for agriculture and
forestry —
Seat index point

The European Standard EN ISO 5353:1998 has the status of a

British Standard

ICS 53.100; 65.060.01

BS EN ISO 5353:1999

National foreword

This British Standard is the English language version of EN ISO 5353:1998.

It is identical with ISO 5353:1995. It supersedes BS 5631:1978 which is
withdrawn.
The UK participation in its preparation was entrusted by Technical Committee
B/513, Construction equipment and plant, and site safety, to Subcommittee
B/513/1, Earth-moving machinery (International), which has the responsibility
to:
— aid enquirers to understand the text;
— present to the responsible international/European committee any
enquiries on the interpretation, or proposals for change, and keep the UK
interests informed;
— monitor related international and European developments and
promulgate them in the UK.
A list of organizations represented on this subcommittee can be obtained on
request to its secretary.
Cross-references
Attention is drawn to the fact that CEN and CENELEC standards normally
include an annex which lists normative references to international
publications with their corresponding European publications. The British
Standards which implement these international or European publications may
be found in the BSI Standards Catalogue under the section entitled
“International Standards Correspondence Index”, or by using the “Find”
facility of the BSI Standards Electronic Catalogue.
A British Standard does not purport to include all the necessary provisions of
a contract. Users of British Standards are responsible for their correct
application.

Compliance with a British Standard does not of itself confer immunity

from legal obligations.

Summary of pages
This document comprises a front cover, an inside front cover, pages i and ii,
the EN ISO title page, page 2, the ISO title page, page ii, pages 1 to 5 and
a back cover.
This standard has been updated (see copyright date) and may have had
amendments incorporated. This will be indicated in the amendment table on
the inside front cover.

This British Standard, having Amendments issued since publication

been prepared under the
direction of the Sector Amd. No. Date Comments
Committee for Building and
Civil Engineering, was
published under the authority 10427 February 1999 Front cover
of the Standards Committee and Corrigendum
comes into effect on
15 January 1999

© BSI 05-1999

ISBN 0 580 30570 8

 BS EN ISO 5353:1999

Contents

Page
National foreword Inside front cover
Foreword 2
Foreword ii
Text of ISO 5353 1

© BSI 05-1999 i
ii blank
EUROPEAN STANDARD EN ISO 5353
NORME EUROPÉENNE
September 1998
EUROPÄISCHE NORM

ICS 53.100; 65.060 Supersedes EN 25353:1988

Descriptors: See ISO document

English version

Earth-moving machinery, and tractors and machinery for

agriculture and forestry — Seat index point
(ISO 5353:1995)

Engins de terrassement, et tracteurs et Erdbaumaschinen sowie Traktoren und

matériels agricoles et forestiers — Point repère Maschinen für Land- und Forstwirtschaft
du siège Sitzindexpunkt
(ISO 5353:1995) (ISO 5353:1995)

This European Standard was approved by CEN on 4 September 1998.

CEN members are bound to comply with the CEN/CENELEC Internal
Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration. Up-to-date lists and
bibliographical references concerning such national standards may be obtained
on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French,
German). A version in any other language made by translation under the
responsibility of a CEN member into its own language and notified to the
Central Secretariat has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium,
Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland,
Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden,
Switzerland and United Kingdom.

CEN
European Committee for Standardization
Comité Européen de Normalisation
Europäisches Komitee für Normung
Central Secretariat: rue de Stassart 36, B-1050 Brussels

© 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national
Members.
Ref. No. EN ISO 5353:1998 E
EN ISO 5353:1998

Foreword Contents
The text of the International Standard from Page
Technical Committee ISO/TC 127 “Earth moving Foreword 2
machinery” of the International Organization for
1 Scope 1
Standardization (ISO) has been taken over as an
European Standard by Technical Committee 2 Normative references 1
CEN/TC 151 “Construction equipment and building 3 Definitions 1
material machines — Safety”, the secretariat of 4 Multiple machine function seats 1
which is held by DIN.
5 Technical requirements 1
This European Standard replaces EN 25353:1988.
Figure 1 — Seat index point device 3
This European Standard shall be given the status of
a national standard, either by publication of an Figure 2 — Seat with SIP device 4
identical text or by endorsement, at the latest by Figure 3 — SIP location 5
March 1999, and conflicting national standards
shall be withdrawn at the latest by March 1999.
According to the CEN/CENELEC Internal
Regulations, the national standards organizations
of the following countries are bound to implement
this European Standard: Austria, Belgium,
Czech Republic, Denmark, Finland, France,
Germany, Greece, Iceland, Ireland, Italy,
Luxembourg, Netherlands, Norway, Portugal,
Spain, Sweden, Switzerland and
the United Kingdom.

Endorsement notice
The text of the International Standard
ISO 5353:1995 has been approved by CEN as a
European Standard without any modification.

2 © BSI 05-1999
EN ISO 5353:1998

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.
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.
International Standard ISO 5353 was prepared by Technical Committee
ISO/TC 127, Earth-moving machinery, Subcommittee SC 2, Safety requirements
and human factors.
This second edition cancels and replaces the first edition (ISO 5353:1978), of which
it constitutes a technical revision.

Descriptors: Earth-moving equipment, agricultural machinery, agricultural tractors, forest

equipment, seats, ground vehicle seats, operator seats, tests, determination, seat index point.

ii © BSI 05-1999
 EN ISO 5353:1998

1 Scope 4 Multiple machine function seats

This International Standard specifies a method and Some seats are designed to locate and fix an
the device for use in determining the position of the operator to perform more than one function with a
seat index point (SIP) for any kind of seat designed given machine. Where a second position of the seat
for earth-moving machinery as defined in ISO 6165, is provided because the machine or tractor has a
and tractors and machinery for agriculture and second set of controls, the SIP of the seat has two
forestry as defined in ISO 3339-0. locations relative to the machine or tractor, one for
This provides a uniform method for defining the each position, as if there were two seats in the
location of the SIP in relation to a fixing point on the machine or tractor. The first location of the SIP
seat. The SIP may be determined on a seat by itself shall be used for those International Standards
or with the seat located in its operating environment appropriate to the first location and set of controls
on the machine. The SIP is a characteristic of the and the second location of the SIP shall be used for
seat; therefore, it may be specified by the seat those International Standards appropriate to the
manufacturer. second location and set of controls.

2 Normative references 5 Technical requirements

The following standards contain provisions which, 5.1 Device for seat index point (SIP)
through reference in this text, constitute provisions determination
of this International Standard. At the time of The device for determining the SIP shall comply
publication, the editions indicated were valid. All with Figure 1. The mass of the device shall
standards are subject to revision, and parties to be 6 kg ± 1 kg. The work surfaces of the device shall
agreements based on this International Standard be of hardwood (sanded with 200 or finer grit paper
are encouraged to investigate the possibility of or equivalent and polished) or equivalent material
applying the most recent editions of the standards with the same performance to provide minimum
indicated below. Members of IEC and ISO maintain friction with the muslin cloth in 5.3.1.
registers of currently valid International Standards.
5.2 Adjustments when determining the seat
ISO 3339-0:1986, Tractors and machinery for index point (SIP)
agriculture and forestry — Classification and
When the relevant adjustments are a part of the
terminology — Part 0: Classification system and
seat and its suspension, the seat shall be adjusted
classification.
according to the following sequential steps before
ISO 6165:1987, Earth-moving machinery — Basic determining the SIP.
types — Vocabulary.
5.2.1 Seat adjustment
3 Definitions All fore, aft, vertical and angular adjustments shall
be placed in their centre position. When no centre
For the purposes of this International Standard, the
position is possible, the nearest adjustment that will
following definitions apply.
move the SIP device upward or rearward of centre
3.1 shall be used.
seat index point; (SIP)
5.2.2 Suspension system
point on the central vertical plane of the seat as
Block the suspension system according to the
determined by the device shown in Figure 1, when
manufacturer’s instruction. If such instruction is
installed in the seat as specified in 5.3
not provided, block the suspension system at the
NOTE 1 The SIP is fixed with respect to the machine and does
not move with the seat through its adjustment and/or oscillation
midpoint of its oscillation range.
range. Non-adjustable suspension shall be blocked in the
NOTE 2 The SIP as established and defined by this vertical position attained with the weighted device
International Standard may be considered, for operator
work-place design purposes, to be equivalent to the intersection
in place.
on the central vertical plane through the seat centreline of the
theoretical pivot axis between a human torso and thighs.
3.2
fixing point
point specified by the manufacturer to which the
SIP is referenced
see Figure 2 and Figure 3 for examples

© BSI 05-1999 1
EN ISO 5353:1998

5.3 Seat index point (SIP) determination NOTE 3 A 75 kg operator approximates the 65 kg weighted
device on the seat.
The SIP shall be determined by using the device Repeat the alternate loading and releasing, and the
illustrated in Figure 1 and applying the following rocking of the device, checking to make sure the
procedures. device is laterally central and level on the seat.
5.3.1 Seat preparation 5.3.3 Measurement
Allow sufficient time to ensure that the seat reaches Make measurements on each side of the SIP
a room temperature of 20 °C ± 2 °C before starting measuring device at points an equal distance from
the measurement procedure. the central vertical plane (see Figure 2). Average the
Place the seat on a level surface. values. Record within ± 1 mm the coordinate
Seat a 75 kg ± 10 kg person in the seat twice dimensions of the SIP from the fixing point on the
for 1 min periods to flex the seat and back cushions. seat assembly (see Figure 3) that is defined by the
Allow the seat to remain unloaded for a minimum manufacturer.
period of 5 min before starting the measurement Some machines have seats which fulfil multiple
procedure. functions, usually by rotating the seat. Functions
Cover the seat with a single layer of muslin cloth of may include using machine equipment or operating
sufficient size to prevent direct contact and the machine in travel mode. For these cases, it may
minimize friction between the cushion surfaces and not be possible readily to calculate the location of
the measurement device. Take care to prevent the the different SIPs relative to the fixing point. In
cloth from influencing the positioning of the device. these cases, repeat 5.2 and 5.3 for each of the
positions.
5.3.2 Device placement
5.4 Report
Place the SIP device, without additional masses,
laterally central on the seat cushion pushing The test report shall include the following
against the back cushion (see Figure 2). Ensure that information:
the device is laterally controlled and level on the a) reference to this International Standard;
seat. b) a full description of any test conditions or
Add masses to bring the total mass of the device adjustments different from those specified in this
from 6 kg ± 1 kg to 26 kg ± 1 kg; the vertical force International Standard;
centre of the added masses shall be 40 mm in front c) a drawing or sketch of the seat assembly
of the SIP mark on the horizontal section of the showing the coordinate dimensions between the
device (see Figure 1). fixing point and the SIP (see Figure 3 for an
To obtain a good fit between the seat cushion, the example);
back cushion, and the SIP measuring device, d) description of the seat adjustment ranges
alternately apply and release a horizontal rearward available relevant to 5.2.
force of approximately 100 N at the location noted in
Figure 1, and rock the device from side to side.
Add further masses to bring the total mass of the
device from 26 kg ± 1 kg to 65 kg ± 1 kg such that
the vertical force centre of the additional masses
is 40 mm in front of the SIP mark on the horizontal
section of the device (see Figure 1).

2 © BSI 05-1999
 EN ISO 5353:1998

Figure 1 — Seat index point device

© BSI 05-1999 3
EN ISO 5353:1998

Figure 2 — Seat with SIP device

4 © BSI 05-1999
 EN ISO 5353:1998

Figure 3 — SIP location

© BSI 05-1999 5
BS EN ISO
5353:1999
BS 6912-27: BSI — British Standards Institution
1999
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