EN ISO 16231-2:2015

SLOVENSKI STANDARD
01-december-2015
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Self-propelled agricultural machinery - Assessment of stability - Part 2: Determination of
static stability and test procedures (ISO 16231-2:2015)
Selbstfahrende Landmaschinen - Bewertung der Standfestigkeit - Teil 2: Bestimmung
der statischen Standfestigkeit und Prüfverfahren (ISO 16231-2:2015)
Machines agricoles automotrices - Évaluation de la stabilité - Partie 2: Détermination de
la stabilité statique et modes opératoires d'essai (ISO 16231-2:2015)
Ta slovenski standard je istoveten z: EN ISO 16231-2:2015
ICS:
65.060.10 Kmetijski traktorji in prikolice Agricultural tractors and
trailed vehicles
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 16231-2
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2015
EUROPÄISCHE NORM
ICS 65.060.01
English Version
Self-propelled agricultural machinery - Assessment of
stability - Part 2: Determination of static stability and test
procedures (ISO 16231-2:2015)
Machines agricoles automotrices - Évaluation de la Selbstfahrende Landmaschinen - Bewertung der
stabilité - Partie 2: Détermination de la stabilité Standfestigkeit - Teil 2: Bestimmung der statischen
statique et modes opératoires d'essai (ISO 16231- Standfestigkeit und Prüfverfahren (ISO 16231-2:2015)
2:2015)
This European Standard was approved by CEN on 29 August 2015.

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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16231-2:2015 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Annex ZA (informative) Relationship between this European standard and the Essential
Requirements of EU Directive 2006/42/EC . 4

European foreword
This document (EN ISO 16231-2:2015) has been prepared by Technical Committee ISO/TC 23 “Tractors
and machinery for agriculture and forestry” in collaboration with Technical Committee CEN/TC 144
“Tractors and machinery for agriculture and forestry” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2016, and conflicting national standards shall
be withdrawn at the latest by March 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this
document.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 16231-2:2015 has been approved by CEN as EN ISO 16231-2:2015 without any
modification.
Annex ZA
(informative)
Relationship between this European standard
and the Essential Requirements of EU Directive 2006/42/EC
This European Standard has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association to provide a means of conforming to Essential
Requirements of the New Approach Directive 2006/42/EC on machinery.
Once this standard is cited in the Official Journal of the European Union under that Directive and has
been implemented as a national standard in at least one Member State, compliance with the normative
clauses of this standard confers, within the limits of the scope of this standard, a presumption of
conformity with the relevant Essential Requirement 3.4.3 of that Directive and associated EFTA
regulations.
WARNING — Other requirements and other EU Directives may be applicable to the product(s) falling
within the scope of this standard.
INTERNATIONAL ISO
STANDARD 16231-2
First edition
2015-09-15
Self-propelled agricultural
machinery — Assessment of stability —
Part 2:
Determination of static stability and
test procedures
Machines agricoles automotrices — Évaluation de la stabilité —
Partie 2: Détermination de la stabilité statique et modes
opératoires d’essai
Reference number
ISO 16231-2:2015(E)
©
ISO 2015
ISO 16231-2:2015(E)
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ii © ISO 2015 – All rights reserved

ISO 16231-2:2015(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Determination of the centre of gravity (COG) of a self-propelled machine .2
4.1 Method to determine and to calculate the centre of gravity of the un-laden machine . 2
4.2 Remarks and items to observe during this procedure . 2
4.3 Methods to determine the centre of gravity of a laden machine or a machine
with attachments . 5
4.3.1 Graphical method . 5
4.3.2 Mathematical method . . . 7
5 Static overturning angle (SOA). 8
5.1 General . 8
5.2 Lateral roll-over: Machines with one fixed and one swivelling axle (without axle
swivel limiting device). 8
5.2.1 General. 8
5.2.2 Graphical determination of the stability . 9
5.2.3 Determination of the stability by calculation .10
5.3 Lateral roll-over: Machines with one fixed and one swivelling axle with swivelling
angle limiting device .11
5.4 Lateral roll—over: machines without swivelling axle .13
5.4.1 Machines on tracks .13
5.4.2 Machines with devices to lock the swivelling axle or to modify the
stability triangle .13
5.4.3 Machines with individual wheel suspension .13
5.5 Tip forward and tip rearward .13
5.5.1 Tip forward .13
5.5.2 Tip rearward .13
5.6 Body levelling systems .14
5.7 Alternative methods .14
6 Comparison of SOA and RSSA .14
Annex A (informative) Example of calculation of centre of gravity (see Clause 4) .15
Annex B (informative) Example of calculation of static overturning angle (see Clause 5) .16
Annex C (normative) Calculation of RSSA .18
Annex D (informative) Impact of dynamic effects on roll-over or tip-over .19
ISO 16231-2:2015(E)
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 23, Tractors and machinery for agriculture and
forestry, Subcommittee SC 3, Safety and comfort.
ISO 16231 consists of the following parts, under the general title Self-propelled agricultural machinery —
Assessment of stability:
— Part 1: Principles
— Part 2: Determination of static stability and test procedures
iv © ISO 2015 – All rights reserved

ISO 16231-2:2015(E)
Introduction
Self-propelled agricultural machinery with a ride-on operator (driver) can be exposed to the hazard of
rolling or tipping over during the intended operation. A risk assessment is used to determine whether
this hazard is to be considered in case of a specific machine and the protective measures to be used in
order to avoid or minimize this hazard for the ride-on operator.
The risk assessment considers the operating conditions in which the machine is intended to be used,
the physical properties of the machine, and the required skills to operate the machine as well as any
other parameter which can have an impact on the risk for roll- or tip-over.
INTERNATIONAL STANDARD ISO 16231-2:2015(E)
Self-propelled agricultural machinery — Assessment of
stability —
Part 2:
Determination of static stability and test procedures
1 Scope
This part of ISO 16231 specifies a method to determine the centre of gravity of un-laden self-propelled
machines, a method to determine the centre of gravity of laden machines and combinations with
attachments, and methods to determine the static overturning angle.
NOTE Requirements related to self-protective structures and ROPS are to be dealt with in a separate
International Standard.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 789-6, Agricultural tractors — Test procedures — Part 6: Centre of gravity
ISO 16231-1, Self-propelled agricultural machinery — Assessment of stability — Part 1: Principles
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16231-1 and the following apply.
3.1
maximum operating slope
MOS
value indicating, for each type of self-propelled machine and each direction, the maximum slope in (%)
on which the machine is intended to work according to good agricultural practice
3.2
slope compensation system
system to improve the functional performance of an agricultural machine working on slopes, without
levelling the main body of the machine, such as a levelling of internal components, adjusting the
kinematics of separating systems, or adjusting air flow or pattern or both
3.3
body levelling system
system to improve the function performance, drivers comfort, ability to work on slopes, and stability
of an agricultural machine working on slopes, by means of levelling the main body of the machine in a
longitudinal or transversal sense or a combination of both
ISO 16231-2:2015(E)
4 Determination of the centre of gravity (COG) of a self-propelled machine
4.1 Method to determine and to calculate the centre of gravity of the un-laden machine
The centre of gravity of the un-laden machine is determined by means of scales and support stands (see
Tables 1 and 2 and Figures 1, 2, and 3).
4.2 Remarks and items to observe during this procedure
4.2.1 Follow the procedure as outlined in ISO 789-6; this method is based on the increasing load on the
supporting axle when the other axle is lifted and supported on a certain height; the lifting angle ω and
the increased load on the scale allow determination of the height of the COG.
4.2.2 It is recommended to use steel wheels in order to avoid deviations due to changing wheel radius
under changing load conditions. For calculation of the COG with the actual tires, see 4.3.
Any suspension system shall be locked. If locking the suspension system is not possible, then inflate all
tires up to the maximum permissible pressure as specified by the tyre manufacturer. The difference in
radius of the wheels on the fixed axle between horizontal and raised position shall not be higher than
1,5 % of the wheel radius.
4.2.3 Ensure that the plane of the scale is horizontal and flush with the ground plane.
4.2.4 Wheels on the scale shall be free to rotate, in order to exclude tangential forces on the tires.
Therefore, the parking brake shall not be applied and the gearbox shall be in neutral or the transmission
shall be in the position for towing the vehicle.
4.2.5 Although not required, lifting the side of the swivelling axle is preferred; in most cases, this is the
axle with the smallest diameter wheels.
4.2.6 Raised wheels shall rest on wheel stands before reading the weight on the scale.
4.2.7 For easy installation of the wheel stands, it can be necessary to lock the swivelling axle with
wedges when lifting the machine.
When resting on the wheel stands, the wedges shall be removed.
4.2.8 The accuracy of this method depends on the height of wheel stand as a proportion of the wheel
base and the accuracy of the scale.
Accuracy of weighing during five consecutive measurements: all values shall fall within a range of 1,0 %
of the maximum measured load from the fixed axle in raised position.
4.2.9 Calculate the COG, using the ± deviation of the accuracy of the scale and determine the deviation
of the height of the COG.
This deviation shall not exceed ±4 %. In case the value exceeds ±4 %, the height of the wheel stands
shall be increased in order to decrease the deviation.
2 © ISO 2015 – All rights reserved

ISO 16231-2:2015(E)
Table 1 — Input data for calculation of centre of gravity(COG)
Data description Symbol Unit
Static load radius wheel fixed axle (see Figure 2) R mm
Static load radius wheel swivelling axle (raised axle) (see Figure 2) r mm
Wheel base (see Figure 1 top view) W mm
Load on left wheel fixed axle in horizontal position (see Figure 1 rear/front view) F daN
fl
Load on right wheel fixed axle in horizontal position (see Figure 1 rear/front view) F daN
fr
Load on swivelling axle in horizontal position (see Figure 1 rear/front view) F daN
sw
Load on fixed axle in raised position (swivelling axle supported on stand) (see Figure 3) F daN
far
Height of stand (see Figure 3) L mm
Distance between outer edges of tires on fixed axle (see Figure 1 top view) o mm
Width of tires on the fixed axle (see Figure 1 top view) p mm
Lateral offset of the swivelling axle pivot point (to the right is positive) (see Figure 1 top a mm
view)
Figure 1 — Rear, top, and side view of the machine
ISO 16231-2:2015(E)
Figure 2 — Machine in horizontal position — Side view
Figure 3 — Machine in raised position — Side view
4 © ISO 2015 – All rights reserved

ISO 16231-2:2015(E)
Table 2 — Calculation of centre of gravity(COG)
Data description Symbol Unit Calculation
Wheel track of fixed axle T mm o – p
Total weight of the machine F daN F + F + F
t fr fl sw
Lateral position of COG (versus centre of fixed axle) y mm [(F * T) + (T/2 + a) * F ] / F – T/2
fr sw t
(positive number means right from centre of fixed
axle in Figure 1)
Longitudinal position of COG (versus centre line of x’ mm W * (F + F ) / F
fr fl t
swivelling axle)
Longitudinal position of COG (versus centre line of x mm W - x’
fixed axle)
2 2
Longitudinal distance between wheel centres w mm √ ((R – r) + W )
2 2
Vertical projection of wheel base in raised position W’ mm √ (w – (L + r – R) )
−1
Angle formed by the line between wheel centres α ° cos (W / w)
and horizontal through the centre of the fixed axle
wheels
−1
Angle formed by the line between wheel centres β ° tan ((L + r – R) / W’)
and horizontal through the centre of the fixed axle
wheels in raised position
Lifting angle ω ° α + β
Vertical projection of longitudinal distance between c mm F * W’ / F
far t
COG and the swivelling axle in raised position
Auxiliary line for calculation (see Figure 3) b mm r + (c / sin ω)
Height of COG z mm b – (x’ / tan ω)
...