prEN 13001-3-7

SLOVENSKI STANDARD
01-maj-2019
Žerjavi - Konstrukcija, splošno - 3-7. del: Mejna stanja in dokaz varnosti
mehanizma - Zobniki in menjalniki
Cranes - General design - Part 3-7: Limit states and proof of competence of machinery -
Gears and gear boxes
Appareils de levage à charge suspendue - Conception générale - Partie 3-7 : États
limites et vérification d'aptitude des éléments de mécanismes - Engrenages et
réducteurs
Ta slovenski standard je istoveten z: prEN 13001-3-7
ICS:
21.200 Gonila Gears
53.020.20 Dvigala Cranes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2019
ICS 21.200; 53.020.20
English Version
Cranes - General design - Part 3-7: Limit states and proof
of competence of machinery - Gears and gear boxes
Appareils de levage à charge suspendue - Conception
générale - Partie 3-7 : États limites et vérification
d'aptitude des éléments de mécanismes - Engrenages
et réducteurs
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 147.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13001-3-7:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions, symbols and abbreviations . 8
3.1 Terms and definitions . 8
3.2 Symbols and abbreviations . 10
4 General requirements . 10
4.1 Gear materials and associated heat treatment . 10
4.1.1 General requirements on materials . 10
4.1.2 Impact toughness of gears . 11
4.1.3 Nitrited steels . 12
4.1.4 Ausferritic spheroidal graphite cast irons, ADI . 12
4.2 Gear housings . 12
4.3 Open gears . 13
4.4 Gear geometry/tolerances . 13
4.5 Surface quality of gears . 13
4.6 Mounting of shaft, gears and gear boxes. 13
4.7 Lubrication of gears . 14
4.8 Exchange of information. 14
5 Load actions . 14
5.1 General . 14
5.2 Load effects depending on brake torques . 15
5.3 Load actions on gears for vertical movements . 15
5.3.1 General . 15
5.3.2 Emergency cut-out, vertical movements . 15
5.3.3 Loads due to dynamic cut-off of hoisting movement by lifting force limiters . 16
5.3.4 Snag load . 17
5.3.5 Loads caused by apprehended failure of mechanism or component . 17
5.4 Load action on gears for horizontal movements . 18
5.4.1 General . 18
5.4.2 Buffer forces . 19
5.4.3 Emergency cut-out, horizontal movements . 19
5.5 Methods to derive gear torque and forces . 20
6 Proof of static and fatigue strength of gears. 20
6.1 General . 20
6.2 Application of principles of the EN 13001 series . 21
6.3 Gears for vertical movements. 22
6.3.1 Application of load class Q of EN 13001-1 . 22
6.3.2 Load actions and their numbers of occurrences . 23
6.3.3 Considerations regarding particular applications . 24
6.3.4 Fatigue of a gear under variable loading . 24
6.3.5 Proof of static and fatigue strength . 25
6.4 Gears for horizontal movements . 26
6.4.1 Application of load class Q of EN 13001-1 . 26
6.4.2 Load actions and their numbers of cycles. 27
6.4.3 Considerations regarding particular applications . 28
6.4.4 Fatigue of a gear under variable loading . 28
6.4.5 Proof of static and fatigue strength . 29
7 Proof of competence of bearings and shafts . 30
7.1 General . 30
7.2 Proof of competence of static strength . 30
7.3 Proof of competence of fatigue strength . 31
Annex A (informative) Heat treatment of gears . 32
A.1 Quenched and tempered steels . 32
A.2 Case hardened steels . 32
A.3 Induction and flame hardened gears. 33
Annex B (informative) Risk coefficients for gears . 35
Annex C (informative) Use of a same hoisting gear in different A-/U-/Q-classes . 36
Annex D (informative) Information to be provided by the gear manufacturer . 37
Annex E (informative) Selection of a suitable set of crane standards for a given application . 38
Annex ZA (informative) Relationship between this European Standard and the Essential
requirements of Directive 2006/42/EC aimed to be covered . 40
Bibliography . 41

European foreword
This document (prEN 13001-3-7:2019) has been prepared by Technical Committee CEN/TC 147
“Cranes – Safety”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
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.
This document is one part of the EN 13001 series. The other parts are as follows:
— Cranes — General design — Part 1: General principles and requirements;
— Crane safety — General design — Part 2: Load actions;
— Cranes — General Design — Part 3-1: Limit States and proof competence of steel structure;
— Cranes — General design — Part 3-2: Limit states and proof of competence of wire ropes in reeving
systems;
— Cranes — General design — Part 3-3: Limit states and proof of competence of wheel/rail contacts;
— Cranes — General design — Part 3-4: Limit states and proof of competence of machinery — Bearings;
— Cranes — General design — Part 3-5: Limit states and proof of competence of forged hooks;
— Cranes — General design — Part 3-6: Limit states and proof of competence of machinery — Hydraulic
cylinders;
— Cranes — General design — Part 3-8: Limit states and proof competence of machinery — Shafts
[Enquiry stage].
For the relationship with other European Standards for cranes, see Annex E.
Introduction
This European Standard has been prepared to provide a means for the mechanical design and
theoretical verification of cranes to conform to essential health and safety requirements. This European
Standard also establishes interfaces between the user (purchaser) and the designer, as well as between
the designer and the component manufacturer, in order to form a basis for selecting cranes and
components.
This European Standard is a type C standard as stated in EN ISO 12100.
The machinery concerned and the extent to which hazards, hazardous situations and events are
covered are indicated in the scope of this standard.
When provisions of this type C standard are different from those which are stated in type A or B
standards, the provisions of this type C standard take precedence over the provisions of the other
standards, for machines.
1 Scope
This document is due to be used together with EN 13001-1 and EN 13001-2 and as such they specify
general conditions, requirements and methods to prevent by design and theoretical verification,
mechanical hazards in gear components of cranes.
This document covers the following types of gears and adjoining components, used in mechanisms for
any principal movement of a crane:
— cylindrical helical and spur gears and bevel gears, with involute profile geometry;
— gears arranged in enclosed housings or as open gears;
— gears made from steel or iron and gear boxes made from steel, iron or aluminium;
— gears and pinions with lubrication;
— gear boxes and single gear arrangements with bearings and shafts supporting the gears.
The following is a list of significant hazardous situations and hazardous events that could result in risks
to persons during normal use and foreseeable misuse. Clauses 4 to 7 of this document are necessary to
reduce or eliminate the risks associated with the following hazards:
— exceeding the limits of strength (yield, ultimate, fatigue);
— exceeding temperature limits of material.
This document is applicable to cranes, which are manufactured after the date of approval of this
document by CEN, and serves as a reference base for product standards of particular crane types.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1561:2011, Founding — Grey cast irons
EN 1563:2018, Founding — Spheroidal graphite cast irons
EN 1564:2011, Founding — Ausferritic spheroidal graphite cast irons
EN 1706:2010, Aluminium and aluminium alloys — Castings — Chemical composition and mechanical
properties
EN 10025-2:2004, Hot rolled products of structural steels — Part 2: Technical delivery conditions for non-
alloy structural steels
EN 10025-3:2004, Hot rolled products of structural steels — Part 3: Technical delivery conditions for
normalized/normalized rolled weldable fine grain structural steels
EN 10025-6:2004+A1:2009, Hot rolled products of structural steels — Part 6: Technical delivery
conditions for flat products of high yield strength structural steels in the quenched and tempered condition
EN 10083-2:2006, Steels for quenching and tempering — Part 2: Technical delivery conditions for non
alloy steels
EN 10083-3:2006, Steels for quenching and tempering — Part 3: Technical delivery conditions for alloy
steels
EN 10084:2008, Case hardening steels — Technical delivery conditions
EN 10085:2001, Nitriding steels — Technical delivery conditions
EN 10293:2015, Steel castings - Steel castings for general engineering uses
EN 13001-1:2015, Cranes — General design — Part 1: General principles and requirements
EN 13001-2:2014, Crane safety — General design — Part 2: Load actions
EN 13001-3-1:2012+A2:2018, Crane safety — General design — Part 3-1: Limit States and proof
competence of steel structure
EN 13001-3-2:2014, Crane safety — General design — Part 3-2: Limit states and proof of competence of
wire ropes in reeving systems
EN 13001-3-3:2014, Crane safety — General design — Part 3-3: Limit states and proof of competence of
wheel/rail contacts
EN 13001-3-4:2018, Crane safety — General design — Part 3-4: Limit states and proof of competence of
machinery — Bearings
EN 13001-3-5:2016, Crane safety — General design — Part 3-5: Limit states and proof of competence of
forged hooks
EN 13001-3-6:2018, Crane safety — General design — Limit states and proof of competence of
machinery — Hydraulic cylinders
prEN 13001-3-8:2018, Cranes — General design — Part 3-8: Limit states and proof competence of
machinery — Shafts
EN 13135:2013+A1:2018, Cranes — Safety — Design — Requirements for equipment
prEN 14492-2:2016, Cranes — Power driven winches and hoists — Part 2: Power driven hoists
EN ISO 148-1:2016, Metallic materials — Charpy pendulum impact test — Part 1: Test method (ISO 148-
1:2016)
EN ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk
reduction (ISO 12100:2010)
ISO 1122-1:1998, Vocabulary of gear terms — Part 1: Definitions related to geometry
ISO 1328-1:2013, Cylindrical gears — ISO system of flank tolerance classification — Part 1: Definitions
and allowable values of deviations relevant to flanks of gear teeth
ISO 1328-2:1997, Cylindrical gears — ISO system of accuracy — Part 2: Definitions and allowable values
of deviations relevant to radial composite deviations and runout information
ISO 4306-1:2007, Cranes — Vocabulary — Part 1: General
ISO 6336-1:2006, Calculation of load capacity of spur and helical gears — Part 1: Basic principles,
introduction and general influence factors
ISO 6336-2:2006, Calculation of load capacity of spur and helical gears — Part 2: Calculation of surface
durability (pitting)
ISO 6336-3:2006, Calculation of load capacity of spur and helical gears — Part 3: Calculation of tooth
bending strength
ISO 6336-5:2016, Calculation of load capacity of spur and helical gears — Part 5: Strength and quality of
materials
ISO 6336-6:2006, Calculation of load capacity of spur and helical gears — Part 6: Calculation of service
life under variable load
ISO 10300-1:2014, Calculation of load capacity of bevel gears — Part 1: Introduction and general
influence factors
ISO 10300-2:2014, Calculation of load capacity of bevel gears — Part 2: Calculation of surface durability
(pitting)
ISO 10300-3:2014, Calculation of load capacity of bevel gears — Part 3: Calculation of tooth root strength
ISO 17485:2006, Bevel gears — ISO system of accuracy
3 Terms and definitions, symbols and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 12100:2010, ISO 1122-1
and ISO 4306-1:2007 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
gear box
power transmission component with gears, shafts and bearings placed in and supported by an enclosed
housing with input and output shafts
3.1.2
open gear
gear transmission where the gear parts are not supported by a compact, integrated housing structure
3.1.3
case hardening
hardening method applicable to steels, changing the chemical composition and microstructure of the
surface layer by adsorption of carbon, nitrogen or a mixture of the two and by diffusion, create a
chemical composition gradient
3.1.4
carburize hardening depth
depth of the gear surface zone with hardness greater than 550 HV for core hardness less than 450 HV,
or greater than 650 HV for core hardness greater than or equal to 450 HV
3.1.5
induction and flame hardening depth
depth of the gear surface zone with hardness greater than or equal to 80 % of the specified surface
hardness
3.1.6
nitrided and nitrocarburized hardening depth
depth of the gear surface zone with hardness greater than or equal to 400 HV, or where the core
hardness is greater than 380 HV, depth of the gear surface zone with hardness greater than the core
hardness plus 50 HV
3.1.7
coupon
sized test piece made from a representative grade of material
3.1.8
vertical movement
movement of hoist load or of a crane part, where the slope of the path of the moved masses is 5 % or
steeper in relation to horizontal level
[SOURCE: EN 13135:2013+A1:2018, 3.29, modified — "Mass" was replaced with "masses" in the
present definition.]
3.1.9
horizontal movement
movement of hoist load or of a crane part, where the slope of the path of the moved masses is less than
5 % in relation to horizontal level
Note 1 to entry: The definition is taken from EN 13135:2013+A1:2018, 5.2.8.5.1.
3.2 Symbols and abbreviations
Table 1 — Symbols and abbreviations
Symbols,
Description
abbreviations
C Total number of working cycles during the design life of a crane/hoist
Design numbers of working cycles for gears, vertical movements, laden (L)
C , C
GVL GVU
and unladen (U) parts of working cycles
C
Design number of working cycles for gears, horizontal movements
GH
h Height of tooth
K
Application factor, ISO 6336-6
A
m Slope of Wöhler curve, EN 13001-1
m
Rated capacity (rated load) of a crane or hoist
RC
m
Mass of the crane or hoist, relevant for a horizontal movement
DW
N Number of stress cycles
p Fatigue exponent in ISO 6336-6
R
Surface roughness
a
s , s , s , s
Acceleration and deceleration distances of movement
AL DL AU DU
S
Safety factor for tooth bending, ISO 6336-3
Fmin
S
Safety factor for surface durability, ISO 6336-3
Hmin
T Operating temperature of gear or gear box
T
Nominal torque
n
X
Average displacement of movement
lin
Y , Z
Life factors
NT NT
ϕ , ϕ , ϕ , ϕ etc.
Dynamic load factors, EN 13001-2
1 2 5 L
γ
Partial safety factor, EN 13001-2
p
γ
Risk coefficient as defined in EN 13001-2
n
γ
Specific safety factor for brakes
sB
4 General requirements
4.1 Gear materials and associated heat treatment
4.1.1 General requirements on materials
Commonly used materials for gears and their associated heat treatments are listed in Table 2.
See Annex A for more guidance on heat treatment recommendations.
Table 2 — Typical materials for gears
Type of material Material standard Selected qualities
EN 10083-3 25CrMo4+QT 42CrMo4+QT
36NiCrMo16+QT 34CrNiMo6+QT
Quenched and tempered
6+
35NiCr QT 30CrNiMo8+QT
36CrNiMo4+QT
EN 10084 17NiCrMo6–4 16MnCr5
Case hardened
18CrNiMo7–6 20MnCr5
EN 10083-2 C45E C45R
Induction or flame hardened
EN 10083-3 37Cr4 42CrMo4
41Cr4
EN 10085 41CrMoV9
Nitrited
EN 10083-3 34CrMo4+QT 30CrNiMo8+QT
36NiCrMo16+QT
EN 1563 EN-GJS 600-3 EN-GJS 700-2
Cast iron
EN 10293 GE 300
Structural steels EN 10025-3 S420 S460
EN 10025-6 S500 S690
Other materials than those mentioned in Table 2 may be used, provided that the material properties
and characteristics are specified in a manner corresponding to referenced European Standards and
fulfil the requirements specified to the listed material qualities, especially regarding:
— chemical composition;
— mechanical strength;
— surface hardness;
— elongation at fracture;
— hardenability and the Jominy probe test results.
Verification of material properties shall be in accordance with the standards given in Table 2.
Grey cast irons, bronzes and alloys containing aluminium or zinc are not permitted for gears in
mechanisms for vertical movements.
Classification of material quality grades related to the heat treatment procedure, in accordance with
ISO 6336-5, shall be applied. Three classes ML, MQ and ME are defined. Generally, the class MQ is
recommended. Where the class ME is applied, the provisions shall be specified and the compliance with
the requirements of ISO 6336-5 be documented in detail. The class ML should not be applied for high
risk applications.
4.1.2 Impact toughness of gears
Steel qualities listed in Table 2 and delivered in accordance with the relevant standard may be used as
such for gears in operating temperatures −10 °C and higher.
For lower operating temperatures the additional provisions of this clause shall be applied.
For materials other than case hardened, the impact toughness shall be proven with a Charpy-V impact
test in accordance with EN ISO 148-1 and the values shall meet the requirements given in Table 3.
Table 3 — Impact toughness requirements for gear materials
Operating temperature Impact test temperature Minimum impact toughness Av
−10 °C > T ≥ −20 °C −10 °C 27 J
−20 °C > T ≥ −30 °C −20 °C 27 J
−30 °C > T ≥ −40 °C −30 °C 27 J
−40 °C > T ≥ −50 °C −40 °C 27 J
For case hardened steels the impact toughness requirement is fulfilled for operating temperatures
−50 °C and higher provided that
— the steel has a content of nickel of 1,4 % or more and
— the steel has a martensitic structure on surface layer conforming to ISO 6336-5.
Special considerations regarding alloy ingredients of the steel may be needed to reach the impact
toughness.
Operating temperature is the minimum specified temperature in operating condition of the room,
enclosure or the outdoor space, where the gear is located. Benefit of any external heating system
provided may be taken into account.
4.1.3 Nitrited steels
The relevant provisions given in ISO 6336-5 shall be applied.
NOTE More guidance is provided in the Bibliography [9].
4.1.4 Ausferritic spheroidal graphite cast irons, ADI
Ausferritic spheroidal graphite cast irons are specified in EN 1564. Those materials are not in the scope
of this document, because specification of fatigue design parameters is not available in the
ISO 6336 series.
NOTE These materials could be used for internal gears in planetary gear arrangements.
4.2 Gear housings
A gear box housing shall be rigid enough in order to prevent any deformation having a detrimental
influence on the function of the gears.
Gear housings made by welding shall be stress-relieved before machining in order to guarantee their
geometric stability. Their oil tightness shall be measured and the results documented.
Gear housings in mechanisms for vertical movements shall conform to the following:
— spheroidal graphite cast iron used in housings shall have a sufficient impact toughness taking into
account the maximum wall thickness and the minimum operation temperature; the elongation at
fracture A shall be 7 % or greater;
— the use of gear housings made of grey cast iron in accordance with EN 1561 or aluminium alloys
shall conform to the limitations given in EN 13135 for high risk applications.
For commonly used materials of gear housings see Table 4.
Table 4 — Typical materials for gear housings
Type of material Material standard Selected qualities
Structural steel EN 10025-2 S 355
a EN-GJL 250
EN 1561
Cast iron
EN 1563 EN-GJS 350-22 EN-GJS 400-15
EN-GJS 400-18 EN-GJS 500-7
a AlSi9Cu3
Cast aluminium
EN 1706
a
See the limitation of use of this material in the paragraph above.
4.3 Open gears
Open gears should usually be lubricated. Attention shall be paid to the compatibility between the gear
mesh speed and the lubrication, e.g. viscosity and adhesiveness of the lubricant, frequency of lubrication
(manual or automatic), method of lubrication (brush, spray).
For open gears, a quenched and tempered driven gear should be associated with a ground, case
hardened pinion with tip and root profile modifications. Where both the pinion and the gear wheel or
the rack are quenched and tempered, hardness of the pinion should be greater than that of the wheel by
30 HBW or more, to reduce wear and cold scuffing of the tooth flanks.
4.4 Gear geometry/tolerances
Tooth flank tolerances of cylindrical gears shall be specified in accordance with the ISO 1328 series.
Tooth flank tolerances of bevel gears shall be specified in accordance with ISO 17485.
4.5 Surface quality of gears
Enclosed gears require smooth tooth surfaces to ensure the design load capacity. Smooth surfaces are
especially important with regard to micro pitting resistance. For external ground gears, flank surface
roughness should be Ra = 1,6 μm or better. For internal gears or external cut-finished gears, flank
surface roughness should be Ra = 3,2 μm or better.
4.6 Mounting of shaft, gears and gear boxes
Statically indeterminate mounting of shafts is acceptable only, where the forces and stresses are
derived by elastic analysis, taking into account the most unfavourable manufacturing accuracy and
bearing tolerances.
For shrink-fitted gear wheels, both the rim thickness and the tightness of the fit effect on the tooth root
stresses. The combined effect of these two quantities shall be taken into account in the tooth root stress
analysis. However, the effect of shrink fit on gear stress analysis may be omitted, provided that
— the rim thickness at the tooth root is equal to or greater than 2,7 times the tooth module for
external gears and 3,5 times the tooth module for internal gears and
— the shrink fit is 2/1 000 times the fit diameter or smaller.
The gear manufacturer shall inform on using any shrinking-on assemblies associated with gluing for
acceptance by the crane manufacturer.
4.7 Lubrication of gears
Gear transmissions shall be provided with suitable lubrication maintaining the correct operating
conditions of the components, so that the lubricating film is never broken, even when the gear is
stationary under loading. Selection of the lubricant and the lubrication system should be based on
ISO/TR 18792:2008, Clauses 5 and 6.
NOTE Due to the limitation of the scope of the ISO 6336 series, this document does not cover non-lubricated
gears.
4.8 Exchange of information
The crane manufacturer shall deliver to the gear manufacturer all relevant loading data, in line with this
standard, with an itemization of their number of occurrences and related number of rotations of the
gear. All relevant, crane related design factors shall be included in the loading data, e.g. dynamic load
factors (ϕ ), factors (γ ) and the risk factor (γ ). The application of design factors related to ISO gear
i B n
standards is the responsibility of the gear manufacturer. An example is illustrated in Table 10.
Between the crane manufacturer and the gear manufacturer, exchange of substantial amount of
technical information is needed, in addition to the loading data mentioned above. The following is a list
of example information, which could be needed in common cases:
— gear ratio;
— weight of the gear/gear box;
— support arrangement of gear/gear box with interface dimensions;
— necessary interface data regarding e.g. shafts and couplings;
— type of couplings used in the gear box;
— type of lubrication of gears;
— corrosion protection of the gear box, both external and internal.
Annex D gives example of the data needed for the Technical File of the crane, collected and kept by the
crane manufacturer.
5 Load actions
5.1 General
Gears shall be designed for load actions specified in EN 13001-2 and as further detailed in this standard
regarding internal load effects in the mechanisms. The basic load effects on a gear shall be taken as the
torque and forces, effecting either on the secondary (output) side or on the primary (input) side. The
design load effects can be derived from the global load actions on the drive mechanism or the load
effects can be derived from the local (internal) load actions depending on arrangement of the
mechanism and characteristics of the driving unit and its dynamic behaviour in special incidents.
Attention shall be paid to the fact that, depending e.g. on the detailed arrangement of brakes and motors
on an input shaft, a gear on a shaft and the shaft itself might see a different load effects under the same
load action.
5.2 Load effects depending on brake torques
Where the braking torque depends on friction, the actual torque developed might vary largely and this
variation shall be taken into account by a specific safety factor. The brake torque applied in gear design
shall be the set value of a brake torque multiplied by a factor γ as follows:
B
— γ = 1,15 for organic brake lining materials;
B
— γ = 1,30 for sintered brake lining materials.
B
The brake torque does not fully affect in all cases on a gear, depending on the arrangement of
mechanism. Limitations and deductions made before applying the brake torque on a gear, are specified
in relevant clauses of this standard.
Brake arrangements asymmetric in relation to the rotation axis induce radial forces, which shall be
taken into account in design of shafts and bearings.
5.3 Load actions on gears for vertical movements
5.3.1 General
A general description of the load actions, which shall be taken into account, is given in the Table 5.
Selected, exceptional load actions are specified more detailed in the next clauses. The number of
occurrence of the load actions is specified in Clause 6. The used symbols refer to EN 13001-2. Besides
hoisting movements, the requirements of 5.3 shall be applied, as relevant, to mechanisms for any
vertical movement.
Table 5 — Load actions for vertical movements
No. Description Further specifications
1 Steady lifting at the rated load
2 Steady lowering at the rated load
Effect of the reeving system on the rope force and
further on the gear torque shall be taken account.
3 Steady lifting without payload
4 Steady lowering without payload
ϕ on the test load
5 Dynamic test load
6 Static test load
7 Loads caused by emergency cut-out See 5.3.2
Loads due to dynamic cut-off of hoisting
8 See 5.3.3
movement by lifting force limiters
9 Snag load See 5.3.4
Risk coefficient needs not to be included,
Loads caused by apprehended failure of
mechanism or component
see also 5.3.5
5.3.2 Emergency cut-out, vertical movements
The emergency cut-out shall be assumed to occur at the most unfavourable combination of hoisted
mass, speed and direction of the movement. The following conditions shall be taken into account,
depending on the brake arrangement:
a) Only service brakes are installed, on the input shaft of a gear box: The design torque on the gear box
effecting on the input shaft shall be based on the sum braking torque of the service brakes,
deducted by the torque taken to decelerate the rotating movement of masses on the input shaft.
In case a direct acting lifting force limiter is installed, the force limitation may be taken into
account, when determining the torque on the gear, see 5.3.3.
b) Service brakes and backup brakes are provided in the mechanism:
The design torque on the gear box effecting on the input shaft, shall be as in item a) above.
As a second case, the braking torque of the backup brake shall be assumed to effect on the output
shaft of the gear box. The torque effect from the hoisted load shall not be deducted as the most
unfavourable condition is movement upwards and possibly without payload.
Simultaneous engagement of backup and service brakes shall not be assumed. For an example of
brake arrangement, see Figure 1.

Key
1 Gear box
2 Motor (drive unit)
3 Service brake on input (primary) shaft
4 Service brake on input shaft (alternative/additional arrangement)
5 Backup brake, on output (secondary) shaft
6 Rope drum
Figure 1 — Example of a hoisting mechanism arrangement with optional brake locations
5.3.3 Loads due to dynamic cut-off of hoisting movement by lifting force limiters
In case of an indirect acting lifting force limiter (IFL), the design torque on a gear shall be determined
from the load factor ϕ , which is defined and the calculation method given in EN 13001-2.
L
In case of a direct acting lifting force limiter (DFL), the design torque on a gear shall be determined, as
given in the Formula (1), from the set value of the limiter system and applying an additional factor γ
B
in 5.2 for limiters relying on friction:
TTγ× (1)
d BS
where
T is the design load effect (torque or force) in the mechanism, when the limiter operates;
d
γ is the factor for limiters relying on friction in accordance with 5.2; for hydraulic and
B
pneumatic limiters the factor is set to γ = 1;
B
T is the set value of the limiter system (torque or force).
S
5.3.4 Snag load
Snag load means jamming of the lifted load/load attachment after this has been lifted up from the
ground and the motion is running, possibly at full speed. Snag load is currently not included in
EN 13001-2. Snag load shall only be taken into account in applications, where it is by risk analysis
deemed possible.
Snag load case is typical for cranes unloading container ships. There a lifted container or an empty
container spreader might get jammed (by skewing) between the guides in the ship.
Snag load shall be assumed to occur at the most unfavourable combination of hoisted load and speed,
which combination is typically the maximum hoisting speed with an empty spreader.
5.3.5 Loads caused by apprehended failure of mechanism or component
This load action shall be applied, where mechanisms or components are, for safety reasons, duplicated
or secured by other means.
The following, principally different arrangements of ropes, drums and gear boxes can be distinguished:
a) The hoist rope is duplicated in a fully symmetric reeving, one gear box and one rope drum.
Failure of one rope shall be assumed and a dynamic factor ϕ = 1,5 applied on the hoisted mass.
b) The number of gear boxes is duplicated, i.e. there are in the mechanism two gear boxes with service
brakes and drive units of their own, one rope drum and one or more hoist ropes.
Failure of a gear box or a component at the input shaft of the gear box shall be assumed. The
remaining gear box shall be calculated for the total hoisted mass and with a dynamic factor
ϕ = 1,25 applied on the hoisted mass.
c) The hoist rope is duplicated in a fully symmetric reeving and both of the ropes have their own rope
drum and a gear box with service brakes and drive units. The two rope drums are not mechanically
coupled. Example of this arrangement is shown in Figure 2.
Failure of any single component in the other half of the mechanism shall be assumed and as a
consequence the total hoisted mass is taken on the remaining rope and the relevant mechanism
including the gear box. A dynamic factor ϕ = 1,5 shall be applied on the hoisted mass.
=
Key
1, 2 Rope drums
3, 4 Gear boxes
1.1 Rope of drum 1
1.2 Rope of drum 2
Figure 2 — Example of a fully symmetric (cross over) rope reeving and duplicated components
5.4 Load action on gears for horizontal movements
5.4.1 General
The load actions, which shall be taken into account are given in Table 6. The used symbols refer to
EN 13001-2. The number of occurrences of the load actions is specified in Clause 6.
Travel resistance of the movement, including influence of the slope of the runway, shall be taken into
account where relevant. Rolling resistance in steel-on-steel rolling contact shall be in accordance with
EN 13135.
For a crane/hoist working outdoor, a wind force resisting the movement shall be taken into account as
indicated in Table 6, the wind forces calculated in accordance with EN 13001-2.
Table 6 — Load actions on gears for horizontal movements
No. Description Further specifications
1 Acceleration of the movement at the rated load
2 Steady movement at the rated load
3 Deceleration of the movement at the rated load
Wind effect level W3 of EN 13001-2 shall be
applied for outdoor cranes.
4 Acceleration of the movement without payload
5 Steady movement without payload
6 Deceleration of the movement without payload
ϕ on the acceleration, wind effect level W2
7 Driving against the in-service wind
of EN 13001-2
Skewing forces and in-service wind in steady-
8 Wind effect level W3 of EN 13001-2
state movement
Moving of the dynamic, 110 % test load,
ϕ on the acceleration
acceleration as in regular use
ϕ on the buffer force, see 5.4.2
10 Buffer forces
11 Loads caused by emergency cut-out See 5.4.3.

5.4.2 Buffer forces
Buffer forces shall be calculated in accordance with EN 13001-2, taking into account the relevant
additions and modifications given in relevant product type standards.
The deceleration of the rotating mechanism is determined either directly by the deceleration of the
crane movement or, in case of driving by friction contact, the deceleration of the driving mechanism as
limited by the friction.
The torque on the input
...