SIST-TS CEN/TS 13001-3-2:2008

SLOVENSKI STANDARD
SIST-TS CEN/TS 13001-3-2:2008
01-december-2008
1DGRPHãþD
SIST-TS CEN/TS 13001-3-2:2005
SIST-TS CEN/TS 13001-3-2:2005/AC:2007
Dvigala (žerjavi) - Konstrukcija, splošno - 3-2. del: Mejna stanja in dokaz varnosti
jeklenih vrvi pri vrvnih pogonih
Cranes - General design - Part 3-2: Limit states and proof of competence of wire ropes in
reeving systems
Krane - Konstruktion allgemein - Teil 3-2: Grenzzustände und Sicherheitsnachweis von
Drahtseilen in Seiltrieben
Appareils de levage à charge suspendue - Conception générale - Partie 3-2: Etats limites
et vérification d'aptitude des systèmes de mouflage
Ta slovenski standard je istoveten z: CEN/TS 13001-3-2:2008
ICS:
53.020.20 Dvigala Cranes
SIST-TS CEN/TS 13001-3-2:2008 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST-TS CEN/TS 13001-3-2:2008

---------------------- Page: 2 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
TECHNICAL SPECIFICATION
CEN/TS 13001-3-2
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
September 2008
ICS 53.020.20 Supersedes CEN/TS 13001-3-2:2004
English Version
Cranes - General design - Part 3-2: Limit states and proof of
competence of wire ropes in reeving systems
Appareils de levage à charge suspendue - Conception Krane - Konstruktion allgemein - Teil 3-2: Grenzzustände
générale - Partie 3-2: Etats limites et vérification d'aptitude und Sicherheitsnachweis von Drahtseilen in Seiltrieben
des systèmes de mouflage
This Technical Specification (CEN/TS) was approved by CEN on 5 February 2008 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 13001-3-2:2008: E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
Contents Page
Foreword.4
Introduction .5
1 Scope .5
2 Normative references .5
3 Terms, definitions, symbols and abbreviations .6
3.1 Terms and definitions .6
3.2 Symbols and abbreviations .6
4 General.8
5 Proof of static strength .8
5.1 General.8
5.2 Vertical hoisting.8
5.3 Non vertical drives.12
5.4 Limit design rope force .15
6 Proof of fatigue strength.15
6.1 General.15
6.2 Design rope force .16
6.3 Limit design rope force .18
6.4 Further influences on the limit design rope force.20
Annex A (normative) Number of relevant bendings .25
Annex B (informative) Guidance for selection of design number of hoist ropes used during the
useful crane life.28
Annex C (informative) Selection of suitable set of crane standards for a given application.29
Bibliography .30

Figures
Figure 1 — Example for the acting parts of hoist mass . 9
Figure 2 — Example for Rope reeving efficiency . 10
Figure 3 — Angle ββββ . 11
max
Figure 4— Horizontal force. 12
Figure 5 — Examples for non vertical drive. 13
Figure 6 — Example for rope tightening . 13
Figure 7 — Lifting positions . 18
Figure 8 — Fleet angles . 22
Figure 9 — Groove radius. 23
Figure A.1 — Number of relevant bendings. 27
2

---------------------- Page: 4 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
Tables
Table 1 — Symbols and abbreviations.6
Table 2 — Partial safety factors γ .14
p
Table 3 — Minimum rope resistance factor γγγγ .15
rb
Table 4 — Classes S of rope force history parameter s .19
R r
Table 5 — Reference ratio R .21
Dd
Table 6 — Factor f .22
f3
Table 7 — Factor f .23
f6
Table 8 — Rope type factors .24
Table A.1 — Bending counts.25
Table A.2 — Examples for the number of relevant bendings w .26

3

---------------------- Page: 5 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
Foreword
This document (CEN/TS 13001-3.2:2008) has been prepared by Technical Committee CEN/TC 147
“Cranes — Safety”, the secretariat of which is held by BSI.
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 will supersede CEN/TS 13001-3-2:2004.
CEN/TC 147/WG 2 "Cranes — Design" is held by DIN.
This European Technical Specification is one part of EN 13001 and CEN/TS 13001, Cranes — General
design. The other parts are:
Part 1: General principles and requirements;
Part 2: Load actions;
Part 3-1: Limit states and proof of competence of steel structures;
Part 3-3: Limit states and proof of competence of wheel/rail contacts;
Part 3-5: Limit states and proof of competence of forged hooks.
The following has been changed:
 6.4.8, Rope type – the last paragraph has been changed and Table 8 has been added;
 Annex C has been updated.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

4

---------------------- Page: 6 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
Introduction
This Technical Specification has been prepared to be a harmonized standard to provide one means for the
mechanical design and theoretical verification of cranes to conform to the essential health and safety
requirements of the Machinery Directive, as amended. This Technical Specification 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 Technical Specification is a type C standard as stated in EN ISO 12100-1:2003.
The machinery concerned and the extent to which hazards are covered are indicated in the scope of this
Technical Specification.
1 Scope
This Part 3-2 of the Technical Specification CEN/TS 13001 is used together with Part 1 and Part 2 and as
such they specify general conditions, requirements and methods to prevent mechanical hazards of wire ropes
in reeving systems of cranes by design and theoretical verification.
NOTE 1 Specific requirements for particular types of crane are given in the appropriate Technical Specification for the
particular crane type.
Exceeding the limits of strength could result in risks to persons during normal use and foreseeable misuse.
Clauses 5 to 6 of this Technical Specification are necessary to reduce or eliminate these risks.
This Technical Specification is applicable to cranes which are manufactured after the date of approval by CEN
of this Technical Specification and serves as reference base for the Technical Specifications for particular
crane types.
NOTE 2 CEN/TS 13001-3-2 deals only with the limit state method in accordance with EN 13001-1.
2 Normative references
The following referenced documents are indispensable for the application 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 1990:2002, Eurocode: Basis of structural design
EN 12385-2, Steel wire ropes — Safety — Part 2: Definitions, designation and classification
EN 12385-4, Steel wire ropes — Safety — Part 4: Stranded ropes for general lifting applications
EN 13001-1, Cranes — General design — Part 1: General principles and requirements
EN 13001-2, Cranes — General design — Part 2: Load actions
EN 13411-1, Terminations for steel wire ropes — Safety — Part 1: Thimbles for steel wire rope slings
EN 13411-2, Terminations for steel wire ropes — Safety — Part 2: Splicing of eyes for wire rope slings
5

---------------------- Page: 7 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
EN 13411-3, Terminations for steel wire ropes — Safety — Part 3: Ferrules and ferrule-securing
EN 13411-4, Terminations for steel wire ropes — Safety — Part 4: Metal and resin socketing
EN 13411-6, Terminations for steel wire ropes — Safety — Part 6: Asymmetric wedge socket
EN ISO 12100-1:2003, Safety of machinery — Basic concepts, general principles for design — Part 1: Basic
terminology, methodology (ISO 12100-1:2003)
ISO 4306-1:1990, Cranes — Vocabulary — Part 1: General
ISO 4309, Cranes — Wire ropes — Care, maintenance, installation, examination and discard
3 Terms, definitions, symbols and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 12100-1:2003, EN 1990:2002
and Clause 6 of ISO 4306-1:1990 apply.
3.2 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in Table 1 apply.
Table 1 — Symbols and abbreviations
Symbols,
Description
abbreviations
a Acceleration
C Total number of working cycles (see EN 13001-1) during useful life of crane
D Relevant diameter
D Minimum pitch diameter of drum
drum
D Minimum pitch diameter of sheave
sheave
D Minimum pitch diameter of compensating sheave
comp
d Rope diameter
d Diameter of bearing or shaft
bearing
F Equivalent force
equ
F
gd Part of F induced by gravity, exclusive of mass of payload, amplified by γ
equ p
F
gl Part of F induced by gravity forces of mass of payload, amplified by γ
equ p
F
o Part of F induced by any other forces, amplified by γ
equ p
F Limit design rope force for the proof of static strength
Rd,s
F Limit design rope force for the proof of fatigue strength
Rd,f
F Design rope force for the proof of static strength
Sd,s
F Part of F induced by resistances, amplified by γ
r equ p
F Design rope force for the proof of fatigue strength
Sd,f
Ft Part of F induced by rope tightening forces, amplified by γ
equ p
F Minimum rope breaking force
u
F Part of F induced by wind forces, amplified by γ
w equ p
f Factor of further influences
f
f Factor of diameter ratio influence
f1
f Factor tensile strength of wire influence
f2
f Factor of fleet angle influence
f3
f Factor of lubrication influence
f4
f Factor of multilayer drum influence
f5
6

---------------------- Page: 8 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
Table 1 (continued)
Symbols,
Description
abbreviations
f Factor of groove radius influence
f6
f Factor of rope type influence
f7
f Rope force increasing factor from rope reeving efficiency
S1
f Rope force increasing factor from non parallel falls
S2
f Rope force increasing factor from horizontal acceleration
S3
*
f Rope force increasing factors in fatigue
Si
g Gravity constant
i Index for cycles of lifting and lowering
k Rope force spectrum factor
r
l Number of ropes used during useful life of the crane
r
q Normalized height distribution
m Mass of hoist load (see EN 13001-2)
H
m Mass of hoist load that is acting on the rope falls under consideration
Hr
m Rotatory rope driven mass
red
m Translational rope driven mass
trans
n Number of contact points passed by rope
n Number of falls or reeving lines
f
n Number of fixed sheave between drum and moving part
fs
n Mechanical advantage
m
R Minimum tensile strength of the wire used in the rope
0
R Reference ratio of rope bending diameter to rope diameter
Dd
R Tensile strength level of wire
r
r Groove radius
g
S Class of rope force history
R
s Rope force history parameter
r
t Rope type factor
t Experimentally derived rope type factor for experiment i
e,i
t Arithmetic mean of t
e e,i
w Number of relevant bendings per lifting movement
w Bending count
c
w Number of bendings at reference point
D
w Total number of bendings
tot
z, z, z , z z Height coordinates
i min max, ref
α Angle of slope
β, β Angles between falls and line of acting force
max
Angle between gravity and projected rope in plane of F and g
γ h
γ Risk coefficient
n
γ Partial safety factor
p
γ Minimum rope resistance factor (static)
rb
γ Minimum rope resistance factor (fatigue)
rf
δ Design fleet angle
ε Angle between sheave planes
η Efficiency of single sheave
s
η Total efficiency of rope drive
tot
Relative total number of bendings
ν
r
Dynamic factor for inertial or gravity effects
φ
*
φ Dynamic factor for inertial or gravity effects in fatigue
Dynamic factor for hoisting an unrestrained grounded load
φ
2
Dynamic factor for loads caused by acceleration
φ
5
Dynamic factor for test load
φ
6
Angle between the sheave groove sides
ω
7

---------------------- Page: 9 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
4 General
In all cranes running wire ropes are stressed by loads (described by a load spectrum) and by bendings. Both
constitute the rope force history, classified in classes S (see 6.3.2). Classes S are used for the selection of
R R
the wire rope and diameters of drums and/or sheaves. They are independent of time.
The proof of competence for static strength and the proof of competence for fatigue strength shall be fulfilled
for the selection of ropes and components. This Technical Specification is for design purposes only and
should not be seen as a guarantee of actual performance.
To ensure safe use of the rope, the discard criteria in accordance with ISO 4309 shall be applied.
The wire rope should be in accordance with EN 12385-4. Rope terminations shall meet the requirements of
EN 13411-1, EN 13411-2, EN 13411-3, EN 13411-4 and EN 13411-6.
5 Proof of static strength
5.1 General
For the proof of static strength it shall be proven that for all relevant load combinations of EN 13001-2
F ≤ F (1)
Sd,s Rd,s
where:
F is the design rope force;
Sd,s
F is the limit design rope force.
Rd,s
5.2 Vertical hoisting
5.2.1 Design rope force
The design rope force F in vertical hoisting shall be calculated as follows:
Sd,s
m ⋅ g
Hr
F = ⋅φ⋅ f ⋅ f ⋅ f ⋅γ ⋅γ (2)
Sd,s S1 S2 S3 p n
n
f
where:
m is the mass of the hoist load (m ) or that part of the mass of the hoist load that is acting on the
Hr H
rope falls under consideration (see Figure 1). The mass of the hoist load includes the masses of
the payload, lifting attachments and a portion of the suspended hoist ropes. In statically
undetermined systems, the unequal load distribution between ropes depends on elasticities and
shall be taken into account;
g is the acceleration due to gravity (gravity constant);
n is the number of falls carrying m ;
f Hr
φ is the dynamic factor for inertial and gravity effects as shown in 5.2.2;

f to f are the rope force increasing factors as shown in 5.2.3 to 5.2.5;
S1 S3
8

---------------------- Page: 10 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
γ is the partial safety factor (see EN 13001-2):
p
γ = 1,34 for regular loads (load combinations A),
p
γ = 1,22 for occasional loads (load combinations B),
p
γ = 1,10 or exceptional loads (load combinations C);
p
γ is the risk coefficient (see EN 13001-2), where applicable.
n

Figure 1 — Example for the acting parts of hoist mass
5.2.2 Inertial and gravitational effects
5.2.2.1 Dynamic factors
For vertical hoisting the maximum inertial effects from either hoisting an unrestrained grounded load or from
acceleration or deceleration shall be taken into account by the dynamic factor φ., given in 5.2.2.2 to 5.2.2.4.
5.2.2.2 Hoisting an unrestrained grounded load
φ =φ (3)
2
where:
φ is the dynamic factor for inertial and gravity effects when hoisting an unrestrained grounded load
2
(see EN 13001-2).
5.2.2.3 Acceleration or deceleration of the hoist load
a
φ = 1+φ ⋅ (4)
5
g
where:
φ is the dynamic factor for loads caused by acceleration (see EN 13001-2);
5
a is the vertical acceleration or deceleration;
9

---------------------- Page: 11 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
g  is the acceleration due to gravity (gravity constant).
5.2.2.4 Test load
φ =φ (5)
6
where:
φ is the dynamic factor for testload (see EN 13001-2).
6
5.2.3 Rope reeving efficiency
The rope force increasing factor from rope reeving efficiency f shall be calculated as follows:
S1
1
f = (6)
S1
η
tot
The total efficiency of the rope drive η shall be calculated as follows:
tot
n n
fs m
(η ) 1− (η )
S S
η = ⋅ (7)
tot
n 1−η
m S
where:
η is the efficiency of a single sheave:
S
η = 0,985 for sheave with roller bearing,
S
η = 0,985 × (1 - 0,15 × d / D ) for sheave with plain bearing;
S bearing Sheave
NOTE Other values for ηS may be used if verified by test results for the applied rope, sheave or bearing.
n is the mechanical advantage (see example in Figure 2);
m
n is the number of fixed sheaves between drum and moving part.
fs

Figure 2 — Example for Rope reeving efficiency
5.2.4 Non parallel falls
When the rope falls are not parallel, the rope force is increased. The rope force increasing factor f shall be
S2
determined for the most unfavourable position. For simplification f may be calculated by
S2
10

---------------------- Page: 12 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
1
f = (8)
S2
cosβ
max
where:
β is the maximum angle between the falls and the direction of load (see Figure 3).
max

Figure 3 — Angle ββββ
max
5.2.5 Horizontal forces on the hoist load
The rope force increasing effect of the horizontal forces (e.g. by crab or crane accelerations, wind) may be
neglected in applications with free swinging loads.
However in applications with several non parallel ropes (rope pyramid, see Figure 4) the horizontal forces
increase the rope force considerably. This effect shall be taken into account. For simplification the rope force
increasing factor f may be calculated by
S3
F
h
f = 1+ ≤ 2 (9)
S3
m ⋅ g⋅ tanγ
H
where:
F is the horizontal force on the hoist load;
h
m is the mass of the hoist load;
H
g is the acceleration due to gravity (gravity constant);
γ is the angle between gravity and the rope projected in the plane of F and g.
h
11

---------------------- Page: 13 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)

Figure 4— Horizontal force
5.3 Non vertical drives
5.3.1 Design rope force
The design rope force F in non vertical drives (see examples in Figure 5 and Figure 6) shall be calculated
Sd,s
as follows:
F
equ
F = ⋅φ⋅ f ⋅ f ⋅γ (10)
Sd,s S1 S2 n
n
f
where:
F is the equivalent force acting on the rope falls under consideration as shown in 5.3.2. In statically
equ
undetermined systems, the unequal load distribution between ropes depends on elasticities and
shall be taken into account;
n is the number of falls or reeving lines;
f
φ is the dynamic factor for inertial effects as shown in 5.3.3;

f , f are the rope force increasing factors as shown in 5.3.4 and 5.3.5;
S1 S2
γ is the risk coefficient (see EN 13001-2), where applicable.
n
12

---------------------- Page: 14 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)

Key
m , m , m rotatory rope driven masses, referred to the coordinate of acceleration
r1 r2 r3
m , m m translational rope driven masses, referred to the coordinate of acceleration
D L,
F , F , F forces, see 5.3.2
equ w r
Acc., a accelerations
n number of falls
f
Figure 5 — Examples for non vertical drive


Key
m , m , m rotatory rope driven masses, referred to the coordinate of acceleration
r1 r2 r3
m translational rope driven mass, referred to the coordinate of acceleration

F tightening forces, see 5.3.2
t
n number of falls
f
Figure 6 — Example for rope tightening
5.3.2 Equivalent force
In general the load actions of gravity forces, resistances (e.g. rolling or gliding, wheels, bearings), rope
tightening forces, wind forces and any other forces (e.g. buffer forces, forces from climatic effects) contribute
to the equivalent force F as illustrated in Equation 11. Those load actions shall be amplified by partial safety
equ
factors γ (see EN 13001-2) for the load combination under consideration, as given in Table 2.
p
F = F + F + F + F + F + F (11)
equ gd gl r w t o
where:
F is that part of F that is induced by gravity forces of the rope driven masses, exclusive of the
gd equ
mass of the payload, amplified by the relevant partial safety factor;
13

---------------------- Page: 15 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
F is that part of F that is induced by gravity forces of the rope driven mass of the payload,
gl equ
amplified by the relevant partial safety factor;
F is that part of F that is induced by resistances, amplified by the relevant partial safety factor;
r equ
F is that part of F that is induced by wind forces, amplified by the relevant partial safety factor;
w equ
F is that part of F that is induced by rope tightening forces (see example in Figure 6), amplified by
t equ
the relevant partial safety factor;
F is that part of F that is induced by any other forces, amplified by the relevant partial safety
o equ
factor.
Table 2 — Partial safety factors γ
p
Regular loads Occasional loads Exceptional loads
Description

Load combinations A Load combinations B Load combinations C
Gravitation on masses,
exclusive of mass of 1,22 1,16 1,1
F
gd
payload
Gravitation on payload 1,34 1,22 1,1
F
gl
Inertia 1,34 1,22 1,1
φφ
φφ
Resistances 1,34 1,22 1,1
F
r
Rope tightening 1,22 1,16 1,1
F
t
Wind forces: in service — 1,22 1,16
F
w
Wind forces: out of service — — 1,1
Snow and ice — 1,22 1,1
F Temperature — 1,16 1,05
o
Buffer forces — — 1,1

5.3.3 Inertial effects
In non vertical drives the inertial effects from accelerations shall be taken into account by the dynamic factor φ
calculated as follows:
( m + m )⋅ a⋅φ ⋅γ
∑ trans ∑ red 5 p
φ = 1+ (12)
F
equ
where:
Σm is the sum of translational rope driven masses, referred to the coordinate of acceleration;
trans
Σm is the sum of rotatory rope driven masses (see examples in Figure 5 and Figure 6), referred to
red
the coordinate of acceleration;
a is the acceleration or deceleration;
φ is the dynamic factor for loads caused by acceleration (see EN 13001-2);
5
γ is the partial safety factor, as given in Table 2, line inertia;
p
F is the equivalent force.
equ
14

---------------------- Page: 16 ----------------------

SIST-TS CEN/TS 13001-3-2:2008
CEN/TS 13001-3-2:2008 (E)
5.3.4 Rope reeving efficiency
The increase of the design rope force by the rope reeving efficiency is given by the rope force increasing
factor f , calculated as shown in 5.2.3, Equations 6 and 7.
S1
5.3.5 Non parallel falls
The increase of the design rope force by non parallel falls is given by the rope force increasing factor f ,
S2
calculated as shown in 5.2.4 and Equation 8.
5.4 Limit design rope force
The limit design rope force F is given by
Rd,s
F
u
F = (13)
Rd,s
γrb
where:
F is the minimum breaking force of the rope as specified by the manufacturer;
u
γ is the minimum rope resistance factor.
rb
The minimum rope resistance factor γ is dependent on the geometry of the reeving system and is given by
rb
5,0
γ = 1,34 + (14)
rb
0,8
D
 
− 4
 
d
 
where:
D is the minimum relevant diameter: D = Min(D ; 1,125 × D ; 1,125 × D )
sheave drum comp
d is the rope diameter.
Table 3 gives minimum rope resistance factors for selected ratios of D/d.
Table 3 — Minimum rope resistance factor γγ
γγ
rb
D/d 11,2 12,5 14,0 16,0 18,0 20,0
γγγγ 3,06 2,75 2,52 2,30 2,16 2,05
rb

6 Proof of fatigue strength
6.1 General
According to test results the fatigue strength of ropes in terms of number of bendings (rope force to number of
bendings relationship) is approximately inversely proportional to the second power of the
...