EN 15011:2011

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Krane - Brücken- und PortalkraneAppareils de levage à charge suspendue - Ponts roulants et portiquesCranes - Bridge and gantry cranes53.020.20DvigalaCranesICS:Ta slovenski standard je istoveten z:EN 15011:2011SIST EN 15011:2011en,fr,de01-julij-2011SIST EN 15011:2011SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 15011
January 2011 ICS 53.020.20 English Version
Cranes - Bridge and gantry cranes
Appareils de levage à charge suspendue - Ponts roulants et portiques
Krane - Brücken- und Portalkrane This European Standard was approved by CEN on 18 December 2010.
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, 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:
Avenue Marnix 17,
B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15011:2011: ESIST EN 15011:2011

Guidance for specifying the operating duty according to EN 13001-1 . 53Annex B (informative)
Guidance for specifying the classes P of average number of accelerations according to EN 13001-1 . 62Annex C (informative)
Calculation of dynamic coefficient φφφφh(t) . 63Annex D (normative)
Loads caused by skewing . 66Annex E (informative)
Calculation of stall load factor for indirect acting lifting force limiter . 73Annex F (informative)
Local stresses in wheel supporting flanges . 75Annex G (normative)
Noise test code . 80Annex H (informative)
Actions on crane supporting structures induced by cranes . 89Annex I (informative)
Selection of a suitable set of crane standards for a given application . 91Annex ZA (informative)
Relationship between this European standard and the Essential Requirements of EU Directive 2006/42/EC . 92Bibliography . 93 SIST EN 15011:2011

(IEC 60825-1:2007) EN 60947-5-5, Low-voltage switchgear and controlgear — Part 5-5: Control circuit devices and switching elements — Electrical emergency stop device with mechanical latching function (IEC 60947-5-5:1997) EN ISO 3744:2010, Acoustics — Determination of sound power levels and sound energy levels of noise sources using sound pressure — Engineering methods for an essentially free field over a reflecting plane (ISO 3744:2010) EN ISO 4871, Acoustics — Declaration and verification of noise emission values of machinery and equipment (ISO 4871:1996) EN ISO 11201, Acoustics — Noise emitted by machinery and equipment — Determination of emission sound pressure levels at a work station and at other specified positions in an essentially free field over a reflecting plane with negligible environmental corrections (ISO 11201:2010) EN ISO 11202:2010, Acoustics — Noise emitted by machinery and equipment — Determination of emission sound pressure levels at a work station and at other specified positions applying approximate environmental corrections (ISO 11202:2010) EN ISO 11203:2009, Acoustics — Noise emitted by machinery and equipment — Determination of emission sound pressure levels at a work station and at other specified positions from the sound power level
(ISO 11203:1995) EN ISO 11204:2010, Acoustics — Noise emitted by machinery and equipment — Determination of emission sound pressure levels at a work station and at other specified positions applying accurate environmental corrections (ISO 11204:2010) EN ISO 11688-1, Acoustics — Recommended practice for the design of low-noise machinery and equipment — Part 1: Planning (ISO/TR 11688-1:1995) EN ISO 12100-1:2003, Safety of machinery — Basic concepts, general principles for design — Part 1: Basic terminology, methodology (ISO 12100-1:2003) SIST EN 15011:2011

Part 1: General requirements ISO 3864 (all parts), Graphical symbols — Safety colours and safety signs ISO 6336-1, Calculation of load capacity of spur and helical gears — Part 1: Basic principles, introduction and general influence factors ISO 7752-5, Lifting appliances — Controls — Layout and characteristics — Part 5: Overhead travelling cranes and portal bridge cranes ISO 12488-1, Cranes — Tolerances for wheels and travel and traversing tracks — Part 1: General 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN ISO 12100-1:2003,
EN ISO 3744:2010, EN ISO 11202:2010, EN ISO 11203:2009, EN ISO 11204:2010 and the following apply. 3.1 bridge crane crane, fixed or able to move along track(s) having at least one primarily horizontal girder and equipped with at least one hoisting mechanism NOTE Building structures, where hoists are mounted, are not regarded as bridge cranes. 3.2 gantry crane crane, fixed or able to move along track(s)/roadway surfaces having at least one primarily horizontal girder supported by at least one leg and equipped with at least one hoisting mechanism NOTE Building structures, where hoists are mounted, are not regarded as gantry cranes. 3.3 rated capacity mRC
maximum net load (the sum of the payload and non-fixed load-lifting attachment) that the crane is designed to lift for a given crane configuration and load location during normal operation 3.4 hoist load mH
sum of the masses of the load equal to the rated capacity, the fixed lifting attachment and the hoist medium 3.5 hoist medium part of the hoisting mechanism, either rope, belt or chain, by which the fixed load lifting attachment is suspended SIST EN 15011:2011

1.1 Generated by machine parts or work pieces, e.g. by:
1.1.2 relative location 5.6.2 1.1.3 mass and stability 5.2 1.1.4 mass and velocity 5.2, 5.3.6, 5.4.4, 5.6.1 1.1.5 inadequacy of mechanical strength 5.2 1.2 Accumulation of energy inside the machinery, e.g. by:
1.2.2 fluids under pressure 5.4.1 1.3 Elementary forms of mechanical hazards
1.3.1 Crushing 5.1, 5.6.2, 7.2 1.3.2 Shearing 5.6.2.4 1.3.3 Cutting or severing
1.3.5 Drawing-in or trapping hazard - moving transmission parts 5.6.2.5, 5.6.2.6 1.3.6 Impact 5.5.3.1, 7.2 1.3.9 High pressure fluid injection or ejection
hazard 7.3.3
2 Electrical hazards due to: 5.3 2.1 Contact of persons with live parts (direct contact) 5.3.2, 5.3.3 2.2 Contact of persons with parts which have become live under faulty conditions (indirect contact) 5.1 2.3 Approach to live parts under high voltage 5.3 2.4 Electrostatic phenomena 5.3.1 2.5 Thermal radiation or other phenomena such as the projection of molten particles and chemical effects from short-circuits, overloads, etc. 5.1
3.1 burns and scalds, by possible contact of persons with objects or materials with an extreme temperature, by flames, by radiation, etc. 5.4.8.1, 7.3.3 3.2 Hot or cold working environment 5.6.1
4 Hazards generated by noise, resulting in:
4.1 Hearing losses 5.6.4 4.2 Interference with speech communication, signals 5.6.4, 7.3.1
5 Hazards generated by vibration
5.2 Whole body vibration, particularly when combined with poor postures 5.2.2.6, 5.6.1
6 Radiation
6.0 External radiation See Introduction 6.5 Lasers 5.4.8.2
7 Processed materials and substances, used materials, fuels
7.1 Hazards from contact with harmful fluids, gases, mists, fumes and dusts 5.4.8.4 See Introduction 7.2 Fire or explosion hazard 5.4.8.3 See Introduction
8 Neglected ergonomic principles in machine design, e.g. hazards from:
8.1 Unhealthy postures or excessive efforts 5.6.1 8.2 Inadequate consideration of hand-arm or foot-leg anatomy 5.6.1 8.3 Neglected use of personal protection equipment 7.3.3 8.4 Inadequate local lighting 5.6.3 8.6 Human errors, human behaviour 5.5.2 8.7 Inadequate design, location or identification of manual controls 5.3.5, 5.6.1 8.8 Inadequate design or location of visual display units 5.7
Table 1 — List of significant hazards and associated requirements (continued) No. Hazard (as listed in EN 1050:1996) Relevant clause(s) in this European Standard 10 Unexpected start-up, unexpected overrun/over speed (or any similar malfunction) from:
10.1 Failure/disorder of control systems 5.3.4 10.3 External influences on electrical equipment 5.3.5.3, 5.4.2 10.4 Other external influences (gravity, wind, etc.) 5.3.5.3, 5.3.6, 5.4.2, 5.5.2.2, 5.5.4 b) and c) 10.5 Errors in the software 5.3.4, 5.3.5.3, 5.4.2 10.6 Errors made by the operator (due to mismatch of machinery with human characteristics and abilities, see No. 8.6) 5.3.5.3, 5.4.2
11 Impossibility of stopping the machine in the best possible conditions 5.4.4.1, 5.4.5.1, 5.5.2.2 13 Failure of the power supply 5.3, 5.4.2 14 Failure of the control circuit 5.3, 5.6.1, 5.4.2 16 Break-up during operation 5.2, 5.4.3.6.1, 7.3.3 16.1 Thermal effect on the crane 5.3 17 Falling or ejected object or fluid 5.4.1, 7.3.3 18 Loss of stability / overturning of machinery 5.2.3 19 Slip, trip and falling of persons (related to machinery) 5.6.2 20 Relating to the travelling function
20.2 Movement without an operator at the driving position 5.3.5.3, 5.3.6, 5.6.1 20.4 Excessive speed of pedestrian controlled machinery 5.6.1 20.5 Excessive oscillations when moving 5.4.4.3, 5.5.4 e), 7.2 20.6 Insufficient ability of machinery to be slowed down, stopped and immobilized 5.4.3.6.1, 5.4.4, 5.5.2.2, 7.2 20.7 From derailment due to travelling 5.4.4.5
21.1 Fall of persons during access to (or at/from) the work position 5.6.2 21.2 Exhaust gases / lack of oxygen at the work position 5.4.8.4.1 21.3 Fire (flammability of the cab, lack of extinguishing means) 5.4.8.3, 5.6.1 21.4 Mechanical hazards at the work position
- contact with the wheels - fall of objects, penetration by object - contact of persons with machine parts or tools (pedestrian control) 5.6.2.5, 5.6.1 21.5 Insufficient visibility from the working position 5.6.1 21.6 Inadequate lighting 5.6.3 21.7 Inadequate seating 5.6.1 21.8 Noise at the driving position 5.6.4 21.9 Vibration at the driving position 5.6.1 21.10 Insufficient means of evacuation/emergency exit 5.6.2, 5.4.8.3 22 Due to the control system 5.6.1 22.1 Inadequate location of controls /control devices 5.6.1 22.2 Inadequate design of the actuation mode and/or action mode of controls 5.6.1 23 From handling the machine (lack of stability) 5.4.4.3 25 From/to third persons
25.1 Unauthorized start-up/use
25.2 Drift of a part away from its stopping position 5.4.5.2 25.3 Lack or inadequacy of visual or acoustic warning means 5.7 26 Insufficient instructions for the driver / operator
26.1 Movement into prohibited area 5.5.3.1, 7.2 26.2 Tipping - Swinging 7.2 26.3 Collision: machines-machine 5.5.3.1, 5.5.3.3, 5.5.4 e), 7.2 26.4 Collision: machines-persons 5.5.3.1, 5.5.4 e), 7.2 26.5 Ground conditions 7.3.1 26.6 Supporting conditions 7.3.1 SIST EN 15011:2011

Table 1 — List of significant hazards and associated requirements (continued) No. Hazard (as listed in EN 1050:1996) Relevant clause(s) in this European Standard 27 Mechanical hazards and events
27.1 from load falls, collision, machine tipping caused by:
27.1.1 lack of stability 5.2.3, 5.4.8.5 27.1.2 Uncontrolled loading - overloading – overturning moment exceeded 5.2.1.5, 5.2.1.6, 5.4.3.1 to 5.4.3.4, 5.4.8.5, 5.5.1, 5.5.2.1, 5.5.4 a) 27.1.3 Uncontrolled amplitude of movements 5.5.3.3, 7.2 27.1.4 Unexpected/unintended movement of loads 5.3.4, 5.4.1, 5.4.2, 5.4.3.1, 5.6, 7.2 27.1.5 Inadequate holding devices / accessories 5.4.1, 7.2 27.1.6 Collision of more than one machine 5.5.3.1, 5.5.3.3 27.1.7 Two-block of hook to hoist 5.4.3.1, 5.5.3.2 27.2 From access of persons to load support 7.2 27.3 From derailment 5.4.4.5, 5.4.4.6 27.4 From insufficient mechanical strength of parts Loss of mechanical strength, or inadequate mechanical strength 5.2, 5.4.3, 5.4.5.3, 5.4.6, 5.4.7, 7.3.3 27.5 From inadequate design of pulleys, drums 5.2, 5.4.1, 5.4.3.1 27.6 From inadequate selection/ integration into the machine of chains, ropes, lifting accessories 5.2, 5.4.1, 5.4.3.1, 5.4.3.6.2, 7.2 27.7 From lowering of the load by friction brake 5.4.1 27.8 From abnormal conditions of assembly / testing / use / maintenance 5.4.3.6.3, 5.5.4 d) 27.9 Load-person interference (impact by load) 5.6.1, 5.7, 7.2, 7.3.1
28 Electrical hazard
28.1 from lightning 7.3.3 29 Hazards generated by neglecting ergonomic principles
29.1 insufficient visibility from the driving position 5.6.1, 5.6.3
EN 13001-2:2004+A3:2009, Table 10. Where cranes work in atmospheres contaminated by process debris, such material accumulations deposited upon the upper surfaces of the crane shall be taken into account in the dead load computation. 5.2.1.3 Determination of dynamic factors 5.2.1.3.1 Hoisting and gravity effects acting on the mass of the crane The masses of the crane shall be multiplied with factor φ1 = 1 + δ when calculating the stresses in load combinations in accordance with EN 13001-2. For cranes belonging to the mass distribution class MDC1, δ = 0,1 and φ1 = 1,10. For cranes belonging to the mass distribution class MDC2, which have both favourable and unfavourable effects, the dynamic factor shall be taken as φ1 = 1,10 for unfavourable effects and φ1 = 0,90 for favourable effects. 5.2.1.3.2 Determination of factor φφφφ2 5.2.1.3.2.1 General principles The hoist load shall be multiplied by factor φ2 that represents the additional dynamic force applied on the crane, when the weight of a grounded load is transferred on the hoisting medium (ropes or chains). When assuming the most extreme conditions, the hoisting medium is slack whilst the hoist mechanism reaches its maximum hoisting speed. In this condition the dynamic additional force is directly proportional to the hoisting speed, with a coefficient that depends upon the stiffness properties and mass distribution of the crane (β2 in EN 13001-2). A calculation model for the determination of the dynamic rope force history at the hoisting event, and resulting theoretical factor φ2t, is presented in Annex C. In physical crane operation there are other factors that influence the actual dynamic effect, such as control systems, dampening and flexibility of other than main components (e.g. hoist slings, other lifting devices, load itself, crane foundation). These dependencies and determination of factor φ2 are represented by hoisting classes in EN 13001-2. When hoisting class is used it shall be selected according to 5.2.1.3.2.3. The hoisting speed used for the determination of the dynamic coefficient shall reflect the actual use and possible exceptional events of the crane in a realistic way. Two events shall be considered as follows:  crane in normal use where hoisting commences at a mechanism controlled speed from a slack rope condition – cases A and B as per EN 13001-2; SIST EN 15011:2011

φ2t = max{φh(t); t < 3 s}. (A similar simulation can be used for a crane with a chain hoist.); — use one of the simplified Equation (1). a) for a crane with a rope hoist:
b) for a crane with a chain hoist: where vh,max
is the maximum steady hoisting speed in metres per second; Rr
is the rope grade according to EN 12385-4; fuc
is the ultimate strength of the chain steel in newtons per square millimetre; lr, lc
is the length of rope/chain fall in metres; Za is the actual coefficient of utilization of the rope/chain (total breaking force of the rope/chain reeving system / hoist load). The length lr / lc shall be taken as the typical distance between the upper and lower rope sheaves / chain sprockets, when hoisting a grounded load. Where a loaded part, or all of the hoist media deviates from the vertical, the length of the rope/chain fall shall be adjusted to give the equivalent flexibility in vertical direction. NOTE This simplified equation takes into account the rigidity and the masses of the crane parts and load and gives values which are approximately same as calculated according to Annex C. 5.2.1.3.2.3 Selection of hoisting class The hoisting class shall be determined in accordance with Table 2. 2/1max,215045,08.21××+×+=acuchtZlfvφ2/1max,2150045,08.21××+×+=arrhtZlRvφ(1) SIST EN 15011:2011

λλλλφ2t ≤ 1,07 + 0,24vh,maxHC1 1,07 + 0,24vh,max λ<λφ2t ≤ 1,12 + 0,41vh,maxHC2 1,12 + 0,41vh,max λ<λφ2t ≤ 1,17 + 0,58vh,maxHC3 1,17 + 0,58vh,max λ<λφ2t HC4
5.2.1.3.2.4 Selection of the hoisting speed The hoisting speed representing the normal use in load combinations A and B, and an exceptional occurrence in load combination C, shall be selected according to the hoist drive class, HD, provided by the system and in EN 13001-2:2004+A3:2009, Table 3. 5.2.1.3.2.5 Determination of φφφφ2 and hoisting class by testing The dynamic factor φ2 can also be determined by measurement from an equivalent crane. The values measured with different hoisting speeds shall be directly used in calculations, without reference to a hoisting class. NOTE The dynamic increment of deflections found by measurement or dynamic simulation may include the dynamic effects from the mass of the crane including the trolley, see 5.2.1.3.1.
The portion represented by the factor δ = 0,1 could be removed from the evaluation of the final φ2 to avoid it being considered twice in φ1 and also in φ2. 5.2.1.3.3 Load caused by travelling on uneven surfaces
The dynamic actions on the crane by travelling, with or without hoist load, on roadway or on rail tracks shall be considered by the specific factor φ4. For continuous rail tracks or welded rail tracks with finished ground joints without notches (steps or gaps) the specific factor φ4 = 1. For roadways or rail tracks with notches (steps or gaps) the specific factor φ4 shall be calculated according to EN 13001-2:2004+A3:2009, 4.2.2.3. For rubber tyred cranes the flexibility of the tyre shall be taken into account. 5.2.1.3.4 Loads caused by acceleration of drives For crane drive motions, the change in load effect, ∆S, caused by acceleration or deceleration is presented by the following equation: ∆S = S(f) - S(i)
(2) where S(f)
is the final load effect; S(i)
is the initial load effect. SIST EN 15011:2011

∆F = F(f) - F(i) where
F(f) is the final drive force; and
F(i) is the initial drive force. Loads induced in a crane by acceleration or deceleration caused by drive forces may be calculated using rigid body kinetic models. The load effect S shall be applied to the components exposed to the drive forces and where applicable to the crane and the hoist load as well. As a rigid body analysis does not directly reflect elastic effects, the load effect S shall be calculated by using an amplification factor φ5 defined in
EN 13001-2:2004+A3:2009, 4.2.2.4 as follows:
S = S(i) + φp ⋅ φ5 ⋅ a ⋅ m
(3) where S(i) is the initial load effect caused by F(i); φ5 is the amplification factor; φp
is the factor for effect of sequential positioning movements; a is the acceleration or deceleration value; m is the mass for which a applies. The factor φ5 shall be taken from Tables 3 and 4 unless more accurate factors are available from elastic model calculations or measurements. The factor φp shall be taken from Table 5. Where the force S is limited by friction or by the nature of the drive mechanism, this frictional force shall be used instead of calculated force S. Table 3 — Factor φ5 for travel, traverse and slewing mechanism Drive type Applied speed control range Factor
φφφφ5 Minimum practical backlash Considerable backlash Stepless speed control 1: 100 1,1 1,4
1: 30 1,3 1,7 Multi step speed control --- 1,6 2,0 Two step speed control --- 1,8 2,2 Single step speed control --- 2,0 2,4
Factor φφφφ5 lowering Stepless speed control 1: 100 1,05 1,10 1: 30 1,10 1,15 Multi step speed control --- 1,15 1,20 Two step speed control --- 1,20 1,35 Single step speed control --- 1,20 1,30
NOTE 2 Factors in Tables 3 and 4 take account for switching on/off the speed and speed change. Table 5 — Factor φφφφP Class of load positioning in accordance with EN 13001-1
φP P0 and P1 1,0 P2 1,15 P3 1,3
NOTE 3 Positioning movements may increase the total load effects, when made in non-optimal manner. This is taken into account by factor φP dependent upon the class P. Guidance for determining the class P is given in Annex B. 5.2.1.4 Loads caused by skewing 5.2.1.4.1 General Skewing forces for top running cranes and trolleys shall be calculated in accordance with 5.2.1.4.2 to 5.2.1.4.4 and Annex D, which provide simplified methods for calculating the forces generated when considering both RIGID and FLEXIBLE crane structures. Skewing forces for underhung cranes shall be calculated in accordance with 5.2.1.4.5. In general the skewing forces shall be addressed to load combination B. In cases where anti-skew devices are provided the forces calculated without the effect of anti-skew devices shall be addressed to load combination C. If the crane can be used without anti-skew devices functioning, the forces shall be addressed to load combination B. NOTE 1 The method given in EN 13001-2:2004+A3:2009, 4.2.3.4 is applicable to rigid structures. Bridge and gantry cranes can possess both rigid and flexible characteristics; therefore, a more general method is required as given here. With this method also flexible structures, uneven number of wheels, unequally distributed wheel loads as well as different types of guide means and anti-skewing devices can be considered. SIST EN 15011:2011

twgαααα++=
where α is the skew angle to be considered in design; αg is the skew component
sg/wb; αw is the component due to wear - rail and wheel flange/guide roller; αt is the component due to alignment tolerances of rail/wheel. The values for skew angles shall be determined according to Table 6. SIST EN 15011:2011

gα Track clearance
bggWs/min=α
when min34ggss≤ bggWs/75,0⋅=α
when min34ggss>
Minimum values for crane travelling mm10=≥minggss mm5=≥minggss
Minimum values for trolley traversing mm4min=≥ggss mm2min=≥ggss tα Tolerances (wheel alignment and straightness of the rail) 0010,t=α rad wα Wear of wheel flanges/rollers and rails bhwWb/10,0⋅=α bhwWb/03,0⋅=α
The skew angle shall be rad 015,0≤α in order to achieve good travel behaviour of the crane or the trolley. NOTE For larger track clearances the skew angle is reduced to 75 % because bridge and gantry cranes and their trolleys use the full track clearance only rarely. Usually only the forward guide means is in contact with the rail. 5.2.1.4.3 Friction slip relationship The following simplified empirical relationship shall be used to calculate the friction coefficient for longitudinal and lateral slip:
()σµµ25001−−=ef
(4) where
µf is the slip coefficient; µ0 is the adhesion factor equal to 0,30; e is the base of natural logarithms, 2,718; σ is the slip factor. NOTE The slip factor is the ratio of the slip distance – transverse and/or longitudinal – to the corresponding travel distance. For the transverse slip the slip factor is equal to the instantaneous total skewing angle (α or α+∆α). See D.3.2. If other values lower than 0,3 are utilised for µ0, a more sophisticated relationship shall be adopted, e.g. on the basis of an adhesion factor measurement. The relationship shall consider the geometry of the affecting surfaces, the contact pressure and the used materials. SIST EN 15011:2011

Bridge crane, trolley.
Even, horizontal, almost stiff. Guide means on only one end carriage. Method RIGID
B
Crane with articulation, respectively crane with flexible support (•= articulation about an axis parallel with crane track). Guide means on both end carriages. Each end carriage shall be calculated separately with the method RIGID.
Concerning the skewing forces the crane divides into two almost independent, individually guided carriages.
C
Crane without articulation. Guide means on both end carriages. Method RIGID. D
Crane without articulation. Guide means on only one end carriage. The method depends on the flexibility of the structure.
The decision is made by the result of the method RIGID. Procedure: a) Calculate the skewing forces with the method RIGID; b) Supply a fixed support for the end carriage with guide means. Supply a floating support for the unguided end carriage (see Figure D.2c)). Apply the forces calculated with method RIGID to the floating end carriage. The originally parallel end carriages receive an angle position α∆ to each other. Calculate ()ααµ∆+f according to 5.2.1.4.3; c) If ()()15,1>∆+αµααµff then the skewing forces have to be calculated with the method FLEXIBLE.
Otherwise the calculation with the method RIGID is sufficient. E.g.: ()()()()ααµααµ∆+−−=∆+25001ef and ()()()αµαµ25001−−=ef. SIST EN 15011:2011
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