safety for productions and events loads suspended above

Safety for Productions and Events Loads Suspended above Persons Television, radio, film, theatre, events The solutions described in this “Berufsgenossenschaftliche Information” guide (BGI) do not preclude other, at least equally safe solutions which may have been set out in rules issued by other member states of the European Union, Turkey or other states which are party to the Agreement on the European Economic Area. VBG – Your statutory accident insurance institution The VBG (institution for statutory accident insurance and prevention in the administrative sector) insures around 6.7 million workers as well as voluntarily insured employers, persons undergoing inpatient or rehabilitation treatment, students at vocational training institutions and social volunteers. All in all, the VBG insures some 26 million people. Its 550,000 member enterprises include service providers from over 100 sectors, e.g. banks and insurance companies, temping agencies, members of the liberal professions, IT firms and sports clubs. Safety for Productions and Events Loads Suspended above Persons Television, radio, film, theatre, events Contents 1. Introduction............................................................................................................................. 3 2. Basic safety requirements ...................................................................................................... 4

2.1 Inherent safety ensured by work-equipment calculation.................................................. 4 2.2 Single-fault tolerance provided by safety elements/secondary safety components ........ 6 2.3 Design-related safety requirements................................................................................. 7 2.4 Special applications......................................................................................................... 7

3. Provision and use of work equipment .................................................................................... 8 3.1 Attaching loads to building structures .............................................................................. 9 3.2 Attachment gear .............................................................................................................. 9 3.2.1 Wire ropes .................................................................................................................. 10 3.2.2 Rope terminations....................................................................................................... 13 3.2.3 Webbing slings and round slings made of man-made fibres ...................................... 14 3.2.4 Chain slings ................................................................................................................ 18 3.3 Connection elements ..................................................................................................... 21 3.4 Load-bearing elements .................................................................................................. 30 3.5 Safety elements ............................................................................................................. 32

Annex 1 .................................................................................................................................... 37 Protection objectives and their legal basis ............................................................................... 37 Annex 2 .................................................................................................................................... 39 Technical rules which contain safety requirements.................................................................. 39

Loads Suspended above Persons 13.03.07

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Annex 3 .................................................................................................................................... 41 Terminology.............................................................................................................................. 41


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1. Introduction

The requirements and explanations in this document apply to all productions and events where loads are suspended above workers or visitors. Production and event facilities for the entertainment industry:

Film, radio, television – Studios and other production venues Drama, musical and dance performances – Theatres, multi-purpose halls, open-air

theatres, acting and performance areas in concert halls, stages in cabarets, music halls and schools

Events - Shows, open-air concerts, trade fairs, exhibitions and discotheques This guide aims to illustrate the required level of safety for the work methods customary in the industry. Protection objectives relating to safety when moving loads above persons and holding them in place above persons are defined in legal and “Berufsgenossenschaft” (statutory accident insurance institution) regulations (see Annex 1). Generally speaking, occupational safety and health rules forbid the continuous presence of employees below suspended loads. Additional, suitable measures thus have to be defined and applied for events and productions. The measures described in this document reduce the risk to the level accepted in the industry. To ensure a higher level of safety where loads are held and moved above persons, all work equipment used to hold or move the loads has to comply with special requirements. Examples of such equipment include load fixings, connection elements, fasteners, load-bearing elements and safety wire ropes. This guide does not cover the design-based protection provided by mechanical equipment for events and productions, e.g. scenery hoists, barrel hoists and stands, to prevent loads from falling. Such protection is subject to the requirements of the German Equipment and Product Safety Act (“Geräte- und Produktsicherheitsgesetz”) and the relevant DIN and DIN EN standards. This “Berufsgenossenschaftliche Information” guide (BGI) was drawn up jointly by the VBG, and the working group of safety engineers from the following TV/radio stations and studios: BR, Bavaria, DR, DW, HR, IRT, MDR, NDR, RBB, ORF, RB, RBT, RTL, SF, SR, SRT, Studio Hamburg, Studio Babelsberg, SWR, WDR and ZDF. Its contents reflect the joint position of

DGUV – Deutsche Gesetzliche Unfallversicherung (German Statutory Accident Insurance)

and the following German event and production associations and safety and health at work associations:

BVB – Bundesverband Beleuchtung und Bühne e. V. Deutscher Bühnenverein – Bundesverband der Theater und Orchester Deutscher Städtetag DTHG – Deutsche Theatertechnische Gesellschaft e. V. EVVC – Europäischer Verband der Veranstaltungs-Centren e. V. (European Association of

Event Centers) VDSI – Verband Deutscher Sicherheitsingenieure e. V. ver.di – Vereinte Dienstleistungsgewerkschaft VPLT – Verband für professionelle Licht und Tontechnik e. V. (Professional Lighting and

Sound Association of Germany)


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2. Basic safety requirements

Work equipment for moving or holding loads above persons must be designed and operated in such a way that the loads are held safely. This must be ensured for the entire period of use. The work equipment is always calculated in accordance with the principle of inherent safety. Adherence to the principle of single-fault tolerance can also be necessary. For certain applications, the two principles are combined to create a system which has single-fault tolerance and consists of inherently safe elements. In both methods, the design requirements set out in Section 2.3 must be met as a minimum. 2.1 Inherent safety ensured by work-equipment calculation

Inherent safety is mainly achieved by doubling the working coefficients of all elements which make up the suspension system. However, with this principle, if there is only one single suspension line, a fault would result in a substantial increase in risk. Consequently, there are additional requirements which have to be met to ensure safe functioning, i.e.:

provision of quality-controlled products, proper use, regular inspections so that faults or damage are detected in good time and special care when using portable equipment, which is mainly subject to wear and tear

during transport, assembly and disassembly. This generally accepted principle of adequate risk reduction is supported by the specifications made in standards and technical regulations. The specifications are based on many years of experience in quality-oriented production at a high level of industrial development. This approach considerably decreases the risk of parts failing, allowing the equipment to be deemed to have an inherently safe design. For the purposes of equipment calculation, manufacturers usually indicate the load-bearing capacity or the breaking load. If the breaking load is indicated, it has to be divided by the necessary working coefficient in order to calculate the maximum permissible load-bearing capacity. If the load-bearing capacity (e.g. WLL) is indicated, the load applied to the equipment must not exceed half of the figure given. Equipment whose load-bearing capacity for holding loads above persons is certified is used in accordance with the information supplied by the manufacturer. Working coefficient Put simply, the working coefficient is the ratio between the breaking load and the load-bearing capacity (rated load) of a part. Item 4.1.2.5. of Annex 1 of the Ninth Ordinance relating to the Equipment and Product Safety Act (“Neunte Verordnung zum Geräte- und Produktsicherheits-gesetz”) specifies working coefficients for attachment gear. The working coefficients for other suspension components (e.g. wire ropes, chains and clamps) are defined in the manufacturing standards (DIN standards).


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Working coefficients (safety factors) for attachment gear (calculations do not include dynamic processes)

In acc. with the 9th Ordinance relating to the Equipment and Product Safety Act

(Machinery Directive) Annex 1

Working coefficient in acc. with BGV C1

Working coefficient

9th Ordinance relating to the

Equipment and Product Safety Act, Annex 1,

4.1.2.5

Doubled working coefficient in acc.

with Annex 1, 6.1.2

Inherent safety

BGI 810-3

Wire ropes

5

10

10*

Chains

4

8

8

Textile fibres Ropes/belts/

slings

7

14**

14**

Other metal

parts

4***

8

8

Table 1 *) The working coefficient for wire ropes being used as attachment gear is 12 due to the

dynamic processes involved. **) Only with additional metal safety component. ***) Special connection elements, e.g. shackles as specified in DIN 82101, have a lower working

coefficient. See also Table 6c. If several suspension lines are required in order to hold a load, each suspension line must be calculated with double the working coefficient (inherently safe) in a manner appropriate for the load distribution. Example load distribution on a truss with several suspension lines


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When determining the forces which occur where moving loads are involved, the dynamic forces (acceleration and deceleration of the load) must also be taken into account. An extra allowance of 20% has proved a good reference value for these dynamic forces. 2.2 Single-fault tolerance provided by safety elements/secondary safety components

For certain applications, safeties are required as an additional measure. This method ensures single-fault tolerance and can compensate for any errors. This is necessary, for example,

to provide a safeguard against errors in use or assembly, where there is a risk that connections might loosen and when using work equipment which does not fully meet the design requirements (as set out

in Section 2.3). In practice, the safety of suspension systems for lighting, PAs, monitors, decorations and other objects in events and media productions which are installed using fixing devices intended to allow the equipment to be used in different places (e.g. spigots and sleeves or C hooks), is influenced by the quality of the way in which the equipment is installed each time it is moved. Such applications thus require a secondary safety component. If the equipment is installed in a permanent position, the second, independent safety component (secondary safety component) is not necessary if the fixing element is sufficiently dimensioned, can only be loosened using a tool and is secured to prevent it loosening of its own accord, thus making it inherently safe. If the safety element (safety rope or chain) is such that the load can drop, the force which develops when the load drops into the safety element must also be taken into account. The length of the drop is the crucial factor. Experiments using a drop of 30 cm have shown that this force can be as high as 50 times the falling load. The requirements for these safety elements are described in Section 3.5.


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2.3 Design-related safety requirements

The load-carrying elements and safety elements must be designed in such a way (with regard to materials and shape) that they comply with the following basic requirements. Design requirements for load-bearing elements and safety elements:

All connections must be positive (“form-fitting”/“form-locking”).

All elements must possess at least the following characteristics: - Dimensional stability - Standardised or known strength properties - Assured production/manufacturing quality (e.g. in the form of a test report as specified in EN 10204) - It must be possible to see clearly whether connections which are relevant to safety (for example, connections which lock into place, are self-locking or are bolted or screwed) are functioning correctly - Connections are secured to prevent them loosening of their own accord - Damage can be detected by means of a visual inspection

Depending on the expected conditions of use, the materials to be used must possess the

following characteristics: - Weather resistance - Temperature resistance - Ageing resistance

The work equipment must be marked in an appropriate manner, have information for use

supplied with it and be uniquely identifiable (e.g. manufacturer, type, year of manufacture).

The intended use of the work equipment must be indicated clearly (e.g. load-bearing capacity, details of impermissible use, if applicable, and warnings). The removal-from-service date and criteria for periodic testing of the equipment must also be defined.

2.4 Special applications

The basic safety requirements can only be deviated from if an assessment of the hazards provides clear evidence that suspended loads will not cause harm to health if they fall. This can be the case, for example, when curtains are hung using straps or when the cord grip of a microphone cable carries the load.


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3. Provision and use of work equipment

To help explain the terminology, the following diagram shows all parts in the load path:

Verbindungselement Connection element/fastener Tragwerk Supporting structure Bauwerk Building structure Lastaufnahme Load-attachment point Bauwerk Building structure Tragmittel Load-bearing element Kettenverkürzer Shortening clutch Sekundärsicherung Safety Elektrokettenzug Electric chain hoist Anschlagmittel Attachment gear Drahtseil Wire rope Anschlagmittel Attachment gear Rundschlinge Round sling Verbindungselement Connection element/fastener Lastaufnahmemittel Load-bearing element Loads Suspended above Persons 13.03.07

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3.1 Attaching loads to building structures

Suspension and mounting points on supporting components must be sufficiently strong (see also the Ordinance on Industrial Safety and Health (“Betriebssicherheitsverordnung”), Annex 1, Item 3.2.1). The roof structures of above-ground buildings are generally not dimensioned to cope with double the rated load. Where information is provided on the load-bearing capacity of building structures, it usually relates to vertical static loads (without any dynamic forces). (Note for planners: See the notes on DIN 15018 in Annex 2). The following loads should be assumed as the basis for calculating the supporting structure (design loads):

double the rated load to calculate the load-attachment point and the rated load to calculate the supporting structure.

Loads may only be attached to building structures if the operator is able to give precise details concerning the rated load capacity of the suspension points. In particular, the following details are required:

the rated load capacity figure, the rated load capacity based on the direction of force and consideration must be given to dynamic coefficients and the applicable simultaneity factor.

The rated load capacity of the suspension points cited by the operator may not be exceeded during assembly, dismantling or operation. When planning the production/event, consideration must be given to dynamic forces, potential loads caused by failures and additional loads during operation, assembly and dismantling in addition to the equipment’s self-weight. For instance, additional forces develop due to diagonal rigging, acceleration of loads and abrupt stopping of loads. In the field of event technology, loads are attached to building structures using attachment gear, which is fixed to attachment devices such as beam clamps or eyes. Loads can only be directly attached (in the form of a choked basket) to supporting structures using attachment gear if doing so does not interfere with preventive fire safety measures, e.g. fire-protection coating. In order to avoid bending strain on construction elements which are only designed to bear tensile loads or pressure (e.g. diagonals), such elements must not be used as attachment points. 3.2 Attachment gear

The term “attachment gear” refers to the connecting parts (e.g. quick-end links, shackles, ropes or slings) between the load-bearing element and the load. Attachment gear must be appropriately designed and sufficiently dimensioned to cope with the loads which occur. Attachment gear in the event industry must adhere to the principle of inherent safety (cf. Section 2.1). The load-bearing capacity of attachment gear in the area of lifting equipment is often given as the WLL (Working Load Limit). The load on such attachment gear must not exceed half of the load-bearing capacity specified by the manufacturer. Definition of WLL using the example of wire ropes Loads Suspended above Persons 13.03.07

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WLL is defined as follows:

WLL = Fmin x KTZp x g [kg]

where Fmin = Minimum breaking strength of the attachment gear [N] KT = Factor which takes into account the efficiency of the termination

(In the case of ropes with ferrules, KT must be 0.9) Zp = Working coefficient, also referred to as the “safety factor”

(= 5 in the case of steel ropes) g = Ratio of force to mass

= 9.81 [N/kg] Source: DIN EN 13414-1: 2003, Section 5.2.4 The WLL for other work equipment is calculated in the same way. Information on the use of round slings which are used for choked hitches can also be found in GUV-I 8634 / VPLT SR 1.0 “Provision and use of truss systems” (“Bereitstellung und Benutzung von Traversensystemen”). 3.2.1 Wire ropes

Wire ropes are manufactured in accordance with different standards for different purposes. For lifting purposes, only ropes which comply with DIN EN 12385-4 or the former DIN 3060 (round strand ropes, 6 x 19 standard) with a rated wire strength of 1,770 N/mm² to 2,160 N/mm² may be used. This corresponds to rope grade 1960, which is the rope quality upon which the following requirements are based. Wire ropes with different rated strengths and materials must be specially assessed. If ropes with ferrule-secured loops and thimbles are used as terminations, they must be manufactured in accordance with DIN EN13414-1. Where loads are suspended above persons, the load on wire ropes must not exceed half of the load-bearing capacity specified by the manufacturer. Special consideration must also be given to any dynamic forces which might occur. Load-bearing capacity Load-bearing capacity of round strand ropes used to attach loads above persons

Round strand rope 6 x 19 with fibre core, rope termination with thimble and ferrule (efficiency 0.9) Rope grade 1960, minimum rated strength 1770 N/mm²


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Load-bearing capacity for loads suspended above persons

Single leg Total load

[kg]

Double leg Total load

[kg] with inclination angles from 0° to 45° from 45° to 60°

Rated rope diameter

Minimum breaking strength

[kN]

for ropes ≥ 6 mm

in acc. with EN 12385-4; Table 7

for ropes 3 - 5 mm

in acc. with EN 12385-4; Table 12

3 mm 5.4 40 55 40 4 mm 9.6 70 100 70 5 mm 15 110 155 110 6 mm 23.3 175 245 175 8 mm 41.4 310 435 310 10 mm 64.7 485 680 485 12 mm 93.1 700 975 700 14 mm 127 950 1335 950

Table 2 Where the angle of inclination is between 0° and 45°, the load-bearing capacity decreases by 30%; where the angle is between 45° and 60°, the decrease is 50%. Inclination angles of more than 60° should be avoided.


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Use Heavy bending also reduces a rope’s load-bearing capacity. The radius of the bend (R) must be larger than (or equal to) the rope’s diameter (d). Where necessary to prevent the rope bending across sharp edges (R<d), beam clamps or effective edge protectors should be used. (Placing fabric, e.g. jute sacks, underneath the rope is not sufficient, nor does it comply with the applicable fire-safety regulations). If the radius of the bend is larger than three times the rope diameter, the reduction in the load-bearing capacity is negligible.

Influence of bend radius on load-bearing capacity

Bend radius Load-bearing capacity

R = 3 d 100%

R = 2.5 d 85%

R = 2 d 80%

R = 1.5 d 75%

R = d 62% Table 3

Wire ropes must be checked for damage before and after each time they are used. Wire ropes must be inspected at least once a year by a person charged with this task by the employer (e.g. a competent/qualified person). Depending on the conditions of use, additional inspections may be required between the annual inspections. Damaged wire ropes must be withdrawn from use. Wire ropes must be stored in a dry place and protected against damaging influences. Restrictions on use

Use of wire ropes with a fixed protective plastic hose is not permitted.

The ropes must not be attached in such a way that they can kink at the ferrules or that the ferrules can bend.

Wire ropes used for attachment purposes must not be shortened by forming a choked hitch

using the load hook.

Wire ropes must not be knotted.


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Removal from service If the removal-from-service date has been reached, the wire ropes may no longer be used. Removal-from-service criteria for wire ropes:

Strand rupture Crushing Bird-caging Kinks/bruises Rust damage, e.g. corrosion pits Extreme overheating Extreme wear on the rope termination, e.g. the ferrule or splice Protruding or damaged hemp core Number of visible wire ruptures as described in BGR 151 (Section 5)

Further information and examples can be found in BGI 556 "Anschläger" (“Load-attachment personnel”). 3.2.2 Rope terminations

The rope terminations used are mainly ferrules and rope clamps of the type specified in the EN 13411 series of standards, “Terminations for steel wire ropes”. Rope terminations can be formed in accordance with the following standards:

EN 13411-1: Thimbles for steel wire rope slings EN 13411-2: Splicing of eyes for wire rope slings EN 13411-3: Ferrules and ferrule-securing EN 13411-4: Metal and resin socketing EN 13411-6: Asymmetric wedge socket EN 13411-7: Symmetric wedge socket

Forming the rope terminations in accordance with these standards ensures that the termination transmits at least 90% of the rope’s load-bearing capacity without any damage; for wedge sockets, the figure is 80%. Aluminium ferrules on fibre-core ropes may only be used in temperatures of no higher than 100°C; for aluminium ferrules on steel-core ropes, the limit is 150°C. Since the temperature of and near the casing of a spotlight can be higher, there must be sufficient space between the ferrules and the hot parts of the spotlight when safety ropes are attached directly to the casing.

Each ferrule must be marked at least with its size and its manufacturer’s name or ID. Ropes with a diameter of 8 mm or more should have their load-bearing capacity visibly imprinted on the ferrule or on an attached tag. In the case of ferrules for ropes with a diameter of less than 8 mm, the information can be marked on the packaging instead.


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In principle, wire-rope eyes without thimbles are not used. Wedge sockets Only wedge sockets whose features are guaranteed in a declaration by the manufacturer may be used. It must be borne in mind that using wedge sockets reduces the load-bearing capacity of the ropes to 80%. Normative specifications are contained in: – DIN EN 13411-6, Terminations for steel wire ropes - Safety - Asymmetric wedge socket

and – DIN EN 13411-7, Terminations for steel wire ropes - Safety - Symmetric wedge socket Asymmetric wedge sockets Diagrams taken from DIN EN 13411-6 and DIN EN 13411-7 Wedge sockets may only have loads attached to them when they are under tension. They must also be secured so as to prevent unintended loosening; this is achieved by clamping the end of the rope which is not carrying the load. In the case of asymmetric wedge sockets, the load-carrying rope is not clamped as well. (See Figure C 1, EN 13411-6 and Figure B 1, EN 13411-7). Informative Annex C of EN 13411-6 gives details of how to ensure safe use. Markings: – Manufacturer – Nominal size/size range

Restrictions on use

Rope grips of the type specified in the former DIN 1142 or DIN EN 13411-5 may not be used to form rope terminations. Due to the rope’s elasticity, the diameter of wire ropes fluctuates significantly if the load is frequently changed. This can cause the rope grips to loosen, making it impossible to guarantee a safe termination in the long run.

Wire-rope grips for terminations of the type specified in DIN 1142 or DIN EN 13411-5 may not be used!

Adjustable rope terminations which provide a non-positive connection and which cannot be checked for safe functioning must not be used to hold loads above persons.

3.2.3 Webbing slings and round slings made of man-made fibres

Webbing slings and round slings were originally used for lifting processes in the manufacturing industry. In the area of event technology, webbing slings and round slings made of man-made fibres are primarily used for rigging truss systems.


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The webbing slings and round slings are marked (on a label) with the manufacturer’s name/ID, the CE mark, their load-bearing capacity and year of manufacture. Preferably, webbing slings and round slings bearing the GS “tested safety” mark should be used. Webbing slings and round slings which do not have any information marked on them must not be used. Webbing slings and round slings with a green label are made of polyamide (PA); webbing slings and round slings with a blue label are made of polyester (PES). These types of attachment gear are intended for a temperature range of –40°C to +100°C. Attachment gear made of man-made fibres and bearing a brown label is made of polypropylene (PP) and is intended for a temperature range of –40°C to +80°C. Load-bearing capacity When used above persons, the load on webbing slings and round slings must not exceed half of the load-bearing capacity specified by the manufacturer. Special consideration must also be given to any dynamic forces which might occur. The load-bearing capacities of and materials used in webbing slings and round slings can be determined by checking the colours of the slings and/or the labels. The related specifications are set out in DIN EN 1492-1.


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Webbing slings and round slings made of man-made fibres

Colour/WLL Load-bearing capacity for loads suspended above persons

Basket hitch

with inclination angle β

Colour of sling

Load-bearing capacity WLL

Single leg

Single choker hitch

Basket hitch up to β =6°

from 7° to 45°

from 45° to 60°

- 500 kg 250 kg 200 kg 500 kg 350 kg 250 kg Purple 1000 kg 500 kg 400 kg 1000 kg 700 kg 500 kg Green 2000 kg 1000 kg 800 kg 2000 kg 1400 kg 1000 kg Yellow 3000 kg 1500 kg 1200 kg 3000 kg 2100 kg 1500 kg Grey 4000 kg 2000 kg 1600 kg 4000 kg 2800 kg 2000 kg

Table 4 Where the angle of inclination is between 0° and 45°, the load-bearing capacity decreases by 30%; where the angle is between 45° and 60°, the decrease is 50%. Inclination angles of more than 60° are not permitted. Use Due to the thermal behaviour of the materials used in them, webbing slings and round slings may only be used above persons if combined with a sufficiently dimensioned secondary safety component (see Section 3.5). Alternatively, webbing slings and round slings with an inner wire-rope loop (“steel flex”) can be used. Attachment gear made of man-made fibres must be stored in a dry, well-ventilated place and protected against atmospheric influences and aggressive substances. Maintenance work on webbing slings and round slings may only be carried out by the manufacturer. When using webbing slings and round slings, it must be ensured that the radius (R) of the edges is larger than the thickness (d) of the slings. If the load has sharp edges (R < d) or an abrasive surface, attachment gear made of man-made fibres may only be used if the areas of the gear which are at risk of damage are protected. This is done by, for example, using a protective hose or a fixed protection layer. Protection must be provided against both the lower and the upper sharp edges.


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Sling thickness and bend radius

Attachment gear made of man-made fibres must be inspected at least once a year by a person whom the employer has charged with the task and instructed. Depending on the conditions of use, additional inspections may be required between the annual inspections. A visual inspection of the sling must be carried out before each use. If faults which are detrimental to safety are detected, the man-made-fibre webbing slings must be withdrawn from use. Restrictions on use

Webbing slings and round slings must not be pulled across sharp edges.

Attachment gear made of man-made fibres must not be knotted or hitched to other attachment gear.

In the case of webbing slings with eyes, the angle at the fixed end of the eye must not

exceed 20° at the connection points.

Webbing slings and round slings may only be used within the permitted temperature range.

Man-made-fibre attachment gear without any information concerning the manufacturer, load-bearing capacity or materials must not be used.

Removal from service Removal-from-service criteria for webbing slings and round slings:

Yarn breaks or yarn tears in the fabric, measuring more than 10% of the total cross-section

Damage to the load-bearing seams

Thermal deformation, e.g. due to radiation, friction or contact

Embrittlement caused by physical factors (e.g. UV radiation)

Withdrawal-from-service age specified by manufacturer has been reached


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3.2.4 Chain slings

Steel chains are available in many forms and grades. Tested round-steel chains which have welded chain links and whose quality has been verified are suitable for lifting loads. These types of chain are marked at every metre with a stamp, as follows:

Grade 5 chain stamp (DIN 5687-1)

Marking: green pentagon

Grade 8 chain stamp (DIN 5687-3 and DIN EN 818)

Marking: red octagon

The grade for chains for lifting and transporting is taken from the first digit of the stress-at-break figure; e.g. grade 5 means a stress at break of 500 N/mm².

Only chain slings of at least grade 5 (DIN 5687-1 or DIN 5688-1) are used for loads suspended above persons. In the event industry, most of the chains used are grade 8 (DIN 5687-3, 5688-3 and DIN EN 818-2). Higher-grade chain slings (e.g. 8S or 10) are also permitted and bear a manufacturer-specific marking. The chains’ grades are indicated by differently shaped and coloured tags (see below). The number of sides the tag has indicates the grade. Tags for grade 5 are green. The octagonal tags on grade 8 chains are red.

Marking of tags in accordance with EN 818 Single-leg chains Front Inclination angle up to 45° Reverse Inclination angle 45° to 60° Multiple-leg chains


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Load-bearing capacity When used above persons, the load on round-steel chains must not exceed half of the load-bearing capacity specified by the manufacturer. Special consideration must also be given to any dynamic forces which might occur. Load-bearing capacity of chains Load-bearing capacity for loads above persons

Double leg

Triple and quadruple leg

with inclination angles

with inclination angles

Rated chain thick-ness

Minimum breaking strength

Load-bearing capacity

Single leg

from 0 to 45

from 45 to 60

from 0 to 45

from 45 to 60

Grade 5 chains as specified in DIN 5688-1: 1986 6 mm 30 kN 750 kg 375 kg 500 kg 375 kg 800 kg 560 kg 8 mm 50 kN 1250 kg 625 kg 850 kg 625 kg 1325 kg 900 kg10 mm 80 kN 2000 kg 1000 kg 1400 kg 1000 kg 2125 kg 1500 kg Grade 8 chains as specified in DIN 5688-3: 1986 6 mm 40 kN 1000 kg 500 kg 700 kg 500 kg 1050 kg 750 kg 8 mm 80 kN 2000 kg 1000 kg 1400 kg 1000 kg 2120 kg 1500 kg10 mm 128 kN 3200 kg 1600 kg 2240 kg 1600 kg 3375 kg 2400 kg

Table 5


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Use Chains must be checked for damage before and after each time they are used. Chain slings must be inspected at least once a year by a person charged with this task by the employer (e.g. a competent/qualified person). Depending on the conditions of use, additional inspections may be required between the annual inspections. Only chains with a pitch which is no larger than three times the diameter of a chain link may be used to lift loads. The pitch is the inside length of a chain link. Long-link chains may only be used if freely suspended, e.g. in a bridle, to adjust the length of a leg. They must not be used for choke-hitching of loads or supporting structures since the risk of them breaking is higher in such applications. Use of short-link chains

RIGHT WRONG


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Shortening clutches for adjusting the chain length are available in various designs. It is particularly important that the information for use is heeded in order to ensure correct use. Shortening clutches may only be used in the intended operating position. Only shortening clutches which have safeguards to prevent unintended unhooking may be used. In particular, the functional safety of load-bearing bolts and safeguards, e.g. locking bolts on shortening clutches, must be checked. Restrictions on use Examples:

Damaged chains must not be used

Chains must not be knotted

Chains must be placed around the load’s sharp edges in such a way that no chain links are bent

Twisted chains must not be used for attaching loads

Load-bearing elements (hoist chains) which have been removed from service must not be used as chain slings N.B.: Chain slings’ stretch at break must be at least 20%. An extremely stretched chain sling is a clear indication to any load-attaching worker that the chain has been overloaded. If it is extremely overloaded, the load remains on the ground and the chain is pulled stiff. This additional protection against overloading is necessary for chain slings. This is the reason why hoist chains which have been removed from service are never re-used as chain slings, since their stretch at rupture is only 5 to 15%.

Removal from service Removal-from-service criteria for chains:

Broken chain link Cracks; corrosion pitches which decrease the load-bearing capacity Deformation of a single chain link Deformation caused by bending or twisting Diameter worn down by more than 10% Elongation of individual chain links or the total length of the chain by more than 5%

3.3 Connection elements

Various connection elements are used in the load path between the attachment point on the building structure, the attachment gear and the load. Connection elements are also used when secondary safety components are used. Connection elements are subject to the guidelines set out in Section 2, “Basic safety requirements”.


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They must be selected and dimensioned on the basis of the expected load. In particular, the following types of connection element are used:

Elements specifically intended for holding loads above persons in the event industry (Table 6a)

Connection elements from the field of personal protective equipment or, for example, mountaineering equipment (Table 6b)

Connection elements intended for general lifting operations. These are only subjected to loads weighing half of the load-bearing capacity specified by the manufacturer (Table 6c).

The manufacturer must mark the connection elements as described below. Marking of connection elements All connection elements must be marked with at least the following information. The information can also be included in the manual instead. – Manufacturer – CE mark, if applicable – Standard – Load-bearing capacity


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Elements specifically intended for holding loads above persons in the event industry Connection element Features Quick links for the event industry, as specified in DIN 56926 (E DIN 56927).

The indicated lifting capacity (working coefficient 10) of these connection elements is half that of links used for lifting operations though the diameter is the same.

Kettbiner (brand name)

The indicated lifting capacity (working coefficient 10) of these connection elements is half that of links used for lifting operations though the diameter is the same. E.g. Kettbiner 90 x 8 (breaking strength 2000 kg), load-bearing capacity as specified in BGV C 1: 200 kg.


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Connection element Features Hooks and clamps for projectors and luminaires as specified in DIN 15560-24 Connecting elements and transition pieces as specified in DIN 15560-25

Base plate, pipe clamp, pivot plug, socket for pivot plug for photo luminaires and reportage luminaires. Rotary base, sockets with fixing screws for suspended luminaires, stand socket, stand support, closed pipe clamp with joint, open pipe clamp, transition pieces. These connection elements have an inherently safe design and are used for loads weighing no more than 60 kg. The portable projectors and luminaires which are fixed into place using these elements are also secured with a safety rope. See also Sections 2.3 and 3.5. N.B. If the additional locking pin is used when fixing a projector with a ZC pivot plug and a HB socket with fixing screw, a secondary safety component is not required.

Connection elements for attaching decorative items, e.g. ‘Plafond-Ring’ (see photo).

The suspension or fixing points and the design of the decorative items must be such that the expected loads can be carried. N.B. Decorative items must be attached to load-bearing elements or the load-bearing structure. If there are several suspension points, the load must be evenly distributed. It must be ensured that it is not possible for parts of decorations to become loose and fall.


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Connection element Features Connection elements for attaching trusses, e.g. truss adapters

The design of connection elements used for attaching trusses must be such that the expected loads can be carried safely. The truss adapter is also marked with a type designation, the year of manufacture or a serial number. N.B. These elements must be used as specified by the manufacturer.

Connection elements for attaching sound and lighting systems

The design of connection elements used for attaching sound and lighting systems must be such that the expected loads can be carried safely. Inherently safe sound and lighting systems and their inherently safe suspension systems (e.g. flying frames) do not require any additional anti-fall protection within the assembly. N.B. These elements must be used as specified by the manufacturer. They may only be used in assemblies for which the manufacturer guarantees compatibility. These connection elements may only be used in the intended operating position.

Table 6a


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Connection elements from the field of personal protective equipment and mountaineering Connection element Features Connectors for mountaineering equipment UIAA Safety Label

Only tested connection elements (e.g. bearing a UIAA Safety Label) may be used. Such elements are connectors/fasteners which comply with DIN EN 12275, “Mountaineering equipment – Connectors – Safety requirements and test methods”. They are lockable connectors/fasteners, which are tested with a static force of 20 kN. Thus, the maximum load which may be applied to these connection elements is 200 kg. Marking as specified in DIN EN 12275: – Name of manufacturer – Connector type – Minimum strength

Hooks or karabiners for personal protective equipment against falls from a height

Only connection elements which meet the requirements applicable to personal protective equipment against falls from a height and which bear a conformity mark and a CE mark to that effect may be used. Such elements are: – self-closing, self-locking or manually lockable connectors of the

type specified in DIN EN 362 “Personal protective equipment against falls from a height – Connectors” and

– lanyards of the type specified in DIN EN 354 “Personal protective equipment against falls from a height - Lanyards”

They are lockable connection elements, which are tested with a static force of 15 kN. Thus, the maximum load which may be applied to these connection elements is 150 kg. Marking as specified in EN 365: – Name of manufacturer – Type – Year of manufacture – Serial or batch number

Table 6b Warning: If a connection element of this kind is used as attachment gear, it must immediately stop being used to provide personal protection against falls from a height. N.B.: Where a combination of aluminium and steel elements is used, the level of wear may be higher due to the different material properties (e.g. hardness). This must be taken into account when selecting and inspecting the connection elements.


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Connection elements intended for general lifting operations. Usually, only loads weighing half of the load-bearing capacity specified by the manufacturer may be applied to these elements. Connection element Features Quick links for lifting purposes

Quick links of the kind customary in lifting operations are not standardised. Their shape is similar to those specified in DIN 56926 (E DIN 56927). Examples of load-bearing capacities specified by manufacturers: – 4 mm diameter: WLL 180 kg – 5 mm diameter: WLL 280 kg – 6 mm diameter: WLL 400 kg

The working coefficient in these cases is usually 5. Consequently, loads applied to the above-mentioned quick links must not exceed half of the load-bearing capacity specified by the manufacturer.

Shackles as specified in DIN EN 13889 and EN 1677-1

Grade 6 shackles of the type specified in DIN EN 13889 have a working coefficient of 5. High-strength shackles are subject to the requirements of EN 1677-1 and have a working coefficient of at least 4. When using this type of shackle in the event industry, a working coefficient of at least 8 for the load applied must be ensured by halving the load. N.B.: When there is no load on a shackle, there is a risk that the pin may loosen itself. Pins must therefore be secured in place, e.g. using a cotter pin or lock nut. Caution: Shackles of the type specified in DIN 82101 only have a working coefficient of 3.


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Connection element Features Turnbuckles

Only turnbuckles which have closed terminations (e.g. a welded eye or fork-end fitting) and whose load-bearing capacity is known may be used. Normative specifications are contained in: – DIN 1480 and DIN 82004, Turnbuckles Loads applied to the device must not exceed half of the load-bearing capacity specified by the manufacturer, nor must they exceed one tenth of the minimum breaking strength. Wedge sockets and turnbuckles may only be subjected to tensile forces. They must also be secured so as to prevent unintended loosening. Turnbuckles must be secured so as to prevent the screws falling out.

Beam clamp

Only beam clamps whose load-bearing capacity is known may be used. Loads applied to the device must not exceed half of the load-bearing capacity specified by the manufacturer, nor must they exceed one tenth of the minimum breaking strength.


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Connection element Features Shortening clutches

There are no normative specifications for shortening clutches. The only shortening clutches which may be used are those for which the conditions of use have been defined, information for use has been supplied and which are equipped with a safeguard to prevent unintended unhooking. Loads applied to the device must not exceed half of the load-bearing capacity specified by the manufacturer, nor must they exceed one tenth of the minimum breaking strength.

Load hooks

Only load hooks whose features are guaranteed in a declaration by the manufacturer may be used. Normative specifications are contained in: – DIN EN 1677-2, Forged steel lifting hooks with latch, grade 8 or – DIN EN 1677-3, Forged steel self-locking hooks, grade 8 N.B.: When using load hooks, it must be ensured that the mechanism which provides protection against unintended unhooking is in working order. Self-locking hooks provide a particularly high level of protection. The free movement needed for safe operation must be ensured (e.g. using swivel load hooks).

Karabiners

Often, karabiners do not meet the minimum requirements for use in the event industry. There are, however, specifications for light metal spring hooks (DIN 5290) and steel snap hooks (DIN 5299). Caution: The karabiners with screw-type locking (“Schraubkarabinerhaken”) defined in the above-mentioned standards only have a working coefficient of 2. For this reason and due to their poor locking function, this type of karabiner is not used in the event industry.

Table 6c


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Use When selecting interlocking parts of a connection, e.g. the shackle and thimble of a rope termination, it must be ensured that they are mechanically compatible and can move freely when the connection is closed. The risk of notching when materials of different hardnesses are used in combination must also be borne in mind. Impermissible use If the load-bearing capacity or WLL is not indicated on the connection element or has not been specified by the manufacturer, the connection element must not be used. Visibly damaged connection elements must be removed from service. 3.4 Load-bearing elements

The load-bearing elements typically used in the field of event technology are:

Trusses Load bars Load hooks

They must be set up in such a way that the load is borne by means of a positive (“form-fitting”/ “form-locking”) connection. In the field of event technology, trusses are bracing structures, intended for setting up load-bearing structures for mounting lights, loudspeakers and similar equipment. The requirements for selecting, using and inspecting truss systems are described in GUV-I 8634/VPLT SR 1.0 “Provision and use of truss systems” (“Bereitstellung und Benutzung von Traversensystemen”). The skills required of an event rigging expert are set out in VPLT SR 3.0 “Event Rigging Expert: Qualification” (“Sachkundiger für Veranstlatungs-Rigging: Qualifikation”). Structural analyses and/or records of type examinations must be provided for the truss elements used in the field of event technology. In some cases, these analyses and records may also include specifications for standardised mounting methods. In the case of non-standardised mounting methods, separate analyses must be carried out. Truss systems are usually calculated in accordance with the requirements set out in DIN 4113, Parts 1-3 “Aluminium constructions under predominantly static loading” and DIN 4112 “Temporary structures”, not in line with the principle of a double rated load. When selecting trusses, it must be ensured that their load-bearing capacity is such that they cannot be overloaded. It makes sense not to utilise the full load-bearing capacity. Using approximately 20% less than the overall capacity has proved to be good practice. Testing and removal-from-service criteria for truss systems are described in Section 5 of GUV-I 8634/VPLT SR 1.0. Load bars are mainly used with scenery battens, which are primarily installed on theatre stages. Scenery battens are manufactured in accordance with DIN 56950.


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Load-bearing capacity details are provided for these types of load bar. They indicate the possible total load, permissible line loads and maximum point loads. The load-bearing capacity details take into account the higher level of safety described in Section 2. Dynamic forces must also be taken into consideration. Load hooks are described in Table 6c.


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3.5 Safety elements

A safety element (secondary safety component or second independent safeguard) usually consists of a wire rope, rope termination and connection element. In certain special cases, round-steel chains are used. In principle, safety ropes and chains, rope terminations and connection elements are subject to the same requirements and conditions of use as those described in Sections 3.2.1, 3.2.2 and 3.3. The following requirements also apply:

A safety rope consists of a wire rope manufactured in accordance with DIN EN 12385-4 (or the former DIN 3060, round strand rope 6 x 19 standard with fibre core) with a rated wire strength of 1770 N/mm² or 1960 N/mm². The following requirements are based on this rope grade (see also DIN 56927). Wire ropes with a different rated strength and different materials must be separately assessed.

Rope terminations for safety ropes must comply with DIN EN 13411-3 (Ferrules and

ferrule-securing) or the former DIN 3090-2 (aluminium ferrules/‘Pressverbindungen mit Pressklemmen aus Aluminium-Knetlegierungen’) and have a thimble which complies with DIN EN 13411-1.

The dimensions of the elements must be calculated in such a way that the dynamic forces which occur when the load is absorbed are taken into account. The manufacturer must supply a type 2.2 inspection document as specified in DIN EN 10204, for each individual element. It is preferable to use connection elements which are attached to the safety rope or chain in such a way that they cannot be lost. Load-bearing capacity Safety ropes and connection elements must be selected based on the criteria shown in tables 8 and 9. The tables refer to wire ropes with a length of at least 60 cm and at least 100 cm respectively. The dimensions given in tables 8 and 9 are based on the specifications in E-DIN 56927: 2007-04. N.B. When an object is arrested by the safety element, the rope is subjected to a shock. Part of the shock is absorbed by the rope’s stretching. The specifications in E-DIN 56927 give different dimensions for the one-leg and two-leg securing methods. However, the differences in the figures are so low that this differentiation is not important in practice. The calculations are based on a rope elongation of 1.8% in the event of a fault.


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Safety rope (0.6 m) used as a secondary safety component

Connection element High-strength shackle as specified in DIN EN 1677-

1 [kg]

Safety rope*,

length 0.6 m or longer

Rope

diameter [mm]

Calculated necessary minimum breaking strength

[N]

Diameter of quick link

[mm] as specified in

DIN 56927

Kettbiner (brand name) 90 x 8 Load-

bearing capacity as specified in

BGV C1 200 kg

Size:

Bow diam. [mm]

Pin size

Up to 5 3 3830 3.5 Yes 3 5 M6 Up to 10 4 7660 4 Yes 3 5 M6 Up to 15 5 11488 5 Yes 4 6 M8 Up to 20 6 15318 6 Yes 4 6 M8 Up to 30 7 22978 7 Not

permitted 5 8 M10

Up to 40 8 30636 8 Not permitted

5 8 M10


6 10 M12


7 11 M14


8 13 M16

Table 8 Safety rope (1 m) used as a secondary safety component

Connection element High-strength shackle as

specified in DIN EN 1677-1

[kg]

Safety rope*,

Length 1 m or longer

Rope diameter

[mm]

Calculated necessary minimum breaking strength

[N]

Diameter of quick link

[mm] as specified

in DIN 56927

Kettbiner (brand name) 90 x 8 Load-

bearing capacity as specified in

BGV C1 200 kg

Rated size

Bow diam. [mm]

Pin size

Up to 8 3 3802 3.5 Yes 3 5 M6 Up to 15 4 7129 4 Yes 3 5 M6 Up to 25 5 11881 5 Yes 4 6 M8 Up to 35 6 16633 6 Yes 4 6 M8 Up to 50 7 23762 6 Not

permitted 5 8 M10


5 8 M10


6 10 M12


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7 11 M14

Table 9

* Rope of type specified in EN 12385-T4, with a rated strength of 1770 N/mm² up to and including 6 mm rope diameter, as in Table 12 in the standard (= 6 x19 M), rope diameter above 6 mm, as in Table 7 in the standard (= 6 x 19). The 10% reduction caused by the ferrule has been taken into account. Chains may also be used as secondary safety components.


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Use The safety rope must be attached to the fixing point defined by the manufacturer, e.g. the equipment’s eye or bow. The manufacturer should label the fixing point with, for example, a pictogram. Safety ropes must not be attached to parts of a piece of equipment which are not suitable for that purpose, e.g. handles. Example sign for the fixing point for a safety rope

Safety ropes and chains must be attached in such a way that the drop distance of the object being secured is as short as possible. The drop distance must not be more than 20 cm. Attachment methods for safety ropes Two-leg suspension method One-leg suspension method Where connection elements, e.g. quick links are used, a safe connection can only be achieved by ensuring the screw joints are completely closed and fastened finger-tight. A safety element which has already been used to absorb a falling load or is visibly damaged must be removed from service. Safety elements must be inspected in line with the way in which they are used and in a manner which ensures that damage is identified in good time. A visual inspection must be carried out before each use. Damaged elements must be withdrawn from use and disposed of. If connection elements other than those listed in the table are used, it must be ensured that

their breaking strength is at least equal to the values in tables 8 and 9 and


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they are secured so as to prevent them loosening of their own accord. For larger loads or where round-steel chains are used as safety elements, separate dimension calculations must be carried out taking into account the dynamic drop movement. It must be ensured that the maximum possible drop distance of the object being secured is as short as possible (almost zero, ideally). This is best achieved using chains. Impermissible use Ropes or webbings made of natural or man-made fibres must not be used as safety elements because they do not provide sufficient safety when subjected to thermal influences (projectors) or in the event of fire. Warning Both the ferrule (on a rope) or the links (of a chain) and the connection element used can be stamped with load-bearing capacity details (e.g. WLL). The load-bearing capacity details usually apply to load-lifting and load-carrying processes during lifting operations. They do not indicate the maximum permissible weight which the safety rope/chain is designed to arrest in the event of the secured object falling. The weakest part of a secondary safety component determines the overall load-bearing capacity of the secondary safety component.


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Annex 1

Protection objectives and their legal basis

Where are the protection objectives defined? Fundamental protection objectives relating to safety when holding loads above persons are described in legal rules and rules issued by the “Berufsgenossenschaft” institutions for statutory accident insurance and prevention. Minimum requirements concerning the use of work equipment for lifting loads, based on the Occupational Safety and Health Act (“Arbeitsschutzgesetz”), are contained in the Ordinance on Industrial Safety and Health (“Betriebssicherheitsverordnung”) and the Workplaces Ordinance (“Arbeitsstättenverordnung”).

Ordinance on Industrial Safety and Health, Annex 1, Item 2.5

Minimum regulations for work equipment

If falling .... objects can be expected when using the work equipment, suitable protective devices must be in place. Ordinance on Industrial Safety and Health, Annex 2, Item 4.1.1

The employer must take precautions to ensure that:

suspended loads are not moved above unprotected workplaces and that there are no employees present below suspended loads. If it is not possible to avoid the presence of employees below suspended loads without interrupting the work flow, suitable measures must be specified and applied. Load-bearing elements which use a non-positive connection must not be used for this purpose.

Workplaces Ordinance, Annex 1, Item 2.1 Protection against falls from a height and falling objects, access to hazard zones Workplaces and traffic routes where there is a risk of employees falling from a height or objects falling or which are located adjacent to hazard zones must be fitted with devices which prevent employees falling from a height or being injured by falling objects or entering hazard zones. Workplaces and traffic routes of the type described in sentence 1 must be secured against unauthorised access and clearly marked as hazard zones. Suitable measures must be taken to protect persons who have to access such zones.


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These rules thus require suitable measures to be taken when employees are present below suspended loads. To reduce the risk of falls from a height, the design and dimensions of the work equipment have to meet higher-than-normal safety requirements to provide protection against failure on the part of the suspension systems. The increase in safety is determined by assessing the requirements concerning the design and operation of cranes and lifting equipment. However, persons are not intended to be present below the loads in such cases. One of the ways in which safety is ensured in those cases is to define working coefficients for machinery. Work coefficients are also specified for other work equipment, e.g. wire ropes, chains and trusses, in technical rules. As one possible way of increasing safety when loads are suspended above persons, the working coefficient of suspension systems is doubled, in accordance with the specifications in Annex 1 of the Ninth Ordinance relating to the Equipment and Product Safety Act (“Neunte Verordnung zum Geräte- und Produktsicherheitsgesetz”), Item 6.1.2, concerning the lifting and conveying of persons. 9th Ordinance relating to the Equipment and Product Safety Act, Annex 1, Item 6.1.2 (extract) The ... specified working coefficients are not sufficient for machinery used to lift and convey persons; they usually need to be doubled. Staging and Production Facilities for the Entertainment Industry BGV C 1 / GUV-V C 1 The accident-prevention regulation on “Staging and Production Facilities for the Entertainment Industry” (“Veranstaltungs- und Produktionsstätten für szenische Darstellung”, BGV C 1 / GUV-V C 1) contains protection objectives, which take into account special hazards in staging and production facilities for the entertainment industry, i.e.:

movements (e.g. scenery hoists moved for staging reasons), inadvertent movements (e.g. loads falling from a height) and falling objects (e.g. breaks in suspension systems).

The above protection objectives are achieved by various methods, including higher dimensioning and suitable material properties or additional securing of work equipment, i.e.:

The higher level of safety for load-bearing elements and attachment gear is achieved by doubling the working coefficients (see also Instruction relating to Section 9, BGV C 1 / GUV-V C 1).

Portable suspended equipment (e.g. luminaires, projection equipment and loudspeaker

systems) must be secured from falling by two devices which act independently of one another (see also Section 7, Subsection 6, BGV C 1 / GUV-V C 1).

The equipment must be installed and used by specially qualified workers.

Special inspections are required in order to guarantee that the equipment remains in a

safe condition permanently.


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Annex 2

Technical rules which contain safety requirements

The technical implementation of the protection objectives described in Section 2 is done by, for instance, applying event technology standards relating to work equipment.

TRBS 2111-2 Measures to provide protection against uncontrolled moving parts (“Maßnahmen zum Schutz vor unkontrolliert bewegten Teilen”) Possible technical measures: - positive-connection (“form-fitting”/“form-locking”) holding devices, clamps, fixing devices or limit stops - absorbing protective devices (= secondary safety components)

DIN 56950 – Entertainment technology: “Machinery installations, safety requirements”

contains requirements concerning the design of all structural and load-bearing elements. The rated load must be doubled when calculating the load-bearing elements between the fixing point of the mechanical device and the termination of the load-bearing element.

DIN 15560-46 "Movable holding devices for spotlights" requires two load-bearing elements

per suspension point, which must be set up in such a way that the tensile force of each rope provides at least tenfold safety (i.e. ten times the minimum breaking strength) when subjected to the rated load.

EN 13411 “Terminations for steel wire ropes – Safety”: Buyers who order products

specified to this standard are recommended to specify in the purchase contract that the supplier must operate a quality assurance system audited by an independent body. The aim of this measure is to ensure that products which are supposed to comply with the standards attain the required level of quality.

DIN VDE 0100 Part 718 – “Erection of low-voltage installations in buildings designed for

events” – contains the following requirements: Devices for attaching luminaires must be able to carry five times the weight of the luminaire. Luminaires with a mass of over 5 kg must be secured by two independent suspension lines. Each suspension line must be able to carry five times the weight of the luminaire. Safety ropes or safety chains may be used as the second suspension line. (N.B. This applies to luminaires which are fixed into place and those which cannot be lowered).

DIN 15018 – “Cranes; principles for steel structures” – Provides guidance on how to plan structures which support dynamic loads. Where there are oscillating loads, notching in the supporting structure and on the attachment point is an important factor – again, DIN 15018 offers solutions geared to ensuring adequate dimensioning. The problem which arises with oscillating loads is that, if the component’s dimensions were incorrectly calculated or if it was incorrectly designed, fatigue may occur, and with it cracking, years after production. The following is an example of an extreme case: the load-bearing capacity of a steel component (S235JR – previously St37) is sufficient for primarily static loads with a tensile stress of dN = 160 N / mm² but only for a maximum of dN = 27 N / mm² if there is load-level fluctuation and a maximum notch effect.


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DIN 56927 – “Safety bond to secure objects up to 60 kg dead weight” – Defines

dimensions, safety requirements and tests for safety ropes which are used to provide protection against falling portable objects.


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Annex 3

Terminology

Loads suspended above persons “Loads suspended above persons” is a generic term, covering the suspension of loads and all other processes for which terms such as attachment, lifting or carrying of loads are also used. Measures to hold loads safely are intended to prevent loads and load-bearing elements from falling.

Load-bearing elements

A “load-bearing element” is a component or piece of equipment which is not part of the lifting gear, enables loads to be held and is attached between the machine and the load or to the load itself, or which is intended to be an integral part of the load and placed on the market separately; attachment gear and its components are also considered to be load-bearing elements

Working coefficients

Put simply, the working coefficient is the ratio between the size of the load which is just slightly too much for the machine or element to hold (breaking strength) and the rated load of the machine or element. Working coefficients for the safe use of technical products, such as wire ropes, chains, trusses and clamps, are defined in Annex 1 of the Machinery Directive and in DIN standards for lifting gear and cranes (see also 9th Ordinance relating to the Equipment and Product Safety Act, Annex 1, Item 4.1.1.)

Rated load

The sum of the load (static load) and the dynamic forces during operation.

Positive (“form-fitting”/“form-locking”) connections Positive connections are created by at least two interlocking elements. The holding or load-bearing capacity is determined solely by the design and dimensioning of the elements. A typical example is a pin connection, e.g. a trailer coupling.

Non-positive connections

Non-positive connections are the result of the effect of pressure and friction within the connection system. The holding or load-bearing capacity depends on the initial tension, the shape and the material properties of the connection elements. A typical example is a clamp connection.

Adequate risk reduction

Risk reduction which reflects the state of the art and at least meets the legal requirements (Section 3.17 EN ISO 12100-1).

Inherently safe design

A piece of work equipment is deemed to have an inherently safe design if its design features have been selected in such a way as to prevent hazards and reduce risks (Section 3.19 EN ISO 12100-1).

Published by: Postal address: 22281 Hamburg Article number Loads Suspended above Persons 13.03.07

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Published: March 2007 Cover photo:


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safety for productions and events loads suspended above

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