(2.0 E)
7-8
WARNING!
attached to d&b loudspeaker cabinets and are secured using either
screws or bolts fastened to threaded inserts fitted in the
loudspeaker cabinets. For attaching rigging, d&b loudspeaker
cabinets are fitted threaded inserts.
Where provided, the supplied screws or bolts should be used to
attach rigging. Using screws or bolts other than those supplied or
specified can result in an insecure and unsafe fixing. Additionally,
using screws or bolts longer than those supplied or specified can
physically damage a cabinet by penetrating its interior and causing
an air leak.
Load ratings
d&b rigging accessories are designed and constructed to have a
load rating appropriate to their intended use. The safe working
load (SWL) for each d&b rigging accessory is specified in its
respective data sheet and on the relevant page(s) of the d&b
rigging accessories manual.
In general, d&b rigging components are designed with a 10X load
safety factor. Some components, specifically intended only for use
in fixed, permanent installations are designed with a 5X load safety
factor. Other components, for use with moving as opposed to static
loads and therefore subject to the additional wear of dynamic
loading, are designed to have a 12X safety factor.
Safety certificates
In Germany, the health and safety authority together with
industrial and professional associations has published a safety code
for stages and studios. Sound reinforcement equipment installed in
these places has to comply with the provisions of this code,
published as BGV C1 (GUV 6.15) Unfallverhütungsvorschrift
Veranstaltungs- und Produktionsstätten für szenische Darstellung.
The code provisions include:
1. Plastic load bearing components are not permitted.
2. Plastic laminated or coated steel wire ropes are not permitted.
3. Load connector parts must have a load safety factor 10X
greater than their stated SWL (Safe Working Load).
4. Load bearing chains must have a load safety factor 0.5X
greater than the dynamic value specified by the manufacturer
- equivalent to a load safety factor 12X the specified SWL.
Provision #4 needs some explanation. High tensile chains and
related components conforming to EN 818, grade 8 are specified
with a load safety factor 4X their SWL. To comply with the 12X
load safety factor required for load bearing chains under BGV C1
(GUV6.15), the specified SWL for DIN certified chains must be
derated by a factor of three.