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Figure 5.1.12.1 Safety rope system used on a flat roof

Two different trades, namely the installation of the safety rope
system and the installation of the lightning protection system,
meet on the roof which must be coordinated at the intersection
of these two trades. With respect to personal safety, it can even
Figure 5.1.11.7 FEM model of a self-supporting air-termination rod be dangerous if two different tradesmen work on an “unknown”
with brace (length = 8.5 m) system. Each of them should work independently and compe-
tently and observe the warranty obligation of the other party
involved. Therefore, only specialised companies should install
The tilt resistance, break resistance and deflection are the de- safety rope systems and qualified lightning protection special-
cisive factors for designing air-termination rods. The post and ists should work on external lightning protection systems.
air-termination rod must be coordinated to ensure that the Safety rope systems are prone to lightning strikes since they
stress resulting from the wind speed according to wind zone 2 are installed about 30 m above a common air-termination
do not cause tilting of the rod and / or damage it. mesh. Therefore, many manufacturers of safety rope systems
point out in their installation instructions that safety rope sys-
It must be observed that large deflections of the air-termina- tems must be checked for lightning strikes and thus possible
tion rod reduce the separation distance and thus intolerable melting of metal resulting from the injection of lightning cur-
proximities can occur. Higher air-termination rods require addi- rents during their annual inspection. The Central Association
tional braces to prevent such intolerable deflections of the tips of the German Roofing Trade (ZVDH) and the Committee for
of air-termination rods. The measures described above ensure Lightning Protection and Research (ABB) at the VDE has pub-
that self-supporting air-termination rods can withstand wind lished a bulletin in German language (Roof and wall-mounted
speeds of wind zone 2 when used for their intended purpose. external lightning protection systems).

5.1.12 Safety systems and lightning
protection
Service and maintenance work is regularly carried out on the
roof surfaces of industrial and commercial buildings. But also
e.g. cleaning work on gutters and light strips involves a risk of
falling. Therefore, it is quite common today that particularly
flat-roofed industrial buildings are equipped with safety rope
systems. The service personnel can only be hooked into the
personal protective equipment (PPE) of the safety rope system
(Figure 5.1.12.1) or protected from falling by anchor points.
The advantage of a safety rope system over an anchor point is
that operators can walk along the rope by hooking the rope
guide / rope slide into the safety rope system. Anchoring to the
next fixed anchor point is not required. This increases safety at Figure 5.1.12.2 Incorrect installation: Safety rope system intersects
work and the acceptance of such a system. the air-termination system

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