Safety Bond / Safety Cable
Definition
A safety bond (safety cable) is a secondary wire or sling that catches a fixture if its primary fixing fails. It is generally required on overhead fixtures that are not clamped to a secure structural point. The bond is sized for the dynamic force of arresting the fall, which exceeds the static weight of the fixture (see shock load); in Germany, DIN 56927 specifies safety cables for event technology. It is fitted with minimal slack, not as a long loop, to limit the fall to a few centimetres.
In the field
A safety bond rigged as a long loop gives little protection, because the fixture falls the full length of the loop before the bond takes the load, and the shock load grows with the fall. The bond is rigged with near-zero slack so that it is almost taut when the clamp is properly engaged.
Sources
- DIN 56927:2013-07, Veranstaltungstechnik — Sicherungsseil für zu sichernde Gegenstände bis 60 kg Eigengewicht : câbles de sécurité pour objets de 60 kg au plus (Allemagne) · dinmedia.de
- DGUV Regel 115-002 : sécurisation secondaire des équipements suspendus dans les lieux de spectacle (Allemagne) · unfallkasse-nrw.de
- PLASA / NRAG, Guidance: load suspension using electric chain hoists over stages and auditoria (janv. 2021) : rôle des sécurités secondaires (safeties) · plasa.org