Warning: Electrostatic Discharge Damage in Highline Systems

Reports of electrostatic discharges have been reported from all around the world, resulting in damage and full highline system failures. The new report summarizes incidents and their communalities and makes recommendations for highliners in preventing such incidents.

The damage from electrostatic discharges in highlines could easily lead to deadly accidents, which fortunately have not happened until today, let’s keep it this way.
The highlines analysed did not get damaged or fail due to lightning, but due to electric discharges (plasma lightning-arcs), happening in almost all cases underneath tapes and possibly more rarely in dry areas (likely due to backups heavily wrapping around mainlines).

The process of which we assume the highlines fail, is due to electric potential buildup between wet segments of highlines. This happens because a short segment under the tape stays dry and does not allow for conductivity.

All highline lengths can be affected, the longer the line and the more exposed and alpine the line is, the more likely the scenario.

In most cases a storm was announced and nearby (a couple kilometers away), and electricity was felt “in the air”

The highlines failed shortly after it started to rain, even though the actual storm in some cases was still far away

Have a good storm forecast system in place, get regular updates
Don’t rig during the known storm season in your part of the world
Derig the highline if any storm comes near your highline, don’t risk partial damage under the tapes which you can’t see
We always recommend to derig and check properly if you are unsure.
Detape lines and inspect on a regular basis, so burn marks can be found.
We need to find alternative solutions to our current taping and technical solutions in our highlines (e.g. conducting elements along the line). For details and some ideas and recommendations check the discussion below