An encased gas-insulated high-tension line is disclosed especially for regions of the line where disturbing arcs can occur so as to melt a grounding casing of the line. A heat and pressure resistant insulative layer prevents an escape of hot and possibly poisonous insulating gases from the casing in the event of a casing melting. The insulative layer is preferably made of an epoxy resin/glass fiber fabric and is wound around arc-endangered areas at fixed arc regions. An additional heat-resistant insertion may be included between the casing and the insulative layer.
