Linjeunderhåll

Linjeunderhåll refers to the maintenance of linear infrastructure networks, such as electrical power transmission and distribution lines and railway lines, along with their support structures, rights-of-way, and ancillary equipment. The term is used in Sweden and other Nordic contexts to describe systematic activities aimed at keeping these long-span assets in safe, reliable operating condition.

The scope includes both electrical and civil works required to keep the line in service. Typical activities cover regular inspections (visual, infrared, and drone-based patrols), preventive maintenance (replacing components, tightening connections, corrosion protection), vegetation management to maintain clearance, and fault repair after storms or equipment failures. For rail lines, linjeunderhåll also encompasses catenary systems, signaling interfaces, drainage, and related track-side equipment.

Planning relies on asset registers, risk assessments, and structured maintenance plans. Approaches such as condition-based maintenance, predictive analytics, and remote monitoring using sensors and SCADA systems are increasingly applied. Scheduling aims to balance service continuity with safety, weather conditions, and regulatory requirements, while ensuring proper documentation and compliance.

Organizationally, linjeunderhåll is typically undertaken by utility companies, rail operators, and contracted maintenance firms, with coordination among safety, operations, and asset-management functions. Work is performed under strict safety protocols, with permits and, where applicable, railway occupation rules to manage access and protect workers and the public.

Challenges include aging infrastructure, climate-related stresses, and growing demand for reliability. Ongoing trends emphasize automation, drone-enabled inspections, digital twins, and enhanced asset-management systems to improve reliability and reduce life-cycle costs.