EVOSYS provides elite Overhead Line (OHL) Design Services specifically engineered to bridge the gap between the distribution network and the substation environment. Our expertise ensures that every overhead circuit is integrated into the substation gantry or terminal structure with 100% safety, technical compliance, and structural integrity.

Our design philosophy is governed by the Electricity Safety, Quality and Continuity Regulations (ESQCR) and ENA TS 43 series standards, delivering a seamless engineering workstream that sits alongside our civil, primary plant, and protection packages.

Planning, Consents & Route Optioneering

We navigate the complex regulatory landscape of UK infrastructure to secure a viable path for your connection. Our services include:

  • Statutory Consents: Identification and management of Section 37 consents (England/Wales) and NSIP regimes for major transmission projects.
  • Route Selection: Technical and financial comparison of OHL versus underground cabling to optimize the final approach into the substation, ensuring compliance with EMF Codes of Practice and visual impact guidelines.

Mechanical, Structural & Clearance Design

Using advanced modelling tools, we perform high-fidelity calculations to ensure OHL longevity under extreme UK weather conditions:

  • Sag-Tension & Loading: Detailed analysis of wind, ice, and temperature ranges to determine mechanical stresses on conductors, fittings, and foundations.
  • Safety Clearances: Precise verification of electrical and safety clearances from conductors to the ground, roads, railways, and substation perimeter fences, ensuring compliance even at maximum operating temperatures.
  • Structure Selection: Engineering of terminal towers, angle towers, and wood-poles, including bespoke foundation designs to manage the longitudinal and uplift loads unique to substation interfaces.

Substation Termination & Interface Engineering

We specialize in the critical transition point where the overhead line meets the substation busbar:

  • Gantry & Landing Structures: Design of insulator strings (suspension/tension), jumpers, and air-insulated bus connections, ensuring total insulation coordination.
  • Interface Bonding: Specification of downleads and earth-wire bonds to integrate OHL structures safely into the substation earthing grid, mitigating transferred potential risks.

Protection & Safety Design

EVOSYS ensures that overhead circuits are protected by sophisticated, selective schemes:

  • Protection Logic: Defining distance, overcurrent, and auto-reclose arrangements to safeguard the line and the wider network.
  • Operational Safety: Providing GS6-compliant design input for safe working clearances and temporary works planning during the construction of new substation tie-ins.

Detailed Deliverables & Commissioning Support

Our handover includes a complete technical “Birth Certificate” for the OHL assets:

  • As-Built Records: Profile drawings, structure schedules, and conductor span data for asset management systems.
  • Commissioning Support: Participation in energization checks, including phasing, continuity, and insulation verification.