Installing ADSS cable across flat farmland is straightforward. Installing it across a mountain pass with 500-meter elevation changes, valley crossings, and wind channeling is a different discipline entirely. This guide covers the terrain-specific challenges and solutions.
Elevation Changes and Tension
On a steep slope, the cable’s weight component parallel to the slope adds to the pulling tension. For a 30-degree slope over 500 meters, the additional tension can exceed 20% of the flat-terrain value. The pulling tension must be calculated per segment, accounting for slope angle at each sheave position.
Valley Crossings
Valleys create two problems: wind channeling (20-40% higher effective wind speed) and difficult access for mid-span support. For spans exceeding 800 meters across valleys, a double-jacket AT cable is standard. See large span design.
Related Reading: Wind and ice loading · Extreme weather design · Sag and tension · Double-jacket ADSS
Key Takeaways
- Calculate pulling tension per segment accounting for slope angle.
- Valley crossings require double-jacket cable and wind loading analysis.
- Ice loading increases with elevation — use regional ice maps, not flat-terrain assumptions.
Planning a Mountain Route?
Send us your terrain profile — we’ll calculate segment-by-segment tension requirements and recommend the appropriate cable specification.