FORMEC 2026

Digitalized and (semi-) automated design of cable roads by combining different sources of geospatial data and high precision mechanical analysis

Not scheduled

20m

CZU Prague, Czechia

Poster presentation

Speaker

Leo Bont (Swiss Federal Research Institute WSL)

Description

Cable-based technologies have been a backbone for harvesting on steep slopes for decades. The planning of a cable road is a complex task. It essentially comprises the definition of the start and end points of a cable road, as well as the intermediate supports. It must ensure permissible forces (in particular skyline tension) are not exceeded, maintain sufficient clearance between the load path and the ground, identify suitable anchor trees, and minimise intermediate supports where possible.
On the other hand, for ergonomic and silvicultural reasons (work safety, damages to the forest), the skyline should be as high as possible. In practice, finding a solution is often iterative; especially for long lines, where several attempts may be needed to identify a good layout.
We present the QGIS plugin SEILAPLAN which supports cable-road design by automatically searching for the optimal cable road layout while also allowing manual editing. Embedded in a GIS system, it provides direct elevation data and can integrate individual tree data and vegetation height models to identify suitable supports and anchor trees already at the planning stage. The plugin is tailored to Central European conditions and assumes a standing skyline (fixed anchored skyline at both ends). Skyline mechanics are computed using a near-catenary method. When testing the feasibility of the cable road, care is taken that 1) maximum permissible skyline stresses are not exceeded, 2) minimum distance between the load path and the ground is maintained, and 3) for gravity systems, the load path meets a minimum gradient. The developed method calculates the load path curve and the resulting forces with a high accuracy.
The presented QGIS plugin SEILAPLAN is a key step towards digitalized forest operations on steep terrain and is already widely used in Switzerland and beyond. By 2026, version 3.7.1 is available, offering major further development in terms of functionality and user-friendliness compared with the initial version. The poster highlights and focuses on the most actual developments and gives an outlook on further planned features.