Getting started#

OpenOHL is pre-alpha: the engines and both applications are in active development, nothing is approved yet, and every result must be checked by a qualified engineer. Build it with a Rust toolchain (cargo); the examples below run from the top of the source tree.

OHL-Design, the line application#

cargo run --release -p ohl-app -- examples/synthetic-line/synthetic-line.ohl.json \
    --terrain examples/synthetic-line/synthetic-survey.csv \
    --weather examples/synthetic-line/weather-cases.ohlwc

See OHL-Design. On macOS, double-click Start OHL-Design.command at the top of the source tree: it builds both applications and starts the line application on its start page.

The structure application#

OHL-Structure (ohl-structure) edits one structure file on its own — its points and insulators, body, design, loads and finite-element results, its libraries and plugins. Without a file it opens on a start page (Open a structure…, the recent files, New structure…).

cargo run --release -p ohl-structure-app --bin ohl-structure
cargo run --release -p ohl-structure-app --bin ohl-structure -- examples/synthetic-line/Structures/type-02.ohls

On macOS, double-click Start OHL-Structure.command. See OHL-Structure.

A new line, step by step#

A line is made in the steps below, most needing the one before. Its layout is three kinds of record: a route, its alignments (each on one route), and the alignment points of each alignment, in order.

1. The route — File › New project, then name its route (the first window of a new project asks for it; Terrain › Routes later). A route is the path of the line; everything else is put on it.
2. Its alignment and its points — the New alignment tool is held: right-click its points in order (an existing alignment point is used as it is — shared, a junction; a survey or LiDAR point or a structure snaps; elsewhere you type E, N and height), Enter, choose its route (with no route yet, it offers to create one). Or place the points first with the Add alignment point tool (not connected), then pick them one after another with New alignment; Edit alignment later reroutes a stretch, extends an end, or branches off; or type them in Terrain › Alignments and Terrain › Alignment points.
3. The ground and survey — Terrain › Terrain surfaces, LiDAR point clouds (they can come before step 2, to snap the points to them).
4. The structures — Structures › New pylon from a template… (the face of the pylon: its crossarm levels and lengths; build the suspension type, switch to Strain, build the strain type), then Place on alignment points… (the suspension type on every point, the strain type on the angle points: one command; each turned along the line, then it stays as placed — Properties › Placement… › Put it on the line again). One at a time: Structures › Add structure… or the Add structure tool. They go on the route of the alignment they stand on.
5. Their strings — the Add string tool, or the structure's type.
6. The wires — the String wire tool, section by section, then the jumpers.
7. The electrical systems, then the checks (clearances, loads, …).

See Routes and alignments.

Command-line tool#

ohl runs every calculation without a window. ohl --help lists the commands, ohl <command> --help their options.

cargo run -p ohl-cli -- info               # version information
cargo run -p ohl-cli -- validate           # run all validation cases in benchmarks/
cargo run -p ohl-cli -- validate --list    # calculations available to cases
(cd plugins/examples/hello-wasm && cargo build --release --target wasm32-wasip2)
cargo run -p ohl-cli -- plugin info plugins/examples/hello-wasm   # the example plugin, built first

ohl validate exits with a non-zero code if any case fails or exceeds its time limit, and --report report.md writes a Markdown report.

Sag-tension of a tension section#

cargo run -p ohl-cli -- sagtension examples/sagtension/drake-section.toml
cargo run -p ohl-cli -- sagtension examples/sagtension/drake-section.toml --units us --csv chart.csv

The job file names the cable (from the .ohlw wire libraries in libraries/cables/ — see Wire library files), the spans (horizontal length and rise), the weather cases (temperature, radial ice, wind pressure), and either a fixed stringing tension or tension criteria. The report gives the ruling span, the governing stringing tension with the utilisation of every criterion, the tension and sag in each weather case, and a stringing chart; --csv exports the chart in SI units.

Python#

pip install ./crates/ohl-py
python -c "import ohl; print(ohl.convert('length', '1000 ft', 'm'))"   # 304.8

Quantities given as text must always carry a unit ("1000 ft", "16 N/m", "-20 °C"); a bare number is rejected rather than guessed.