HARBOR ENGINEERING / 01

Hoist & Harbor

Balance the load. Land it softly.

Counterweight

Hold the crate inside the teal dock at under 0.35 m/s for 1.5 seconds. Pick a counterweight, then hold Raise or Lower; brake to settle. Release a control to coast.

How the hoist works & source

Planck.js solves the real rope pulley constraint, gravity and rigid-body motion. The ideal rope is inextensible; the winch and brake apply forces. Counterweight choices trade gravity balance against control effort. Educational model; no equipment design advice.

Engine: piqnt/planck.js, MIT, e50e078c. Original challenge interface and GPT-generated cargo/pulley artwork, bundled locally.