Endless Wire Ropeway

Hallidie's claim is where the hanger meets the rope — projecting horizontally from the upper and outer quarter. Plus automatic dumping, plus joints for curves. Note all three.

Fix a dowel upright in a card base at each end of a table, one about 100 mm taller than the other so the line runs downhill.

Fit a pulley at the top of each dowel so both turn freely in the same vertical plane.

Run twine over both pulleys and tie the ends together into a continuous loop. Take up the slack — a slack rope will slip instead of driving.

Bend a wire hook that simply hangs over the top of the rope. Hang a card bucket on it. This is the obvious design — and the one Hallidie improved on.

Half-fill the bucket with clay pebbles and turn the upper pulley by hand. Watch what the hanger does as it approaches the tower.

The hook rides up, twists, and lifts off at the pulley. A loaded top hook cannot pass a support — the whole line must stop to unload.

Bend a second hanger that grips the rope's upper outer quarter and projects sideways, carrying the bucket clear of the rope's centreline.

Load and drive again. The offset hanger passes the pulley on the outside and keeps going. The load never touches the wheel.

Re-hang the bucket on a brass fastener through its side, above its centre of gravity, so it can swing and tip.

Glue a small wire bar across the line just before the low tower, set to catch the bucket's lip. The bucket tips, dumps and rights itself — without stopping the rope.

Add three more hangers spaced evenly round the loop. Turn steadily: buckets load, ride, dump and return in one unbroken cycle. That is what "endless" means.

Count buckets dumped per minute and weigh one load. Multiply: that is the line's throughput — from one loop of twine and two wheels.

The patent. US 110,971, "Improvement in endless-wire-rope ways", granted 17 January 1871 to Andrew Smith Hallidie of San Francisco. It claims attaching the suspension-rods to the rope by a hanger projecting from the upper and outer quarter of the rope, an automatic dump-car, and jointed connections letting cars round curves and angles without leaving the moving rope.

🔴 This is not the cable car patent. You will read everywhere that on 17 January 1871 Hallidie patented the San Francisco cable car. He did not. This document describes an ore-carrying aerial ropeway — a mining machine, of the kind he had already been selling for years. The cable street railway came later: Hallidie worked with engineer William Eppelsheimer on the Clay Street Hill Railroad, which first ran on 2 August 1873, two and a half years after this grant. The date gets attached to the famous thing rather than the actual thing. It is the same error as crediting Vaaler with the paper clip: read the claims, not the legend.

Why the offset hanger matters. A hook over the top of a rope is fine until it reaches a support wheel, where it must be lifted off (steps 5-7). Hallidie's hanger grips the rope's upper outer quarter and reaches out sideways, so the load passes the sheave on the outside and the line never stops (steps 8-9). Continuous operation is the entire economic argument for a ropeway — a system you must halt to unload is just an expensive winch.

The wire rope came first. Hallidie manufactured wire rope in California, building on his father's British wire-rope patent, and the ropeway was a way to sell it. Wire rope itself had been patented decades earlier — John A. Roebling's US 2,720 of 1842 — and everything here depends on it: a rope of many thin wires bends round a wheel again and again without breaking, where a solid bar would fatigue and a natural-fibre rope would chafe through.

Where it sits. Aerial ropeways still move ore, timber and skiers, on exactly this arrangement: a loop, two terminal wheels, hangers offset to clear the towers. The cable car did borrow the principle — a continuously running rope under the street, with each car gripping and releasing it rather than being fixed to it. That grip is the genuine cable-car invention, and it is not in this patent.