Bridles

A two-leg bridle shares one load between two anchor points. The flatter the legs, the harder each one pulls — at 30° from horizontal each leg carries the whole load. The Bridles tab makes that visible.

Set up a bridle

1. Open the Bridles tab.
2. Set the Anchor separation (m) — the distance between the two anchor points — and the Load W (kg).
3. Set the apex with Apex x (m) (distance from anchor 1) and Drop (m) (how far below the anchors the apex hangs), or simply drag the apex in the diagram. Arrow keys move a focused apex 0.1 m; Shift makes it 1 m.
4. Read Leg 1 and Leg 2: Angle from horizontal, Length and Tension, each with its vertical and horizontal component.

Colour bands on the diagram flag flat bridles. The guidance line under the results states the practice: never below 30° from horizontal, prefer 45° or more. Flat bridles also pull the anchors sideways, and house steel is rarely rated for lateral load.

The tension curve

Tension per leg vs. angle (symmetric) plots the whole story, with the landmarks worth memorising:

Below 30° the curve climbs steeply; a 0° bridle would need infinite tension, which is why the tool clamps the geometry and says so.

Asymmetric bridles

When the apex is not centred, the two legs have different angles. The steeper leg carries more of the vertical load, and the horizontal components of both legs must cancel. Show the math walks the force-triangle solution line by line. Check both legs against their WLL, not only the loaded-looking one.

Save and share

Save scenario keeps the bridle in the Saved tab; Copy link encodes it in a URL; Print gives you the diagram, inputs and working on one page. See Training and safety factors for how the Safety factors tab reads the sandbox's worst hoist load.