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. Place the apex with its position from anchor 1 and its Drop (m) (how far below the anchors it 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, Length and Tension, each tension 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 sideways load.

Which angle?

RiggingSense measures each leg's angle from horizontal (α), and says so. Two other conventions describe the same geometry, and the tool shows them alongside:

• From vertical (β = 90° − α) — German sling tables and DGUV Information 215-313 count this way. 30° from horizontal is β = 60°.
• Between the legs (the included angle, 180° − 2α for a symmetric bridle). 30° from horizontal is 120° between the legs — the "120° rule".

Before you compare a number with a course or a table, check which of the three it means.

The tension curve

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

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. Compare both legs with 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, marked as a training exercise. See Training and safety factors for how the Safety factors tab compares a WLL with the sandbox's highest hoist load.