Beam Clamp Reaction and Side-Pull Check
What a bridle leg actually does to the clamp.
Example
You enter
- Leg tension (lb) 860.23
- Leg angle above horizontal (deg, 90 = vertical) 63.43
- Clamp vertical WLL (lb) 2000
- Side-pull rating (lb, 0 = not rated) 500
You get
- Vertical component 769.38
- Horizontal (side pull) 384.77
- Vertical util (%) 38.47
- Horizontal util (%) 76.95
- Pull from vertical (deg) 26.57
Details, formula, and sources
V = T sin(angle), H = T cos(angle), each checked against the clamp's vertical WLL and the manufacturer's side-pull allowance (zero for most beam clamps). The steep 860 lb leg of the two-leg bridle example loads its clamp to only 38% vertically but 77% of a generous 500 lb side-pull rating - the side pull governs, and on an unrated clamp the verdict is re-rig, not pass. A design aid, not a rigging sign-off.
V = T x sin(angle); H = T x cos(angle); pull_from_vertical = atan2(H, V); vertical_util = V / vertical_WLL x 100; horizontal_util = side_pull_rating > 0 ? H / side_pull_rating x 100 : flagged (no rating).
Static force resolution; ASME B30.20 / beam-clamp manufacturer practice (the WLL is a vertical rating; side pull prohibited unless the manufacturer rates it), by name.
Force resolution is a public statics result; ASME B30.20 and the manufacturer's documentation govern below-the-hook hardware. An ESTIMATE only; the hardware ratings and a qualified rigger govern.
Estimate. Head rigger and manufacturer working-load-limit charts govern. Inspect every piece of hardware before the show.
Field names used by the API: leg_tension_lb, leg_angle_deg, vertical_wll_lb, side_pull_lb, vertical_lb, horizontal_lb, vertical_util_pct, horizontal_util_pct, pull_from_vertical_deg
- Vertical rating the clamp WLL applies to a straight-down pull; any documented side-pull allowance is the manufacturer's, not a defaultASME B30.20 / manufacturer practice
- Estimate only the hardware working load limits and a qualified rigger govern the actual pickASME B30.20