How many G's does a grapple swing pull?

A 20m drop on a 25m cable reaches about 19.8 m/s at the bottom, adding ~1.6G of centripetal load to 1G of gravity for ~2.6G total. Untrained humans risk G-LOC blackout above 3–5G.

3D Maneuver Gear

A grapple swing is just a pendulum.

Fire an anchor, drop, and arc. Set the cable and drop height, release, and watch the peak G-force at the bottom of the swing — where a human spine takes the load.

Speed at bottom

— m/s

G-force

— G

Cable tension

— kN

Rig the swing

Cable length · anchor to body25 m

Initial drop height20 m

Gas thrust boost0.0×

Peak G-force at low point

—

drop h gives v = √(2gh) at the bottom

Cable tension vs rope yield— kN

0 kN

Gold line = ~22 kN UIAA climbing-rope tensile yield.

How to use

Drag cable length, drop height, and gas thrust, then hit Release. The body swings down; the gauges track live speed, G-force, and cable tension. The peak readout is the worst-case load at the bottom of the arc. Above ~5G, the banner flags an incoming blackout.

The pendulum math

At the bottom of a free swing, all the drop's potential energy is kinetic: v = √(2gh). From a 20m drop that is v ≈ 19.8 m/s (71 km/h).

Swinging means turning, so the body feels centripetal acceleration a = v²/L. At a 20m drop on a 25m cable that is a ≈ 15.7 m/s² ≈ 1.6G stacked on top of 1G gravity = ~2.6G total at the bottom.

Blackout thresholds

Fighter pilots wear G-suits because at 4–5G sustained, blood pools in the legs → grayout → G-LOC (G-induced loss of consciousness) in 4–7 seconds.

Untrained civilians G-LOC at 3–5G. Canon scouts pull 8G+ swings repeatedly — the math says they should be unconscious before each kill.

Cable tension

At the bottom of the swing, tension T = m(g + v²/L). For a 70 kg soldier at ~2.6G, T ≈ 1,785 N ≈ 1.8 kN.

Climbing-rope tensile yield is ~22 kN, so the cable holds easily. The shoulder socket attaching it to a human? Less reassuring.

Citations

Burton (1988) — The Aerospace Physiology of G-LOC, AGARD-AG-322. Civilian G-LOC at 3-5 G.
Whinnery & Forster (2013) — "The +Gz-induced loss of consciousness curve," Aviat. Space Environ. Med.
UIAA 101 — climbing-rope dynamic test: ≥8 kN max impact, ~22 kN tensile.
Den Hartog (1956) — Mechanical Vibrations, pendulum dynamics.
OSHA 29 CFR 1926.502 — fall-arrest harnesses, ~6 kN max body load.

Built by Joshua Chua · Fable rebuild · vanilla JS + Canvas