Presets
Playback
Cargo and crew
The walkers push on a 3 m radius; the rope winds on a 0.20 m drum on the same shaft. Torque balance sets the heaviest cargo the crew can lift: T_walkers = m g r / eta.
Drive
Model checks
The science
What is modelled
A wheel-and-axle: workers walking inside a large wheel apply a torque to a shaft, and a much smaller drum on the same shaft winds the rope. The big radius ratio (3 m to 0.2 m) lets a few people raise a cargo weighing over a tonne.
Equations
- Available torque
N x F x Rper pair, doubled when the pairs are coupled. - Required torque
m g r_drum / eta; the load is allowed when required does not exceed available (and stays within the historical mode limit). - Rope speed
omega r_drum(shown 18 times faster so a lift is watchable); the tread rim moves atomega R.
Checks run in the page
- Drum torque against m g r / eta.
- Load limit against the 2 t reference and coupled doubling.
- Rope kinematics against the integrated height.
- Walking pace against a human range.
Honest simplifications
A static torque-balance model with constant efficiency and effort: no gait dynamics, rope mass, brake or acceleration phase, and an interpretive geometry. Not a lifting-safety tool.
What to try
- Press Heavy cargo: the required torque passes the available one and the lift is blocked.
- Press Big crew to double the workers and watch the limit rise.
- Switch the drive mode to coupled.