Big Ben — Great Clock Pendulum, Escapement & Bell Acoustics

How a 2-second-beat pendulum, a gravity escapement and a 13.8-tonne bell keep and strike London time.

Presets

Live readouts

Graph

Controls

Regulation: pennies & pendulum

Environment: temperature, pressure, gravity

Escapement drive & friction

Time & display

Bells & sound (audio starts only when you press a button)

Experiment

How many pennies fix the clock?

Adds 0–10 coins to the tray in turn, simulates the pendulum (RK4 + escapement) for ~17 minutes each and measures the seconds-per-day shift against the analytic prediction.

Coin on the tray

Not run yet.

The clock is losing (s/day)2.0

Independent numerical checks

Does the simulation agree with theory?

The science

Equations, assumptions and honest simplifications

Educational model. Elizabeth Tower (96 m), the Great Bell (13.76 t) and the clock (installed 1859, designed by Denison, built by Dent) are real; the internal mass distribution, the escapement geometry, the source level of the bell and the coin tray position are modelling assumptions stated above. Not affiliated with, or endorsed by, the Houses of Parliament.