Musing (as one does) about the escapement on pendulum clocks, web search came up with "Clock and Watch Escapement Mechanics" an online book by Mark V. Headrick.
https://www.abbeyclock.com/ttoc.html

The site also provides simulations of the movements of various types of escapements.
https://www.abbeyclock.com/escapement.html
#PendulumClock #escapements