A relatively recent side interest of mine is rail electrification, and I found this a very useful explainer of the way weights, pulleys and droppers are used to keep the contact wire level in overhead electrification:

https://youtube.com/watch?v=8MCfWPpJhXM

(At some point, I will get around to finishing @25kV’s excellent book on the subject, available as a free download here: https://ocs4rail.com)

#rail #railways #OverheadLineEquipment #catenary #electrification