The drawing below is from Gustave Eiffel's book describing the tower that bears his name. There are 53 of them in total.
XXIII bis. Upper part and continuation of the mechanism
This technical sheet explains the different components and the way in which the Roux lift, Combaluzier and Lepape are installed. if this plan is complex enough, it is not necessary to understand it to know how was made the Eiffel Tower. This is the continuation of the previous plate.
See also: