This was posted a couple of weeks ago. It's for the wiring.
https://ogrforum.ogaugerr.com/...Wiring%20diagram.pdf
As far as the rest of the assembly: See the second link for a 22 page booklet.
https://ogrforum.ogaugerr.com/...-bascule-bridge-help
Also, use the search feature in the Blue bar at the top of the page. Type in Lionel 313 bridge and a whole bunch of posts will pop up.
Good Luck.