Kit bash an Atlas 3-Rail Pratt Truss Bridge Kit with custom hinges and a gas spring.
(Also posted in the Track Plans and Layout Design Forum.)
Information and How-to sections have been added to my website. If links aren't working copy/paste.
Atlas 3-Rail Pratt Truss Bridge with Lift Assist Project Description
http://www.slsprr.net/features/bridges1.htm
Engine Safety Relays for protection at the Atlas lift bridges.
http://www.slsprr.net/features/wiringIntermbrgRly.htm
Atlas 3-Rail Pratt Truss Bridge with Lift Assist - Construction Photos and Drawings