3 x 3

Pulleys and bracing arms

Gears

Hydraulics

Bridge 1

Arch and Cable Stay

Pulleys will pull the road bed up along a track and the braces will hold the track in place.

Gears will slide the road bed along a track.

A hydraulic arm will push the road bed into a track.

Bridge 2

Cantilever

Pulleys will lift the road bed up into the top of the bridge
Easiest

Gears will lower the road bed then slide it beneath the bridge creating a wide enough opening

Hydraulic arms will raise the section of the deck up to the required height.

Bridge 3

Truss

Will not work with a truss bridge.

Gears can fold the road bed up and create an opening.
Very hard

Basic draw bridge with hydraulic arms raise and lower road bed.