Retractable Bridge Prototype

A team-designed retractable bridge prototype developed to operate within tight urban constraints.

As part of a team of five, we designed and built a scale retractable bridge capable of allowing road, water, and air traffic to coexist. The project focused on compact mechanical design, controlled motion, structural integrity, and safe operation within strict spatial, cost, and performance constraints.

The final prototype demonstrated reliable motor-driven retraction, maintained required clearances throughout motion, and met nearly all defined design objectives through analysis, testing, and iteration.

Project Media

Isometric CAD view of the final retractable bridge design:

Isometric CAD view of retractable bridge

Skills & Tools Used

Mechanical system design
Structural analysis (shear, moment, failure modes)
Design for laser cutting (kerf, tolerances, tabbed joints)
Laser cutting (plywood structural components)
CAD modeling and kinematic simulation (Onshape)
3D printing (PLA components, fixtures, bushings)
Fabrication and assembly (wood, steel, fasteners)
Design for manufacturability and assembly
Electric motor actuation and wiring
Prototyping and experimental testing
Team-based engineering design

Design Process

This project followed a complete engineering design cycle. Work began with a client-style problem definition and proposal, followed by background research on existing retractable bridge mechanisms. Multiple design concepts were generated and evaluated using weighted decision matrices before selecting a final concept.

The selected design was developed through CAD modeling, prototyping, structural analysis, fabrication, and assembly. A full design report was produced documenting objectives, concept selection, analysis, testing procedures, and results. The final prototype was then physically tested and evaluated against the original design requirements, with lessons learned documented for future iterations.