Bridge Project


Project Objective:

The objective of this event is to evaluate student knowledge of statics, force vectors, and balancing torques. Model bridges are intended to be simplified versions of real-world bridges, which are designed to accept a load in any position and permit the load to travel across the entire bridge.

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Physics Concepts:

    1. Students will investigate the various forms of stress including:
      1. Compression
      2. Tension
      3. Shear
    2. Students will examine the relationship between stress and strain and be able to make informed decisions about their bridge design according to these principles.
    3. Students will investigate the concept of torque, moment arm, and beam stresses.
    4. Students will use the concept of vectors to calculate the directions and magnitudes of two dimensional forces.
    5. Students will resolve two-dimensional vectors into their components and calculate the magnitude and direction of a vector from its components.
    6. Students will solve two-dimensional problems involving balanced forces (statics).


  1. The bridge must span a minimum gap of 50 cm and should not exceed 60 cm.
  2. The loading platform is 10 cm wide, 10 cm tall and 45 cm long.  It has two 1.5 cm by 7 cm slots milled 8 cm apart in the center. The loading bucket hangs from two “J” hooks inserted in the platform. The platform MUST rest on a minimum of five interior floor beams of the bridge.
  3. No portion of the bridge may project below the elevation of the support surfaces.
  4. The bridge will be centered on the support surfaces.
  5. The loading plate will be placed at the specified loading location.
  6. The load will be applied from below, as described above.

Performance Metrics:

  1. Strength:
    The bridge will be statically loaded with a weight of 50 N or until failure occurs.
  2. Efficiency:
    Bonus points may be awarded to the designs that support the most weight per gram of structure.


  1. All the component  materials will be made from supplied manila folder stock.  You may supply colored folders as you wish to personalize your bridge.
  2. White PVA glue and mandrel materials will be supplied.  No other adhesives are allowed.
  3. No other materials may be used. The bridge may not be stained, painted or coated in any fashion with any foreign substance including PVA.