Wright State University EGR 190

Bridge Design and Construction Competition


Qualification Criteria

You will be assigned to a team of engineering students that will create a bridge using K'NEX building parts. The process by which teams will be identified and building parts acquired will be described in class. The bridge must conform to the constraints given below to qualify for the test competition.

1) All teams will receive a box having the same type and number of K'NEX parts.

2) K'NEX parts are the only building materials that may be used.

3) Absolutely no modifications or additions to the K'NEX pieces are permitted.

4) All bridges must be free standing and stable under no load conditions.

5) All bridges must have a span of at least forty inches. The span is defined as the smallest distance between two opposite points of support. Points of support are defined as those at which the bridge touches a flat surface upon which it rests. The areas defined by the points of support on either end of the span can be of any shape or size but each must fit within a one foot square.

6) The bridge must provide a center clear span at least 12 inches wide by at least 6 inches deep.

7) All bridges must include an area on the top surface of the span where the loading platform can be placed in a stable position to permit incremental loading during the competition. 


Competition Criteria

All teams must register a bridge. Any bridge that does not meet all of the qualification criteria above will be eliminated from the competition at registration time. During the competition, each qualified bridge will be subjected to an increasing load until it collapses. This maximum load divided by the weight of the bridge will determine the "strength to weight" ratio of each bridge. The bridge that survives the heaviest load wins. In case of a tie, the bridge with the largest "strength to weight" ratio will be the winner of the competition.

Each bridge will start with a load of 50 pounds. The weight will then be increased by 1 to 10 pounds increments until it breaks. 

Prototyping and Testing

Take time to create, test and improve a variety of designs. Past experience has shown that virtually all of the best designs have been tested and modified several times. Loading plates and weights will be available in Russ student lounge from 9:00 AM to 4:00 PM Tuesday, 2 January  through Friday, 5 January 2001

This will give you ample opportunities to determine the "strength to weight" ratio of various configurations and to assure that your final design meets the qualification criteria. You can estimate the weight of your bridge from the number of each type of K'NEX piece you have used in the construction.

You are free to use anyplace on campus to build your bridge, but do not disrupt any campus activities. The Russ lobby and student lounge are ideal locations.

Schedule and Procedures for Registration and Qualification for the Competition

You are required to be present during the entire competition unless excused by Dr. Rowley.

Bridge testing will take place on Saturday, January 6, 2001 from 2:00 to 5:00PM in the Multipurpose Room of the Student Union. Registration and qualification will be from 2:00 to 2:30 PM.  Each bridge will be registered, weighed and examined by the judges to assure that it meets the qualification criteria. Bring with you a list of the number of each type of piece used in your bridge construction. Weight testing will begin at 2:30 PM. 

At the conclusion of the competition, each bridge must be disassembled by the team and the parts placed in the original container. The container is to be checked in Monday, 8 January at room 026 Russ by the team captain.

Team Log Requirements

Each team is to keep a log/diary of the week’s events such as when the team met, the time spent on the project, the different designs that were constructed, why the design failed, etc. The log must be typewritten on a single page and consist entries for each of the days from Tuesday, 2 January  through Friday, 5 January. The logs are to be signed by each team member and turned in during the bridge qualification.


The grade earned for this project will be a "team" grade, that is, each team member will receive the same grade.
   1. A qualifying bridge will receive 2 points.
   2. A bridge that survives a 65 pound load will receive 3 points.
   3. The winning team will receive a free dinner at a local restaurant with Dr. Rowley.


K'Nex Pieces


Approximate Weight  per Piece

Quantity per Team

Blue Connector



Purple Connector



White Connector



Yellow Connector



Green Connector



Red Connector



Light Grey Connector



Dark Grey Connector



Tan Wheel-Axle Connector



Grey Rod



Red Rod



Yellow Rod



Blue Rod



White Rod



***NOTE: The maximum weight for the total inventory of parts should be approximately 1848.75 g.