Teams must satisfy certain prerequisites before competing in the National Student Steel Bridge Competition. Competing teams must first participate in a conference-level competition before moving on to the national competition. The scores received and the number of teams competing in each conference determine which teams are accepted from each conference to compete nationally. In conferences consisting of four or fewer teams, only the top scoring team advances. In conferences of between five and 10 teams, the top two scoring teams advance. And in conferences of more than 10 teams, the top three teams go on to compete nationally. All teams must be held in good standing by the American Society of Civil Engineers.
The primary rules and objective of the NSSBC each year is put forth in the form of a problem statement. For example, the 2011 competition specifies that the teams build a deck bridge for access over a river within a park. The bridge must allow clearance for boating on the river, and it must be able to sustain a specified weight. For environmental reasons, supports for the bridge may only be placed on the banks of the river with a cantilever span, and equipment may be used from one side of the river only. River barges, however, may be used. Teams are to build the model bridge to a 1:10 scale.
All teams must use only structural steel to construct their bridges. Each steel component used must not exceed 20 lbs. in weight or 3 feet by 4 inches by 6 inches in dimension. All materials before construction must be separated or rigidly joined such as through welding--parts may not be hinged or jointed. A bridge may not use nonmechanical components such electronic control systems, wire or tubing or motors.
The construction site is limited to builders and judges during construction. All persons within the site must wear a hardhat with a peak. There may be no lubricant within the construction site at any time. All tools and temporary piers must not exceed 20 lbs. in weight.