A Bridge Too Many

A Bridge too Many, from the Centre for Science Education, is a set of teaching materials which offer a cross-curricular approach to learning about engineering. The context for the activities is a challenge based on a large model bridge that has been pre-constructed using prefabricated components, with weak pins joining the structure together. The challenge is to remove the bridge from over a railway without dropping anything on the tracks.

The bridge model is clad in Techcard (to mimic steel cladding sheet) and contains an internal structure, consisting of pipes under the top girders and a form of conveyor system mounted on the bottom girders. The students are able to examine the bridge, but not to do any work on it before the end of the project.

Students, working in teams, have to use the information supplied (drawings, technical information on the weight, strength, etc., of the girders), information on how to calculate the loads in a pin-jointed framework, information on the weights of the various pipes, conveyor components, cladding sheets, technical data on a range of cranes and so on, to plan the dismantling and removal of the bridge. They should prepare a detailed report to the Railway Safety Officer (the Tutor), who approves or rejects it. Students have a set of components available if they wish to construct a model to confirm the results of their calculations experimentally.

Once the plan has been prepared, the team is required to remove the model bridge from over the railway, without accident. Successful completion of the task can result in a form of certification for the students.

This task cannot be completed without the students working well together as a team. It is assumed that some form of preparation will be carried out to raise their awareness of the different roles that individuals play in a team, the roles that they are most suited to play, and of team dynamics.

• URL: http://stem.org.uk/rx87v