Two members of the Young Members’ Committee from the Welding Institute, Matthew Haslett and Andreea Crintea, delivered the Welding with Chocolate Workshop to children aged between 5 and 11 at the Cambridge Science Centre.

This fun and innovative workshop allowed children to experiment designing and then testing bridge girders in a less conventional way: by welding chocolate bars into box section girders and then loading them to determine the maximum bearing weight at their mid span.

The experiments started by testing a plank girder composed of a single Milky Bar which, without surprise, did not withstand too much load. Based on the experimentally obtained limit load of the plank girders, the children were then asked to guess the limit load of a box girder, built by ‘welding’ four chocolate bars. Most answers indicated that the box girder limit load would be 4 times greater than that of the plank girder, mainly based on the fact that 4 times more chocolate bars were used for its construction.

The kids enjoyed some hands-on experience by chocolate welding their own box girders. Bottles of hot water were used as a source of heat for the melting of the chocolate bar edges, which were firstly welded into a V-shape. The long sides of two V-shapes were then further melted in order to be able to weld them into the form of a box girder

Subsequent testing of the box girders showed that they could withstand up to 10 times more load than the plank girder, mostly because of the increased number of chocolate bars and their orientation with respect to the bending axis. 

The children seemed to enjoy the workshop, mainly based on their involvement in answering the questions asked by the presenters. The workshop was very popular, as all available spots for the event sold out within hours of being advertised. Parents and teachers from the audience appreciated the quality of the workshop, with many of them requesting more details and facts sheets in order for them to promote it during their own