The children began by looking at the Traffic Scotland control room (which looks like an incident room from a big movie!) and the miniature models of all of the bridges (which we found out were made by a specialist company in Glasgow) before settling down to a presentation about the new bridge from Elaine, a civil engineer who was our host for the morning. Elaine asked a lot of questions to see how much we had already learned about bridges in advance, and told me at the end that she was extremely impressed with the children's knowledge and understanding of how the bridges worked. Well done, P6/7!
The presentation showed and told us how they have been going about building the new crossing and described the engineering problems which had to be overcome when building a bridge over water. We learned all about caissons which are big empty drums that are twisted down into the rock under the seabed and then filled with concrete, and how the engineers worked out how to fill it up from the bottom so that the first concrete they pumped in would turn to watery sludge, but this sludge would protect the concrete pumping in underneath it, allowing it to dry and driving the water out of the top of the caisson. Although it seems like a better idea to just empty the water out first, Elaine explained that doing that would be like pouring out all the fizzy juice from a can and then squeezing it, making it crumple up - there would be nothing inside to push against the force of all the water on the outside of the caisson, and so the same would happen.
After learning about how the towers were then built up out of moulded concrete, we were shown how the track on the bridge was started on the land and pushed out over the water, to meet up with the track they were already adding to the side of the towers
When the presentation was over, we were split into two groups for an engineering challenge. Each group had to decide a project manager and were also assigned a Quantity Surveyor and a Health & Safety Officer. These officers had to take their jobs very seriously in organising the rest of the team for the building a bridge challenge. We had to split the two groups in half, with each half building a half of the team bridge, to be joined up with the other half when completed. We had to follow structural plans, understanding plan views and elevation side and end views in order to build our bridges correctly. We also had to bring in and apply everything we have already learned about group work, and I must also add that Elaine complimented the children on their level of discussion and recognition of effective group work. Well done again, P6/7!!
A great day and we learned so much about bridges, which is going to be a great help for our further topic work.