This first half-term of the new academic year has flown by, giving us little time to pause for breath. So what have we achieved at Rode Heath in terms of our engineering project? With the curriculum being increasingly squeezed – an extra half hour of PE a day, time needed for well being and diversity – what we really need is one of Hermione’s ‘Time Turners’ in order to fit everything in. Failing that, we must try and be more cross-curricular. Fortunately, there are still many opportunities to do this.
In Year 4, we have been studying the Romans, who are well-known for their remarkable feats of engineering, such as roads, bridges, tunnels and aqueducts. Perhaps one of the most significant achievements was the vast network of roads that they built – some of which you can still see today, over 2,000 years later. We decided to find out how the Romans managed to make these roads so straight.
We discovered that they used a device called a ‘groma’ – a simple cross of wood with arms of equal length. Each arm had a plumb line suspended from the end of it, which was equal in length to the other three plumb lines. This seemed easy enough to make, so we had a go. There were a few examples on the Internet, some made with lollipop sticks, but these proved very hard to fix together without splitting, so in the end we opted for strips of Greyboard, which seemed to work well, some string and a cardboard tube. The children were then left to decide what to use to weight their string so that it kept straight.
Most groups chose paperclips. Those who used Blu tack quickly discovered that the strings tended to stick together when they moved, which wasn’t ideal. The length of string was also found to be significant – too long and the lines were easily tangled.
Having made our gromas, the next step was to try them out on the school playing field. How successful would they be at making a straight line? The idea was to point one of the cardboard arms in the direction of where the children wanted the theoretical road to go and then send someone with a pole about 10 metres in that direction. 
The key was to line up the pole with the two strings and the cardboard tube. This process was then repeated until we had about three pole in a row.
In hindsight it would probably have been easier to line up the strings if we had used a piece of dowel instead of the cardboard tube, as these were rather wide and obscured the string somewhat. The exercise was deemed to be a great success though and the children gained a good understanding of how the Romans made their roads straight.
And, of course, the children were able to write about their experiences in their Engineering Log Books.
Making a Roman Road
This activity naturally led to the children wanting to make their own mini roads, which we did – in shoe boxes. Collecting the materials was surprisingly easy, as one of our parents was having some building work done, so there was a plentiful supply of sand, gravel and various sizes of stone – some of which were actually much larger than the shoe box for which they were intended!
Ideas of how the roads were in fact layered seemed to vary, so we just picked one which best suited the materials to hand. This isn’t something that I have ever attempted before and there are definitely things that I would do differently next time. It did however present opportunities to bring in a number of areas of the curriculum, particularly maths, as using digital scales, we were able to compare the different volume of gravel, stones and sand of the same weight.
Actually layering the different materials proved much more difficult that we anticipated. The aim was to clearly display each layer through a plastic window constructed at the end of the shoe box. However, the sand tended to mix in with everything. We decided that rather than trying to fill the whole box, it would be better just to focus on constructing the layers at one end.
The children had great fun and again will probably remember more about how the roads were built than if they had just researched the topic on the Internet or in books. Here are the children’s constructions.
This exercise lent itself to a set of instructions. which were then presented in either a Word, Publisher or PowerPoint format – Literacy and Computing connections.
Reflecting on learning
It is very important at the end of these sessions to give the children time to reflect on their experiences. We always encourage them to think about and record their successes and failures: what aspects went particularly well; what difficulties did they face and how might they change their approach for next time? This can be quite daunting at first, but improves with practice.
So, what is next on the agenda? Making concrete of course – the Romans are supposed to have invented that too. Clever chaps those Romans . . .
Think Like An Engineer 