WJEC Vocational Award Engineering Level 1/2

WJEC Vocational Award Engineering Level 1/2 To understand the forces that Structural Engineers have to work with when with designing bridges, below is a diagram explaining what compression and tension are. Heavy roof tiles Three wooden joists Weight/force of tiles This joist stops the compressive force from pushing apart the other two joists Here is a house with a cutaway of the roof. Notice how the roof has three wooden joists in a triangular shape. The weight of the tiles puts the roof under compression and tries to force apart the joists making the roof collapse. The third joist stops the two joists that are under compression from being forced apart. The third one is now being pulled apart and is under tension . Here you can see how using simple engineering you can create a roof for a house that will support lots of heavy tiles. Under compression Under tension Under compression The Millau Viaduct The Millau Viaduct is one of the greatest engineering achievements of modern times. It is a cable- stayed bridge that is 343 metres tall and at time of writing holds the record for being the tallest bridge in the world. It spans the valley of River Tarn near Millau in Southern France. It was also designed by a team of Structural Engineers headed-up by the British architect Sir Norman Foster. The Millau Viaduct, Southern France. Sir Norman Foster. Compression: being squashed. Tension: being squeezed. Key terms 134