Complete the crossword, then click on "Check" to check your answer. If you are stuck, you can click on "Hint" to get a free letter. Click on a number in the grid to see the clue or clues for that number.

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 Check 

Across: 1. Any force that acts in order to lengthen, or pull apart the ends of, a structural element. When hanging from a rope, both the rope and your arms, will be under Tension. 4. A framework of connected members, usually made from steel, which together bear the loads on a bridge. 5. A tunnel used by designers to test the effects of high winds on a planned structure. This may be part of a full-size structure, or a small-scale model of the whole structure. 6. The unsupported length of a bridge, between its towers or piers. 7. Any force that acts in order to lengthen, or pull apart the ends of, a structural element. When hanging from a rope, both the rope and your arms, will be under Tension 8. A part of a framework that is carrying tensile forces, or keeping two elements of a structure together. 9. Any force that acts in order to shorten, or push together the ends of, a structural element. When pushing your hands together, your arms will be under compression. The towers of a suspension bridge, and the piers of an arch bridge, are under compression. 11. The central point of a structure. This is often where the structure is at its weakest, and the load at its greatest. 12. The points at which the main cables on a suspension bridge are 'anchored' to the ground at either end of the bridge. 14. A road or rail bridge of considerable length, usually carrying vehicles at an elevated height across a valley or round a mountain side, as opposed to simply across a specific obstacle. 15. Materials whose properties derive from the mixture of their component materials. Individual glass fibres held together by a plastic resin forms the easily moulded, yet strong, 'fibreglass' material used for canoes, car bodies etc. 17. The mouth of a river where it empties into the sea. Due to erosion, estuaries are often extremely wide. 18. A rigid horizontal element that is used to carry a load. A beam bridge often consists of a road deck reinforced with girders. 20. A simplification of the real-life object and situation that preserves their essential nature, and allows a solution using mathematics. 21. The upwards bending in a beam, usually over its piers, that is the counterbalance to sagging in other sections of the beam. 22. A bridge design in which the road deck is supported by a series of cables attached to the top of one or more towers. 26. The tendency of a beam to bend downwards, when acted on by a load, including its own weight. 27. The trapezoidal stones that are often used to form a rounded arch. 29. The stones at the base of a bridge structure that take the loads onto the foundations. 31. The central stone in an arch, and begins the distribution of the vertical 'load' forces down and around the arch. 32. An artificially-made organic material that forms very long and stiff fibres. 33. A channel carrying water from its source (a lake or spring) to where it is needed. 34. A part of a framework that is carrying compressive forces, or keeping two elements of a structure apart. 35. A span that consists of an upwardly curved beam. The forces from the centre are distributed outwards.

Down: 2. The simplest is the semi-circular, but a shallow, flattened semi-circle becomes an ellipse, and many mediaeval stone bridges were built with an... 3. The physical demands laid upon an object or material by the forces acting on it. 10. The internal force that prevents an object from bending freely under the action of the external forces. Sagging and hogging are visible signs of it. 13. The build-up of oscillatory, or wave-like, motion in an object such as a plucked guitar string or the deck of a suspension bridge in a wind. 16. The part of a bridge that carries the roadway. Usually horizontal, and often suspended from cables or resting on an arch. 18. A structure, usually brick or stone, built against a wall for support or reinforcement to resist the sideways pressure of the weight of the building. 19. An arch constructed by successive layers of brick or stone projecting further towards each other from either side of the arch, until the gap is spanned. 21. The vertical rods or cables that are directly attached to the road deck of a suspension bridge, and 'hang' from the two main suspension cables that pass over the towers 23. The side support at either end of an arch bridge, necessary to withstand the horizontal forces generated by the arch's shape. 24. A cofferdam is a temporary watertight enclosure constructed on the spot where a pier is to be built. A cofferdam usually consists of sheets of steel driven into the ground to create a walled chamber. 25. A beam, usually made from concrete or steel, that is designed to strengthen another structural element. 28. A force that is to be carried by a structure. Examples include the weight of traffic on a bridge and the wind on the side of a tent. 30. The part of a bridge that supports the horizontal element, and carries the load to the ground, especially the intermediate support in a multi-arched bridge.