By Alejandro Alvarez – Year 9

• To achieve more direct paths of circulation between two points

• To allow humans, their food, belongings and domestic animals to cross natural and man-made obstacles such as: GorgesTreacherous terrainRivers, waterways, etc.

There were like 4 ropes in total, two that will do the There were like 4 ropes in total, two that will do the job of banisters that people can grab onto. The last job of banisters that people can grab onto. The last two ropes make the main walkway which wooden two ropes make the main walkway which wooden planks are attached to. This bridge is very primative planks are attached to. This bridge is very primative and was first used in 4000 to 2000 B.C.. and was first used in 4000 to 2000 B.C..

The structure is simple, The structure is simple, which makes it quick to which makes it quick to build but not capable of build but not capable of supporting heavy supporting heavy loads, just people. loads, just people.

Rope used a lot because: It is cheapResistant They could do long bridges with rope

Wood used widely because:Easy to getLow costEasy to use

ROPES

WOOD

STICKS

•The problems with these old materials:•The wind can make an early bridge to flip and spin, and that would make it brake.•If there’s a fire, both, wood and rope, would burn and completely destroy the bridge.•The good things about today’s materials:•They are stronger•More resistant•Aerodynamic in some cases, light, etc..

At first, men thought that making a ‘joint’ between two places was impossible, because when they saw the big cliffs and deep lakes they wanted to join, they thought it was impossible. They were so confused that they even tried to fill a cliff, so that people could pass through it, but obviously, this was impossible. A mistake is what made them discover the bridges. In their try to fill the cliff, a big rock fell from one side of the cliff to the other, the rock was holding from both sides, there’s where they thought about doing, instead of filling the cliff, putting something that crossed it. When they made the rope style bridge, they had lots of problems, the bridge was unstable, so they researched and found out that putting a support in the middle of the bridge was better, so that it is stable. They did that, changed the materials, the idea spread out all over the world, and in different countries they had different designs.

The Beam Type: columns Arch Type:

Suspension/Cable-stayed Bridges:

Cantilever Bridges:

A bridge designed using Google SketchUp and made using a tubular construction

A Truss Bridge – designed using Lego Designer and made using Lego pieces