Iron+&+Steel

**Cast Iron** It is made of iron and lots of carbon. It is a very heavy material and a little bit expensive. Cast iron is strong to compression, that’s why arch bridges were made of this material. On the other hand, when iron is stretched, it gets brittle and it snaps easily.

It is made of iron with a touch of carbon. It is an extremely heavy material, and like cast iron it’s kind of expensive. Steel is harder than other material to compression; it takes a lot of compression to blend of break it. Because of this, it is commonly used for columns and skyscrapers. This material is also stronger than any other to tension, and that’s why it is frequently used in bridge’s cables, like in the Golden Gate Bridge in San Francisco, US.
 * Steel**

Corrugated iron is a building material composed by sheets of steel with a linear corrugated pattern in them.
 * What corrugated iron is? **

Corrugated Iron is cheap, easy to transport, durable, strong, supple and available everywhere. It also replaces more expensive materials.
 * Characteristics **

It was invented in 1820’s by a British architect. It has become an icon in Australia, where, at first, it was transported from England.
 * Uses through history **

A structural iron worker needs to combine special skills because they are involved in almost every step of the construction. They have to be in good physical condition and have great strength because this type of job is frequently done at great highs; agility and balance are also essential. People who choose this career should not be afraid of highs or suffer from dizziness. By the other hand, they need classroom training, where apprentices will learn about structure reinforcing, mathematics and welding. With enough experience structural iron workers may eventually become supervisors or going to business for themselves.
 * What it takes to be an iron worker? **

The most important innovation in architecture, since ancient times, is the development of the construction methods using iron and steel. Both of them are cheaper than traditional materials like wood or stone, providing stronger and tallest structures. Cast iron was the first substitute of the traditional materials, but it resists more compression than tension, and this is why it was replaced in the XIX century by steel which is more uniformly strong.
 * __Podcast’s replay __**

About this quotation: “//the old cast iron buildings died out. I'm not really sure whether the new skyscrapers killed them, or the new esthetics//” I think it is a little bit of both. Along with the years the techniques change and the size of the new constructions do it too, this means that, knowing that steel is better for this, why should constructors use cast iron knowing they can use something better?

At first, constructions like basilicas and cathedrals were made form **stone**, which, used in the right way could **bear** high loads, but this material is too heavy, expensive and hard to **quarry**. This is why, with the years, new constructions techniques showed up, making the construction a quicker, cheaper and more effective job. **Concrete** gained more popularity and with it, new materials for structures. Probably, one of the most important innovations for architecture, since the ancient times, was the using of **cast iron** and other metals like steel for construction. They support large **stresses** and they are less expensive than traditional materials