Improved Chariots

The Britons' knowledge of working iron helped them to craft the war chariots that so impressed the Roman invaders. The wheels were wrapped in iron tyres that were purposefully made slightly too small. Wheelwrights would then heat the iron, making it expand. When it was placed around the rim, and allowed to cool, it shrank and bound the wheel’s components together. This was then further fixed to the wheel with large-headed nails that gave extra grip to the iron tyre.