The mine owner, Christopher Blackett had just replaced the wooden waggonway with iron flanged 'L' section plate rails.

He then used it as the chassis for a locomotive constructed to Trevithick's pattern with a single cylinder and a simple straight through fire tube to the boiler.

This was the famous steam locomotive, Puffing Billy which first ran in 1813 and is now preserved at the Science Museum in London.

However, there was still considerable wear to the track, and the engines were rebuilt using twin four-wheeled bogies, introduced in Blackwell's design mentioned above.

In about 1830 the line was relaid with the stronger edge rails, and both locomotives reverted to their original pattern, but with flanged wheels, which is how they are today.