The London and Greenwich Railway (L&GR) was opened in London between 1836 and 1838. It was the first steam railway in the capital, the first to be built specifically for passengers, and the first entirely elevated railway.

Under the Whyte notation for the classification of steam locomotives, 2-2-0 represents the wheel arrangement of two leading wheels on one axle, two powered driving wheels on one axle, and no trailing wheels. This configuration, which became very popular during the 1830s, was commonly called the Planet type after the first locomotive, Robert Stephenson's Planet of 1830.