Stephenson Planet
The Stephenson Planet designation refers to the production batches of Robert Stephenson & Co.'s Planet-type 2-2-2 inside-cylinder locomotives built from 1833 onwards, following the development of the Patentee design in that year. See the main Planet Class entry for the full history of the Planet locomotive design that established the basic configuration of the steam locomotive. This entry covers the post-1833 production locomotives built to the Planet/Patentee specification by Stephenson and other manufacturers, which were supplied to numerous British railways during the early expansion period of the 1830s and 1840s.
The Stephenson Planet designation in this database captures the related Stephenson 2-2-2 production types of the mid-1830s that evolved from the 1830 Planet into the 1833 Patentee and the subsequent standard express locomotive specification. A working replica of the original Planet is preserved at the Science and Industry Museum, Manchester. See Planet Class for full details.
Design and development
See Planet Class entry for the full design history of the Stephenson Planet and its development into the Patentee 2-2-2.
Service and withdrawals
See Planet Class entry.
Identification features
Standard Planet pattern: 2-2-0 with inside cylinders at the smokebox end, cranked rear driving axle, and Stephenson sandwich frames. Detailed proportions varied somewhat with customer specification.
Notable locomotives
- Various individual engines, none preserved