![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/3/32/MR_4-2-2_673%252C_Rocket_150%252C_Rainhill%252C_May_1980_Slides184_%25289859805644%2529_%25E2%2580%2593_edited.jpg/640px-MR_4-2-2_673%252C_Rocket_150%252C_Rainhill%252C_May_1980_Slides184_%25289859805644%2529_%25E2%2580%2593_edited.jpg&w=640&q=50)
4-2-2
Locomotive wheel arrangement / From Wikipedia, the free encyclopedia
For usage in video production, see Chroma subsampling.
Under the Whyte notation for the classification of steam locomotives, 4-2-2 represents the wheel arrangement of four leading wheels on two axles, two powered driving wheels on one axle, and two trailing wheels on one axle.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/3/32/MR_4-2-2_673%2C_Rocket_150%2C_Rainhill%2C_May_1980_Slides184_%289859805644%29_%E2%80%93_edited.jpg/640px-MR_4-2-2_673%2C_Rocket_150%2C_Rainhill%2C_May_1980_Slides184_%289859805644%29_%E2%80%93_edited.jpg)
Other equivalent classifications are:
- UIC classification: 2A1
- French classification: 211
- Turkish classification: 14
- Swiss classification: 1/4
Like other steam locomotive types with single pairs of driving wheels, they were also known as singles.