0-6-0 is the Whyte notation designation for steam locomotives with a wheel arrangement of no leading wheels, six powered and coupled driving wheels on three axles, and no trailing wheels. Historically, this was the most common wheel arrangement used on both tender and tank locomotives in versions with both inside and outside cylinders.
Hackworth's Royal George of 1827
Derwent with a tender at each end
Victorian Railways Z-Class 0-6-0T locomotive Z 526, as restored.
A handcrafted, 1:8 live steam scale model of a Finnish VR Class Vr1
The Whyte notation is a classification method for steam locomotives, and some internal combustion locomotives and electric locomotives, by wheel arrangement. It was devised by Frederick Methvan Whyte, and came into use in the early twentieth century following a December 1900 editorial in American Engineer and Railroad Journal.
Whyte notation from a handbook for railroad industry workers published in 1906