Overview
The 2-6-6-2 wheel arrangement was most often used for articulated compound steam Mallet locomotives. In a compound Mallet, the rear set of coupled wheels are driven by the smaller high pressure cylinders, from which spent steam is then fed to the larger low pressure cylinders that drive the front set of coupled wheels.
This type of locomotive was commonly used in North America on logging railroads. The 2-6-6-2 wheel arrangement was also used in the Soviet Union and in South Africa.
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