Topic summary
Tandem compound
Extracted from the Wikipedia article Compound locomotive.
Tandem
Tandem compound locomotives were very common in the United States prior to WW1, with some railroads such as the Santa Fe having large numbers in several wheel arrangements. A characteristic feature of larger tandem compound locomotives was an "A-frame" crane mounted on each side of the smokebox, to allow removing the front cylinder (typically the LP cylinder) when the rear cylinder required service.