LNER_Class_N8
The NER B and B1 Classes (later London and North Eastern Railway [LNER] Classes N8) were two classes of 0-6-2 tank locomotives designed by Thomas William Worsdell for heavy freight and mineral on the North Eastern Railway, introduced in 1886. They were tank engine versions of the NER C1 Class 0-6-0, using both simple expansion (Class B1) and also the von Borries configuration for two-cylinder compound locomotives (Class B). Both types were later rebuilt using superheated steam and the compounds were also rebuilt as simple expansion locomotives, and eventually formed a single class (albeit with variations in dimensions). Many of the superheated locomotives were also later returned to saturated steam as their original boilers wore out. As a result the classes have had a very complex mechanical history.