The first New York Elevated Forneys were 45 engines built in 1878 and 1879 by Baldwin and the Rhode Island Locomotive Works. There were two designs of different weight, which later became classes B and C. Like all Forneys, they had two coupled axles, the second of which had no flanges, and a trailing bogie that carried the full load of the supplies.
It all started with the locomotives later known as Class C, of which Baldwin supplied 13 and Rhode Island twelve. The engines delivered the following year became Class B and were slightly lighter with a smaller water supply. These consisted of ten pieces each from both manufacturers.