The FFe5y Class is a class of 0-6-6-0 Class locomotives designed by Stanley Knott at the Eastern & Atlantic's Richmond Works.
The Eastern & Atlantic had 3 major yards in Miami, which was less than the 5 at New York. The three major yards were at 60th Street, 107th Avenue and Edgewater. These three yards were rather far away from each other, and required many transfer locomotives. In the 1910's, the locomotive fleet in Miami was sorely lacking in power.
Stanley Knott decided to use the relatively new Mallet technology, in the 0-6-6-0 configuration. This locomotive was succesful as designed, and 65 were produced between 1911-1913.