The M5 Class is a class of dual purpose 2-10-0's designed by Reginald Thornton at the Eastern & Atlantic's Richmond Works.
After World War I, the Eastern & Atlantic regained control of itself from the USRA. Reginald Thornton was hired in 1921, and his first locomotive project was the M5 Class of 2-10-0 locomotives. Designed for both freight and passenger work, the M5 Class also employed a feedwater heater, contributing to it's effectiveness. The class was a success, being a mainstay of many medium-size freight and slow passenger trains in the E&A for many years.
180 locomotives were built at the Trenton Works between 1921 and 1924.