High Quality Content by WIKIPEDIA articles! The SECR N class was a type of 2-6-0 ("mogul") steam locomotive designed in 1914 by Richard Maunsell for mixed-traffic duties on the South Eastern and Chatham Railway (SECR). Built between 1917 and 1934, it was the first non-Great Western Railway (GWR) type to use and improve upon the basic design principles established by GWR Chief Mechanical Engineer (CME) George Jackson Churchward. The N class was based on the GWR 4300 class design, improved with Midland Railway concepts.