The N class was mechanically similar to the SECR K class 2-6-4 passenger tank engine, also by Maunsell. It influenced future 2-6-0 development in Britain and provided the basis for the 3 cylinder N1 class of 1922. Production was delayed by the outbreak of the First World War in 1914, and the first N class rolled out of Ashford Works in 1917, three years after design work was completed. The class replaced obsolete 0-6-0s as part of the SECR's fleet standardisation, as they used parts interchangeable with those of other classes.