The class N of the Burma Railways designated 17 Mallets built by North British in four batches between 1911 and 1921. With an 0-6-6-0 wheel arrangement, they had all weight available for traction. Nevertheless, they were not only intended for freight service, but also for passenger service.
Their area of operation was the Lashio branch and the Southern Shan states. Even though they had a huge pulling power, they had to be assisted by 2-6-2T locomotives on steeper sections. In 1924 Beardmore built five superheated Ns class locomotives and rebuilt the 17 others in the same form. It didn't take long until they were superseded by the Garratts starting with the GA.I.