After the Bengal-Nagpur had tested two class HSG 2-8-0+0-8-2 Garratts for slow and heavy coal trains on inclines, they ordered the 4-8-0+0-8-4 class N in 1929. With a service weight of 234 tons, they are the heaviest locomotives ever to run in India and were perfectly suited to well-laid and relatively straight tracks found on the BNR network. They could haul up to 3,000 tons on the level and even managed 2,400 tons on inclines of one percent.

No. 815 at the Delhi Railway Museum

flickr/TrainsandTravel

To enable the operation on a wider selection of lines, the 16 class N locomotives were joined in 1931 by ten NM class locomotives which were similar, but lighter. To date, these 26 locomotives are the only Garratts ever built with a 4-8-0+0-8-4 wheel arrangement. Two locomotives of class N are still existing. While No. 811 has run a few times in 2006 and 2019 but has an unclear future, No. 815 is on display at Delhi Railway Museum.