The South African Railways Class NG3 4-6-2T of 1907 was a narrow-gauge steam locomotive from the pre-Union era in the Colony of Natal.

In 1912, when these locomotives were assimilated into the South African Railways, they retained their engine numbers, but with an "NG" prefix added.

[1][2][3] By 1906, the Natal Government realised that light railways were essential as feeders to open up fertile districts which were distant from the existing main- and branch lines, particularly when the intervening stretches of country were difficult from an engineering point of view.

Communication was difficult between these two lines, being 100 miles (160 kilometres) apart, with the upper end of the district at 4,700 feet (1,400 metres) above sea level.

Since the cost of building a Cape gauge line across this terrain was considered prohibitive, the farmers accepted the 2 ft (610 mm) narrow-gauge railway which was offered.

When they were delivered in 1907 in anticipation of the opening of the Donnybrook line the following year, they became part of the Class N on the NGR and were numbered in the range from 4 to 9.

[2][3][6] In 1915, shortly after the outbreak of the First World War, the German South West Africa colony was occupied by the Union Defence Forces.