Beginning in 1907, the Buenos Aires Great Southern received a series of Ten-Wheelers with different cylinder configurations from British manufacturers. The first was the class 12A with a two-cylinder compound engine, which was built a total of 32 times by Beyer, Peacock and North British and was later converted to simple expansion and superheated. Also in 1907, nine class 12B locomotives were built by the Vulcan Foundry, using four cylinder compound engines, three of which were superheated in 1924. In 1914 Beyer, Peacock built 20 class 12D locomotives, which had a simple two-cylinder engine and a superheater. 

The Ferrocarril Nordeste Argentino received a large number of locomotives from Neilson in Glasgow when it was founded. These 32 locomotives had the wheel arrangement 0-6-0 and were later converted to 2-6-0. The last surviving representative is the “Yatay”, built in 1888. It has had many upgrades over the years including a coal-fired boiler with a Belpaire firebox in place of the original wood-fired boiler. After more than 90 years in service, it was handed over to the Ferroclub Argentino and remained operational.

At the beginning of the fifties, the General Belgrano Railway in Argentina still used three 0-8-2 rack locomotives built by Maschinenfabrik Esslingen in Germany in 1905. In 1955, these three were replaced by two locomotives of the new class E24, again built in Esslingen. These again had a combined rack and adhesion drive, but now six driving axles and were oil-fired.

Although the inside cylinders were fairly small, the rack wheels were driven by a 2.44 to 1 ratio what greatly increased tractive power. Sadly, they were too complex for their area of operation and suffered from cracks in frames and cylinders. For these reasons they were quickly replaced by diesels and used as stationary steam generators.

In 1926, the Cordoba Central Railway in Argentina received 15 4-6-4T tank locomotives from the North British Locomotive Company. They had been designed by the railway's chief mechanical engineer Lightly Simpson and were used for mixed traffic. Being meter-gauge and having driving wheels of 4 ft 6 in and a great length, they looked very sleek. With a rigid wheelbase of only ten feet at a total wheelbase of 33 ft 7 in, they most likely had good running characteristics in tight curves. In 1939, the whole railway became part of the Argentine State Railway. In 1942 and 1943, they were rebuilt to 4-6-2 tender locomotives in the railway's Alta Cordoba shops to increase their supplies.