Southern Railway (USA) class Ms-4

The Ms-4 was a class of 115 Mikados that was used by the Southern as standard freight locomotive and as occasional replacement for passenger locomotives. It was basically an improved USRA Heavy Mikado with similar dimensions. The first batch, numbered 4800 to 4839, had been built in 1923 by ALCO-Richmond. Schenectady delivered 4840 to 4864 in 1924 and 4865 to 4884 in 1925. 4885 to 4914 followed from Baldwin in 1928.

The firebox surface included 49 square feet in a combustion chamber and 28 square feet in arch tubes. Their feed water heaters had come from Elesco, Worthington and Coffin. The valve gear of the ALCO locomotives was of the Baker type, while Baldwin used Walschaerts valve gear. The Cincinnati, New Orleans & Texas Pacific received 43 similar locomotives from Richmond and Baldwin and the Alabama Great Southern got eight more from Richmond. All were retired between 1952 and 1954.