The type X H1 of the Saxon State Railways was a 4-4-2 “Atlantic” locomotive built for express services on the line between Dresden and Berlin. It was designed in parallel with the XII H1 4-6-0 locomotive for express service on mountainous lines. Both had the same superheated boiler with a Belpaire firebox. The X H1 got four-axle tenders which held either 21 or 28 tons of water.
As early as in World War I, their adhesive weight was not enough anymore for the heavier trains, so that six-coupled locomotives took over on flat lines and eight-coupled locomotives took over in the mountains. In 1925, the Reichsbahn took over 17 of the 18 X H1 which had been built and designated them class 143. The last one was retired in 1932.