The Baldwin locomotive with the works number 60000 was a prototype that was built at their own expense in 1926 and with which the company wanted to set the course for locomotive construction of the future. It had the 4-10-2 wheel arrangement and a three-cylinder compound engine with three cylinders of the same size, the inner one serving as high-pressure cylinder.

What was special about the boiler was that the sides of the firebox were made of four-inch water pipes. They were connected at the top with 26-inch horizontal pipes that continued into the boiler barrel. The pressure was 350 psi (24.1 bars), which was significantly higher than conventional locomotives. In addition, a Worthington 4-BL feedwater heater was used.

The 60000 was intended to pull trains of up to 7,000 short tons and achieved an output of 4,515 hp at the drawbar. It was loaned to the PRR, B&O, Burlington Route, ATSF and Southern Pacific for trials and was even temporarily converted to oil firing by the SP. Although it performed very well and pulled up to 7,700 short tons, the railroads found the maintenance too expensive and no orders were placed. Today the 60000 is in the Franklin Institute Science Museum in Philadelphia.

The class 11 of the Bulgarian State Railways was a 4-10-0 locomotive for heavy mixed traffic. As a part of the Bulgarian standard program, they were heavily influenced by the German standard locomotives of the Reichsbahn. Like most Bulgarian standard locomotives, they had three cylinders. Thanks to the first driving axle being laterally movable, they could negotiate curves with a radius of 140 meters.

The first ten were built in 1941 and 1942 by Henschel. Two other batches of five and seven were ordered from Škoda and Borsig. Due to relocation of production capacities in favor of the war locomotives, the order for Škoda was cancelled. Thanks to the close relationship between Germany and Bulgaria, the order for Borsig was built anyway.

After only a few years, they were only used in freight service. By 1965, they got a mixed coal and oil firing. Even though they were not very popular with their crews, they were only replaced by diesel locomotives around 1970. In 1975, they were officially retired and scrapped.

In search of an even more powerful locomotive than the GE class with the 4-8-0 wheel arrangement, A.J. Stevens expanded this with another driving axle. The only locomotive built with this wheel arrangement was christened “El Gobernator”.

In order to still be able to run through all curves, the last driving axle was mounted so that it could be moved sideways and the third and fourth were designed without wheel flanges. The cylinders were only 21 inches in diameter, but had an extremely long stroke of 36 inches to achieve the power required. The valve gear was of a design Stevens had developed himself.

Although the locomotive was presented to the public, no use was found for this size class at the time. It also turned out that the boiler did not produce enough steam for the large cylinders. It was scrapped about ten years after completion.

To pull heavy freight and passenger trains over the Sierra Nevada, the Southern Pacific ordered large locomotives for mixed service from ALCO Schenectady in 1925. They were the first locomotives in the USA with the 4-10-2 wheel arrangement, so the SP called them "Southern Pacific", which led to the class designation SP-1.

In order to better cope with the boiler's high output, they had three cylinders. While the outer two each had their own Walschaert valve gear, the middle one was controlled via Gresley's conjugated valve gear. It also had a stroke that was four inches shorter. For starting off, a booster was also installed on the trailing axle. 

By 1927, 49 locomotives had been built in three batches, designated SP-1 to SP-3. They were initially supposed to be used at Donner Pass, but the five driving axles proved to be too rigid there. They now came to the Sunset Route, which ran east from Los Angeles, where they pulled heavy trains over the grades at speeds of 30 to 35 mph. Today only SP-2 No. 5021 exists, which was last restored in 1965 and is now in Pomona, California.