2-8-8-0
In the Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-8-8-0 is a locomotive with a two-wheel leading truck, two sets of eight driving wheels, and no trailing truck. Equivalent classifications
Other equivalent classifications are:
UIC classification: 1DD (also known as German classification and Italian classification)
French classification: 140+040
Turkish classification: 45+44
Swiss classification: 4/5+4/4

The UIC classification is refined to (1'D)D for Mallet locomotives. Usage

United States 
The Great Northern Railway used the 2-8-8-0s as their N-1's which were built by Baldwin in 1912. They were rebuilt by GN in 1932 as a N-2, and later re-rebuilt in 1940 as an N-3, The locomotives, after their third rebuild into a N-3, had a larger boiler and bigger tender. The N-3's served on the GN for a collective 45 years (including previous service lives as N-1 and N-2 classes), in use until retired in 1957. The Union Pacific Railroad also operated this type; it was called the "Bull Moose" by Union Pacific crews. The Union Pacific Bull Moose 2-8-8-0s were built in 1918 and 1924 by ALCO-Brooks. The Bull Moose Locomotives were used to haul heavy loads over Sherman Hill on the UP. An example of one is Union Pacific #3559, which was built July 1924 by ALCO-Brooks. The locomotives were most likely retired in the late 1940s to early 1950s because of slow speeds on freight, hauling at 12 miles an hour. In comparison, the 9000 class of the Union Pacific can pull the same weight at 50 miles an hour. Out east, the Reading Railroad had 2-8-8-0s for coal switching on Steep Hills, also known as the Reading N-1, and the Baltimore and Ohio operated this type, with the B&O owning dozens of examples, most notably the EL-3 class. They were retired by the early 1950s. In the Midwest, the Kansas City Southern was a principal user of this configuration. The Atchison, Topeka and Santa Fe Railway was the first to use the configuration. In 1911, their own workshop took a pair of standard 2-8-0 and combined them into a 2-8-8-0 "Consolidation Mallet" articulated locomotive. Four examples were built, but were never entirely satisfactory and were converted back to 2-8-0 in 1923. The first 2-8-8-0 operated by Baltimore and Ohio was numbered EL-1/a, which was built in 1916 at Baldwin Locomotive Works. The western end of their network had ruling gradients greater than 2%, and the 2-8-8-0 offered exceptional tractive effort, enabling a single locomotive to move the heaviest freight trains. As well as building these locomotives from scratch, the last in 1920, ten were converted from 0-8-8-0 configuration in 1920 and a further ten from 2-8-8-2 in 1922. These locomotives remained in operation until after World War II, the last being withdrawn in 1955. No 2-8-8-0 locomotive survives today. However, one tender from the 2-8-8-0 #759 of the Kansas City Southern Railroad has been preserved, while the locomotive was scrapped. It is now preserved at the Illinois Railway Museum. Indonesia 

Indonesia had also been recorded as operating several types of 2-8-8-0 locomotives. This back to the colonial era, under the government of Dutch East Indies by their state railway company named Staatsspoorwegen (SS). In the early of 20th century, especially in West Java or known as Priangan faced with the increase in passenger and freight rail traffics. By 1913, reported that they lack of powerful locomotives to serve the increasingly congested train traffics. This was coupled with the condition of southern Priangan line which passes through the hills required a special locomotive to tackled the heavy and steep contour line there. The only available locomotive of the time were the 0-4-4-2T SS Class 500 (DKA BB10), 2-6-6-0T SS Class 520 (DKA CC10) and the 2-12-2T SS Class 800 (DKA F10) or known as Javanic. However, they also have their drawbacks, the SS 500 and SS 520 were considered not so powerful enough. While the SS 800 with 6 pairs of driving wheels arranged in long rod apparently not suitable on the winding Priangan lines. This was exacerbated by the outbreak of first world war which paralyzed many industries in Europe. Amid limited choices and demands to get new locomotive immediately, SS decided to order giant locomotives based on their specifications to American Locomotive Company (Alco) in 1916. In just 6 month, 8 2-8-8-0s of the first batch arrived and soon classified as SS Class 1200 (1201–1208) which were the largest locomotives in Dutch East Indies. With the total weight of 133 tons, these locomotives have the profile of American giant engines but made for narrow gauge (3 ft 6 in). It turned out that the monster size of them were not proportional to their capabilities. SS was disappointed because the SS Class 1200 could only reach the maximum speed of 40 km/h (24.8 mph) which was not suitable to haul the express trains in heavy terrain with the minimum speed of 45 to 50 km/h (28–31 mph). Learning from that, the second batch came with some improvements with 12 units of them in 1920. Albeit they look similar to the first batch, these second batch weigh almost 138 tons as a result of modifications. It is recorded that the second batch of SS Class 1200 (1209–1220) is the heaviest locomotive ever to roam in Java. However, the performance of the second batch of Alco engines was not much different from the first batch, this locomotive was also known to be wasteful of fuel. The other problem was unbalanced steam pressure or back pressure causing cracks to the locomotive's frame which caused to operational and maintenance expense of the series were too costly. By the end of first world war and the European machine builders were back to operational, SS soon ordered 10 new locomotives from 3 manufacturers : Hanomag, Sachsische Maschinenfabrik (Hartmann) (Germany) and Werkspoor, N.V. (Netherlands), came in 1923–24. These locos were made based on Alco design but with a large number of refinements as a result to the length which was stretched up to 21 meters (69 feet), weigh around 135 tons and classified as SS Class 1250 (1251–1260). If the Alco's SS 1200s use bar frame, those on the European SS 1250s use plate frame. The SS 1250 was indeed faster, able to reach a speeds of 50 km/h (31 mph) but the back pressure problem got worse. Finally, in 1926, the SS Experimental Service managed by de Gruijter made modifications to SS 1260. After the back pressure was solved, double chimney were also installed to maximize the engine performance. As by result, the power output jumped to 1700 hp (horsepower) while driving at a constant speeds of 45 km/h (28 mph), modifications were finally made to the entire of SS Class 1250s and 12 units of the second batch of SS Class 1200. While the first batch of SS 1200s had severe crack in the frame, so it were not modified. The next modification was aiming to operational efficiency, this locomotive requires a large amount of crew so that's why SS tried to install a mechanical stoker that automatically put coal into the firebox. However, this modification was called off, because it increased the axle weight from 12 tons to 13 tons above the rail capacity. During Great Depression in the 1930s, SS preserved their giant locomotives as a saving measure due to wasteful fuel, as well as declining traffics. But in 1938, these locomotives were reactivated to haul freight trains except for the first batch SS Class 1200 which had been stripped down as spare parts. After Japanese occupation and Indonesian Independence, these locos were renumbered to DD50 (first batch), DD51 (second batch) and DD52 (SS 1250s) used by Djawatan Kereta Api (DKA) or Department of Railways of the Republic of Indonesia. When Japanese arrived in 1942, these giant locos continued to work on Purwakarta–Banjar line. They're also known as Si Gombar or The Monster by locals along with CC50 counterparts due to the size and ability in mountain lines. DD50 and DD51 were retired in late 1960s, but DD52 was luckier because there were few units of them still operational in the early 1970s. At the time, the DD52 was the only operational 2-8-8-0 Bull Moose locomotive in regular service in the world. Over time, these giants gave up due to their poor technical condition and faced difficult maintenance hastened to their retirement. Unfortunately, none of these giants were preserved as static exhibits in the museum, all of them were endly scrapped. References

88,2-8-8-0