The closely linked Atlanta & West Point and the Western Railway of Alabama had to pull the Southern Railway's "Crescent" between Atlanta, Georgia and Montgomery, Alabama. So they each ordered one locomotive, which was given the numbers 290 (AWP) and 190 (WRA). Like the Southern Ps-4, they were based on the USRA Heavy Pacific, but like them also had smaller drivers. The diameter was initially 73 inches and was later increased to 74 inches with thicker tires, which explains the designation P-74.

Both machines were operated together. While one hauled the northbound Crescent, the other simultaneously took over the southbound one. They were retired in 1954, after which the 190 was scrapped. The 290 was saved by the “290 club”, but remained non-operational for the time being. It was finally refurbished between 1986 and 1989 and was used until 1992, when maintenance work on the running gear was required. It now resides at the Southeastern Railway Museum in Duluth, Georgia, awaiting visual restoration.

The IV f was an express locomotive with which the Munich company Maffei had won a competition held by the Grand Duchy of Baden State Railways in 1905. After three pre-series models built by Maffei, 32 more machines followed from the Karlsruhe mechanical engineering company. It was the first locomotive in Germany with the axle configuration 4-6-2, which is also known internationally under the American designation “Pacific”. The well-known Bavarian S 3/6 was later to become a development of the IV f.

The Pacific design and the bar frame instead of a plate frame were approaches that had been taken over from American locomotive construction. Nevertheless, the entire locomotive received a filigree and streamlined appearance, which was in contrast to the bulky American locomotives. In addition, the four-cylinder compound engine based on the Von Borries design was a typical feature of southern German express train locomotives.

Since the IV f was also to be used in mountainous areas away from the main Rhenish route, its 1,800 mm diameter coupled wheels were relatively small. As a result, a higher tractive force could be achieved on inclines than with larger wheels, but the entire engine reached high rotational speeds on flat land at high speeds, which also led to increased wear and consumption. To enlarge the grate area, the firebox was pulled behind the driving wheels and widened so that it is clearly visible from the outside. It was only because of this change and the resulting increased overhang that the 2'C wheel arrangement had to be abandoned and the trailing axle added. By balancing the load between the two rear axles, it was possible to increase the adhesive weight by around three tons on well-developed routes.

When it was taken over by the Reichsbahn in 1925, 22 of the 35 engines were still in use, which became the class 18². While the more numerous former S 3/6 remained in service for a long time despite the high-maintenance power plant, all examples of the former IV f were retired by 1930.

The Grand Duchy of Baden State Railways used the IV f from 1907 on its 413 km long main line from Mannheim to Constance. However, this was unable to cope with long, fast routes with its driving wheels, which were only 1,800 mm large. Thus, in 1915, the IV h was ordered from Maffei in Munich, where the IV f and the S 3/6 had already been manufactured. Since only use on flat routes was planned, the IV h received driving wheels with a diameter of 2,100 mm. This negatively affected acceleration, but made it possible to maintain high speeds for a long time. The certification was only for 110 km/h, which was 10 km/h faster than its predecessor series. It was only in the thirties that it proved on test drives at speeds of up to 155 km/h that it ran very smoothly even at higher speeds. It was therefore equipped with more powerful brakes and approved for 140 km/h.

The locomotive was powered by a four-cylinder compound engine, which combined characteristics of the De Glehn and Von Borries types. The low-pressure cylinders drove the second coupled wheel set and had to be located on the outside due to their large diameter. While the outer high-pressure cylinders on the De Glehn type were pulled back to achieve shorter connecting rods, the outer cylinders were at the height of the smoke chamber. Thus, the high-pressure cylinders were on the inside and drove the first set of coupled wheels. Since they were also pulled very far forward, they could be clearly seen from the outside.

When they were taken over by the Reichsbahn, they became the class 18³. After about ten years of service on the Baden trunk line, the 20 built IV h were replaced by class 01 standard locomotives and relocated to other locations. Although they had a higher fuel consumption than the newer locomotives, it later turned out that they could almost keep up with the 01 and even surpassed the 03 in terms of power. After all, the power measurements were in a range from 1,950 to 2,200 hp. 

Die Lokomotive, August 1925

After the war, all 19 remaining examples went to the Bundesbahn and only road number 18 314 ended up being traded for an S 3/6 to the Reichsbahn, where it was fundamentally rebuilt. All others were initially retired because their Number was very small. However, three were subsequently reactivated and modernized for use as brake locomotives or for other trials. The 18 316 was preserved and was again in running condition between 1995 and 2002, but was parked again after damage.

No. 5303 “President Madison” without streamlined fairing

Howard Locomotive Photographs

No. 5301 “President Adams” with streamlined fairing

collection Taylor Rush

In 1927, the B&O put a total of 20 examples of the P-7 class into service, which at the time were the most powerful Pacifics ever. The power was achieved with a coupling wheel diameter of 80 inches and cylinders measuring 27 by 28 inches. The firebox, with a combustion chamber and thermosiphons, came in at 394 square feet. The first locomotive was manufactured with a booster on the trailing axle, the others were only prepared for its later installation. They were given names after the first 20 Presidents of the United States, beginning with No. 5300 “President Washington”.

The P-7 pulled the most important express trains of the B&O. Over time, there was no uniform modernization of the class, but various conversions. This resulted in the classes P-7a to P-7d, which differed primarily in the heating area and, among other things, had different superheaters. The P-7a and P-7d also featured a streamlined fairing. They pulled important trains such as the “Royal Blue” and the “Cincinnatian”. Their service ended in 1958 after the introduction of diesel locomotives in express service.

The Bavarian S 3/6, later designated as the class 18^4-5, was probably one of the best-known express steam locomotives in Germany. Developed by the Munich company Maffei, it was not only procured by the Royal Bavarian State Railways from 1908, but even the Deutsche Reichsbahn commissioned new series until 1931.

Although more than 150 km/h had already been achieved with the S 2/6 trial locomotive in 1906, the speed to be reached with the S 3/6 was reduced to 120 km/h, which was more suitable for everyday use. Their performance program stipulated that a train weighing 400 tonnes should reach at least 115 km/h on the level. The same train should still be pulled at 95 km/h at 0.5 percent and at 65 km/h at one percent.

The locomotive was based on the Baden IV f and was given a driving wheel diameter of 1,870 mm as a compromise. This enabled the S 3/6 to cover long distances at a high line speed without excessive wear on the engine, without having to sacrifice too much traction for climbing. As with previous Bavarian express train locomotives, the running gear was built on a bar frame. 

Die Lokomotive, November 1908

Of the 159 locomotives of series a to o, only 18 locomotives of series d and e were built with wheel diameter of 2,000 mm in order to be able to drive at a constant speed of 120 km/h on flat lines between the largest cities in Bavaria. These were mainly the Munich-Nuremberg and Munich-Augsburg routes, on which there were hardly any significant inclines. They were soon given the nickname “Hochhaxige” (“the high-heeled one”) to distinguish them from the rest of the S 3/6.

Traction was provided by a four-cylinder compound engine, which enabled very smooth running and led to consumption that did not need to fear comparison with the later two-cylinder standard locomotives. Despite the significantly higher maintenance effort due to the internal cylinders, the S 3/6 continued to be procured in several series even after the Deutsche Reichsbahn was founded. This can be explained, among other things, by the fact that the new standard express train locomotive of the class 01 had an axle load of 20 tonnes and many main lines were not strengthened accordingly at the time. With an axle load of 18 tonnes, the last S 3/6 could also be used on almost all main routes until a lighter standard express locomotive became available with the class 03.

After the Second World War, all locomotives came to the Bundesbahn, where they were extensively modernized. Despite their still comparatively very good performance and economy, however, all of them were retired between 1961 and 1965, since a miscalculation during the rebuilding process had meanwhile made it necessary to reduce the boiler pressure and thus the power.

A few years before the First World War, Jean-Baptiste Flamme developed a very powerful boiler that was to be installed in a freight locomotive and an express locomotive at the same time. So from 1909 the type 36 with the 2-10-0 wheel arrangement and from 1910 the type 10 Pacific were built. Since the boiler was relatively short with a large diameter and the chassis of the Pacific naturally had a long overall wheelbase, the appearance of the Locomotive somewhat unusual with a long overhang in front of the smoke box.

The boiler had a grate area of five square meters and narrowed in front of the firebox. It delivered 2,250 hp, making the type 10 one of the most powerful Pacific locomotives in Europe. Since the bogie hardly had to carry any weight from the smoke box, the load was kept within limits despite the four cylinders with simple steam expansion. Due to the special arrangement of the cylinders, the inner cylinders were accessible from above, which made maintenance easier. Although the cylinders were in one plane, the inner ones drove the first driving axle and the outer ones the second. The problem, however, was the weight of the large firebox, which made the load of the trailing axle too high. The Type 36 didn't have this problem as the weight was carried by the coupled axles. 

As a result, the second batch from 1912 was delivered with a smaller grate surface in order to reduce the axle load on the trailing axle. However, this reduced the power to 1,950 hp, while the service weight of the locomotives was reduced by around four tons. A total of 58 pieces were made by 1914, when production was stopped due to the war.

Locomotive Magazine, July 1910

In the 1920s, the locomotives received double chimneys and new feed pumps. From 1931 there was a major conversion with new feedwater heaters, a larger superheater, new safety valves and smoke deflectors. The result was an output of 2,700 hp for the first batch and 2,400 hp for the second batch. 1938 followed the installation of Kylchap blast pipes. A large proportion of the engines were retired in 1956 and some continued to run on a different route for three more years.

The last ten Pacifics that the Boston & Maine purchased were also the last Pacifics that Lima manufactured. Their task was regional traffic over distances of up to around 200 miles, and they were designed for an average speed of 70 mph or 113 km/h. The firebox contained three thermic syphons and arch tubes. The coffin feed water heater was concealed in the smokebox. Initially there was a skyline casing on the top of the boiler, which was later removed. The locomotives from the two production years 1934 and 1937 were designated P-4a and P-4b. They were given names that were chosen in a competition among kindergarten children and students. Only 3713, which is currently being overhauled in Steamtown, has been preserved.

After the First World War, the Canadian Pacific realized that a significantly more powerful Pacific was needed for the new, six-axle heavyweight passenger cars. Chief engineer William H. Winterrowd then developed the class G3 with a driving wheel diameter of 75 inches, which was intended for the flatter routes. A total of 26 examples of the G3a, b and c variants, which were almost identical in construction, were completed by 1923.

In 1926, 25 examples of the G3d followed, the most important innovation of which was a boiler made of nickel steel. This allowed the boiler pressure to be increased from 200 psi (13.8 bars) to 250 psi (17.2 bars). Although the cylinders were made smaller at the same time, the starting tractive effort could be increased.

Twelve years later, the 27 examples of the G3e and f followed, which in turn benefited from new advances in boiler construction and now had a boiler pressure of 275 psi (19 bars). The cylinder diameter was reduced again, while the starting tractive effort remained about the same. The G3g, h and j reached the largest number with 93, which only followed in the forties and were almost identical to the series e and f in terms of the engine. However, they had a boiler with fewer tubes and were used with smaller tenders. They were real multi-purpose locomotives and were also used in front of freight trains.

Although it was precisely the later variants that came up at a time when other railways had already switched to 4-6-4 or 4-8-4, they were relatively strong compared to other Pacifics and had a better ratio of adhesive to service weight than other locomotives and had less of a tendency to slip. The period of use ended in 1959, when there were already enough diesel locomotives for their area of operation. Today only number 2317 still exists, which belongs to class G3c.

Starting in 1946, the Canadian Pacific had class G5 Pacific locomotives built for use on branch lines. With an adhesive weight of only 151.000 pounds, these had a low axle load by North American standards. Contrary to the field of application of most locomotives with this wheel arrangement, they were intended for use in front of passenger and freight trains, which was also noticeable in the driving wheel diameter of only 70 inches.

From an initially planned number of 600, only 102 were finally built, as more and more diesel locomotives were put into service. For the same reason, only ten years after the end of production, the first examples were retired and in 1960 the last ones disappeared. Today there are still six that are currently only on static display, but could possibly be made operational again.