Western Union UP400 (4-8-8-4) Big Boy steam locomotive as a 3D wooden model

The Union Pacific Railroad (UP) Class 4000, known as Big Boy, is the largest and most powerful steam locomotive series of the UP and the largest and most powerful steam locomotive in operation in the world.

You can find the tender that matches the model of the steamtrain under order number 6637 here in our online shop

A total of 25 examples of the type were built by the American Locomotive Company (ALCO), 20 in 1941 and five in 1944. The machine was designed by a team led by Otto Jabelmann.
The name Big Boy comes from an unknown employee of the ALCO works, which he wrote in chalk on the smokebox. The name quickly became common for the UP Class 4000 locomotives.
The locomotives were designed by the Union Pacific Railroad specifically for use in front of freight trains in the Rocky Mountains in order to avoid the labor-intensive use of pilot and pusher locomotives on the gradient routes across the Continental Divide. The most difficult section on the Union Pacific transcontinental route was a long gradient over Sherman Hill in Albany County (Wyoming) south of the Ames Monument with a maximum gradient of 15.5 ‰. The new locomotives were to be able to pull trains weighing 3600 short tons (about 3300 t) over this gradient without a pilot or pusher locomotive, but also be fast enough to travel the entire route between Cheyenne (Wyoming) and Ogden (Utah) without changing locomotives.

The required performance data resulted in an articulated locomotive with a 4-8-8-4 wheel arrangement.
No other locomotive was ever built with this wheel arrangement. The machines were - like many of the newer US articulated locomotives - not Mallet locomotives in the true sense of the word, because the steam engines worked with simple steam expansion without compound effect. In American English, this design is therefore referred to as simple articulated. The frames of both engines were integral cast frames including the cylinders, the trailing axles are mounted in a delta trailing frame that was also cast. The axle and rod bearings were roller bearings.

To fire with low-quality coal, the firebox was designed to be very large with a grate area of ​​almost 14 m². The locomotives have a mechanical grate feed via a stoker. During an individually documented journey with a train mass of 3530 tons and a speed of 41.1 mph or 66 km/h, a consumption of 8.8 tons of coal per hour was determined.
The 4005 locomotive was converted to oil firing as a trial, but this did not prove successful and so it was converted back to coal firing.

With a total weight of 548.3 t and a maximum continuous output of 6290 hp on the drawbar (at 48 km/h), the 4000 series machines are among the heaviest and most powerful steam locomotives ever built and, with a maximum permissible speed of 110 km/h (70 mph), they are also among the fastest articulated steam locomotives. The design was even designed for 130 km/h (80 mph) in order to offer a high safety reserve.

In order to be able to use the locomotives, the route between Ogden (Utah) and Green River (Wyoming) (Overland Route) had to be rebuilt in several places. Almost every curve was rerouted so that two 4000 series locomotives could meet. The superstructure was also reinforced.

The locomotives were designed by the Union Pacific Railroad specifically for use in front of freight trains in the Rocky Mountains in order to avoid the labor-intensive use of pilot and pusher locomotives on the gradient routes across the Continental Divide. The most difficult section on the Union Pacific transcontinental route was a long gradient over Sherman Hill in Albany County (Wyoming) south of the Ames Monument with a maximum gradient of 15.5 ‰. The new locomotives were to be able to pull trains weighing 3600 short tons (about 3300 t) over this gradient without a pilot or pusher locomotive, but also be fast enough to travel the entire route between Cheyenne (Wyoming) and Ogden (Utah) without changing locomotives.

The required performance data resulted in an articulated locomotive with the wheel arrangement (2’D)D2’ h4 (Whyte notation: 4-8-8-4). No other locomotive was ever built with this wheel arrangement. The machines were - like many of the newer US articulated locomotives - not Mallet locomotives in the true sense of the word, because the steam engines worked with simple steam expansion without compound effect. In American English, this design is therefore referred to as simple articulated. The frames of both engines were integral cast frames including the cylinders, the trailing axles were mounted in a delta trailing frame that was also cast. The axle and rod bearings were roller bearings.

For firing with low-quality coal, the firebox was It is very large, with a grate area of ​​almost 14 m². The locomotives have a mechanical grate feed via a stoker. During an individually documented journey with a train mass of 3530 tons and a speed of 41.1 mph or 66 km/h, a consumption of 8.8 tons of coal per hour was recorded. The 4005 locomotive was converted to oil firing as a test, but this did not prove successful and was therefore converted back to coal firing.

With a total mass of 548.3 t and a maximum continuous output of 6290 hp on the drawbar (at 48 km/h), the 4000 series machines are among the heaviest and most powerful steam locomotives ever built and, with a maximum permissible speed of 110 km/h (70 mph), they are also among the fastest articulated steam locomotives. The design was even designed for 130 km/h (80 mph) in order to offer a high safety reserve.

The Big Boys fully met the expectations placed on them. The main area of ​​operation was the route over the Rocky Mountains from Wyoming to Utah: from Cheyenne (Wyoming) over the Sherman Hill Pass to Laramie (Wyoming) and further over Green River (Wyoming), Evanston (Wyoming) and through Echo Canyon (Utah) to Ogden (Utah). In practice, they pulled trains weighing up to 6,000 tons and in a test on the plains, one of these locomotives was even able to keep a 25,000-ton train moving on its own after it had been pushed by other locomotives.

From 1941 to 1957, the locomotives were regularly used in freight transport in front of freight trains. All 25 machines were stationed in Cheyenne and were all in daily service until 1957.
From 1958, only ten locomotives were needed. In the western and more demanding section of the line over the Wasatch Mountains between Ogden and Green River, they were first replaced by the gas turbine locomotives of the Union Pacific Railroad. The only remaining section was the 120-kilometer section over Sherman Hill from Laramie to Cheyenne. On July 21, 1959, locomotive 4015 pulled the last scheduled train with a Big Boy. Some examples were still used occasionally as diesel replacements in freight train service until the summer of 1961. Each of the locomotives built in 1941 and 1944 covered a total distance of more than 1.6 million kilometers. After the end of the unscheduled use, four locomotives were kept operational as a reserve in Cheyenne until September 1962.

Before the locomotives could be used, extensive expansions to the infrastructure were required. In 1941, the 100-foot turntables (30 m) in the Ogden (Utah), Green River (Wyoming) and Laramie (Wyoming) depots were replaced by 135-foot turntables (41 m).
The turntable in Cheyenne (Wyoming), which is located a little further east, with a length of 126 feet still exists today. It was installed in 1941 as a replacement for a 100-foot turntable. With a total wheelbase of 117 ft 7 in (35.83 m), these were just enough to turn the locomotive with an overhang. This required caution due to the risk of accidents for people and waiting locomotives, as well as when stopping the locomotive.
The stalls in the roundhouse in Cheyenne were too short for the locomotives, so some had to be extended by adding on extras. The main workshop in Cheyenne had the necessary facilities (cranes, machine tools, axle sinkers) to carry out major repairs on the machines.

Eight of the 25 Big Boys built have been preserved, currently (2019) only 4014 is in working condition:

No. 4004: Holliday Park, Cheyenne (Wyoming).

No. 4005: Forney Transportation Museum, Denver
No. 4006: Museum of Transportation, St. Louis (Missouri)
No. 4012: Steamtown National Historic Site, Scranton (Pennsylvania)
No. 4014: was in the RailGiants Train Museum, Pomona (California) until 2013, repurchased from the Union Pacific and is housed in the Cheyenne Depot Museum (Wyoming)
No. 4017: National Railroad Museum, Green Bay (Wisconsin)
No. 4018: until 2013: Age of Steam Railroad Museum, Dallas, moved to the Museum of the American Railroad Frisco (Texas), museum was still under construction in 2014, partially open to visitors.
No. 4023: Kenefick Park, Omaha (Nebraska)

Recommissioning of the UP 4014
The Union Pacific already maintained the Challenger 3985 of the predecessor 3900 as the largest operational steam locomotive in the world and was of the opinion for a long time that it was not worth reconditioning and putting a Big Boy into operation, as its area of ​​application was very limited due to the small curve radii of many routes and the large overhang of the locomotive. The UP Challenger 3985 looks very similar to a Class 4000 locomotive and also has the advantage of being oil-fired, whereas a Big Boy would be coal-fired.

On July 24, 2013, however, the UP announced in a press release that it had acquired locomotive No. 4014 from the Southern California Chapter of the Railway & Locomotive Historical Society in Pomona, California. The machine was to be brought to the Union Pacific workshop in Cheyenne and restored to working order by 2019. During the restoration, the locomotive was converted to oil firing.

Locomotive 4014 had covered around 1.65 million km in twenty years of operation. It was retired in December 1961.

In the fall of 2013, the machine was overhauled in Pomona so that it was ready to roll again. It was moved over a provisionally laid track in the County Fairplex parking lot and then prepared for transfer to Cheyenne at the Union Pacific rail yard in Colton. The locomotive arrived there on May 8, 2014 after a journey of several days.

As part of "The Great Race to Ogden", the 4014 left the Cheyenne Depot Museum under its own steam on May 4, 2019, arriving in Ogden on May 9, one day before the 150th anniversary of the completion of the first transcontinental railroad connection. It played a major role in this anniversary.

Source: Wikipedia

Please note that this kit is not a children's toy and can only be "played with" to a limited extent.

Please keep the items away from small children under 6 years of age. It contains small parts that can break off and be swallowed. We therefore declare the model as a puzzle or decoration.

Item Description:

Material:  4mm wood
Dimensions approx. ca. in cm:  (L x w x H)  114 x 14,6 x 22
Weight approx: 1.5 kg
Content: 1 x lasered kit with  628 parst / assembly instructions (only as PDF Download)

The kit is made of wood and has been lasered. This will cause the edges to look burnt and possibly leave traces of soot and smoke on the wood. These can be easily removed with fine sandpaper.
All components are laser cut so that there is a "beautiful" front and a marked, production-related "bad" back. Make sure that the good side always points to the visible side.
These soot and smoke marks as well as the fact that wood is a natural product, which is dimensionally influenced by basic physical laws such as temperature and humidity, there are certain limitations in the nature of the products, which must be consciously accepted.
We offer the most careful choice of material and the most modern production methods, nevertheless one has to accept with wood the peculiarities and unimpeachable characteristics, which are to be observed again and again in the practice - therefore these can not be claimed by the buyer as a material defect.