The "Big Boy", Road Number 4014 The Union Pacific Railroad (UP) class 4000 known as the "Big Boy" is surely one of the most popular American steam giants, if not even worldwide. Initially, 20 of this articulated locomotive (road numbers 4000-4019) with a 4-8-8-4 wheel arrangement were built in 1941 at ALCO resulting from the continuation of the "Challenger" concept, the extremely successful UP articulated locomotive with a 4-6-6-4 wheel arrangement. Another small series of five units (road numbers 4020-4024) followed in 1944. The conception of the "Big Boys" resulted from the usual requirements as with all other American large locomotive designs: Fewer locomotives were supposed to pull heavier trainloads at higher speeds. The UP bought the 25 units only for a single line: From Cheyenne, Wyoming 830 km / 519 miles west through the foothills of the Rocky Mountains across Sherman Hill to Ogden, Utah. The result was thus a gigantic unit for fast freight service with a service weight of 548 tons (including the tender). In July of 1959, the Big Boy era was finally past and the fire in all of the locomotives was put out. Yet on May 10, 2019, the 150th anniversary of the completion of the transcontinental railroad ("150 Years of the Golden Spike") was due to be celebrated. After all, the Union Pacific was one of the two railroads, which had accomplished this grandiose achievement. Therefore, something spectacular should honor this event fittingly. Thus in 2013 the first rumors started that a "Big Boy" was supposed to be put into operation again. At least eight units were still in existence. The UP's steam locomotive specialists checked out each of the eight surviving locomotives in order to find the best candidate for restoration. Finally, the final selection fell to road number 4014 at the RailGiants Train Museum in Pomona, since the mild California climate had attacked the locomotive the least and its boiler was in the best condition of all the preserved units. However, the locomotive now had to be transported to Cheyenne. Its transfer to Cheyenne was finally over on May 8, 2014 after a trip of several days. It was soon determined that about 60% of the parts had to be replaced due to decades of standing idle and the rest required a complete restoration. The UP steam shops with its nine workers originally planned five years for the restoration of the Big Boy. Yet, a main overhaul of the UP steam locomotive, road number 844, had to be done in the same timeframe, so that in the end putting road number 4014 back into operating condition required a timeframe of only two and a half years. It was not until February 6, 2019 that an important milestone could be successfully mastered in the restoration of road number 4014. It passed the water pressure test for the boiler. The work now accelerated rapidly. On April 9, the oil burner for road number 4014 was lit for the first time. Yet time was getting short, because the locomotive was supposed to be seen under steam on May 9 at a big event in Ogden. A short test was thus scheduled for road number 4014 on May 2 and was successfully completed. According to estimates, the UP had had to spend at least four million US dollars for the restoration. Yet from this day on this railroad was again running the largest and most powerful operational steam locomotive in the world in its roster. The special run of road number 4014 together with road number 844 May 4 – 19 from Cheyenne to Ogden and back for the anniversary "150 Years of the Golden Spike" formed a first absolute highlight and of course also a mass spectacle.