The equivalent UIC classification is refined to (2′D)D2′ for Mallet locomotives.
4-8-8-4 Big Boys were only produced for the Union Pacific Railroad. Twenty-five such engines were built between 1941 and 1944, numbered 4000 to 4024. Eight of these locomotives survive, seven of which are on static public display at various sites in the United States. Union Pacific announced plans in August 2013[1] to restore No. 4014 to operation for use in mainline excursion service. No. 4014 underwent restoration between 2016 and 2019, and completed its first post-restoration test run on May 2, 2019.[2][3]
The UP Big Boys were an expansion of the 4-6-6-4 "Challenger" type articulated locomotive. Adding four driving wheels increased the pulling power of the locomotive and reduced the need for helper locomotives over steep grades. Although their wheels were an inch (25.4 mm) smaller than those of the Challengers, they were still able to sustain similar high speeds.
Other American railroads considered buying 4-8-8-4s, including the Western Pacific Railroad, which already rostered large 2-8-8-2s and 4-6-6-4s, but diesel locomotives were gaining popularity and soon were able to displace these Big Boy locomotives.
References
^Union Pacific Community Ties. "UP: Big Wheels Not Yet Turnin'". Retrieved 9 December 2017.
^Trains Magazine. "Union Pacific Big Boy: Rebirth of a Legend". Retrieved 22 October 2013.
^Union Pacific Community Ties. "America Celebrates the Transcontinental Railroad". Retrieved 3 May 2019.
External links
Web Site of ToyTrains1 4-8-8-4 Big Boy Steam Locomotives
This steam locomotive-related article is a stub. You can help Wikipedia by expanding it.
whyte, notation, classification, steam, locomotives, wheel, arrangement, locomotive, with, four, wheel, leading, truck, sets, eight, driving, wheels, four, wheel, trailing, truck, only, model, locomotives, ever, used, this, configuration, that, commonly, known. A 4 8 8 4 in the Whyte notation for the classification of steam locomotives by wheel arrangement is a locomotive with a four wheel leading truck two sets of eight driving wheels and a four wheel trailing truck Only one model of locomotives has ever used this configuration and that is commonly known as Union Pacific Big Boys after the railroad that operated them A Big Boy locomotive This example is Union Pacific 4014 4 8 8 4 wheel arrangement Other equivalent classifications are UIC classification 2DD2 also known as German classification and Italian classification French locomotive classification 240 042 Turkish locomotive classification 46 46 Swiss classification 4 6 4 6 The equivalent UIC classification is refined to 2 D D2 for Mallet locomotives 4 8 8 4 Big Boys were only produced for the Union Pacific Railroad Twenty five such engines were built between 1941 and 1944 numbered 4000 to 4024 Eight of these locomotives survive seven of which are on static public display at various sites in the United States Union Pacific announced plans in August 2013 1 to restore No 4014 to operation for use in mainline excursion service No 4014 underwent restoration between 2016 and 2019 and completed its first post restoration test run on May 2 2019 2 3 The UP Big Boys were an expansion of the 4 6 6 4 Challenger type articulated locomotive Adding four driving wheels increased the pulling power of the locomotive and reduced the need for helper locomotives over steep grades Although their wheels were an inch 25 4 mm smaller than those of the Challengers they were still able to sustain similar high speeds Other American railroads considered buying 4 8 8 4s including the Western Pacific Railroad which already rostered large 2 8 8 2s and 4 6 6 4s but diesel locomotives were gaining popularity and soon were able to displace these Big Boy locomotives References Edit Union Pacific Community Ties UP Big Wheels Not Yet Turnin Retrieved 9 December 2017 Trains Magazine Union Pacific Big Boy Rebirth of a Legend Retrieved 22 October 2013 Union Pacific Community Ties America Celebrates the Transcontinental Railroad Retrieved 3 May 2019 External links Editwww steamlocomotive com Web Site of ToyTrains1 4 8 8 4 Big Boy Steam Locomotives This steam locomotive related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title 4 8 8 4 amp oldid 1126426739, wikipedia, wiki, book, books, library,
