Athearn Genesis G1021 HO Scale 4-6-6-4 Challenger w/Oil Tender Union Pacific UP 3939 DCC/Sound E-Z Track Minimum Curve: O54 icon

Minimum Curve: O54 icon

with an internal spring and dampener

Easy way to model "tip-up" concrete panel construction used for all types of trackside warehousing

Factory assembled chassis with built in R/C unit

Athearn Genesis G1021 HO Scale 4-6-6-4 Challenger w/Oil Tender Union Pacific UP 3939 DCC/Sound E-Z Track Minimum Curve: O54 iconAthearn Genesis G1021 HO Scale 4 6 6 4 Challenger w Oil Tender Union Pacific UP 3939 DCC Sound ALCO constructed the first 4 6 6 4 locomotives in the world, numbered 3900 to 3914, for the Union Pacific Railroad in 1936. These huge engines were named the Challenger Simple Articulated, or CSA 1, class. The railroad received 25 near copies, classified as CSA 2, the following year. Unlike compound Mallet engines that crawled along with drag freights, the