BLI 7231 N Scale Big Boy 4-8-8-4 Steam Loco Union Pacific UP 4012 Paragon4 F104 precision machined flywheels

precision machined flywheels

ribbed roof with capped exhaust stack

To make it easy on race technical inspection during spec races

Pacific Blue dense gel specially developed to mimic the waters of the Pacific Ocean

Hat-section posts at the bolsters

BLI 7231 N Scale Big Boy 4-8-8-4 Steam Loco Union Pacific UP 4012 Paragon4 F104 precision machined flywheelsBLI 7231 N Scale Big Boy 4 8 8 4 Steam Loco Union Pacific UP 4012 Paragon4 Often called the largest steam loco ever made, and certainly a contender for the Worlds Most Famous Locomotive, the Big Boy was forged under some of the most strenuous demands ever placed on a locomotive. The UP Railroad needed a locomotive that could be used to pull a 3,600 ton train over Sherman Hill and the 1. 14% grade from Ogden to Wasatch, Utah without the need for