These large, modern, distinctive-looking engines were known for their ability to handle heavy freights on fast schedules. Born out of a need to develop a new model with improvements in speed and horsepower over W.W.-era USRA 2-8-2 locomotives then in use, these advanced locomotives incorporated a larger firebox that required the support of a four-wheel trailing truck. A 2-8-2-turned-2-8-4, modified by a Lima Locomotive Works design engineer, tested on the Boston & Albany in 1925 and demonstrated an impressive increase in power over the rolling mainline through the Berkshire Hills. The wheel arrangement was quickly dubbed the "Berkshire." Over the next few years Lima improved the design and, acting on the specifications of the "Advisory Mechanical Committee" of the railroads controlled by the Van Sweringens, constructed 2-8-4s with 180cm drivers for high-speed freight service. These impressive machines were ordered by the Nickel Plate Road, Pere Marquette and Chesapeake & Ohio. While all built to similar specifications, each had details and some small appliances unique to their owning railroads. All were built in the 30s and 40s, and most were retired with the coming of diesels in the mid- to late-50s. n 2007, one Pere Marquette and two NKP Berks survive in excursion service, and many others are on display. Van Sweringen 2-8-4 Berkshires feature over 50 hand-applied parts, roadname-specific detailing, blackened nickel-silver wheels with RP-25 wheels, driver and tender electrical pickup, front and rear working knuckle couplers and LED headlight and backup light. These smooth-running models are powered by a powerful, flywheel-equipped five-pole motor with skew-wound armature. The locomotives run on code 55 track with radii as sharp as 25cm and each comes with working knuckle couplers.