This detailed Atlas HO Scale Master Silver GE B23-7 Phase 1 Low Nose is modeled after units built as part of General Electric's Dash 7 locomotive line which was introduced as a replacement for the older Universal Series of the 1960s and early 1970s. Dash 7 series improvements included increased fuel efficiency, tractive effort and reliability. The B23-7 was a direct replacement for the 2,250hp U23B model. The first units were produced for Conrail in September, 1977 (ironically, 3 months after the last U23B was delivered to Conrail). Production continued through 1984, with a total of 535 units built. Conrail was the largest purchaser of the model, with a total fleet of 141 units.
 
Several features distinguished B23-7s from predecessor models. The long hood stepped outward in the area of the exhaust stack to accommodate a relocated oil cooler. In addition, the frame was 2 feet longer than that of the U23B. An FB-2 style truck was offered as standard equipment on B23-7s, but some railroads opted to use trade-in trucks. Therefore, AAR type B and Blomberg trucks could be found on some models. The six power assembly doors (located near the center of the long hood) indicated that the B23-7 was powered by a 12-cylinder GE FDL engine.
 
There were three distinct phases of GE 4-axle Dash 7 locomotive production. Models on this run represent both phase 1 and phase 2 units. Phase 1 units feature a 36'2" wheelbase and were built through the spring of 1979. Phase 2 units feature a 37' 2" wheelbase, and production lasted from the spring of 1979 through the fall of 1980. This Atlas model features a five-pole, skew-wound motor with dual flywheels, directional LED lighting, Accumate(R) magnetic knuckle couplers, accurate decoration and roadname-appropriate body details. This diesel comes equipped with an 8-pin DCC socket for easy decoder installation when you're ready. This GE B23-7 is one of many Atlas HO Scale locomotives.