stylists created the GP30's trademark "hump" and cab roof profile. The hump-like bulge started at the front of the cab and enveloped the air intakes for the central air system and the dynamic brake blister. Units ordered without dynamic brakes were the same shape, but lacked the intakes to cool the dynamic brake resistor grids. A high short hood could be ordered, but only holdouts Norfolk and Western Railway and Southern Railway received such units. EMD originally planned to name the locomotive the GP22, but EMD's marketing department decided to leapfrog GE's numbering to make the new locomotive seem more advanced. Marketing literature claimed 30 distinct improvements from the GP20 and that this was the reason for the number. Sales and in service The GP30 successfully countered the GE threat and kept EMD in the dominant position in the North American diesel market. While losing a little power to the GE and ALCO competition, the solidity and reliability of the GP30—and the familiarity of railroad mechanical departments with EMD products—ultimately won many more orders for EMD. 948 were sold, in comparison to 476 U25Bs. In addition, the GP30 was only sold until the end of 1963, while the U25B was available until 1966. Most major railroads ordered GP30s, and many smaller ones did too. The largest orders were from the SOU (120), UP (111), ATSF (85), and the B&O (77). The sole purchaser of B units (by the mid-1960s generally an outdated concept) was the UP, who kept the practice of running its locomotives in matched sets much longer than others. Thirteen of those GP30B units were fitted with steam generators for heating passenger trains, the only GP30s to receive them. Prior to Amtrak, UP would use a GP30 and two boiler equipped GP30Bs on passenger trains when no E8s or E9s were available. Some units for the GM&O, MILW and SOO were built using trucks from ALCO trade-ins and therefore ride on ARR type B trucks instead of the EMD standard Blomberg Bs. An indisputable tribute to the quality of the GP30 design is the fact that a good number are still in service as of 2015, which is a service lifespan of over 50 years and well in excess of the design life of 25–30 years for the average diesel locomotive. Furthermore, when life-expired, some railroads chose to give them major rebuilds instead of scrapping them. Specifically, the