An excerpt from Joe Strapac's Southern Pacific Historic Diesels - Volume Nine - ALCo PA / PB PAssenger Locomotives : " More importantly, by 1952 SP had grown weary of the poor maintenance record of the type # 244A engines in these units. Beginning in July 1952, the type #244A prime movers were replaced by current production #244D engines with water cooled, ALCo - built turbochargers. Then in the mid - fifties the complex General Electric Amplidyne control system received an upgrade and simplification. Every one of the class DP - 5 units was to receive an electrical upgrade between 1956 and 1960 in order to install more reliable components, simplify cabling arrangements and ease maintenance problems. "
ALCo rushed the 244 series diesel into production; Santa Fe & T&NO's early PA's had issues with block flex resulting in loose main & rod bearings, and of course that air - cooled turbo was not up to the job. At least Espee stuck with the 244 series prime mover and its' 2000 H.P. rating. Santa Fe, Rock Island ( FA's ), and MoPac among others would re - engine their PA's with EMD prime movers, which had quickly become the industry's Energizer Bunny for running and running and running. Santa Fe's " Christine " set of re - engined PA - PB - PA were dogs, until a sharp diesel mechanic noticed several electrical circuits has been mis - wired and / or overlooked in the rebuild. Once repaired, they were race horses.