page_title: EMD SDP40F
section_title: Freight use
hierarchical_section_title: EMD SDP40F / History / Freight use
caption_attribution_description: English: Santa Fe Railroad 5261, an SDF40-2, works in an eastbound train in Caliente, on its way to the Tehachapi Loop in the late 1980s. Photo by Sean Lamb (User:Slambo)
context_page_description: The EMD SDP40F is a six-axle 3,000 hp C-C diesel–electric locomotive built by General Motors Electro-Motive Division from 1973–1974. EMD built 150 for Amtrak, the operator of most intercity passenger trains in the United States. Amtrak, a private company but funded by the United States government, had begun operation in 1971 with a fleet of aging diesel locomotives inherited from various private railroads. The SDP40F was the first diesel locomotive built new for Amtrak and for a brief time they formed the backbone of the company's long-distance fleet.
  A series of derailments in the mid-1970s shattered Amtrak's confidence in the locomotive, and many railroads banned it from their tracks. Multiple investigations pointed to issues with the locomotive's trucks, the weight of the water and steam generators used for train heating, or the harmonic vibration of baggage cars behind the locomotive. In 1977 Amtrak decided to move on from the SDP40F in favor of the EMD F40PH, which was already in use on short-distance routes. Amtrak traded most of its fleet into EMD; the components were incorporated into new F40PHs.
context_section_description: In 1984 Amtrak, low on light-duty power, traded 18 SDP40Fs to the Santa Fe for 43 switchers: 25 CF7s and 18 SSB1200s. Santa Fe rebuilt the traded locomotives for freight use. Modifications included removing the steam generators and regearing for lower speed. The locomotives were also given front steps and platforms, and notched noses in order to improve boarding access. The rebuilt locomotives were designated SDF40-2. The SDF40-2s continued in service with the BNSF Railway, successor to the Santa Fe, until their retirement in 2002.
caption: Santa Fe SDF40-2 No. 5261 in California in the late 1980s.
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