The ATSF CF7 is a type of four-axle 1,750hp rebuilt diesel locomotive rebuilt by the Santa Fe (Atchison, Topeka, and Santa Fe) railroad from 1970 to 1978 from various F series cab locomotives (although it was first planned in 1969).
Over 150 or so were built (primarily in the ATSF's Cleburne, Texas Shops), but were all retired from the ATSF by the mid-1980's into the early-1990's and were sold to various different shortlines and other companies (including Amtrak); as well as various different railways throughout Canada and parts of Mexico and the rest of the Latin American region.
Although many are still in service, most have been retired, scrapped, or rebuilt from past owners; though one (in particular) is preserved at the Kentucky Railroad Museum in Lexington, Kentucky in its original "Yellowbonnet" ATSF livery.
HistoryEditDuring the early years of the Diesel Era in the 1960's, when railroads scrapped and retired all or the majority of their steam locomotives; there was a shortage of spare locomotives for most railroads. Most were already aging, or were used primarily for passenger service. Locomotive manufacturers had a shortage of supplies due in part to experimenting with steam and gas turbine-powered locomotives, and railroads were desperate for having new types of diesel locomotives to operate on most of their trains (especially owning once-costly six-axle diesel locomotives). One such afflicted railroad was the ATSF, which had a shortage of funds to purchase more freight diesel locomotives (such as the GP30 and GP35). Because it was a large railroad with multiple business sources and track conditions, the ATSF was in dire need of a new type of locomotive which was an affordable, multi-purpose, and convienient diesel locomotive capable of hauling any train at any time without any extra requirements or needs (such as having an additional turbocharger, additional traction motors, etc.)
Hence, the answer to solve the problem was by rebuilding their fleets of old and aging EMD F Series units, and converting or rebuilding them into a new type of locomotive: the CF7. (The "C" actually meant "Converted".)
The CF7 was revolutionary, and it originally was meant to be a mainline or multi-purpose ("road switcher") type of four-axle diesel locomotive; to which it had a great amount of horsepower and tractive effort (at the time), and was also compatable with the ATSF's fleets of other four-axle EMD types or models of diesels owned by the railroad. was capable of hauling long freight trains for mainline service, or switch or shunt trains in various different yards. Although they served their initial purpose, the ATSF eventually began to purchase their first fleets of six-axle, high-horsepower diesel locomotives (such as the SD40 and SD45) which replaced the need for the CF7 and other four-axle units to haul mainline freight trains, and thus ultimately displacing them to yard and branchline service instead. The CF7 spent the rest of its life on the ATSF in yards switching out rollingstock with other mid-horsepower four-axle units; such as the GP20, GP7, GP9, GP30, and GP35 (the GP30 and GP35 in-turn served as an initial replacement for the CF7 later-on).
The CF7 was retired during the mid-1980's, and many still exist on shortline and heritage railroads across the US, as well as parts of Canada and Mexico.
Early CF7's were built with a shorter and smaller cab with a round roof, which was actually from an F7.
Amtrak also owned a fleet of CF7's to be used as yard switchers for sorting coaches and locomotives.
The ATSF was actually one of the last US Class 1 railroads to convert from primarily four-axle diesel locomotives to primarily using six-axle diesel locomotives.