4-Axle Slugs

photos contributed by: (your name here)

Santa Fe's slugs are basically old locomotive frames, heavily ballasted, mounted on trucks with traction motors. The slugs have no prime movers of their own; their traction motors receive current from a separate unit coupled to the slug, called a "slug mother." This setup spreads the slug mother's power over more axles, resulting in higher tractive effort at low speeds.

During the SPSF-era, Santa Fe's 4-axle slugs were usually mated to 1310-class GP7's, though they did occasionally mate to 1556-class SD39's. They could be found at some of the larger Santa Fe yards, primarily east of the Rocky Mountains. Two 4-axle slugs made it into the red and yellow scheme, and were paired with the two similarly attired 1310-class GP7's. Slug 109 was generally mated to GP7 1327, while 123 was paired with the 1316. The latter pair is known to have worked at Ponca City, OK for a time in SPSF dress.

In mid-1989, the slugs were renumbered into the 1100's to allow the Superfleet FP45's, in the newly revived red and silver warbonnet, to occupy the 100-series. The 1109 and 1123 were both painted back to blue and yellow in April 1990.

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6-Axle Slugs

140 (2nd)
142 (1st) 143 (1st) 144 (1st) 145 (2nd)
146 (2nd)
photos contributed by: Gregg Fuhriman, Chris Kinoshita

ATSF slug 140

Santa Fe's 6-axle slugs generally worked at the railroad's two hump yards at Barstow, CA and Argentine (Kansas City), KS, though SPSF-painted 129 and SD39 1568 are known to have worked the flat yards at San Bernardino, CA and La Junta, CO at various times in the mid- to late-80's. Rebuilt 1556-class SD39's were the preferred mothers for the 6-axle slugs, but unlike the GP7/4-axle slug sets, the paint jobs of the SD39's didn't always match the slugs they were mated to.

During the SPSF era, Santa Fe was in the process of replacing the original 140-class slugs, built on old Alco frames, with new slugs carrying the same road numbers. In the end, three old slugs and three new slugs got red and yellow paint. Old Alco-based slugs 142-144 wore red and yellow for about two years before being retired in 1987, replaced by new blue and yellow slugs 142-144. New slugs 140, 145, and 146 were built in February and March of 1986 on EMD and GE frames and released in red and yellow paint. They replaced blue and yellow Alco-based slugs of the same numbers. The EMD trucks under slug 140 pictured above are a dead giveaway that this is the "new" 140, built from an N&W SD39, rather than the "old" 140, built from a Santa Fe RSD-5.

Slug 129, rebuilt from a UP SD24B in 1979, is known to have still been in SPSF paint when renumbered to 1129 in 1989. It is not known if 140, 145, and 146 were also still in red and yellow when renumbered.

Red Line - Seperator
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Last modified: December 10, 2000

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