ILSX 929
SP 2685 in Newar, California on 12/1974 (Photo by R. L. Dengler)
This EMD SW1500 locomotive was built in April of 1973 and delivered new to Southern Pacific. The diesel-electric locomotive was primarily used for yard switching duties as well as assembling trains, and industrial switching.
UPY 1229 in Portland, OR on 08/06/2008 (Photo by Brian Miller)
Due to financial problems Southern Pacific Transportation Company was taken over by the Union Pacific Corporation. SP 2685 was restenciled to UP 1229 on August 20, 1997 and then in August of 2001 a Y was added making it UPY 1229.
ILSX 929 on the Dakota Junction, MN on 08/20/2012 (Photo by Brian Kays)
UPY 1229 was retired by Union Pacific
Sources
Picture 1: http://espee.railfan.net/nonindex/sw1500_photos/2685_sp-sw1500-bob_dengler.jpg
Picture 2: https://www4.rrpicturearchives.net/showPicture.aspx?id=1280889
Picture 3: https://www.rrpicturearchives.net/showPicture.aspx?id=3157696#
Information: https://donsdepot.irm.org/dr4233.htm
Information: https://utahrails.net/up-diesel-roster/up-diesel-roster-25.php
Information: https://en.wikipedia.org/wiki/Southern_Pacific_Railroad
Information: https://utahrails.net/up-diesel-roster/up-diesel-roster-21.php