The Last SD45 Ordered* by the SP
First gets all the attention. First place in ratings, first in the race, first on the moon, etc. I get that. But somebody has to be last. Being last in a race or the NFL standings has to hurt your pride.
But last doesn’t always mean worst. Sometimes it just means last.
SSW 9155 with another SD45 and a U33C at Bealville, CA on May 23, 1977.
Cotton Belt 9155 and 2 other 6-axle units are clearly in Run 8 as they strain to overcome the uphill grade at Bealville, California on May 23, 1977.
SSW 9155 was the last SD45 ordered* by the Southern Pacific. It was part of a 4 unit order, SSW 9152-9155. All 4 were built in January of 1970.
But the SP’s love affair with the 20 cylinder engine was far from over. Beginning in 1972, the SP started receiving the first of nearly 250 SD45T-2’s.
* It’s standard form to explain the meaning of an asterisk at the end of a post, but I think I’ll defer to you readers to explain the asterisk in comments. No, you won’t win anything for being the first with the correct explanation, but you will get the satisfaction of being first.
Southwest Rails 
The Cotton Belt #9155 was the last new SD45 ordered by the Espee System. It was not the highest numbered SD45. Cotton Belt #9156 was a rebuild of Cotton Belt SD45 #8971. The 8971 was involved in a crossing accident near Tyler, Texas on June 26, 1970. The train the 8971 was on hit a propane truck.and all five units in consist caught fire. The crew in the lead GP20 and the truck driver were killed in the resulting explosion. The 8971 was sent back to EMD to be rebuilt and emerged from EMD with a new number in June 1971.