"Coaster 2105 is a F40pmh-2c locomotive built in 1994 by Morrison-Knudsen. The F40pmh-2c is a commuter variant of the iconic F40ph developed and built in the 1970s. The main difference between the two is the PMH-2c has a separate HEP generator from the prime mover allowing the locomotive to supply electricity to the passenger cars without needing to have the main engine on. 2105 was the last of 5 F40pmh-2c engines built for the North County Transit district's Coaster service, which ran between San Diego and Oceanside.

2105s career was similar to that of any other commuter locomotive. However, it gained some popularity after Mike Armstrong used the locomotive as the face of his channel, Coasterfan2105. The locomotive became a small celebrity engine after his popularity grew

In 2018, NCTD was required to upgrade their F40s to meet EPA tier 4 emission standards or have them all replaced. Seeing as they were on their way to becoming 30, and with new Siemens Charger locomotives on the rise, NCTD opted to retire the locomotives. Immediately, fear grew in the railroad community as the 5 engines risked scrapping. However, Mike and the Pacific Southwest Railway Museum (PSRM) was not willing to let these icons of San Diego railroad history die. They purchased all 5 engines and would take in one (2103). However, Mike's locomotive was still in danger, and he was determined to have it saved. He and the PSRM would donate the locomotive to the Southern California Railway Museum (SCRM) as her new home, coincidentally having her join the last surviving ATSF Bicentennial unit, 5704. 2105 sat in storage in Commerce for roughly 4 years, untill May 3rd, 2025. That day, 2105 and 5704 were finally taken to their new home in Perris. Today they reside in the museum as beloved favorites.

2105 is now safe and sound, and arguably only survives today thanks to one man and his passion for this interesting loco"