In June 2018, the North County Transit District (NCTD) Board approved the purchase of five Siemens SC-44 Charger locomotives to replace their existing five F40PHM-2C locomotives that were remanufactured by Morrison-Knudsen, with $10.5 million of the estimated $53.9 million cost earmarked from statewide gas tax and vehicle registration fees. In June 2019, the NCTD Board approved the purchase of two additional SC-44 Chargers for expansion purposes; they are due for delivery in late 2022. In September 2020, the NCTD Board approved the purchase of the final two SC-44 Chargers that are planned to replace the two F59PHI locomotives; they will be due for delivery in April 2023. Deliveries of the first five SC-44 Charger locomotives took place from August–October 2020; they began revenue service on February 8, 2021. The five F40PHM-2C locomotives retired at that time will also be donated to the Pacific Southwest Railway Museum.