USA: Southern California Regional Rail Authority formally unveiled its first F125 diesel locomotive at Los Angeles Union Station on July 18. Among those taking part in the celebrations were Metrolink CEO Art Leahy, Electro-Motive Diesel President & CEO Billy Ainsworth, Commissioner Fran Inman from the California Transportation Commission and US Congresswoman Judy Chi.

As launch customer for EMD’s Tier 4-compliant passenger locomotive, the agency has ordered 40 F125s from the Progress Rail subsidiary at a total cost of around $280m. The majority of the locos are expected to be delivered by mid-2017.

Part-funded by grants from the South Coast Air Quality Management District, the new low-emission locomotives are intended to replace the 1990s-built F59PH and F59Phi locomotives currently powering most Metrolink commuter trains. According to EMD, the F125 is the cleanest diesel locomotive in the USA, in terms of reduced particulate matter and NOx emissions. Exhaust gas recycling and urea-based selective catalytic reduction are expected to reduce emissions by around 85% compared to older commuter rail locomotives.

The F125 is 21 m long and 4 445 mm high, fitting the Amtrak D-05-1355 clearance gauge which would permit it to operate in the Northeast Corridor. The full-width monocoque bodyshell incorporating crash energy management was manufactured in Spain by Vossloh Rail Vehicles, now part of Stadler Rail. Total weight in working order is 127 tonnes.

The four-axle locomotive rides on fabricated high speed bogies designed for 200 km/h operation. It is powered by a 20-cylinder turbocharged Caterpillar C175 four-stroke engine rated at 4 700 hp at 1 800 rev/min. Starting tractive effort is 315 kN.

The AC traction motors have individual axle control and extended-range dynamic braking, which is blended with the traditional airbrakes. This configuration permits a degree of regenerative braking to supply head-end power for the train lighting and other electrical requirements, under a process described by EMD as ‘dynamic brake energy recovery’.

  • Read our exclusive interview with Art Leahy about Metrolink's commuter rail expansion in the June 2016 issue of Metro Report International. Available free to subscribers in our digital archive.