On some later versions of the F40PH (and on many rebuilt F40s), a second small auxiliary diesel engine at the rear of the locomotive powers the HEP alternator. In these engines, the prime-mover speed varies in the usual way. They can be identified by the diesel exhaust at the rear of the locomotive and by their quiet idle.

Sadly, the once-commonplace F40s have all been retired, though some have been converted to cab-baggage Non-Powered Control Units (NPCUs). These units can be found at the rear end of many Midwestern trains, as well as in Downeaster service between Boston, MA and Portland, ME.

2022年9月19日 · The engineer’s side of the F40PH features a mix of molded and separate, factory-applied detail parts. Electro-Motive Division F40PH – Rear The rear of the four-axle passenger unit is also rich in details. The wire grab irons are factory-installed and painted. Electro-Motive Division F40PH – Conductor’s side

Built around EMD’s venerable 16-cylinder 645E3 power plant, the F40PH was rated at 3000 HP, but they featured a unique control system to allow them to provide head-end power. The F40’s alternator for the HEP was driven directly off the prime mover, and in order to supply power at the correct 480V and 60Hz, it had to run at exactly 896 RPM.

EMD F40PH Data Sheet

A converted NPCU Amtrak F40PH (from their "Downeaster" train), which was originally one of the last F40PH units operable (visible hatch sidedoors for loading and unloading baggage cargo can be seen as evident in this photo). A rebuilt EMD F40PH-3 (notice how the rear is different.)

While Amtrak began its journey with F40PH diesels nearly a decade ahead of VIA Rail Canada, both passenger carriers would use this four-axle GP40-2 variant as a vital motive power option during the 1980s and through the end of the 20th century, …

Motive Power Industries f40ph-2c Sheet

The EMD F40PH is a four-axle 3,000–3,200 hp (2.2–2.4 MW) B-B diesel-electric locomotive built by General Motors Electro-Motive Division in several variants from 1975 to 1992. Intended for use on Amtrak 's short-haul passenger routes, it became the backbone of Amtrak's diesel fleet after the failure of the EMD SDP40F.

Morrison Knudsen f40ph-3c Sheet