F7 Phase 1 and 2

Model Railroader Prototype information for the modeler
1

Is there an external distinction between F7 Phase 1 and 2 locomotives?

2

Wikipedia does a good job of answering your question…

http://en.wikipedia.org/wiki/EMD_F7

3

Yes, it is quite noticable:

  • Rear roof overhang - the ph 1 has the rear ‘lip’ like the F3

  • DB - the ph 1 has a 36" fan, EMD went to a 48" fan to increase cooling with late ph 2 production

  • Grills - went rom a fabricated grill to the ‘stamped’ grill

  • Louvers - the 4 louvers between the portholes changed to the ‘double vertical slit’ louvers

  • Cab side door - the door changed from curved corners to sqaure corners.

F9 production added a 5th louver ahead of the first porthole. EMD made the changes in the June/July timeframe of 1952 for the most part. The 567B prime mover was also beefed up and EMD ‘played’ with 1700 hp output at times. By 1954, the 567C engine was available and featured a really beefed up lower end and better water seals on the top end. The old Atlas FP7 is a pretty good example of a ph 2 engine. EMD phased in the changed gradually as the stock of older parts was exhausted. PRR had ph 2 FP7’s delivered with 36" fans, for example. Many railroad ‘upgraded’ older engines with new parts as time went on and the appearance changed.

Jim

4

At the bottom of the Wiki F7 page there is this link with additional F7 Phase Information:

http://trainweb.org/jfuhrtrain/CF7frames/F7Phases/F7phase.html

Ed