(2) Grab irons on left front and across nose.
(3) Multiple-unit connections.
(4) Faded anti-glare paint on top of nose.
(5) Grab irons above windshields.
(6) Radio Antenna.
(7) Black/yellow separation: it's an arc, not pointed.
(8) Nathan M-3 (three-chime) horn installed in right-hand position. Note the blanked horn mount on left side.
(9) 48" dynamic brake fan, mounted in flat recess in the roof.
(10) Externally-mounted air cooling coil for the airbrake compressor system.
(11) Spark arrestors: one on each stack (2).
- Left-front grab irons are distinctively Rio Grande.
- M/U connections were added when four-unit F series locomotives began to be broken up for independent operation. This made them more versatile. By the time the F9s showed up, the semi-permanent four-unit sets were a thing of the past.
- The paint started out dark green, having been applied originally circa 1960.
- Above-windshield grabs are also signature Rio Grande F-unit features.
- The sand filler tube is quite prominent.
- Some model railroad manufacturers incorrectly paint this separation as coming to a sharp point in the center.
- Three-chime horns came new on all F units from No. 5701 onward, instead of the paired Leslie A-200 single horns.
- Later F7s and the F9s had a 48" dynamic brake cooling fan.
- The coils are mounted externally to escape the warmer environment inside the carbody, making them more efficient.
- Since the 567 diesel engines are non-turbocharged, they require spark arrestors to reduce the likelihood of starting trackside fires.