NYC F-Unit Dynamic Brakes

[NW_611]

Does anyone have a real good breakdown of which NYC F-units had dynamic brakes, and which ones did not? For the longest time, I believed the "didn't need 'em for the Water Level Route" conventional wisdom, but recent digging around indicates that the conventional wisdom may have been outright wrong.

It doesn't help that I don't know how to tell a dynamic-brake equipped F-unit from one without. Any assistance is appreciated.

[ArtOfRuin]

The best way to tell visually if an EMD F-unit had dynamic brakes is to look at the top of it. F-units have four radiator fans over the engine. If it had dynamic brakes, there would either be vents (on FTs, F2s, and F3s) or a fan (later units) located in between the cab/front end and the radiator fans. On some non-dynamic Fs, some railroads also plated over the grills just below where the vent/fan would be.