Yesterday's post on the FDL engine progression was a bit dry.. so today let's have some pictures! We'll examine the early control stand setups of the U25, U28 and U30 locomotives.
Many people are not aware (anymore) that the U25 locomotives that had high short hoods used controller cabinets that were mounted very high up on the cab wall, leaving space BELOW the controller for the brake equipment. This design was not used on any of the early Universal series locomotives that we know of; rather, it was introduced on the test U25 prototype units numbered GE 751 and 752 along with the new 16-notch KC-99 Master Controller that it contained.
We have here with us a rare find - and a large one! It's a huge GE manual titled GEI-92215A Maintenance Manual Model U25B Diesel-Electric Locomotive 2500 HP. This manual is specific to the New York Central System, and covers road numbers 2500-2529 and 2530-2559. Publication date is 12-64 and only 50 copies were made. We'll use this to give details on the controllers (such as can be found, anyway) after we see the pictures from various operator manuals.
First up.. GEJ-3807, covering prototype U25B locomotives 751 and 752.
Here is the first of two control stand illustrations from this manual. Units 751 and 752 had both different control stand arrangements and different air brake equipment. The manual (oddly) doesn't tell which was which, so we'll just describe this as the first illustration, which of course it is. This unit had 24RL brake equipment, operating handles of which are seen at lower left. Note the controller cabinet location, with throttle handle on the right and selector on the left. The reverser handle protrudes from the slot below and to the left of the speed recorder. Note overhead horn cord. Note also the load meter located on bulkhead, below throttle; the panel below the front window contains brake gauges only. Sand, and slip suppression button, on right below side window. Now let's see the second unit's control setup.
The other unit of this pair was equipped with the new panel mounted No. 26L brake equipment, clearly visible to the left of the engineer's position. Note the many small changes overall that give this the look of being a different model locomotive; while the controller is in the same location essentially, almost all of the other controls have been moved around. Gauge locations are the same; this photo for some reason was taken with the air brake panel's front cover opened and pulled down, but the panel is the same as that shown above. Major controls, including throttle, selector lever and reverser remain the same - and on this unit, as well as the other, and all U25, U28 and U30 units using this controller, the throttle handle controls both power in motoring and braking effort in dynamic braking.
At this point there's no way to tell if originally both units had control setups that were identical, and we might suspect they were. Perhaps one unit was modified with improved control layout and the new brake equipment at the same time, or perhaps not. We don't know. Date of this manual is 5-60.
This illustration is that found in manual GEJ-3810, issued 12-60 which covers high-hood production model U25B locomotives like those furnished to Union Pacific and the Frisco. Note the overall more "finished" look that this illustration shows - no doubt, some further changes as a result of having worked out the design with the experimental 751/752. Most important to note is the addition on this picture of a "Power Limit Switch" (on front of controller, next to the two black headlight switches) that limits the unit to Notch 7 output even if the throttle is above this setting to limit slip on the unit while trailing units respond to the full throttle range. Note also that the load meter has joined the air brake gauges in the panel below the front window.
This setup naturally wouldn't work with a low-nosed or "low short hood" unit. GE then redesigned the whole control setup to not only get everything mounted on the floor but also to provide a totally unobstructed view through the very large one-piece windshield it originally fitted to the U25B and U25C locomotives. Originally this stand had a very short, stubby throttle lever but this was quickly changed to a much longer design more suited to the extreme stiffness associated with the strong latch spring fitted to the controller. It is this slightly later design we'll show now.
This illustration would be generally typical for late U25, all U28 and many U30 locomotives. It is taken from GEJ-3834, the operating manual for the U28 when built in the U25 style carbody, and which was printed 1-66. This is essentially the "classic" early GE control stand since as we know the vast majority of units were NOT high-short-hood. Although it's obvious, we should note that high-hood U28 and U30 units (Southern, N&W) had floor-mounted stands. We also are almost certain that the few PRR U25B units that had dual controls used two floor mounted stands.
What's not too obvious here is that there were several submodels of the KC99 controller differentiated by their mounting and internally contained equipment. This is where the aforementioned NYC manual comes in handy with this description of the various models of KC99 controller, at least as of 9-63 when this manual's section CE-1 / Master Controller was printed. Remember that sometimes these manuals foreshorten model numbers for ease of reference, and officially the "KC99" controller is GE model series 17KC99. Here are the model delineations:
17KC99A: This controller is overhead mounted. Braking and accelerating is controlled by one handle (THROTTLE). The controller housing contains the control switches, circuit breakers, lights, and braking-throttle control resistors.
17KC99B: This form has a different cover and wiring, and it contains three more resistor tubes than the form A controller. The form B controller is wall mounted.
17KC99C: This controller has no resistors. It is floor mounted.
17KC99D: This controller omits the console, the switches, and the resistors. It is floor mounted.
17KC99E: This controller is floor mounted. It contains switches which are designed differently than those found on other forms of this controller.
17KC99F: This controller omits the console, is overhead mounted, and contains a dynamic braking commutator and resistor as shown in figure 1.
The above is RIGHT OUT OF THE MANUAL, word for word. We won't show "Figure 1" here but I can tell you, looking at the illustration that it's my best guess that this controller was for use in either the UP's or the Frisco's U25B units for controlling field loop dynamic brake systems in EMD locomotives. (Normally GE units were potential control.)
If we look at the first two pictures of 751 and 752's cabs, we might guess that these are showing two different mounting styles and might be the A and B models of controller -- although that's a very hazardous guess. What seems clear is that between the illustrations I've shown, and those I haven't, there are more than enough to cover all of these stated model changes in the U25 series alone.
I hope you've enjoyed this little in-cab look - when we return to GE locomotives it's back to the FDL engine series.