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Re: 1969 Cuesta grade derailment-Yes U-33 problem....
Author: Railbaron
Date: 02-02-2017 - 16:28
While the early GE and EMD units used the single handle to control both power and dynamic the method of selecting the type of operation were quite different. To make matters worse the GE version from U28's, U30's, and early U33's had a very poor design that could easily lead to confusion for somebody not overly familiar with these control stands and probably resulted in this accident.
While EMD and GE used the same handle for power and dynamic EMD used a smaller handle to select power or dynamic. From "Off" it was 1 click forward for power; from "Off it was 1 click back for dynamic. If already in one or the other it would be 2 clicks back to go from power to dynamic or 2 clicks forward to go from dynamic to power.
The flaw on GE units as listed above was that the selector was combined with the reverser - there was no separate selector to change from power to/from dynamic. On GE's the reverser was moved 1 notch forward (or back if running long hood forward) from idle to go into power. From there it was a matter of pushing down slightly (if I remember correctly) and then moving the reverser forward another notch to go into dynamic.
An employee not overly familiar with this arrangement, especially in a dark cab, might not remember to push down to move the reverser forward into dynamic and might assume that since the reverser simply won't go forward any further that it's in dynamic. At this point movement of the "power handle" will add power rather than dynamic.
Shortly after this both EMD and GE came out with the newer AAR control stand that had separate handles moving in opposite directions for power and dynamic.
While EMD and GE used the same handle for power and dynamic EMD used a smaller handle to select power or dynamic. From "Off" it was 1 click forward for power; from "Off it was 1 click back for dynamic. If already in one or the other it would be 2 clicks back to go from power to dynamic or 2 clicks forward to go from dynamic to power.
The flaw on GE units as listed above was that the selector was combined with the reverser - there was no separate selector to change from power to/from dynamic. On GE's the reverser was moved 1 notch forward (or back if running long hood forward) from idle to go into power. From there it was a matter of pushing down slightly (if I remember correctly) and then moving the reverser forward another notch to go into dynamic.
An employee not overly familiar with this arrangement, especially in a dark cab, might not remember to push down to move the reverser forward into dynamic and might assume that since the reverser simply won't go forward any further that it's in dynamic. At this point movement of the "power handle" will add power rather than dynamic.
Shortly after this both EMD and GE came out with the newer AAR control stand that had separate handles moving in opposite directions for power and dynamic.
