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  • mystery lever

  • Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.
Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.

Moderator: GOLDEN-ARM

 #110870  by SRS125
 
I beleve that the small red handle to the far right is the selcter lever. Older locos had a lever in which you could slect the speed in which you wanted to run in. Think of it as like haveing standered shift.
 #110871  by LCJ
 
gitrplaya5u wrote:wat is the use of the lever above and to the right of the throttle of some older units?

and also what is the thing to the left of this lever?

That's a selector lever, Zack. It's use is selection of power or dynamic braking function of the throttle handle. On these earlier models, the throttle controlled the power operation and the dynamic brakes.

The object to left of it on the first photo was a little window that indicated which position the throttle was in -- numbered 1 to 8. In power, there are 8 separate notches, while in DB, the lever moves smoothly across the numbers up to full braking at 8.

The second photo has different indicator that shows either Power, Off (locked), or Brake. There was a separate indicator for handle position just like the one above.

After a nasty fatal accident with an EMD unit in control of a train heading down a steep grade (where they surmised that the engineer who died in the wreck thought he was in braking but was actually in full power) a new standard control stand was designed that had two separate handles. One handle was a throttle for power that was pulled back to operate, and one for braking that was pushed forward for operation of DB.

Also, the load meter was changed to indicate power and braking in two directions on the face of the meter -- forward for motoring, and back for braking.

On earlier (pre -2) EMDs, the selector lever also had an OFF position where the throttle was locked. The second photo looks like one of those. The first photo is a -2 model of some sort, I believe.

I have also seen some even older models on which the selector also selected the transition level -- 1, 2, 3, 4. I'm not sure, but perhaps this was a manual transition system.(?)

 #110876  by Railpac
 
The first photo is of a DDA40X, and actually your assumption of it being a Dash 2 is well founded, as the technology introduced on the DDA40X's in 1969 was the same used on the Dash 2 line introduced in 1972. The DDA40X's were the "test bed" so-to-speak for this new technology.

 #110881  by emd_SD_60
 
Wasn't it also ironic the SD45X (replaced by SD45-2) of 1970 was the testbed for the new HT-C trucks as well? While all other six axle power used Flexicoils?

 #110885  by LCJ
 
Railpac wrote:The first photo is of a DDA40X...
So that's why the double loadmeters -- one for each traction alternator.

Actually, the -2 control stand was an intermediate between the old style and the later AAR controller I described above. On it, the selector was moved forward to choose power, and back to choose braking. It would stay in the position chosen. They also had the bi-directional loadmeter I described above.

On the older models, the selector lever always spring returned to center after moving in whichever direction desired. This was so there could be more than just the three possible choices as on the newer, -2 version.

Note that in the first photo, the lever is in the forward, power position, while in the second photo, it's in the center.

The first AAR controller I saw was on one of the very first PC U23Bs when it showed up in Selkirk one day in 1970.
Last edited by LCJ on Sat Mar 26, 2005 11:07 am, edited 1 time in total.

 #110886  by LCJ
 
Oh, and Zack, who are you trying to convince with that signature? :wink:
Last edited by LCJ on Sat Mar 26, 2005 1:18 am, edited 1 time in total.

 #110887  by Railpac
 
emd_SD_60 wrote:Wasn't it also ironic the SD45X (replaced by SD45-2) of 1970 was the testbed for the new HT-C trucks as well? While all other six axle power used Flexicoils?
Yes the SD45X was the test bed for the HT-C trucks, however it was not replaced by the SD45-2. The SD45X was rated at 4,200 hp from a 20-645E3A. The SD45-2, was simply an updated SD45 rated at 3,600 hp from a 20-645E3, same as the other Dash 2 variants of previous models.

The Espee had expressed intrest in the 45X, and tested 4 of the 7 demonstrators extensively, however, no additional orders followed.

hee

 #110944  by gitrplaya5u
 
Oh, and Zack, who are you trying to convince with that signature? Wink
Teehee :-D

 #110945  by emd_SD_60
 
One of the ex-SP SD45X's went to Morris-Knudsen Leasing, had the SD45-esque 4 fanned radiator assembly replaced with a common SDP35 radiator assembly, derated to a SD40-2, and painted in the MK yellow/black scheme with a huge "MK" emblazoned on the sides. I think it was leased out to MKT. Unfortunately it was scrapped in October of 1991. :(

 #111127  by SSW9389
 
Actually there were only four demonstrator SD45X units. The other three were owned outright by Espee. The Espee then bought three of the four demonstrators from EMD. Experiments with the SD45X led SP away from that model and caused the development of the Tunnel Motor locomotive.
Railpac wrote:
Yes the SD45X was the test bed for the HT-C trucks, however it was not replaced by the SD45-2. The SD45X was rated at 4,200 hp from a 20-645E3A. The SD45-2, was simply an updated SD45 rated at 3,600 hp from a 20-645E3, same as the other Dash 2 variants of previous models.

The Espee had expressed intrest in the 45X, and tested 4 of the 7 demonstrators extensively, however, no additional orders followed.

 #111456  by nickleinonen
 
i see and understand the selector for the combined power/brake handle [only seen a few of them out my way]

in the second picture, i've only seen that once on one old gr12... it had something to do with selecting how the main gen field excitation was controlled i believe... it has like shunt, auto, road as the settings... in shunt it builds the amps real quick [this little gr12 loaded to like 550amps in N1 very quick off the line] i don't really know for sure how it is wired into the controlling system as it is an older design than most of the electricians at my workplace are use to working on....

 #111524  by Engineer Spike
 
Like other posters said, the later selectors had 3 positions. Left= d/b centered = off, and right for power. Some earlier units were spring loaded, and the handle returned to the center. Nothing was said about the origional function of the selector. You will note that some of the spring loaded ones have a number "1" for power. Some earlier ones had 1, 2, 3, 4. These were positions for stages of transition. Even after EMD offered automatic transition, the selectors still had those positions for leading a manual unit.
I don't like the fact that some of the -2 units have a selector, and some have a a 2nd handle for d/b. The bad thing is that the throttle is used on the selector units. d/b increases as the handle is moved to the left. The d/b handle works left to right. This really makes the engineer have to pay attension to which type of unit is used.