Western Railroad Discussion > Santa Fe SD40-2s and 88” noses

I’ve notice that the SD40-2s ATSF had in the late 80’s and 90’s and especially after the head light relocation to the nose and MKM rebuilds, that a lot of these ended up with 88” noses. Was this part of the MKM rebuild, was this an options ATSF went with from EMD? What was the additional length in the nose needed for.

Just to clarify, I’m not talking about the snoot nosed SD40-2, those noses were longer to accommodate additional electronics...

Thanks

Posted from iPhone



Edited 1 time(s). Last edit at 09/10/19 08:47 by jdebroux.

EMD went from the 81 to the 88 inch nose in 1978 when the FRA "Clean Cab" requirement came about.
Santa Fe didn't rebuild or replace any 81 inch noses with 88 inch. There was no need for it.

So some of Santa Fe’s SD40-2s have 81” noses ?

Posted from iPhone

No Santa Fe SD40-2's had 81 inch noses. They were delivered with either 88 inch or 123 inch noses. The 123 inch noses were on 5020 - 5027 and 5109 - 5140. These were Locotrol equipped units.

...And here is BNSF 1880, ex-ATSF 5111, with one of those longest-length 123-inch noses, on the Casper Switcher over Center St. in Casper, WY switching out the old roundhouse lead on July 20, 2019. === === = === JLH



Edited 1 time(s). Last edit at 09/10/19 14:20 by highgreengraphics.

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PHall Wrote:
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> EMD went from the 81 to the 88 inch nose in 1978
> when the FRA "Clean Cab" requirement came about.
> Santa Fe didn't rebuild or replace any 81 inch
> noses with 88 inch. There was no need for it.

It came about in 1977. Same year as the first for Conrail and ATSF.

Posted from Android



Edited 1 time(s). Last edit at 09/18/19 20:18 by NYSWSD70M.

Locotrol?

Posted from iPhone

jdebroux Wrote:
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> Locotrol?
>
> Posted from iPhone

An early distributed power system.

I was curious as to how they could MU multiple units together back then. No it seems like a no brainer, WiFi, Satellite etc...was it all done through the MU cables ?

Posted from iPhone

Then as now, MU'd through the MU cables. Remote operation outside the coupled locomotive consist is via radio, called Locotrol in its first incarnation in the 1960's and 70's, unsuccessful then due to no microprocessors Remote locomotives then were called Slave Units, now DPU's. === === = === JLH

They've been MU'ing diesels since the first "road" units came out in the 1930's.

JLH, thanks for the response. Would the trailing locomotives have to be put in a certain mode to be part of an MU’d consist? Interesting how the simple technology that’s decades old prevails over the newest in this case

Posted from iPhone

Locotrol was a radio based system for controlling locomotives in the middle or end of the train, much like DPU today.  It was pushing the analog technology a bit far at the time so it was troublesome.

MU cables are usually used when the locomotives are operating together in a group, or on passenger trains with cars specifically wired to carry MU signals from one end of the train to the other.

highgreengraphics Wrote:

> Then as now, MU'd through the MU cables. Remote
> operation outside the coupled locomotive consist
> is via radio, called Locotrol in its first
> incarnation in the 1960's and 70's, unsuccessful
> then due to no microprocessors

Santa Fe used remote mid-train helpers more or less continuously from 1967 on up through the BNSF merger.  They didn't deploy it as extensively as DPU is now, but RCE-controlled mid-train helpers were commonplace on freight moving over Raton and Glorieta Passes in the 1970's through the 1990's. 

Yes, locomotives have MU selectors to be converted to trailing use, as well as cutouts for Independent and Automatic air brake valves. === === = === JLH

highgreengraphics Wrote:
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> Yes, locomotives have MU selectors to be converted
> to trailing use,

Please elaborate on such a "selector", that is NOT related to air brake features.

as well as cutouts for
> Independent and Automatic air brake valves. ===
> === = === JLH

HotWater Wrote:
-------------------------------------------------------
> highgreengraphics Wrote:
> --------------------------------------------------
> -----
> > Yes, locomotives have MU selectors to be
> converted
> > to trailing use,
>
> Please elaborate on such a "selector", that is NOT
> related to air brake features.
>
> as well as cutouts for
> > Independent and Automatic air brake valves. ===
> > === = === JLH

The Headlight Control switch. Right there on the Engine Control Panel. Usually sits right above the Isolation Switch.
Of course the unit with the Control and Fuel Pump, Generator Field Switch and the Engine Run Switches all in the ON position is the "Lead" unit.
They have to be off in the trailing units or things will not respond well.



Edited 1 time(s). Last edit at 09/12/19 18:16 by PHall.

PHall Wrote:
-------------------------------------------------------
> HotWater Wrote:
> --------------------------------------------------
> -----
> > highgreengraphics Wrote:
> >
> --------------------------------------------------
>
> > -----
> > > Yes, locomotives have MU selectors to be
> > converted
> > > to trailing use,
> >
> > Please elaborate on such a "selector", that is
> NOT
> > related to air brake features.
> >
> > as well as cutouts for
> > > Independent and Automatic air brake valves.
> ===
> > > === = === JLH
>
> The Headlight Control switch. Right there on the
> Engine Control Panel. Usually sits right above the
> Isolation Switch.

Which has absolutely NOTHING to do with building a consist for MU control of power and direction. Can't tell you how many times I've seen that "Headlight MU Control" switch ignored or placed in the incorrect position. It has NOTHING to do with MU control of power!

Well Jack, what about the field loop switch?
For the newbies, the field loop setup switch had to be set for the number of EMD units equipped with dynamic brake in a consist.  The switch had positions 1, 2, 3, and 4.  An all ALCo consist would run without field loop jumpers, but a mixed consist of ALCos and EMDs had to have field loop jumpers installed and switches positioned.
This was in effect from the advent of MU dynamic brake on EMDs until ABOUT the GP20s, when EMD went to potential control.

The SP special instructions at the time said "...A trailing DP Class ALCo is capable of dynamic brake without field loop jumper installed."
G

ExSPCondr Wrote:
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> Well Jack, what about the field loop switch?
> For the newbies, the field loop setup switch had
> to be set for the number of EMD units equipped
> with dynamic brake in a consist.  The switch had
> positions 1, 2, 3, and 4.  An all ALCo consist
> would run without field loop jumpers, but a mixed
> consist of ALCos and EMDs had to have field loop
> jumpers installed and switches positioned.
> This was in effect from the advent of MU dynamic
> brake on EMDs until ABOUT the GP20s, when EMD went
> to potential control.
>
> The SP special instructions at the time said "...A
> trailing DP Class ALCo is capable of dynamic brake
> without field loop jumper installed."
> G

Yes, except the title of this whole thread is concerning "Santa Fe SD40-2s......", none of which had field-loop dynamic brake.