GP40X - What are they?

Well, suit yourself but, you will probably get a LOT more information from Google than what I remember.

The various GP40X units were the "Experimental" forerunners of the "50 Series" units (GP50 and SD50). Some GP40X units even had the "Experimental HT-B" Hi-Adheasion two axle truck. From memory, four railroads received GP40X models, AT&SF, SP, Southern, and UP.

If I remember, the SP got 4 with regular trucks, but "elephant ears" for the cooling system.

Dominic Mazoch posted:

If I remember, the SP got 4 with regular trucks, but "elephant ears" for the cooling system.

You might recheck that builder photo, posted above. That SP unit has the HT-B trucks.

Again, Google will provide more information than anyone would want about the various EMD GP40X units.

UP and SP had HT-B trucks, ATSF had Blomberg M, and Southern had the Blomberg M with a special spring  arrangement (some sources refer to it as "plank and wedge.").

Stuart

Wouldn't the T-2 variant models have predated this picture? Weren't the SD40/SD45T-2 models considered successful to EMD? If so, why the elephant ears here, any why not a "GP40TX" for SP?

I remember six then-new GP40X's in service on the Union Pacific although I wasn't directly involved with them. They were essentially factory demonstrators working in regular service, generally on hotshot trains and often as matched sets. They had 3500HP ratings with pre-production 16-645F engines, as compared to the thousands of very successful standard-production 3000HP SD40-2 locos with 16-645E3 engines. Like HW said, they were the forerunners for the EMD 50-series locomotives produced 1981 - 1985. EMD had their Field Service Reps checking on these units regularly when they came through the main loco service facilities.

Union Pacific's GP40X units had the unusual experimental HT-B "high traction" truck. A good explanation of those trucks here, and why they were superseded by other developments:

http://www.railroad.net/forums....php?f=6&t=63379

 photos from internet

The 645F engines were basically tweaked versions of generally similar 645E3 engines, same bore and stroke. The F versions had strengthened crankcases for the higher HP, modified cams and injectors and turbochargers (some similarities to 3300HP 16-645E3A engines in the DD40's), and "rocking piston pins" IIRC to handle the higher loads.

Sam Jumper posted:

Wouldn't the T-2 variant models have predated this picture? Weren't the SD40/SD45T-2 models considered successful to EMD? If so, why the elephant ears here, any why not a "GP40TX" for SP?

The problem with a tunnel motor variant on a four axle unit is the extra length that it would have to be without being overweight.

Stuart

Stuart posted:

Sam Jumper posted:

Wouldn't the T-2 variant models have predated this picture? Weren't the SD40/SD45T-2 models considered successful to EMD? If so, why the elephant ears here, any why not a "GP40TX" for SP?

The problem with a tunnel motor variant on a four axle unit is the extra length that it would have to be without being overweight.

Stuart 

Yeah and besides that, there were only 23 GP40X units built. SP had just four of them and it wasn't worth the special engineering to make a small run of special tunnel-motor versions for SP.

On a side note, UP had a lot of run-through trains with SP and to cope with the SP tunnels the newer UP SD40-2's used radiator fan switch settings 10-degrees lower than standard, which was hoped to help get them through the tunnels before they overheated. So I was told. I asked my superiors why UP was getting the lower settings on new locos circa 1980 because it would not be optimal operating efficiency for general service, and there was lots of interest in improving fuel efficiency back then.

On another side note, the experimental Krauss-Maffei locos for SP and DRGW had a special manually-activated radiator water-spray feature which was intended to provide temporary enhancement for radiator cooling in tunnels. Wonder if it helped much?

Ace posted:

Stuart posted:

Sam Jumper posted:

Wouldn't the T-2 variant models have predated this picture? Weren't the SD40/SD45T-2 models considered successful to EMD? If so, why the elephant ears here, any why not a "GP40TX" for SP?

The problem with a tunnel motor variant on a four axle unit is the extra length that it would have to be without being overweight.

Stuart 

Yeah and besides that, there were only 23 GP40X units built. SP had just four of them and it wasn't worth the special engineering to make a small run of special tunnel-motor versions for SP.

Correct, but another point was, the GP40-2, GP40X, and subsequent GP50 units were designed/used for fast freight (think intermodal) and NOT for use dragging upgrade through the various tunnels & snow sheds on the SP, as were the SD40/SD40-2/SD45/SD45-2/SD45T-2/SD40T-2 on the SP. Also, the SP was NOT about to pay for, and accept the additional weight for the "Tunnel Cooling System Modification" on ANY GP type unit. As it was, the GP40-2 units on the SP were VERY heavy (something like 270,000 lbs), and had restrictions imposed on them as to where they could operate.

On a side note, UP had a lot of run-through trains with SP and to cope with the SP tunnels the newer UP SD40-2's used radiator fan switch settings 10-degrees lower than standard, which was hoped to help get them through the tunnels before they overheated.

Never heard THAT before. Can't imagine how that would help cooling in tunnels anyway.

So I was told. I asked my superiors why UP was getting the lower settings on new locos circa 1980 because it would not be optimal operating efficiency for general service, and there was lots of interest in improving fuel efficiency back then.

On another side note, the experimental Krauss-Maffei locos for SP and DRGW had a special manually-activated radiator water-spray feature which was intended to provide temporary enhancement for radiator cooling in tunnels. Wonder if it helped much?

The "radiator water spray system" was developed by the D&RGW, and EMD had it listed in the Sales Engineering "Price Book", for virtually all models of road diesels. It was VERY successful for the D&RGW, and even their SD50 units were delivered with the water spray system. Never understood why no other railroad with tunnels ordered that modification. 

For what it's worth, the "Tunnel Cooling System Modification", developed for the SP, was designed for INCREASING the cool-down rate of the prime mover cooling water upon exiting a tunnel/snow shed, and prior to entering the next tunnel/snow shed. The "Tunnel Cooling System Modification" was NOT designed for, nor could it prevent, overheating of the prime mover in long tunnels. The SP tunnels & snow sheds were relatively short, but close together, thus, the "Tunnel Cooling System" with its much lower fresh air intakes would quickly cool down the radiator system, prior to entering the next tunnel/snow shed.

Hot Water posted:

Well, suit yourself but, you will probably get a LOT more information from Google than what I remember.

The various GP40X units were the "Experimental" forerunners of the "50 Series" units (GP50 and SD50). Some GP40X units even had the "Experimental HT-B" Hi-Adheasion two axle truck. From memory, four railroads received GP40X models, AT&SF, SP, Southern, and UP.

See...I knew you could do it, Hot Water.  I mean after all...you worked for EMD  (which will make it a much more interesting answer)...and...this is a FORUM...not a Google reference center.  Thanks, Matt

boin106 posted:

Hot Water posted:

Well, suit yourself but, you will probably get a LOT more information from Google than what I remember.

The various GP40X units were the "Experimental" forerunners of the "50 Series" units (GP50 and SD50). Some GP40X units even had the "Experimental HT-B" Hi-Adheasion two axle truck. From memory, four railroads received GP40X models, AT&SF, SP, Southern, and UP.

See...I knew you could do it, Hot Water.  I mean after all...you worked for EMD  (which will make it a much more interesting answer)...and...this is a FORUM...not a Google reference center.  Thanks, Matt

However,,,,,you should STILL do the "Google Search", as you will not believe what you will learn from it.

Hot Water posted:

boin106 posted:

Hot Water posted:

Well, suit yourself but, you will probably get a LOT more information from Google than what I remember.

The various GP40X units were the "Experimental" forerunners of the "50 Series" units (GP50 and SD50). Some GP40X units even had the "Experimental HT-B" Hi-Adheasion two axle truck. From memory, four railroads received GP40X models, AT&SF, SP, Southern, and UP.

See...I knew you could do it, Hot Water.  I mean after all...you worked for EMD  (which will make it a much more interesting answer)...and...this is a FORUM...not a Google reference center.  Thanks, Matt

However,,,,,you should STILL do the "Google Search", as you will not believe what you will learn from it.

Yeah...I believe it...I've used it many a time...there's a time and place for Google searches...this ain't one of them.  Sometimes it's more interesting to learn from the Forum...from personal human experience and information shared there. Again...remember that's why it's a FORUM (you could google that word).  Matt 

boin106 posted:

Hot Water posted:

boin106 posted:

Hot Water posted:

Well, suit yourself but, you will probably get a LOT more information from Google than what I remember.

The various GP40X units were the "Experimental" forerunners of the "50 Series" units (GP50 and SD50). Some GP40X units even had the "Experimental HT-B" Hi-Adheasion two axle truck. From memory, four railroads received GP40X models, AT&SF, SP, Southern, and UP.

See...I knew you could do it, Hot Water.  I mean after all...you worked for EMD  (which will make it a much more interesting answer)...and...this is a FORUM...not a Google reference center.  Thanks, Matt

However,,,,,you should STILL do the "Google Search", as you will not believe what you will learn from it.

Yeah...I believe it...I've used it many a time...there's a time and place for Google searches...this ain't one of them.  Sometimes it's more interesting to learn from the Forum...from personal human experience and information shared there. Again...remember that's why it's a FORUM (you could google that word).  Matt 

I guess if you are not all that interested in learning more about the EMD GP40X, then what can I say. I went from memory, and since it all happened "under my watch", I don't really care anymore. Seems like I had to assign Field Engineers to many places throughout the USA to watch over those things, which pretty well reduced my staff of available Field Engineers for other deliveries and service commitments.

Hot Water posted:

boin106 posted:

Hot Water posted:

boin106 posted:

Hot Water posted:

Well, suit yourself but, you will probably get a LOT more information from Google than what I remember.

The various GP40X units were the "Experimental" forerunners of the "50 Series" units (GP50 and SD50). Some GP40X units even had the "Experimental HT-B" Hi-Adheasion two axle truck. From memory, four railroads received GP40X models, AT&SF, SP, Southern, and UP.

See...I knew you could do it, Hot Water.  I mean after all...you worked for EMD  (which will make it a much more interesting answer)...and...this is a FORUM...not a Google reference center.  Thanks, Matt

However,,,,,you should STILL do the "Google Search", as you will not believe what you will learn from it.

Yeah...I believe it...I've used it many a time...there's a time and place for Google searches...this ain't one of them.  Sometimes it's more interesting to learn from the Forum...from personal human experience and information shared there. Again...remember that's why it's a FORUM (you could google that word).  Matt 

I guess if you are not all that interested in learning more about the EMD GP40X, then what can I say. I went from memory, and since it all happened "under my watch", I don't really care anymore. Seems like I had to assign Field Engineers to many places throughout the USA to watch over those things, which pretty well reduced my staff of available Field Engineers for other deliveries and service commitments.

I am interested...in what you had to say about it because I respect your knowledge on the subject...no matter how detailed.  I was interested in YOUR answer...not Googles.  Again...that is why I asked it on the FORUM...and didn't Google it.  That's understandable that you and your staff were busy for EMD...no problem.  I liked the answer you gave.  I enjoy the elements of the Forum.  If everybody always "Googled" everything...no on would be here...on OGR.  Sometimes people don't want straight, dry facts.  They want to hear from people who rode the engines, built the layout, rode in a caboose, or knows how to fix that electrical problem with a transformer because they had a similar problem.  You can't find a lot of that on Google.   So...my interest was satiated and I am not going to Google it.  Thanks again, Matt.

Well, thanks Matt. However, you didn't indicate ANY of those desires with your original question, otherwise I would NOT have suggested Google. I thought you were only interested in "technical" facts/features about the GP40X model.

Hot Water posted:

Well, thanks Matt. However, you didn't indicate ANY of those desires with your original question, otherwise I would NOT have suggested Google. I thought you were only interested in "technical" facts/features about the GP40X model.

No prob.  I will end this with a story.  We have a very close friend of the family.  He is my dad's best friend and we have known him for over 60 years.  Like you...he is from a railroad family.  He was originally from Pennsylvania.  His mom...at one time... worked for Reading RR and his dad for Baldwin Locomotive Works.  He ended up here on the West Coast after serving in the Navy during the Korean War.  He got hired by the Southern Pacific RR.  He was not as talented as you...he started as a spotter.  He worked for the SP for 42 years.  He ended his career as the Yardmaster of the SP Bayshore Yard here in Brisbane, CA.  He loved the railroads and loved his job.  I have sat down with him many times and talked trains.  He is very knowledgeable, like you.  Over the years I asked him many, many questions about every aspect of railroading...and...he never once told me to "Google it."  Have a great day, Hot Water.  Matt

Face to face discussions are one thing, especially when one actually knows the person!

Hot Water posted:

Ace posted: 

... On a side note, UP had a lot of run-through trains with SP and to cope with the SP tunnels the newer UP SD40-2's used radiator fan switch settings 10-degrees lower than standard, which was hoped to help get them through the tunnels before they overheated.

Never heard THAT before. Can't imagine how that would help cooling in tunnels anyway.

If the cooling system is running a little cooler before entering a tunnel, it buys you a little more time before it overheats in a tunnel. That was the apparent thinking; I questioned whether it really helped much. I never saw any supporting tests or documentation in the files. But I specifically remember that the UP SD40-2 radiator fan switches all had lower settings than standard EMD specs circa 1978-80. I inspected dozens of new locos at EMD and signed for their release so I remember that stuff.

So I was told. I asked my superiors why UP was getting the lower settings on new locos circa 1980 because it would not be optimal operating efficiency for general service, and there was lots of interest in improving fuel efficiency back then.

On another side note, the experimental Krauss-Maffei locos for SP and DRGW had a special manually-activated radiator water-spray feature which was intended to provide temporary enhancement for radiator cooling in tunnels. Wonder if it helped much?

The "radiator water spray system" was developed by the D&RGW, and EMD had it listed in the Sales Engineering "Price Book", for virtually all models of road diesels. It was VERY successful for the D&RGW, and even their SD50 units were delivered with the water spray system. Never understood why no other railroad with tunnels ordered that modification. 

That's very interesting, can you tell about the spray water tank location and spray system? Would it have a manual activation switch on the control stand with trainlined control for a matched consist? DRGW was a smaller railroad with mountain routes and a smaller loco fleet, so it made more sense for them.

For what it's worth, the "Tunnel Cooling System Modification", developed for the SP, was designed for INCREASING the cool-down rate of the prime mover cooling water upon exiting a tunnel/snow shed, and prior to entering the next tunnel/snow shed. The "Tunnel Cooling System Modification" was NOT designed for, nor could it prevent, overheating of the prime mover in long tunnels. The SP tunnels & snow sheds were relatively short, but close together, thus, the "Tunnel Cooling System" with its much lower fresh air intakes would quickly cool down the radiator system, prior to entering the next tunnel/snow shed.

 

Another GP40X story: a co-worker in another city told me the GP40X units had a large flat area on top of the traction motors - convenient for taking a nap after posting your blue flag while the unit was on a service track. If someone asked, he would just say he was inspecting the traction motor brushes etc.

ACE,

The D&RGW radiator water spray system was all automatic, with a separate water tank. Obviously, the maintenance personnel had to keep that water tank resupplied at appropriate service stops. Then, the D&RGW was a fairly small y railroad and VER close-nit family operation, so those sorts of special modifications work well for their system.

Interesting. The Krauss-Maffei loco operating manual mentions optional manual control so I was thinking they might sometimes be used preemptively. That was the first place I had heard of a radiator spray system on a locomotive.

Radiator Water Spray System  [Krauss-Maffei ML 4000 C'C' diesel-hydraulic road locomotives]

If the cooling effect of the cooling system is not sufficient, its capacity is increased by spraying water on the radiators. The spray-pump is started automatically by a thermoswitch. Furthermore the pump can be started with the switch at the engineer's desk.