Drawings of the never-built EMD GP50T?

[Snowman]

This is a unit which was requested of EMD by the D&RGW, and though never built, I have the idea it was at least designed and put to paper.

Have any of you ever stumbled across these drawings by chance? I have basic GP50 drawings (Mainline Modeler), as well as drawings (in the data book, and also by Hundman publishing), of the GP15, which sports the same rooftop radiators as do the SD40T-2, SD45T-2 and MP15 AC, and what it probably a single large fan pulling cooling air from walkway height upward and through the top mounted radiators. A GP50T would have at least two I'm sure (as does the SD40T-2) but probably not three (as does the SD45T-2). The last--three fans--just seems like it would take up too much hood length for the short 4-axle frame. And if it did, it would probably be overthrust at both ends, perhaps even over the anti-climbers.

It's a puzzler. Imagineering, really, what EMD might have done, or just tried to do but never quite pulled together.

Any GP50 internal diagrams would help too. Thanks.

 

[gjslsffan]

This is an interesting idea. And one I never had heard, I worked as a machinist at Burnham in Denver for a bit. It would have been a success for cooling, but the rest of the GP50 issues would have perhaps been problematic. The aft part of the tunnel unit, the section rear of the eng comp, and the eng dept fwd would be all GP50 maybe. It would be easier for me to build in HO, than draw it on a PC, as my PC skills are somewhat lacking LOL. Being as this was a DRGW request, I will opine with what I know concerning locomotives operating on the Moffat Sub, ex-DRGW.

First off, I like the idea myself. Adhesion would be problematic, 3500 hp to 4 axles at 10-12mph with back to back rail oilers would be/is a problem. Some of the most miserable units to get on a westbound train out of Denver are those stinking GE C-4's, you know the units with the #2, 5 axles as idlers. Slipperiest engines I have ever ran. This GP would have been about 900 hp less but still an issue. The only way to put that power to the rails is to keep hpt up and keep the trains climbing speed above say 19 mph, this kind of speed would get you thru the tunnels fast enough that you would not need the cooling enhancements from the tunnel unit design. I have been on those trailing units (trying to restart them) climbing the Moffat Sub and you cant imagine the heat and smoke buildup on those trailing units especially 3-5 back.
Anyways my initial thoughts.

 

[gjslsffan]

This is a completly believable, as well as do-able concept/project. I just measured a couple Athearn BB, GP and SD TM shells and the aft sections of both are just a couple inches different. Heck I might build one just to do it. On the prototype the air compressor might extend into the open section under the radiators, another interesting aspect.
I hope someone has the drawings.

 

[Smudge617]

This is a completly believable, as well as do-able concept/project. I just measured a couple Athearn BB, GP and SD TM shells and the aft sections of both are just a couple inches different. Heck I might build one just to do it. On the prototype the air compressor might extend into the open section under the radiators, another interesting aspect.
I hope someone has the drawings.

I believe Progress Rail are the Manufacturer of the EMD brand, have you thought about contacting them about this, if there was a design for this they may be able to help with drawings or other information and even perhaps the name of one of the design team.

 

[gjslsffan]

I believe Progress Rail are the Manufacturer of the EMD brand, have you thought about contacting them about this, if there was a design for this they may be able to help with drawings or other information and even perhaps the name of one of the design team.

Thats a good idea.

 

[Smudge617]

Thats a good idea.

Going from this article I found, this guy seem to know his way round the GP50's, he may also be able to shed some light on the subject for you.

https://www.american-rails.com/786251.html

 

[gjslsffan]

GP 50 series shared some shared design problems in relation to the GP35 series. The EMD late 645 (GP/SD series) prime movers shared some of the same issues as the late EMD 547 (GP/SD35) prime mover series, as they were over rated, under built/engineered, over hyped, under performing locomotives.
In the years since they were produced, many carriers put into storage both the 35 series and 50 series, as soon as traffic volumes allowed.
The GP/SD 60's locomotives were and are, very good locomotives. But thats a whole nother story, and I got a few

 

[dave1905]

The MP put the GP50's on the Chicago to Houston intermodal trains. At the time I was working at a yard just outside of Houston. When the first set ran I got a call from the power bureau and he threatened my first born son and the next generation if I touched those engines. He said they might look like a GP38 (our normal yard engine) but they were to stay on the intermodal train, I was not to cut one off to swap out switcher power.

 

[DanRaitz]

There is a drawing of GP60T at paintshop.railfan.net by Joshua Moldover.

"GP60T"

as to its drawing scale, it's not specified.

Dan

 

[Snowman]

This is an interesting idea. And one I never had heard, I worked as a machinist at Burnham in Denver for a bit. It would have been a success for cooling, but the rest of the GP50 issues would have perhaps been problematic. The aft part of the tunnel unit, the section rear of the eng comp, and the eng dept fwd would be all GP50 maybe. It would be easier for me to build in HO, than draw it on a PC, as my PC skills are somewhat lacking LOL. Being as this was a DRGW request, I will opine with what I know concerning locomotives operating on the Moffat Sub, ex-DRGW.

First off, I like the idea myself. Adhesion would be problematic, 3500 hp to 4 axles at 10-12mph with back to back rail oilers would be/is a problem. Some of the most miserable units to get on a westbound train out of Denver are those stinking GE C-4's, you know the units with the #2, 5 axles as idlers. Slipperiest engines I have ever ran. This GP would have been about 900 hp less but still an issue. The only way to put that power to the rails is to keep hpt up and keep the trains climbing speed above say 19 mph, this kind of speed would get you thru the tunnels fast enough that you would not need the cooling enhancements from the tunnel unit design. I have been on those trailing units (trying to restart them) climbing the Moffat Sub and you cant imagine the heat and smoke buildup on those trailing units especially 3-5 back.
Anyways my initial thoughts.

Very helpful, thank you. I would have bet long odds against stumbling across a former Burnham shop man here, as this seems to be a pretty small forum in terms of bodies...but here you are!
IIRC, the GP50 had a few new technologies, one of which was ground-speed measuring radar, and I suspect it might have been a help for the sanding--perhaps making it automatic if it wasn't already. I would guess the seventeen SD50's sported similar equipment as well.
I understand the SD40T-2's were equipped with PTC (postive traction control) which I would guess is some sort of automated wheel slip vs. rail-slipperiness device. Sort of like a limited slip differential on a high horsepower sports car. I imagine the the radar speed device might have tweaked that to make it even more effective than it already was on the 40's*...but it's really just a guess.

[* not sure if the GP40-2s also had PTC, but I have the idea earlier units like the SD-45s or original GP40s did not--not yet approved for commercial use when those arrived, I don't think.?]

Happen to know if 50 models traction motors would take more heat than the 40s? I think there was still the issue of short-time ratings, and I'm sure it didn't suddenly vanish with arrival of the 50s, but perhaps there would have been more of a time-cushion. Hadn't occurred to me the tunnels would have cut that, although it's obvious if I think about it. Maybe better heat radiation from 50's type traction motors would giveth...but then the tunnels would taketh back away any improvement....

-------

I have always had the idea the tunnel-motors were untimately purchased with the sheer length of Moffat Tunnel as the primary consideration (SP had its level-fall sheds like Nordon of course, and sat inside them waiting for meets and passes), although the actual MT up-grade was a much kinder 0.3%. Even at that for "only" about three miles, the other three miles (and two-tenths more) being is Run 0 or traction braking mode. Of course, and now that I think about it too, even the bottom end dynamic-braking takes the front end twenty-four axles up to Run 4 right off the bat, and regardless of the position of the dynamic braking lever. Just to dump heat from the toasters.

Maybe THAT would have been the three miles with the greatest heat-intake problem, and not the two enclosed climbs, and even though on the downgrade?

 

[Snowman]

There is a drawing of GP60T at paintshop.railfan.net by Joshua Moldover.

"GP60T"

as to its drawing scale, it's not specified.

Dan

That's really helpful, thanks for finding it! Since the GP50T-s were never built, and since the SD50's apparently ran well enough without tunnel motor intakes, I just assumed the "T" idea died right there. Looking for a GP60T (probably-if-not-certainly imagineered), just never occurred to me. Brilliant thinking, thanks.

Also interesting in that drawing is the assumption that the rear hood would have ended flat, as with the SD40T-2s, which makes sense: Maximize the the tunnel section's intake area, while keeping a sandbox of roughly the same volume as the SDs. They'd never have run rear-end forward at speed anyway (the Rio Grande isn't the N&W, and long end forward running ended with the Alco hoods a LONG time back), so a flat rear end seems "correct" to me. Moreover, it brings back the possibility of cramming in three air intake fans. THAT makes sense if they could fit them in after all (still might not have worked with all the internals, but it's interesting to mull the idea over).

Rio Grande did buy three GP60's--from the Missouri Pacific IIRC--about the time they secured (as a consolation prize) trackage rights east of Pueblo, but they did not sport any kind of tunnel intake section, and never went further west than Pueblo, AFAIK. North to Denver on the Joint Line, but no further west on the Moffat line, even in pusher service. I suppose they could also have run over Tennessee Pass, but if they ever ventured west out of Pueblo, I've never seen photographic evidence of it. Yet....

As dave said, I think they would have been hotshot power mostly, rather than used much (or at all) for coal train service, even on grades typical of the great plains. As far as know on the D&RGW most or all coal trains (or maybe only the triple and quad-hopper trains), were limited by timetable rule to 50 mph--I think it was if there were more than 25 loaded cars even where max speed running for other types of trains was allowed--so I will GUESS that this Rio Grande rule applied even east of Pueblo on MP trackage...thus the GP60 HP might have been wasted anyway in a sort of drag-service.

It's fun to think about and to kibitz about. Thanks all.

 

[Snowman]

I believe Progress Rail are the Manufacturer of the EMD brand, have you thought about contacting them about this, if there was a design for this they may be able to help with drawings or other information and even perhaps the name of one of the design team.

I believe Progress Rail are the Manufacturer of the EMD brand, have you thought about contacting them about this, if there was a design for this they may be able to help with drawings or other information and even perhaps the name of one of the design team.

I have not, and it's a good idea.

 

[Snowman]

This is a completly believable, as well as do-able concept/project. I just measured a couple Athearn BB, GP and SD TM shells and the aft sections of both are just a couple inches different. Heck I might build one just to do it. On the prototype the air compressor might extend into the open section under the radiators, another interesting aspect.
I hope someone has the drawings.

This is a completly believable, as well as do-able concept/project. I just measured a couple Athearn BB, GP and SD TM shells and the aft sections of both are just a couple inches different. Heck I might build one just to do it. On the prototype the air compressor might extend into the open section under the radiators, another interesting aspect.
I hope someone has the drawings.

I have the vague idea I purchased an Athearn blue-box GP50 many years ago (BN paint), so if you have one of those, it's a good starting point. Not sure if the hood width issue was correct by then or not (two inches too wide on early Athearn units), but that wouldn't be a huge hurdle. Or even necessary unless you are counting your own rivets.

 

[gjslsffan]

Very helpful, thank you. I would have bet long odds against stumbling across a former Burnham shop man here, as this seems to be a pretty small forum in terms of bodies...but here you are!
IIRC, the GP50 had a few new technologies, one of which was ground-speed measuring radar, and I suspect it might have been a help for the sanding--perhaps making it automatic if it wasn't already. I would guess the seventeen SD50's sported similar equipment as well.

I enjoy these discussions very much.
The 50 series radar ststem had issues early on, in that the screen would get covered with grease and dirt and quit working (units drops load), also when operating over open deck bridges (no ballast or slag to reflect radar) they would drop their load. But these were worked out. I was told to work on a DRGW SD50 one time that was smoking like a steam engine during a self load test, I mean I bet a lot of people called about all that smoke it was making, crazy how much it was. Turns out GP 60 (710 cui) fuel injectors had been installed on that SD50 (645 cui) engine, and were delivering way too much fuel, I am surprised the thing even ran, but thats an EMD for you.

I understand the SD40T-2's were equipped with PTC (postive traction control) which I would guess is some sort of automated wheel slip vs. rail-slipperiness device. Sort of like a limited slip differential on a high horsepower sports car. I imagine the the radar speed device might have tweaked that to make it even more effective than it already was on the 40's*...but it's really just a guess.

[* not sure if the GP40-2s also had PTC, but I have the idea earlier units like the SD-45s or original GP40s did not--not yet approved for commercial use when those arrived, I don't think.?]

The PTC was a Canadian feature the DRGW applied to all Tunnel units (no GP's). An axle generator was affixed to each axle and when one sliped it would reduce the load and keep the tractive effort to most effective, it worked really well, so well that a DRGW SD40T-2's had the same tonnage rating as the SD50's. If you look at later versions of PTC equipped DRGW tunnel units the #3 axle, had an axle generator on both sides of the same axle, PTC on one side, speed recorder on the other, this was kinda rare as most axles only had the splines on one end of an axle, so DRGW Tunnel units had the #3 traction motors special built.

Happen to know if 50 models traction motors would take more heat than the 40s? I think there was still the issue of short-time ratings, and I'm sure it didn't suddenly vanish with arrival of the 50s, but perhaps there would have been more of a time-cushion. Hadn't occurred to me the tunnels would have cut that, although it's obvious if I think about it. Maybe better heat radiation from 50's type traction motors would giveth...but then the tunnels would take any improvement back away again....

50 and later series locos had thermal protection (micro-processors) for the traction motors that would de-rate power output to the TM's to keep them from over heating, even in short time. They basically turn themselves into lower HP units while the temps were hi. SP had what they called Maxitrax systems installed on some of their rebuilt SD's that was similar in effect. I remember getting Maxitrak locos on trains with AC locos, and told, "go with it". And sure as the world those SD's turned themselves into GP9's.

-------

I have always had the idea the tunnel-motors were untimately purchased with the sheer length of Moffat Tunnel as the primary consideration (SP had its level-fall sheds like Nordon of course, and sat inside them waiting for meets and passes), although the actual MT up-grade was a much kinder 0.3%. Even at that for "only" about three miles, the other three miles (and two-tenths more) being is Run 0 or traction braking mode.

The over heating problems come from slow speeds (6-10 mph) thru the back to back tunnels climbing the front range. Add insult to injury and the rail oilers make wheel slip, that de-rate your power, further decreasing your speed.
The Moffat tunnel flattens out a bunch, speed picks up and throttle reduced eventually, also the Moffat tunnel is vented or clean-er air in there so the heat build up is usually not as intense.
I tell you it really sucks when your train is slower than the smoke from your power is, in getting out of those tunnels. I been on trains that loose units to overheating, and shut down and you hopefully, get out of the tunnel before you stall. Now these engines are HOT, its not at all uncommon for them to boil water out, and not be able to re-started. Adding another 200 ton boxcar to your tonnage, now let the locos you have left on-line cool for while, and if you think you can start that train and try to get thru the rest of the tunnels. Sometimes, you just dont have the power to do it, then you call the DS and tell them you need a help. Then the whole RR is tied up for at least 4 hrs. Prolly re-crew 3/4 of the trains out there. And all that because the power desk somewhere in a cubicle said, "they only need this much hpt" and make sure every ton is on that train. Now were mountain grade RRing.

Of course, and now that I think about it too, even the bottom end dynamic-braking takes the front end twenty-four axles right up to Run 4 right off the bat, and regardless of the position of the dynamic braking lever. Just to dump heat from the toasters.

Maybe THAT would have been the three miles with the greatest heat-intake problem, and not the two enclosed climbs, and even though on the downgrade?

Dynamic brake heating makes no where near the heat form locos in hi throttle/amp applications at slow speeds. Speed is the key to getting thru the tunnel district (uphill LOL). Working with DRGW and SP power in my early years I had no idea what extended range dynamic brakes meant, I mean real world stuff. Not until I was on a set of BN SD40-2's coming out at winter park and going to dyn-8 and feeling the slack run out on the power at 20mph. They (flat range dyn brakes) dont even work at the speeds we operated at (25mph~) for the most part. Better off dragging your feet off the bottom step.

Again great inputs and discussion.

 

[gjslsffan]

I have the vague idea I purchased an Athearn blue-box GP50 many years ago (BN paint), so if you have one of those, it's a good starting point. Not sure if the hood width issue was correct by then or not (two inches too wide on early Athearn units), but that wouldn't be a huge hurdle. Or even necessary unless you are counting your own rivets.

I got both GP 50/60 Athearn shells on hand, (correct width). But I gotta say I like the idea of a GP60-T over the 50-T. But thats just me. The prototype internals has me thinking its not so easy, but do-able. Look at a SD shell, you can see the 2 doors behind the inertial filter screens, thats the generator room, the next 8 doors are the prime mover compartment, then next 2 shorter doors are the start station and some oil cleaner/cooler/water components. Then the electrical/sock oil filters (depending on the side your looking at), after that is the air compressor. I think the air compressor would be in the bottom open tunnel section of a GP-T unit. Which is not at all a deal breaker, the priority is the intake location, the idea, that air compressor might be in there is of no consequence, in fact may be good for the air compressor, as they get hot. Another interesting thing is air compressors on locomotives are/were lubricated with castor bean oil. Reason is if the train line or compressed air, is vented to the cab or other crew compartments the air has at least a plant or organic based fluid for compression lube = safer.
Bonus is the truck tower clip on the model can be painted grey with rudimentary detailing to reflect a compressor and could solve detail as well as fundamental components painted gray of course

 

[Snowman]

Castor (bean) oil? It's been vented into my own compartment on suggestion alone. Ewww...I need my Immodium right about now. Even if I'm organically based.

As for the rest of what you offered before...I can't hope to keep up, but I will try.

That said, you are a star, and I thank you. Grateful for every bit of knowledge about it all.

Allow me until Tuesday at the earliest. A lot of sh** on my plate right now, which is part of why it took me two days to even acknowledge the help (all of you) chimed in with. I'm suddenly sh** up against it.

 

[gjslsffan]

Castor (bean) oil? It's been vented into my own compartment on suggestion alone. Ewww...I need my Immodium right about now. Even if I'm organically based.

As for the rest of what you offered before...I can't hope to keep up, but I will try.

That said, you are a star, and I thank you. Grateful for every bit of knowledge about it all.

Allow me until Tuesday at the earliest. A lot of sh** on my plate right now, which is part of why it took me two days to even acknowledge the help (all of you) chimed in with. I'm suddenly sh** up against it.

LOL Thank you... Not trying at all, to be that know it all dude. I will shut-up, this kind of proposal type project stirs my interest and perhaps too much my experience. Now that I am a retired locomotive engineer, I need to know and remember "relax man".
Kindest regards to all.

 

[Snowman]

LOL Thank you... Not trying at all, to be that know it all dude. I will shut-up, this kind of proposal type project stirs my interest and perhaps too much my experience. Now that I am a retired locomotive engineer, I need to know and remember "relax man".
Kindest regards to all.

Oh, no, please keep rambling. Just don't wait on me--I suddenly have a lot dumped on my plate.
There are so many of your comments and thoughts I want to reply to (ask for more), but it's a case of sh** suddenly hitting the fan here, and I want to go through them slowly, but just don't have the time this AM. Nor until Tuesday at least. Moving too fast, and needing more coffee than I should drink (is two pots--twenty four cups a day--too much?)

Oh, Flo................

 

[Snowman]

BT

LOL Thank you... Not trying at all, to be that know it all dude. I will shut-up, this kind of proposal type project stirs my interest and perhaps too much my experience. Now that I am a retired locomotive engineer, I need to know and remember "relax man".
Kindest regards to all.

BTW, and as to the project: ("Should you choose to take this assignment on and be discovered, the agency will disavow any knowledge of you"...[Mission Impossible])...don't wait on me. Anything I would make of the idea of building a theoratical GP50T would be plastered in my own road's paint and roster scheme anyway...*

[*almost exclusively, although also with a few exceptions too]

...so if you want to run with the idea and actually build one for the D&RGW--in any scale--I have no objection. Go for it!

 

[Snowman]

Bridges. I'm counting them mentally here, and I come up with these: The first is at the west (?) end of Leyden siding, before the long right hander across the fill (just one degree of curvature, that--more than a full mile of radius on that long fill), when moving west. A short beam or girder bridge over a road/hwy, that one.

Next: The short girder midway through the horseshoe curve that runs the horseshoe moving west at first, but then turns back east almost 180 degrees before entering tunnel one. That one crosses Hwy....geez I forget the number (Flo! More coffee! And double the caffeine!) Hwy...83?...is well known. Then it's a while to the next before running up the highway to Wondervu.

Aside: I took my road bike up that highway (83? No. It's 72!) more than a few times before I destroyed my left achilles tendon, and I can even tell you how many curves there are until you reach the Peak-to-Peak highway...88. "One, one, one, one, one"...tangent....then "two, two, two, two, two"...another tangent, etc. Each repeat being a downstroke/heartbeat combo on the bicycle pedals.

Next...the (beam?) bridge coming west out of T-29...then the double pile trestle (main and siding both) at...east Pinecliff....then another not far above west Pinecliff, after the end of the siding--it's a left hander (if, again, moving west). Then...the beam bridge just after West Rollinsville (crossing the dirt road)...then...the pile trestle (right hander) over the creek before east Tolland (right hander moving west)...and then the famous girder over that same dirt road at the right-left S-bend before the switch at East Portal. Many a photo was taken there.

AFAIK, all of those are ballasted.

I have driven and climbed over a lot of the tunnel district terrain over the years--probably up Eldorado Canyon up to Tunnel 8-10 if climbing most often (T-9 long ago daylighted after the fire back...geez...a hundred years or so now), other'n the drive up to MT itself. Pinecliff, Gross Resevoir, and over Rollins Pass at least twice, before Needles Eye tunnel collapsed. Up the east side to Yankee Doodle even after road travel all the way over the pass was no longer viable.

It's quite cool to meet someone whose gone up all these same hills...but on the actual rails themselves.

-------------

My first exposure to a Tunnel Motor was when I saw one sitting at the west end of the East Portal siding. I was enthralled, and also curious as all get out as to the open area...that you could SEE all the way through...the back end.

And a Grande Man steps down the right front corner of the lead unit...sees me gawking...and he proudly starts telling me a few things about it.

"This is a SD40T-2 (he showed me the EMD logos and builders plates)"....

Just so cool. It's one of those memories of a day that you keep close to you until you die.