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sd15

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sd15
Posted by IA and eastern on Monday, January 4, 2021 2:03 PM

IF i went to EMD and wanted a 1500 hp version of a sd39. What would EMD call thiis locomotive.Would be sd15 or sd1500 or sd37. Gary

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Posted by Overmod on Monday, January 4, 2021 2:19 PM

Interestingly it might follow something like MP-15 with a prefix like SD.  It's hard to imagine why anyone would want a six-motor unit with SD-7 horsepower, though; I'd expect light construction on six axles for extremely low axle load to have its own special designation, perhaps derived from export practice.

By that time I'd expect GM-EMD to be classifying its locomotives by series, not "horsepower" -- the -x9 code referring to an engine that would NOT be downrated to only 1500 hp  Mr. Goding would know more about the kind of special designation EMD would likely use if you wanted an SD35 'light' with a smaller motor new.

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Posted by M636C on Monday, January 4, 2021 6:01 PM

The ones they actually built were model G22C...

Most of these were metre gauge or 3'6" gauge.

There were units on standard gauge and 5'6"gauge in Argentina.

EMD would possibly have offered one of these to a domestic customer who really wanted one.

In Australia and New Zealand, many of these were rebuilt to GT22C, becoming the equivalent of an SD39...

They did of course build two RS 1325s which were a road switcher version of an SW1200 which was a 567 engine equivalent of the sort of unit we are talking about, but with only four motors. So "SD 1500" is possible.

The Swedish operator MTAB has four standard gauge units at the iron ore mine in Kiruna which look like a cartoon version of the standard EMD G12 stretched to 18.64 metres with the cab behind a very long high hood. These weigh 150 tonnes and switch the heavy iron ore trains which are hauled onward by electric locomotives. These are called "Type T46".

Peter

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Posted by Shadow the Cats owner on Monday, January 4, 2021 6:07 PM

EMD did build a SDL39 for the Milwaukee RR in the 60's or 70's that was designed for their lightweight branchlines.  They were sold to the Wisconsin Central when it was founded and I think all are now scrapped.

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Posted by bogie_engineer on Monday, January 4, 2021 6:32 PM

You'd first have to tell them whether you want new or rebuilt, AC or DC traction, if it is has to meet US safety and emission regs, what axle load, minimum curve requirement, and clearance. That would determine if the starting point is an SD70ACe or a GT model if new. You'd probably get an engine rated at 2,000 HP traction, derated if you won't except that much.

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Posted by IA and eastern on Tuesday, January 5, 2021 1:16 AM

In 1970 the railroad decided to replace Baldwins in branchline service with locomotives with same hp.The sd15 would be about same as the Baldwins.Gary

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Posted by M636C on Tuesday, January 5, 2021 5:25 AM

Shadow the Cats owner

EMD did build a SDL39 for the Milwaukee RR in the 60's or 70's that was designed for their lightweight branchlines.  They were sold to the Wisconsin Central when it was founded and I think all are now scrapped.

 
All but the first SDL39 are alive and well and operating in Chile, modified for 5' 6" gauge.
 
 
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Posted by M636C on Tuesday, January 5, 2021 5:46 AM

IA and eastern

In 1970 the railroad decided to replace Baldwins in branchline service with locomotives with same hp.The sd15 would be about same as the Baldwins.Gary

 
The specific fuel consumption of a turbocharged 12-645E3 is better than that of a 12-645E. You would probably be able to buy an SD39 for a lower price than a special build, even if the change was just substituting a blower engine for a turbo engine in the same locomotive. Depending on the duties, an SD39 might end up using less fuel even if it is providing more power.
 
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Posted by Overmod on Tuesday, January 5, 2021 9:37 AM

M636C
The specific fuel consumption of a turbocharged 12-645E3 is better than that of a 12-645E.

But the sfc of a turbocharged 8-645 is likely better still, and might be derated to make the desired hp at the rpm the turbo would spool properly even at 'part load' -- I'm presuming he needs all 6 TMs at 1500hp for a valid reason.

You would probably be able to buy an SD39 for a lower price than a special build, even if the change was just substituting a blower engine for a turbo engine in the same locomotive. Depending on the duties, an SD39 might end up using less fuel even if it is providing more power.

Into this, though, you need to factor whether he'd be using the clutch in that turbo, a known fragile part, by going up and down through the critical notches excessively, or if his track imposed additional shock on the turbo bearings with it spooled up enough to provide economical levels of exhaust boost.

It couldn't be that difficult to put additional mounting locations at the proper balance point, adjust connections, etc. and perhaps relocate the stack slightly to get the smaller engine, which I believe would have been in series production and perhaps had its balancing foibles solved by the time of Gary's "project", in either a regular or lightweight '35 chassis.  I don't think any change to permanent series-parallel wiring of the motors using only field weakening for transition would be out of line for the prospective service -- but I'll let the actual EMD people confirm or reject that.

I don't remember if there were satisfactory blower 8-645s in the line; the dominant marketing 'line' seemed to be replacing a blower 12 or even 16 with the turbo 8, with the fuel savings and presumably lower wear and tear on a smaller turbo making up for any turbo-related disadvantages.  If I recall correctly, at least one (stillborn, as things turned out, but for no lack of engineering acumen) rebuild proposal from EMD did precisely this as part of the job.

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Posted by IA and eastern on Friday, January 8, 2021 1:41 PM

On low profit branches the turbo is an extra cost where simple is better. One ideal was a RS1325 with SW1500 long hood on a SD35 frame but EMD would charge more for that than for a SD39 with a 1500hp engine. Gary

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Posted by Overmod on Friday, January 8, 2021 2:44 PM

IA and eastern
On low profit branches the turbo is an extra cost where simple is better.

But then you need a bigger engine that eats more fuel in higher notches... at least, from EMD.

I still haven't seen the magic reason for a six-motor chassis with only 1500hp that has to be special-ordered from EMD.

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Posted by SD70Dude on Friday, January 8, 2021 2:49 PM

Maybe he wants to replace his old worn out SD7's that are perfect for his jobs.

Greetings from Alberta

-an Articulate Malcontent

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Posted by Overmod on Friday, January 8, 2021 3:22 PM

SD70Dude
Maybe he wants to replace his old worn out SD7's that are perfect for his jobs.

But those were too expensive even when built.

What he'd need is a remanufactured SD7 in that case, not a new locomotive -- and that might just have been an SD15 to go with the GP15.  The probable point being that none of those rebuilds turned out to have a market, not even with EMD enticing railroads to go for the four-axle version.  He could just go to any other railroad with less-clapped-out SD7s (or 9s )and get a couple, perhaps with cheap parts units thrown in,  and reuse all his spare parts and knowledge effectively...

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Posted by IA and eastern on Friday, January 8, 2021 8:47 PM

GE proposed the U18C and ALCO proposed the C620 but no buyers. If i went to EMD and told them that i wanted to buy SD15. EMD would either die laughing or tell me to go see someone otherwhere else. Gary

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Posted by CSSHEGEWISCH on Saturday, January 9, 2021 10:05 AM

The market for such a locomotive is so small that none of the major builders would catalog such a model.  Rebuilders like Knoxville or NRE might reply to such a proposal if a concrete request was made.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
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Posted by Overmod on Saturday, January 9, 2021 10:14 AM

CSSHEGEWISCH
Rebuilders like Knoxville or NRE might reply to such a proposal if a concrete request was made.

...and perhaps, for such unusual characteristics, upon proper vetting of the current equivalent of letters of credit.Wink

Some (re)builders might construct a unit of novel configuration or technology partly 'on spec' if they thought a future market in the design might develop.  In this particular case, a builder like Republic Locomotive would carefully ask not about what the customer 'self-designs' but about the intended service, other costs of maintenance or operation, anticipated changes in loadings or connections, etc. -- as they have their own designs that might easily 'fill the bill' at lower cost, higher resale value, and less risk.

I think it is important to re-note that this is 'the EMD of the early 1970s' not the Berkshire Partners or Progress EMD.  They would likely laugh less and use in-house (including other GM) technology more -- but a proposal would still include proven 'ability to pay', and review of the real needs.  I'd be pretty sure they'd try to sell him a SW1500 with appropriate trucks and better slip control', or after 1974 a MP15.

As an aside concerning 'what if' timing: EMD was carefully studying wheel/rail interaction from 1972 on, with active prototyping of 'creep control' systems after 1978, resulting in 'Super Series' system introduction.  Someone like Don or Mr. Goding will probably know much more about this.  I would expect a MP15 with creep control to do every bit as good a job as a 'SD7 clone' and with much more capable overall length and shorter effective truck wheelbase; certainly the KCS unit I observed in the early 1990s was 'doing the impossible' using it.

 

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Posted by Erik_Mag on Saturday, January 9, 2021 11:27 AM

I suspect that an MP15 with creep control would need a bit better track structure than an SD7, albeit if there are a lot of 15 degree curves a B-B would be a better choice than a C-C. MC stated that the D&RGW/SP limited power to B-B's over La Veta Pass to minimize maintenance issues with the not so great track over the pass.

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Posted by Overmod on Saturday, January 9, 2021 12:01 PM

Erik_Mag
suspect that an MP15 with creep control would need a bit better track structure than an SD7

Why? (Granted, we are assuming the MP15 would be built 'lightweight' if needed to match the nominal axle load if that's ASSumed to be critical in the same way buff load was in Kinki-Sharyo testing...Whistling)

It is difficult to describe how effective creep control on a switcher can be until you stand next to one on a near-impossible load, at high notch, and hear the wheels ringing almost like bells as they microslip and re-establish.

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Posted by rdamon on Saturday, January 9, 2021 12:43 PM

Is this a modern version of the creep control system?

http://s7d2.scene7.com/is/content/Caterpillar/CM20170915-58074-37058

 

Would AC traction be a benefit at this level of poer or use?

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Posted by Backshop on Saturday, January 9, 2021 3:20 PM

Just like in his 600hp switcher "what if", the OP needs to be more specific on his timeframe and what the intended purpose is and why it can't be modified.

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Posted by IA and eastern on Saturday, January 9, 2021 3:37 PM

In 1970 needed new locomotives to replace Baldwin road switchers and 1500hp was all that was needed for these branchline locomotives.This routes were hill and dale and light rail that needed the extra TE to get up the grades . Think like the old logging railroads. Gary

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Posted by Overmod on Saturday, January 9, 2021 4:29 PM

In 1970 the solution was a 1500hp reposed of the Baldwin chassis.  Take your pick of 567C/D or Alco "RS18 above the deck" as was done for the PRR sharks...

There were railroads that did these conversions that could advise exactly what to to, what not to do, and what to do better from experience.  You also keep the hexapole motors that no one but N&W ever figured out how to kill.

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Posted by SD70Dude on Saturday, January 9, 2021 4:30 PM

Back to substituting a blower 12-645 in a SD39, what modifications to the electrical and control systems would be necessary to make that work?

Greetings from Alberta

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Posted by Overmod on Saturday, January 9, 2021 4:42 PM

SD70Dude
Back to substituting a blower 12-645 in a SD39,

Why not a 16-567C out of someone's trade-in F unit or even a D-block?  Ought to have little if any mounting issue.  By then you'd probably want the alternator and the corresponding rectifier arrangement, but is that not a bolt-on or nearly so?

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Posted by Backshop on Saturday, January 9, 2021 7:08 PM

IA and eastern

In 1970 needed new locomotives to replace Baldwin road switchers and 1500hp was all that was needed for these branchline locomotives.This routes were hill and dale and light rail that needed the extra TE to get up the grades . Think like the old logging railroads. Gary

 

SD38.  What the OP described is the McCloud River Railroad.  They had Baldwin C-C's and replaced them with SD38s.  It's all about ballasting, not horsepower.  EMD could make them as light or heavy as you wanted them. End of topic.

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