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  • EMD SD50 series official thread (covers all variations)

  • 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

 #711465  by RickRackstop
 
While we are on the subject,is it possible to upgrade to an EB turbo for the older locomotives. The entire utex pool for marine engines was purged of E turbos for 17.9 EB turbos about 1982. That and the spring drive gear helped a lot in the torsional problems resulting in frequent clutch failure especially on 12 cylinder engines. The 40 series locomotives had E engines while the 50 series introduced the F series. Did EMD produce some 40 series locomotives with the EB and EC engines without a change in model designation. There are several marine units built to those model designation and older units have up graded components mostly laser hardened liners and pistons with hardened ring lands. They also keep up with the latest advances in fuel injectors. There is a lot of stuff that can be done to the old E engine to improve its thermal efficiency There are some very old E4 engines with do-it yourself split aftercooler systems ( 2 MP45's on Nantucket that meet Massachusetts's emission reg.s for NOx) that will either give you 5% more power or the same power for 5% less fuel.
 #711495  by Allen Hazen
 
WVU--
I wish there were a website making available more or less technical documents of potential interest to serious railfans (or, more generally, people with a serious interest in railroads). I had a vague notion that the "3" after the "E" in "645E3" stood for locomotive, with other numbers for marine, etc, engines, but couldn't have been any more specific than that. ***ONE*** of the documents I would like to see as an available file on my imagined "Railroading Background Data" site would include the list (and principles for decoding serial numbers) you gave two posts back!

Many thanks!
 #747812  by hotbike
 
Okay, I hope I can get an answer here, without starting a new post.

I have heard of several SD50-3's being released from the shops. I would like to know what has been upgraded in these SD50-3's.

In the past , I have heard that the SD50's had problems with their electronics, and that is why the SD40 is so popular, but we never hear about the SD50's.

It sounds like a good idea, to upgrade the SD50's to dash-3 status.

But I would like some more specific information.

I would also like an example of an SD50 that has low-mileage, posibly side-lined due to elctronics problems, but otherwise with very little wear on its mechanical components.

Tell me more about the SD50-3's.
 #747847  by WVU
 
The SD50-3 that was upgraded on CSX. All of the Modules was removed. New electric lockers was applied to the unit with a computerized excitation control system. The unit still has mechanical fuel injection and they are rated for 3000 HP.
 #747936  by RickRackstop
 
I think CSX's version of SD50-3 has a Wabtec Q-tron controller while NS's version uses EMD's EM2000 controller for the definitive SD40. All they need for perfection in medium horsepower locomotives would be a steerable truck.
 #747938  by bogieman
 
RickRackstop wrote:I think CSX's version of SD50-3 has a Wabtec Q-tron controller while NS's version uses EMD's EM2000 controller for the definitive SD40. All they need for perfection in medium horsepower locomotives would be a steerable truck.
Just for clarification, "steerable truck" is GE's designation, to keep it pure EMD it would need a radial truck.
 #819286  by sully
 
Could a company run an SD50 in pax service? I know the HEP complications exist, but could those be solved without adding a power car, overhaul the SD. Has anyone ever done this?
 #819293  by DutchRailnut
 
Running a SD unit would kill track and switches at passenger speeds, also cab visibility sucks on freight style units.
Yes the springs can be modified so unit rides better but still when last 6 axle passenger unit built and succesfull.
 #819309  by Allen Hazen
 
What Dutch said as to the general suitability of an SD-50 as passenger power: it's designed as a heavy freight locomotive.

Sully's question seems to be about the HEP issue. Certainly an SD-50 produces lots of electricity, and wouldn't need its full output to pull a comparatively light-weight passenger train. The current produced by the traction alternator, however, is variable in voltage and frequency: what you want for HEP is more or less constant-voltage AC at a standard (60 hz) frequency. The conversion can be done (my impression is that Alaska Railroad has equipment on its SD70MAC locomotives that allows one pair of traction motors to be taken off line and the current that would otherwise go to them to be converted for HEP use), but it would require extra equipment, and the SD-50 carbody wasn't designed to leave a place for this extra equipment.

Freight units are sometimes used on passenger specials (excursions, business car specials), but I think it is common in such cases to have a power car (or, if not enough HEP is required to justify a separate power car, a diesel-generator set on a business car) to provide "hotel" power.
 #819310  by DutchRailnut
 
The Alaska units are cute, but the Passenger speed barely exceeds 60 mph on ARR
 #819377  by MEC407
 
The Reading Blue Mountain & Northern Railroad often uses SD50s for their passenger trains, but I suspect they don't go much faster than 25 or 30 MPH, since sightseeing is part of the attraction. They also have a steam locomotive that they sometimes use, so I suspect that they either have a power car or their cars have onboard generators.
 #1109266  by Tadman
 
You *could* use an SD50 for passenger service, but it would be one heck of an engineering feat to make it work. The basics would include re-gearing it. I'd ignore comments about freight unit visibility - somehow NJT runs roadswitchers every day in passengers service and seems to get by with it. But the method of fitting HEP to the locomotive would be a real crapshoot. It's hard to find space, or you'd have to modify the alternator to provide HEP like a screamer. I'm not sure what that would require, possible a new alternator.

Given all that, and the surplus of passenger power in the US, it's not worth the trouble other than in a case like RBMN, where they just happen to have an SD50 that works fine on a tourist pike.
 #1109329  by MEC407
 
Tadman wrote: But the method of fitting HEP to the locomotive would be a real crapshoot. It's hard to find space, or you'd have to modify the alternator to provide HEP like a screamer. I'm not sure what that would require, possible a new alternator.
Several years ago, Vermont Rail System somehow shoehorned an HEP genset into a GP38. I have no idea how difficult or easy it was, but they did it. In theory it should be easier on something like an SD50 because the prime mover is the same size, but the frame and carbody are longer, so (again, in theory!) there ought to be more space to work with.

Despite potential space constraints, I do believe that putting in an HEP genset would be an order of magnitude easier than attempting to convert these types of locomotives into screamers... and probably less expensive to boot.
 #1208345  by Engineer Spike
 
I have not been in many SD50s, but the SD60 has enough room to hold a town meeting between the compressor and sand box.

I agree that a six axle truck is tougher on track, but somehow they ran E and PA units on really fast passenger trains for years. Hey Dutch, what about the 6 wheel truck on the rear of your FL4 1/2s? The ex CR SD50s with the Flexicoil trucks seem to be shorter. I don't kow if the axle spacing changed, but I do know that the frame is longer to have all motors face the same direction.
 #1208434  by Allen Hazen
 
Engineer Spike--
E and PA units had two-motor trucks: the center axle is unmotored. I don't know how much side-play the axles have, but that MIGHT help make the E and PA trucks easier on the track. They were also MUCH lighter: 50,000/55,000 pounds on each axle(*), where the SD50 is over 65,000.
-
(*) On at least some, the weight on the carrying, centre, axle was GREATER than that on the powered axles. This makes sense on a high-speed passenger unit: weight for traction isn't as great an issue as it is on a drag freighter, and enough of the motor is unsprung mass that "dynamic augment" will make a powered axle harder on the track than an idler axle with the same static weight.