I’m looking for any info on Milwaukee Road’s SD10 rebuilds. There was an article done some time back (fall of '09 IIRC) that had some info, but was also conflicting. Specifically looking for the finer details, like which phase were the MILW SD7/9’s used in the program, horn type, pilot type, differences between original GP cabs and those [few] that used Spartan cabs (GP35 cabs as stated in roster). Also wonder on some conflicting info that I’ve got. I plan to model then in their 1985 condition, patched out for my RR. Details won’t go much beyond what I’ve listed, but I will weather, eventually. Depends if I’ve done any weathering before that or not (wouldn’t want to make my show case engines look crappy). I also will try different methods, I live in an apartment and the layout will be in a bedroom so I’m trying to avoid air brushs (the noise and price) and look into other methods. Dry brushing and chalk seem pretty good.
The other quirk I found was between two sources, the article stating, and leading me to believe, all locomotives were re-powered with 645 engines, and another source (MILW roster) stating hp figures coinciding with original prime movers. Which one was really used? If they did use 645 prime movers why didn’t MILW just use standard GP/SD38 2000hp rating? Or could this have been some kind of advent to the 1500hp 645 prime mover used in GP15’s.
The Milw ‘SD10’ program was used to upgrade old SD7 & SD9 engines on the Milw roster. There was no order as how existing engines were selected, other than they started numbering the SD10’s between 542 and 561., plus 532 & 534. As they ran into existing un-rebuilt SD9’s, those SD9’s were renumbered into used SD7 slots(engines that had been rebuilt). The previous ‘GP20’ program used new 16-645 prime movers/main generators in old GP9 car bodies. By the time the SD7/9’s were rebuilt, Milw was just doing an upgrade of the existing 16-567 prime mover. IIRC, they were rated at 1850 hp and may have just been an application of 645 ‘power packs’ in the existing 567B or 567C blocks. The SD10 engines were used on light rail branches and speed(HP) was not a big issue. This allowed using existing rebuilt cooling systems and main generators. External changes included chopping the nose and re-positioning of the air tanks. Most of the rebuilding happen in the 1974 time frame. Engine 555 had a ‘Sparten’ cab applied after a wreck, and eventually was rebuilt into a ‘SD10’ in 1974.
The SD7-9 body stayed relatively the same throughout the production run. The marker lights in the upper corners are the main difference, until you get to the later production SD9s with 2 48" radiator fans. The louvers and such are pretty much the same. Most SD10s were rebuilt from SD7s, as they were older and needed it more. I think there was something in the eletrical system that limited HP to 1800. Upgrading to 2000 HP would have required a lot more money for upgrades.
They might have put new/different crankcases in, as 567B blocks won’t accept 645 power assemblies. Some of the later SD7 might have had C blocks in them, but left at 1500 HP rating. The water jacketing is different-better on C blocks and newer. Earlier blocks had issues with water leakage. 645 power assemblies can be retrofitted to C blocks without difficulty.
The 555 started life as SD7 2211, then renumbered to 511. After a wreck, a GP35 style cab was added. There were only 3 SD7 with 2 fuel tanks, 2209-2211, later 509-511. When rebuilt into SD10s, the extra fuel tanks were taken off.
The 567B block needs to be upgraded to a 567BC status. Even if no 645 power assemblies are used, this has been a very popular upgrade through the years as it gets rid of 1/2 of the water leakage issue with the older 567A & 567B blocks(there was a 567AC conversion as well). Many railroads upgraded 567B’s to the ‘BC’ configuration as the locomotives were shopped. If 645 power assemblies are used, the couterweights must be adjusted to offset the larger dynamic augment of the 645 power assembly’s mass. BN set the fuel racks on their ex-GN GP7’s to 1850 hp. West Burlington shops tested one of the early rebuilds at 2200 hp - the cooling was not large enough to handle the load. Increasing power output of a locomove leads to other issues if you want to use all of that power:
Electrical - Main generator and wire/control circuits may need to be replaced/upgraded.
Cooling - Usually larger radiator cores are required to offset the heat generated by the increase.
Home shops remanufacturing programs have gone by the wayside as many large railroad shops have been closed. Future large programs have been outsourced, and now will need to meet Tier II fuel emmision requirements. Older 567 or 645 powered locomotives will need to be repowered with something like the EMD 710ECO package, or possible CAT options.
As I already stated, I have the article. The author/modeler also put road number 548 on his model, which according to info I found and given here, never existed. It would be kind of dumb if I used a sound decoder with 645 sounds on loaded on if that prime mover was never used now wouldnt it? I did do a google search. Came up with about 6 photo’s of the actual locomotives (only 3 different road numbers if I do believe), and right about the same from another modeler who was also kitbashing an SD10. I did my research.
Thanx for responding ot the others, notebly Jim. He’s helped me out with other MILW questions if asked before. Now knowing the 555 was the only unit with the spartan cab I probably won’t model that one. It looks like the knew apartment owners manage with the big oscar meyer’s instead of their mind so the wife and I are starting to look at apartments, unfortunetly she’s looking at 1 bedrooms so now the status of a railroad is up in the air again. I still don’t think that will let me get in the way of modeling this locomotive though, or a BQ23-7 I would like to spin off from my Bachmann B23-7. I need to get better looking trucks on it before anything. The Bachmanns are just to bland and toy looking. It worked good I found out how to fry a decoder on DC power, I’ve checked it all out the motor seems to be fine. With the exception of the wires pulling off the motor leads (little strips, look like brass) when I removed the body.
Well I did thank everyone for responding. That included you. I will not however appologize for having an annoyingly crappy memory, most likely due to a car roof collapsing on my head in a crash that should have most likely killed me. Geez maybe I should believe in god ey? I remembered it was an '08 article, but way after I first replied. The air in my wallet can’t pay for internet (for some reason other place won’t accept it as cash either lol) so I have to use public computers at an internet lab or library, so I didn’t get a chance to even send a responce when I got home and could look at the magazine. At least I remembered it was MR right? right?
This does go to prove that Google is a failure. I will take fault in not really looking for general info on loco’s, but I did do a search for images. And just to prove how…how to say this with out cussing…spongey my memory is I remember getting hits from rrpicturearchives but did NOT get that many. I think it’s obviously not the site I was at, whether that’s how it’s remembered in my head or not. I would try to get a brain transplant surgery, but I’m afraid if I do that my telepological device will no longer function and I will not be able to keep in communication with my home world or the mother ship. Will be hard for my people to pick me up in 2 years, 9 months, 4 days, 7 minutes and 54 seconds when my mission on Earth is complete if I can’t phone home.