MK5000C - MagnumMacKivler/RLCPT2 GitHub Wiki
A demonstrator MK5000C likely on the Union Pacific (with an SD70M demonstrator behind it.) Photo credit Joseph Blackwell
The MK5000C is a Morrison Knudsen (or MK Rail around the time), 5000 horsepower, C-trucked locomotive that was offered by the MK Rail corporation (Later Motive Power Industries or MPI) between 1994 and officially 2002 (production has ceased with a bankruptcy in 1996).
With origins in the locomotive rebuilding business (with notable rebuilds such as Southern Pacific's SD40M-2 rebuild program that converted SD40s, SD45s, and SDP45s into locomotives with V16 prime movers and Dash 2 electronics, as well as Southern Pacific's Sulzer repowered U25Bs), Morrison Knudsen (or MK Rail) wanted to start their hand into the new locomotive building business. With competitors such as Electro-Motive Division with their SD70M and SD70MAC line up, as well as General Electric and their Dash 9 series of locomotives and AC traction AC4400CW offering only around 4000-4500 horsepower, MK saw their chance to corner the market with a higher 5K horsepower locomotive to give out to railroads looking to do more trains with less engines. After securing a prime mover from Caterpillar, the CAT 3612 V12, MK then announced in around 1992 it was ready to start creating locomotives of its own; MK would also then move onto a planned 5500 model, and then finally a 6000 model as time progressed.
While it utilized Dofasco trucks (last seen on later model Canadian MLW's M- and HR-series locomotives), and an EPIC 3102, 26L schedule airbrake system, those two items bear the only resemblance to manufacturers before. Featuring a proprietary (and unique) 3 window cab design, traction control system (MK-LOC), traction motors (MK1000s), hood, and frame, this locomotive was from the ground up different. While it might appear like a copycat EMD, under the skin of this locomotive was an entirely new locomotive
Two Southern Pacific MK5000Cs sit with a test car in Denver before heading up the Moffat Route. Photo credit Mark Bau.
Southern Pacific, eager to replace it's aging tunnel motor fleet, was looking for something to take long and heavy trains over steep grades (such as Tennessee Pass and Donner Pass). Soon, they put in an attentive order of 50 locomotives, and tested 2 fully dressed in SP speed lettering across the system. Main issues like bearing failures, lack of parts interchangeability, less powerful DC motors (compared to competitors' AC motor offerings) and other teething bugs with the electronics sent SP over to General Electric for AC4400CWs to handle their trains, returning the 2 MK units and cancelling further orders. Union Pacific, also testing these units, found similar problems too with proprietary parts to stock as well as teething troubles with the new units. Further problems stemmed with MK Rail was sold off after MK Corp (The holding company) was bankrupt in 1996, leaving the MK high horsepower programmed to be altogether abandoned, ensuring no other MK5000s would see the rails. Overall, 6 units were produced, with another 4 in progress being cut up by new holding company Motive Power Industries in the early 2000s.
A Utah Railway MK5000C, now converted to an MK50-3, sits on the top of Soldier Summit; note the SD50/GP50 EMD hood post-prime mover swap. Photo credit James Belmont.
Out of the 6 produced, all went to Utah Railway after they were interested in having their coal trains pull up steep grades. After issues with main bearings on the CAT engine and KATO alternator failing from heavy use required in mainline service (after all, the CAT engine was designed to be a stationary generator or construction equipment, not a locomotive prime mover), MPI later removed the CAT/Kato combo and swapped all 6 units with (ironically more reliable) 645F and AR11 engine/alternator sets and engine hoods from 6 retired Union Pacific SD50s & GP50s, later being renamed "MK50-3"s . These units, now owned by Gennessee and Wyoming who took over Utah Railway, currently see active service on the Kyle Railway in Kansas to this day (12/2023).
PT-Specific Information
| General Info | - |
|---|---|
| Prime Mover | CAT (Caterpillar) 3612 V12 |
| Horsepower | 5000 |
| Truck Type | Dofasco 40in Hi-Ad (1) |
| Axles | 6 |
| Traction Motors | 6 |
| Minimum Weight | 368,000 lbs |
| Maximum Weight | 420,000 lbs ⚠ |
| Model Base Speed | 70 MPH |
| Top Speed | 70, 75, 79, 84, or 93 |
| Electrical System | - |
|---|---|
| Generator Max Current | 8400 Amps |
| Max Traction Motor (TM) Current | 1800 Amps (2) |
| Max Continuous TM Current | 1630 Amps (2) |
| Traction Motor Type | DC |
| Factor of Adhesion | 29% (3) |
| Transition Mode | Automatic, no Selector |
| Transition Groups | 1 |
| Transition Shunts | 1 |
| Generator Transition | Yes |
| Traction Control | Electronic Traction Control |
| Dynamic Braking (DB) Mode (if used) | Electric Blowers |
| DB Max Current | 1200 Amps |
| DB Max Continuous Current | 900 Amps |
| Blended Braking | No |
| Miscellaneous | - |
|---|---|
| Head-End Power (HEP) | No |
| HEP Power Consumption | N/A |
| HEP Standby/Run Mode | N/A |
| Load Ramp Speed | 2 Amps/Tick |
| TM Overload Protection | No |
| Starter Mode | Manual Primer, Manual Start |
| Air Brake Schedule | 26-L |
| Compressor CFM | 254 (Gardner Denver WLN @ 900RPM) |
| Main Reservoir Volume | 35 Cubic Feet |
(1): 42" wheels were optional for the MK5000C, but none were equipped with them.
(2): The MK5000C came with proprietary MK1000 motors, which are apparently General Electric 752AG traction motor clones; data used from C40-8 page which has GE 752AGs
(3): The Dofasco Hi-Ad truck and the GE 752AG traction motor both have a factor of adhesion of 29%
Notes
⚠: Not Verified or Educated Guess