SW7 - MagnumMacKivler/RLCPT2 GitHub Wiki
BN 117 doing what it was built to do in Kansas City, MO. Photo credit Craig Garver
The SW7 was an uprated NW2. As EMD modernized their line of equipment post-war, the 1000 horsepower switcher received a modest uprating along with a general upgrade to the rest of the locomotive to correct flaws present in previous designs. The new design, dubbed the SW7 (EMD's naming convention for the switcher line is completely bogus, don't even try to make sense of it), would go on to sell a strong 489 over just over a year, thanks to dieselization.
EMD also offered the SW7 as a cow-calf pair, dubbed the TR4. They were identical mechanically and electrically to the SW7, with the only differences being in the calf unit's lack of cab and rear steps, and the cow unit's second control stand.
PT-Specific Information
| General Info | - |
|---|---|
| Prime Mover | V12-567A |
| Horsepower | 1200 |
| Truck Type | AAR Type A |
| Axles | 4 |
| Traction Motors | 4 |
| Minimum Weight | 220,000 lbs ⚠ |
| Maximum Weight | 250,000 lbs |
| Model Base Speed | 45 MPH |
| Top Speed | 45 MPH |
| Electrical System | - |
|---|---|
| Generator Max Current | 1500 Amps |
| Max Traction Motor (TM) Current | 1000 Amps |
| Max Continuous TM Current | 700 Amps |
| Traction Motor Type | DC |
| Factor of Adhesion | 25% |
| Transition Mode | Automatic, optional disable switch |
| Transition Groups | 4, 2 |
| Transition Shunts | 1, 1 |
| Generator Transition | No |
| Traction Control | None |
| Dynamic Braking (DB) Mode (if used) | N/A |
| DB Max Current | N/A |
| DB Max Continuous Current | N/A |
| 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 | Number 6 |
| Compressor CFM | 230 (Gardner Denver WBO @ 835 RPM ) |
| Main Reservoir Volume | 34 Cu.Ft |
Notes
⚠: Not Verified or Educated Guess