U28C - MagnumMacKivler/RLCPT2 GitHub Wiki
Burlington Northern 5663 is a very typical early body U28C. Of note are air reservoir location (in a cabinet behind the cab), and trucks (GE's own trimount). BN would be the only RR to own true early frame U28C's after the CB&Q and NP became BN.
The U28C was, functionally and physically, an uprated U25C. As part of GE's scramble at the time to catch up to EMD, who were trialling 3000 horsepower at the time through the 645 line, GE began aggressively uprating the FDL during the U25's lifetime, selling several production demonstrators to various roads (namely NP, ACL, and PRR). First uprating to 2750 HP, and later 2800, these "U25CU"s were demonstrated on their respective roads a full year prior to the introduction of the U28C. As GE had the single most frightening generator known to man (the infamous GT-598), GE managed to get away with 2800 HP on the same generator as the aforementioned U25C.
GE had never intended to sell a 6 axle locomotive on the U25 chassis, and the original body reflected this. Recycling equipment originally made for electric locomotives (namely the E33 and E44), the U28C carried this odd frame and body at the beginning of production. GE was fully intending to replace it (and the trimount trucks it rode on) as they were developing what would later become the FB3 and the standardized Universal body and frame.
The first locomotives to ride on the redesigned Universal chassis would be yet another set of production demonstrators, in the form of eight L&N units built in May 1966 and one UP unit built in June. By August, the new Universal body was fully deployed, and the last original frame U28 (NP #2811) rolled out of Erie. In total, 28 U28C's would be built on the earlier chassis (all for CB&Q and NP), while the other 53 were in the later carbody.
More changes would come to the U28C through the new body, mainly through iterative updates to the FDL and the electrical gear. GE was quietly preparing the GTA-9 alternator to replace the GT-598, however it would only be introduced at the very end of production. Other notable developments during this time were ATSF's landmark order for U28CG's, one of only three times GE would build a locomotive model with a steam generator, the other two being U30CG's for ATSF again and U36CG's for NdeM.
Towards the very end of U28C production, GE finally introduced the GTA-9, however the only true U28C's to get the GTA-9 were PRR's one order for 15 units. Confusingly, SP placed an order for U28C's that were built after PRR's order for U28C's, however these units came with GT-598's. Ultimately the SP order would be the last U28C's built as the next order to arrive (four units for ACL) would be changed to U30C's during production, thus finally bringing GE up to spec with EMD and ALCO.
The only U28C's to get alternators were PRR's. PRR also owned U25C's factory uprated to 2800 by GE, however these carried generators. Photo credit Craig Garver
PT-Specific Information
| General Info | Early Body |
|---|---|
| Prime Mover | GE 7FDL-16C (1) |
| Horsepower | 2800 |
| Truck Type | GE Heavy Trimount |
| Axles | 6 |
| Traction Motors | 6 |
| Minimum Weight | 360,000 lbs |
| Maximum Weight | 420,000 lbs |
| Model Base Speed | 70 MPH |
| Top Speed | 70 MPH |
| Electrical System | GT-598/Trimount Trucks |
|---|---|
| Generator Max Current | 3600 Amps |
| Max Traction Motor (TM) Current | 1800 Amps |
| Max Continuous TM Current | 1195 Amps |
| Traction Motor Type | DC |
| Factor of Adhesion | 27% ⚠ |
| Transition Mode | Automatic with Selector |
| Transition Groups | 2, 2, 1, 1 |
| Transition Shunts | 1, 0.75, 1, 0.75 |
| Generator Transition | No |
| Traction Control | APR |
| Dynamic Braking (DB) Mode (if used) | Mechanical Blowers (8) |
| DB Max Current | 620 Amps ⚠ |
| DB Max Continuous Current | 620 Amps ⚠ |
| Blended Braking | No |
| Electrical System | GT-598/FB-3 |
|---|---|
| Generator Max Current | 3600 Amps |
| Max Traction Motor (TM) Current | 1800 Amps |
| Max Continuous TM Current | 1195 Amps |
| Traction Motor Type | DC |
| Factor of Adhesion | 29% ⚠ |
| Transition Mode | Automatic with Selector |
| Transition Groups | 2, 2, 1, 1 |
| Transition Shunts | 1, 0.75, 1, 0.75 |
| Generator Transition | No |
| Traction Control | APR |
| Dynamic Braking (DB) Mode (if used) | Mechanical Blowers (8) |
| DB Max Current | 620 Amps ⚠ |
| DB Max Continuous Current | 620 Amps ⚠ |
| Blended Braking | No |
| Electrical System | GTA-9/FB-3 |
|---|---|
| Generator Max Current | 5400 Amps |
| Max Traction Motor (TM) Current | 1800 Amps |
| Max Continuous TM Current | 1195 Amps |
| Traction Motor Type | DC |
| Factor of Adhesion | 29% ⚠ |
| Transition Mode | Automatic with Selector |
| Transition Groups | 2, 1 |
| Transition Shunts | 1, 1 |
| Generator Transition | No |
| Traction Control | APR |
| Dynamic Braking (DB) Mode (if used) | Mechanical Blowers (8) |
| DB Max Current | 620 Amps ⚠ |
| DB Max Continuous Current | 620 Amps ⚠ |
| Blended Braking | No |
| Miscellaneous | - |
|---|---|
| Head-End Power (HEP) | No |
| HEP Power Consumption | N/A |
| HEP Standby/Run Mode | N/A |
| Load Ramp Speed | 3 Amps/Tick |
| TM Overload Protection | No |
| Starter Mode | Latched Primer, Manual Start (2) |
| Air Brake Schedule | 26-L |
| Compressor CFM | 307 CFM (Wabco 3CDCBL @ 1000 RPM) (3) |
| Main Reservoir Volume | 32.4 Cubic Feet (4) |
Notes
⚠: Not Verified or Educated Guess
(1) The FDL-16B only existed as a test engine at Erie, and did not reach production. Changes to the FDL between the A and C included (most notably) firing order changes, moving from a balanced firing order to an uneven firing order changing the exhaust note from a continuous roll to an uneven lump, now known as the characteristic "glug". The FDL would keep this firing order until the very end.
(2) Some units may have had air start. This would probably be earlier units? I have no idea. ⚠
(3) Gardner-Denver WBO's were optional; CFM would be 316.3125.
(4) The early chassis' probably had smaller air reservoirs (as they were nestled into the hood), but I have no way to confirm this.