U28B - MagnumMacKivler/RLCPT2 GitHub Wiki
A Rock Island U28B in Council Bluffs, Iowa. Photo credit Craig Garver
In 1965, EMD announced the 645 line, which would include 3000 horsepower road locomotives in both 4 and 6 axle formats. This was the culmination of the last four years of design work done at La Grange, ultimately forming the AR10 alternator and 645 engine. The first 645 line locomotives to appear were a set of modified SD35's, which were ultimately referred to as SD40X's.
GE was prepared for EMD's advancement, having invested time into the development of the GTA-9 alternator and having bench tested the FDL up to 4000 horsepower, however they were not ready for high horsepower at the same time as EMD was on their frame. Biding their time and providing a modest upgrade for their customers, GE introduced the one year only U28, which was initially little more than a slight uprate to the U25.
Early production U28's were, for all intents and purposes, 2800 horsepower U25's. A handful of late model U25B's and U25C's sent to various customers came with uprates to 2750 HP, and while some were returned to 2500 after purchase, it was clear that the U25 was capable of more than 2500 horsepower. Orders such as P&LE's U28B fleet and Northern Pacific's U28C's are virtually identical to their slightly weaker brethren, with only the modest horsepower increase.
The U25 carbody was not long for this world. GE had never intended to sell a 6 axle U25, which was reflected by the U25C's borrowing of electric era designs and equipment, and GE had big plans to replace it with a more standard carbody for both the 4 and 6 axle frames. This would come to fruition during U28 production when the first new Universal carbodies were rolled out in April for L&N and Union Pacific. GE completed their remaining old carbody orders and finished all new orders in the new carbody.
They had even more in store for the U28 before production ended. The GTA-9 was offered as an extra addition beginning in August, with a handful of purchasers taking the offer. When GE finally made 3000 horsepower road locomotives, a U28 with a GTA-9 could be sent back to GE to become a U30. CB&Q took GE up on this, with one order of U28B's going back to GE to become U30B's.
Production came to an end in late 1966; the next orders to come to GE for 4 axle road locomotives would be filled by the first U30B's which were, ironically, virtually identical to U28B's. Final production of the U28B came to a respectable 149 units.
BN 5455 is very typical of post-April production U28B's. Photo credit Chuck Zeiler
PT-Specific Information
| General Info | - |
|---|---|
| Prime Mover | GE 7FDL-16C |
| Horsepower | 2800 |
| Truck Type | AAR Type B (1) |
| Axles | 4 |
| Traction Motors | 4 |
| Minimum Weight | 260,000 lbs |
| Maximum Weight | 288,000 lbs |
| Model Base Speed | 70 MPH |
| Top Speed | 70, 80, or 85 ⚠ |
| Electrical System | - |
|---|---|
| Generator Max Current | 3600 Amps |
| Max Traction Motor (TM) Current | 1500 Amps |
| Max Continuous TM Current | 1085 Amps |
| Traction Motor Type | DC |
| Factor of Adhesion | 25% |
| Transition Mode | Automatic w/ Selector |
| Transition Groups | 2, 2, 1, 1 |
| Transition Shunts | 1, 0.55, 1, 0.55 |
| Generator Transition | No |
| Traction Control | APR |
| Dynamic Braking (DB) Mode (if used) | Mechanical Blowers (0) |
| DB Max Current | 740 Amps ⚠ |
| DB Max Continuous Current | 740 Amps ⚠ |
| Blended Braking | No |
| Miscellaneous | - |
|---|---|
| Head-End Power (HEP) | No |
| HEP Power Consumption | N/A |
| HEP Standby/Run Mode | N/A |
| Load Ramp Speed | 8 Amps/Tick ⚠ |
| TM Overload Protection | No |
| Starter Mode | Latched Prime, Manual Start |
| Air Brake Schedule | 26-L |
| Compressor CFM | 307cfm (Wabco 3CDCBL @ 1000 RPM) |
| Main Reservoir Volume | 32.4 Cubic Feet |
Notes
(1): Blomberg-Bs could be used from EMD trade-ins. Factor Of Adhesion is the same.