DD40A - MagnumMacKivler/RLCPT2 GitHub Wiki
Diagram of the DD40A from EMD's 1966 "new dimensions" 645 line catalog
The DD40A was the replacement in the "645 line" catalog for the DD35A, replacing the concept of two GP35s on one frame with two GP40s, producing a total of 6000 horsepower. Unlike the DD35/DD35A, the DD40A did not have a DD40 (cabless) companion.
An upgraded version of the DD40A, the DDA40X ("X" denoting it's experimental status, the "A" being moved to avoid confusion), was designed and produced for Union Pacific starting in 1969. These units featured F45-style cabs for more crew space, the first deployment of EMD's modular electrical system, and an experimental version of the 645E3, which increased horsepower to 3300 per motor.
The "double diesel" concept was dropped from the catalog entirely with the end of the "645 line" in December 1971, being deemed more hassle than maintaining two separate locomotives. However, many improvements tested on the DDA40X locomotives, such as the modular electrical system and improvements to the 645 engine - albeit without the increase in horsepower - were implemented in the "dash 2" line, debuting in 1972.
PT-Specific Information
| General Info | - |
|---|---|
| Prime Mover | 2x EMD 16-645E3 |
| Horsepower | 6000 HP |
| Truck Type | EMD "Flexicoil" D |
| Axles | 8 |
| Traction Motors | 8 |
| Minimum Weight | 520,000 lbs |
| Maximum Weight | 565,000 lbs ⚠ |
| Model Base Speed | 65 MPH |
| Top Speed | 65, 71, 77, or 83 MPH |
| Electrical System | - |
|---|---|
| Generator Max Current | 6000 |
| Max Traction Motor (TM) Current | 1500 |
| Max Continuous TM Current | 1050 |
| Traction Motor Type | DC |
| Factor of Adhesion | 25% |
| Transition Mode | Automatic |
| Transition Groups | 1, 1, 1, 1 (1) |
| Transition Shunts | 1, 0.67, 0.53, 0.40 (1) |
| Generator Transition | No |
| Traction Control | APR with sanding |
| Dynamic Braking (DB) Mode (if used) | Mechanical Blowers |
| DB Max Current | 700 |
| DB Max Continuous Current | 700 |
| 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 | 26L |
| Compressor CFM | 254 (WBO @ 900 RPM) |
| Main Reservoir Volume | 33.8 Cubic Feet |
Notes:
⚠: Not Verified or Educated Guess
(1): Later-built DD40As would have had a simplified transition setup: Groups 1 / Shunts 1