DR 12 8 1500 2 - MagnumMacKivler/RLCPT2 GitHub Wiki
PRR's Centipedes spent most of their lives around Altoona with the rest of PRR's Baldwin road unit fleet. They saw a brief stint as hump units, too!
Photo courtesy of Craig Garver
The Baldwin DR-12-8-3000 (internally classified as DR-12-8-1500/2 SC) was Baldwin's first production road unit. Nicknamed the "Centipede," Baldwin's breakout road unit was designed for fast express passenger and freight service (very similarly to what BLW 6000 was designed for). It was available as a 3000 HP single unit or as a 6000 HP A-A set, permanently drawbarred.
Orders came from Seaboard Air Line, Ferrocarriles Nacionales de Mexico (NdeM), Pennsylvania Railroad, and Union Pacific (which would be promptly cancelled). Unforunately, the Centipede was plagued with issues throughout its lifetime, including the shortcomings of the early 608SC and a very unfortunate radiator and electrical cabinet placement. SAL and NdeM got many years of service out of their Centipedes after extensively rebuilding them, while PRR could not find a good place to run their behemoth A-A pairs. Of a production run of 54, none survive.
PT-Specific Information
| General Info | - |
|---|---|
| Prime Mover | L8-608SC 2x (1) |
| Horsepower | 2750 for traction (1) |
| Truck Type | Centipede Truck Set |
| Stand | CE-100 (2) |
| Axles | 12 |
| Traction Motors | 8 |
| Minimum Weight | 410,000 lbs |
| Maximum Weight | 590,000 lbs (3) |
| Model Base Speed | 60 MPH |
| Top Speed | 65, 70, 80, 100 MPH (4) |
| Electrical System | WESTINGHOUSE |
|---|---|
| Westinghouse 471A | Westinghouse 370DZ Motors |
| Generator Max Current | 3600 Amps |
| Max Traction Motor (TM) Current | 1800 Amps |
| Max Continuous TM Current | 900 Amps |
| Traction Motor Type | DC |
| Factor of Adhesion | 25% |
| Transition Mode | Automatic, no Selector (2) |
| Transition Groups | 2, 2, 2, 2 |
| Transition Shunts | 1, 0.69, 0.47, 0.36 |
| Generator Transition | No |
| Traction Control | APR |
| Dynamic Braking (DB) Mode (if used) | Electric blowers |
| DB Max Current | 860 Amps ⚠ |
| DB Max Continuous Current | 750 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 ⚠ (2) |
| TM Overload Protection | No |
| Starter Mode | Latched Primer, Manual Start |
| Air Brake Schedule | 24RL |
| Compressor CFM | 193 (Wabco 3CD @ 625 RPM) (5) |
| Main Reservoir Volume | 36 Cubic Feet ⚠ (5) |
Notes
⚠: Not Verified or Educated Guess
(1): The 608SC before 1950 only ever made 1500 brake horsepower; horsepower for traction was ~1375. SAL's 608A equipped units would have been most likely rated at 3000 HP for traction, although 3200 HP was entirely possible. Source: Will Davis' early 600 series manuals.
(2): CE-100 controllers were factory stock on all Centipedes; however, SAL rebuilt their units to have Westinghouse XM-781 electric throttles which would most likely make them Automatic with Selector. Moreso, Baldwin manuals state that CE-100/D-1 equipped locomotives take "about four seconds for the ammeter to develop a reading". Loading was likely very, very fast once the initial power contactor connection was made and the engine got up to speed. Source: BLH DF-107B manual.
(3): As with most Babyfaces, weight was very inconsistent between models. Seaboard Air Line 4500 was 410,000 pounds but PRR's units were 590,000 each.
(4): BLW sold all production centipedes with 100 MPH max speed, however, other 370 equipped road units were offered with other gear ratios (and most centipedes got lowered gear ratios from rebuilds anyways.) Source: PRR workshop diagrams of model BP-60 locomotives and BLW road switcher manuals.
(5): BLW standard air compressor options were as follows: WAB Co. 6-CD was available that made 385 CFM, a Gardner Denver WXG-9100 that made 352 CFM or a Gardner Denver WBH-9004 water-cooled that made 325 CFM. Ratings are at 625 RPM.