G12 - MagnumMacKivler/RLCPT2 GitHub Wiki
New Zealand Railways DAA (EMD G12) #1401 at Feilding, Manawatu District, June 2, 2018. Photo by Titus Studios.
The G12 was a Locomotive developed by General Motors Electro-Motive Division for Exportation across the world. The G12s were built in several gauges (Ex, 3 ft 6 in, 5 ft 3 in, Etc) This made these engines high demand for Railroads because of its low cost and flexibility. Engines were built by General Motors Electro-Motive Division, The Canadian affiliate General Motors Diesel and Clyde Engineering. Clyde Engineering Built 10 Locomotives for New Zealand in 1957, 5 for Hong Kong, 23 for Queensland, 14 for Western Australia and 7 for the BHP Group. Production of this Locomotive ranged from 1953 to 1968, A total of 1036 units were built during this period.
The G12 was powered by an EMD 567 Series Diesel Engine, rated for 1420 Hp (Some have been rebuilt with EMD 645 Series Engines) providing more then enough power for most general purpose movements. The power generated from this engine would power 4 EMD D19 or D29 Traction motors located on the Bogies of the Locomotive.
New Zealand Railways DA Class
A major purchaser of these engines was New Zealand, totaling in at 146 units. The EMD G12 Locomotives that arrived in New Zealand were denoted the Class, DA. These Locomotives operated on the New Zealand Government Railway System between 1955 and 1989. They were the most numerous class to ever operate in New Zealand, with five more than the AB class steam locomotive.
The DAs came stock with A1A-A1A Bogies, The engine body was altered slightly to run on New Zealand's 3 ft 6 in rail system (And fit the small loading gauge) They were introduced into New Zealand between 1955 and 1967 in three phases, and were the first class of Diesel Locomotives to seriously displace the traditional steam traction that had been in use for many prior years.
Rebuilds
The New Zealand Railways DA Class Locomotives had 2 major rebuilds,
DAA Rebuilds
In 1970, Locomotives DA 1400-1404 were withdrawn from mainline duties and reassigned as Heavy Shunters to work in the new Te Rapa Hump Yard. They received additional low speed controls to assist in these operations and were reclassified as the DAA class. (These can be identifiable by their yellow hood stripes) The locomotives were later superseded by the DSG and DSJ class shunting locomotives, which were purpose-built for shunting as opposed to the DAA class being converted for that purpose, and were withdrawn in the 1980s.
DC Rebuilds
As the old age of the engines started to take toll New Zealand Railways rebuilt 85 DAs Between 1978 and 1983 into the EMD G22AR, This Model became the DC Class. Over 7 years, 80 were rebuilt by Clyde Engineering in Adelaide, while a further five were rebuilt at Hutt Workshops using a mixture of parts built at Hutt and Clyde. Many of the DC class remain in service today with ownership held by KiwiRail, and several were leased to Auckland Transport.
DAR Rebuilds (Withdrawn)
In 1989, Tasman Pulp & Paper was in need to replace their Kawerau shunting locomotive. New Zealand Railways initially offered a DH class locomotive as a replacement, however, Tasman did not feel the locomotive would be up to the task. At the time, New Zealand Railways was withdrawing the last DA class locomotives, and the decision was made to offer DA 512 as a new Heavy Shunter. The locomotive was altered by chopping the front hood containing the dynamic brake components and altering the cab for better forward visibility. It was then renumbered as DA 822 and was painted in Tasman's orange-brown colors before it entered service at Kawerau. It was repainted in the Toll Rail 'Corn Cob' colors in 2005, but was withdrawn from service in September 2008 for an overhaul (which never commenced) and was placed in storage at Hutt Workshops. The locomotive was scrapped in December 2017.
PT-Specific Information
| General Info | - |
|---|---|
| Prime Mover | EMD 12-567C Or EMD 12-567E |
| Horsepower | 1200 HP |
| Truck Type | Flexicoil A1A |
| Axles | 6 |
| Traction Motors | 4 |
| Minimum Weight | 188574 lbs |
| Maximum Weight | 196873 lbs |
| Model Base Speed | 62 MPH |
| Top Speed | 62 |
| Electrical System | - |
|---|---|
| Generator Max Current | 3000 Amps |
| Max Traction Motor (TM) Current | 750 |
| Max Continuous TM Current | 600 |
| Traction Motor Type | DC |
| Factor of Adhesion | 25% |
| 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 with sanding |
| Dynamic Braking (DB) Mode (if used) | Mechanical Blowers |
| DB Max Current | 400 |
| DB Max Continuous Current | 450 |
| 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 | 6-BL |
| Compressor CFM | 299 (WBO @ 835 RPM) ⚠ |
| Main Reservoir Volume | 30.5 Cubic Feet ⚠ |
⚠: Not Verified or Educated Guess