G22AR - MagnumMacKivler/RLCPT2 GitHub Wiki
KiwiRail DC (EMD G22AR) #4041 at Woodville, Manawatu District, November 19, 2017. Photo by Titus Studios.
The G22AR was built by the General Motors Electro-Motive Division for the New Zealand Government Railways. Many of this class was rebuilt from the New Zealand Railways DA Class in the late 1970s and early 1980s, Operated by KiwiRail on freight trains, and formerly on long-distance KiwiRail Scenic passenger trains. After the DA class they were the most numerous class of diesel locomotive on New Zealand's railway network, and remained numerically dominant until the mid-2010s when withdrawals began.
Between 1978 and 1983, 85 of the later-build DAs were rebuilt as General Motors Electro-Motive Division Model G22AR, designated as the DC class, with upgraded engines, new cabs and low short hoods of a style similar to the DX class introduced earlier in the 1970s and the DF class being introduced at the time. Five were rebuilt at the Hutt Workshops near Wellington and the other 80 at Clyde Engineering in Australia.
The class continues to be a major workhorse, operating either as single units or in multiple with other DC units or locomotives from the DFT, DX or DL classes.
The class were used on KiwiRail Scenic's South Island Coastal Pacific, and was also used on the North Islands Northern Explorer until being replaced by a DFB, DFT, DXB or occasionally a DXC unit and on the TranzAlpine until being replaced by two DXC units. A unit is also occasionally employed to haul the Capital Connection service.
Rebuilds
DCP Rebuilds
The DCP sub-class was established in 2002 to differentiate locomotives owned by Tranz Scenic 2001 Ltd from those owned by Tranz Rail Ltd. The DCP classification was retained on these locomotives after the purchase of Tranz Scenic 2001 by Toll NZ, and continues to be used by KiwiRail. Further units since received the classification, though it then referred to those DC locomotives that were fitted with bogie retention wire ropes to stop the bogies falling off in derailments, rather than locomotives dedicated to passenger workings. The practice of reclassifying has now been abandoned by KiwiRail, though most DCs, including all those used on Auckland commuter services, have received the bogie ropes.
Withdraws
As of February 2019, 63 units have been withdrawn from service. Units were withdrawn as a result of accidents, or on account of being surplus to requirements or poor mechanical condition. One unit, DC 4496, was taken out of service for an experimental rebuild that was later cancelled.
PT-Specific Information
| General Info | - |
|---|---|
| Prime Mover | EMD 12-645C Or EMD 12-645E |
| Horsepower (12-645C) | 1200 HP |
| Horsepower (12-645E) | 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 | 26L |
| Compressor CFM | 254 (WBO @ 900 RPM) |
| Main Reservoir Volume | 30.5 Cubic Feet ⚠ |
⚠: Not Verified or Educated Guess
Extra History
Locomotive Upgrades
DC Micro: In May 1988, trials were carried out using GE's BrightStar control system on DC 4588 and DC 4939, which were unsuccessful. In November 1988, DC 4588 was fitted with the Canadian ZTR wheel slip system. The system substantially enhanced traction on the bogies, maximising traction potential. DC 4628 followed in December 1988 and was also a success. Over the next 10 years, 64 DC locomotives had ZTR fitted.
Locolog and Tranzlog: Locolog was an event recorder system similar to a black box on aircraft. It was trialed successfully in 1986 on DC 4070 and DC 4778 before being fitted to all other main-line locomotives. It has since been supplanted by the locally produced Tranzlog system, with both systems having provided significant material to assist in accident investigations.
Fire suppression: In 2014, six of the class were fitted with fire suppression to run passenger services through the 8.8 Kilometre Rimutaka Tunnel on the Wairarapa Line due to a change in requirements resulting from the Commission of Inquiry in the Pike River Mine disaster. This was removed from these locomotives in mid-2015 and reinstalled into the DFB class locomotives which took over the haulage of these services. However, fire suppression has been refitted to several members of the class in order to provide locomotives for passenger charter services and for back-up for The Great Journeys of New Zealand long-distance passenger services.
Cab concerns
In March 2001, the Rail & Maritime Transport Union threatened to set the maximum speed of the DC class to 50 KPH due to corrosion found on cab mounts. This causes the cab of a DC to detach from the frame during a derailment, and a driver had fallen through the floor of a unit. An audit was made on all units and found 19 locomotives had maintenance concerns. The concerned units were regulated to trail-only units, and work was made in a short matter of time to repair the cabs. It was understood the concerned units would be fitted with universal cabs, but this never commenced.
In early 2017, concerns were raised by the RMTU surrounding rusty cab structures, cab mounting, and anti-collision posts. Fearing the cabs could have been ripped off in the course of an accident, all (but one) units were banned from leading in the South Island; again confined to trail-only units until they had been inspected. Although units in the North Island were banned from leading trains, they were seen being used on shunts. Work was carried out at both Hutt and Hillside workshops, most were back leading trains within a couple of months.