GL22MC - MagnumMacKivler/RLCPT2 GitHub Wiki
KiwiRail DFB (EMD GL22MC) #7241 at Whakatu, Hawkes Bay, October 4, 2018. Photo by Titus Studios.
The G22 Series were first introduced in 1968 to replace the popular G12 along with other improvements. They carried a low per axle weight on their Flexicoil Type-GC Bogies and were the first model series to have a low nose as a standard option as well. The G22 series now carried a "U" or "W" suffix after the model designation to indicate the type of traction motors. A "C" indicated six axle trucks, while a "4" indicated A-1-A- trucks. The designations could apply to any kind of export locomotive design of EMD or another licensee of EMD as long as the electrical & mechanical gear was left unaltered.
The New Zealand Railways DF Units were powered by an EMD 12-645 engine, the same prime mover chosen for the DC Class, but were able to make greater use of that power by having six traction motors and Co-Co arrangement as opposed to the four traction motors and A1A-A1A wheel arrangement of the DCs. This gave the DF several advantages, a tractive effort of 45,000 lbf and a maximum speed of 113 KPH (70 MPH), compared to the DCs 31,000 lbf and 100 KPH (62 MPH).
Sub-Classes
DFB Sub-Class
Between 2006-07, Toll Rail installed the Brightstar engine management system into twelve DFT class locomotives, with these locomotives then officially reclassified as DFB. In June 2016, KiwiRail re-introduced the programme for a number of units.
DFM Sub-Class
In the early 2000s a number of DFTs were fitted with the Maxitrax wheelslip control and received an internal sub-classification of DFM. This was used in the Amicus computer system only, and the classification was initially not applied to the locomotives themselves which remained identified as DFT. Although Maxitrax has since been removed from these locomotives some of the units that were classed as DFM have had the designation applied to them when repainted into the KiwiRail livery.
Some Original DF Units were Rebuilt into the class known as the DFT (T for Turbocharged)
Present Day
The class remains predominantly employed on general freight duties on all routes nationwide, with the general exception of through trains on the North Island Main Truck (NIMT) and the Midland Line coal workings. The units operate both in multiple with the other mainline locomotive classes, or as single units, depending on availability and the level of motive power required. Since October 2016, DFBs that are fitted with a fire suppression system, have been assigned to all the North Island KiwiRail Scenic Journeys passenger services, and are occasionally used on the Coastal Pacific in the South Island.
PT-Specific Information
| General Info | - |
|---|---|
| Prime Mover | 12-645E3C |
| Horsepower | 2400 |
| Truck Type | Flexicoil Type-C Co-Co |
| Axles | 6 |
| Traction Motors | 6 |
| Minimum Weight | 192640 lbs |
| Maximum Weight | 212800 lbs |
| Model Base Speed | 70 MPH |
| Top Speed | 70 |
| Electrical System | - |
|---|---|
| Generator Max Current | 3000 Amps |
| Max Traction Motor (TM) Current | 600 |
| Max Continuous TM Current | 475 |
| Traction Motor Type | DC |
| Factor of Adhesion | 25% (50% with BrightStar) |
| Transition Mode | Fully Automatic |
| 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 | 450 |
| DB Max Continuous Current | 400 |
| 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 |
| TM Overload Protection (KiwiRail DFB Class) | Yes |
| Starter Mode | Manual Primer, Manual Start |
| Air Brake Schedule | 26L |
| Compressor CFM | 254 (WBO @ 900 RPM) |
| Main Reservoir Volume | 35 Cubic Feet |
⚠: Not Verified or Educated Guess