The Dotsero Southern ordered 15 SD40T-2 locomotives in September 1975. These units were delivered between January 1976 and March 1976.
The SD40T-2 locomotives were bought along side the opening of the new Busk-Ivanhoe sub-division. These 6-axle locomotives were better equipped to deal with the steeper grades and the enhanced cooling made them less likely to overheat through the many tunnels on the route.
All locomotives were ordered with a horizontal gyralight on the nose and a horizontal headlight on the roof. When ordered, 116 inch noses were used to allow for radio control of the units. Along with keeping the gyralight, flashing ditchlights would be added in 1996. Despite most units on the DSRR roster receiving the "wings" paint scheme by 2004, these units wouldn't. They wouldn't receive this paint due to them being retired only a year later. All the DSRR SD40T-2 locomotives would be given Nathan M5 horns with the 4th and 2nd bells being reversed. This M5 horn would be mounted just behind the cab on the roof.
The SD40T-2 locomotives started the trend of horizontal nose lights on standard cab units.
The SD40T-2 locomotives currently haven't had any major issues over their years of service, though they were stored in wake of new units being bought.
| Unit Number | Build Date | Last Run | Notes |
|---|---|---|---|
| DSRR 2300 | January 1986 | December 31st, 2005 | Stored. |
| DSRR 2301 | January 1986 | December 31st, 2005 | Stored. |
| DSRR 2302 | January 1986 | December 31st, 2005 | Stored. |
| DSRR 2303 | January 1986 | December 31st, 2005 | Stored. |
| DSRR 2304 | January 1986 | December 31st, 2005 | Stored. |
| DSRR 2305 | February 1986 | December 31st, 2005 | Stored. |
| DSRR 2306 | February 1986 | December 31st, 2005 | Stored. |
| DSRR 2307 | February 1986 | December 31st, 2005 | Stored. |
| DSRR 2308 | February 1986 | December 31st, 2005 | Stored. |
| DSRR 2309 | February 1986 | December 31st, 2005 | Stored. |
| DSRR 2310 | March 1986 | December 31st, 2005 | Stored. |
| DSRR 2311 | March 1986 | December 31st, 2005 | Stored. |
| DSRR 2312 | March 1986 | December 31st, 2005 | Stored. |
| DSRR 2313 | March 1986 | December 31st, 2005 | Stored. |
| DSRR 2314 | March 1986 | December 31st, 2005 | Stored. |