| Number | Class | Build Date | Renumbered | Retired | Notes |
|---|---|---|---|---|---|
| 508 | GY-00a | from 268:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother Sold to New Brunswick Southern (NBSR) | ||
| 509 | GY-00a | from 269:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 510 | GY-00a | from 270:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 511 | GY-00a | from 271:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 512 | GY-00a | from 272:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 513 | GY-00a | from 273:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 514 | GY-00a | from 274:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 515 | GY-00a | from 275:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 516 | GY-00a | from 276:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 517 | GY-00a | from 277:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 518 | GY-00a | from 278:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 519 | GY-00b | from 279:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 520 | GY-00b | from 280:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 521 | GY-00b | from 281:1 in 1990 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | ||
| 522 | GY-00b | from 282:1 in 1990 | March 12 2015 | HBU-4 hump booster unit (slug) usually operates with GP38 75xx series mother | |
| 523 | GH-00c | Built new 1980 | Modified for hump service | ||
| 524 | GH-00c | Built new 1980 | Modified for hump service | ||
| 525 | GH-00c | Built new 1980 | Modified for hump service | ||
| 526 | GH-00c | Built new 1980 | Modified for hump service |