4-6-6-4 4-6-6-4 construction roster 4-6-6-4 construction roster

| Railroad_quantity | Class_ | Road_numbers | Builder | Build_year |
|---|---|---|---|---|
| Clinchfield Railroad (12 new, 6 secondhand) | E-1 | 650–657 | ALCO | 1942–1943 |
| Clinchfield Railroad (12 new, 6 secondhand) | E-2 | 660–663 | ALCO | 1947 |
| Clinchfield Railroad (12 new, 6 secondhand) | E-3 | 670–675 | ALCO | 1943 |
| Delaware and Hudson Railway (40) | J | 1500–1539 | ALCO | 1940–1946 |
| Denver and Rio Grande Western Railroad (21) | L-105 | 3700–3709 | Baldwin | 1938 |
| Denver and Rio Grande Western Railroad (21) | L-105 | 3710–3714 | Baldwin | 1942 |
| Denver and Rio Grande Western Railroad (21) | L-97 | 3800–3805 | ALCO | 1943 |
| Great Northern Railway (2 secondhand) | Z-6 | 4000–4001 | ALCO | 1937 |
| Northern Pacific Railway (47) | Z-6 | 5100–5120 | ALCO | 1936–1937 |
| Northern Pacific Railway (47) | Z-7 | 5121–5126 | ALCO | 1941 |