| 1 | A | B | C | D |
| --- | --- | --- | --- | --- |
| 2 | EMD GP30 - Cab-equipped 'A' units |  |  |  |
| 3 | Railroad | Quantity | Road numbers | Notes |
| 4 | Electro Motive Division (demonstrator) | 2 | 5629 | to Union Pacific Railroad 875 |
| 5 | Electro Motive Division (demonstrator) | 2 | 5639 | to Seaboard Air Line Railroad 534, to Seaboard Coast Line Railroad 1343 |
| 6 | Alaska Railroad | 1 | 2000 | - |
| 7 | Atchison, Topeka and Santa Fe Railway | 85 | 1200–1284 | rebuilt versions called GP30u**upgraded at Cleburne, Texas shops.) |
| 8 | Atlantic Coast Line Railroad | 9 | 900–908 | to Seaboard Coast Line Railroad 1300–1308 |
| 9 | Baltimore and Ohio Railroad | 77 | 6900–6976 | - |
| 10 | Chesapeake and Ohio Railway | 48 | 3000–3047 | - |
| 11 | Chicago, Burlington and Quincy Railroad | 38 | 940–977 | to Burlington Northern Railroad 2217–2254 |
| 12 | Chicago and Eastern Illinois Railroad | 3 | 239–241 | - |
| 13 | Chicago Great Western Railway | 8 | 201–208 | to Chicago & North Western Railway 802–809 |
| 14 | Chicago, Milwaukee, St. Paul and Pacific Railroad | 16 | 340–355 | AAR type B trucks. Renumbered 1000–1015 |
| 15 | Chicago and North Western Railway | 14 | 810–832 | - |
| 16 | Canadian Pacific Railway | 2 | 8200–8201 | Built by General Motors Diesel (GMD) in London, Ontario. Renumbered 5000–5001 |
| 17 | Denver and Rio Grande Western Railroad | 28 | 3001–3028 | - |
| 18 | Great Northern Railway | 17 | 3000–3016 | to Burlington Northern Railroad 2200–2216 |
| 19 | Gulf, Mobile and Ohio Railroad | 31 | 500–530 | AAR type B trucks |
| 20 | Kansas City Southern Railway | 20 | 100–119 | - |
| 21 | Louisville and Nashville Railroad | 58 | 1000–1057 | - |
| 22 | New York Central Railroad | 10 | 6115–6124 | to Penn Central 2188-2197, to Conrail same numbers |
| 23 | New York, Chicago and St. Louis Railroad | 10 | 900–909 | to Norfolk and Western 2900-2909 |
| 24 | Norfolk and Western Railway | 44 | 522–565 | High short hood, operated long hood-forward |
| 25 | Pennsylvania Railroad | 52 | 2200–2251 | to Penn Central 2200-2249, 2198, 2199; to Conrail same numbers |
| 26 | Phelps Dodge Corporation | 9 | 24–32 | New Cornelia Branch mine |
| 27 | Reading Railroad | 20 | 5501–5520 | renumbered 3600-3619; to Conrail 2168-2187 |
| 28 | Seaboard Air Line Railroad | 34 | 500–533 | to Seaboard Coast Line Railroad 1309–1342 |
| 29 | Soo Line Railroad | 22 | 700–721 | AAR type B trucks. Eighteen to Wisconsin Central Limited, same numbers |
| 30 | Southern Pacific Railroad | 8 | 7400–7407 | - |
| 31 | Southern Railway | 120 | 2525–2644 | High short hood |
| 32 | St. Louis Southwestern Railway | 10 | 750–759 | - |
| 33 | Toledo, Peoria and Western Railway | 1 | 700 | - |
| 34 | Union Pacific Railroad | 111 | 700–735, 800–874 | - |
| 35 | Totals | 908 | - | - |

Question: What are the three railroads with the greatest number of units?
Answer: The Southern Railway has 120 units, Union Pacific Railroad has 111 units, and Atchison, Topeka, and Santa Fe Railroad has 85 units.