Groton Iron Works was formed ten days after the U.S. entered WWI and had two yards, one in Groton for steel ships and one in Noank for wooden ships. It closed in 1928 and the property is now part of the Electric Boat shipyard. Little more is known about this shipyard. If anyone can provide any information, please e-mail me at tim@coltoncompany.com
| Hull # | USSB # | Original Name | Original Owner | Type | Tons | Delivery | Disposition |
| Built in Noank | |||||||
| 125 | Balsto | US Shipping Board | Cargo Ship | 2,551 | Oct-18 | Scrapped 1925 | |
| 126 | Berea | US Shipping Board | Cargo Ship | 2,551 | Jun-19 | Scrapped 1923 | |
| 127 | Hokah | US Shipping Board | Cargo Ship | 2,551 | Oct-19 | Scrapped 1923 | |
| 128 | US Shipping Board | Cargo Ship | 2,551 | Cancelled | |||
| 129 | US Shipping Board | Cargo Ship | 2,551 | Cancelled | |||
| Built in Groton | |||||||
| 1 | 372 | Tollard | US Shipping Board | Cargo Ship | 6,245 | Apr-19 | Scrapped 1930 |
| 2 | 373 | Nameaug | US Shipping Board | Cargo Ship | 6,339 | Aug-19 | Scrapped 1929 |
| 3 | 374 | Worcester | US Shipping Board | Cargo Ship | 6,213 | Jun-19 | Scrapped 1930 |
| 4 | 375 | Quinnipiac | US Shipping Board | Cargo Ship | 6,202 | Dec-19 | Scrapped 1929 |
| 5 | 376 | Merry Mount | US Shipping Board | Cargo Ship | 5,724 | Oct-19 | Scrapped 1929 |
| 6 | 377 | Hartford | US Shipping Board | Cargo Ship | 5,703 | Dec-19 | Scrapped 1929 |
| 7 | 1542 | Honnedaga | US Shipping Board | Cargo Ship | 6,216 | Jul-20 | Scrapped 1930 |
| 8 | 1543 | Provincetown | US Shipping Board | Cargo Ship | 6,206 | Sep-20 | Scrapped 1938 |
| 9 | 1544 | Hopatcong | US Shipping Board | Cargo Ship | 6,216 | Dec-20 | Later Harpoon 1931, Empire Tarpon 1940, foundered 1942 |
| 10 | 1545 | US Shipping Board | Cargo Ship | Cancelled | |||
| 11 | 1546 | US Shipping Board | Cargo Ship | Cancelled | |||
| 12 | 1547 | US Shipping Board | Cargo Ship | Cancelled | |||
| Lieut. Flaherty | Ferry | 727 | 1921 | Later Beacon 1938, scrapped 1973 | |||