The Maritime Commission only built concrete ships and barges reluctantly, at a point in the war when the steel shipbuilders were all at full capacity. There were five contractors, of which three were significant.
McCloskey & Company developed a shipyard in Tampa FL, to build 24 self-propelled dry bulk cargo ships, to carry sugar. These were the only self-propelled concrete ships: they were 366 feet long, with a deadweight of 5,000 tons. The yard was located at Hookers Point and had 6,000 workers: it closed permanently in December 1945.
Concrete Ship Constructors developed a shipyard in National City CA to build concrete barges. They built both B7 tank barges, which were 375 feet long, with a deadweight of 6,600 tons, and designed to move refined products from the Gulf of Mexico to the Northeast, and B5 covered dry cargo barges, which were 265 feet long, with a deadweight of 1,632 tons. Their hulls 45-47 were completed with reefer capacity and hulls 48-49 were completed as maintenance barges.
Barrett & Hilp developed a shipyard in San Francisco CA to build concrete barges. They built B7 dry bulk barges, which were 366 feet long, with a deadweight of 5,687 tons, designed to carry bauxite.
Nine of these ships are still afloat: visit http://www.discoverpowellriver.com/visitors/gianthulks.html and http://www.concreteships.org/ships/powellriver/ to see some great pictures.
| Hull # | Name | Type | MC # | Delivered | Disposition |
| McCloskey & Co., Tampa FL | |||||
| 1 | Vitruvius | C1-S-D1 | 1045 | Dec-43 | Sunk as a breakwater at Normandy |
| 2 | David O. Saylor | C1-S-D1 | 1046 | Nov-43 | Sunk as a breakwater at Normandy |
| 3 | Arthur Newell Talbot | C1-S-D1 | 1047 | Feb-44 | Sunk as a breakwater at Kiptopeke VA |
| 4 | Richard Lewis Humphrey | C1-S-D1 | 1048 | Mar-44 | Sold in Mexico |
| 5 | Richard Kidder Meade | C1-S-D1 | 1049 | Mar-44 | Sunk as a breakwater at Kiptopeke VA |
| 6 | Willis A. Slater | C1-S-D1 | 1050 | Feb-44 | Sunk as a breakwater at Kiptopeke VA |
| 7 | Leonard Chase Watson | C1-S-D1 | 1051 | Jun-44 | Sunk as a breakwater at Kiptopeke VA |
| 8 | John Smeaton | C1-S-D1 | 1052 | Apr-44 | Afloat as a breakwater at Powell River BC |
| 9 | Joseph Aspdin | C1-S-D1 | 1053 | May-44 | Wrecked and lost 1948 |
| 10 | John Grant | C1-S-D1 | 1054 | Jun-44 | Sunk as a breakwater at Kiptopeke VA |
| 11 | M. H. Le Chatelier | C1-S-D1 | 1055 | Jul-44 | Afloat as a breakwater at Powell River BC |
| 12 | L. J. Vicat | C1-S-D1 | 1056 | Jul-44 | Afloat as a breakwater at Powell River BC |
| 13 | Robert Whitman Lesley | C1-S-D1 | 1057 | Jul-44 | Sunk as a breakwater at Kiptopeke VA |
| 14 | Edwin Thacher | C1-S-D1 | 1058 | Jul-44 | Sunk as a breakwater at Kiptopeke VA |
| 15 | C. W. Pasley | C1-S-D1 | 1059 | Aug-44 | Sunk as a breakwater at Newport OR |
| 16 | Armand Considere | C1-S-D1 | 1060 | Sep-44 | Afloat as a breakwater at Powell River BC |
| 17 | Francois Hennebique | C1-S-D1 | 1061 | Sep-44 | Sunk as a breakwater at Newport OR |
| 18 | P. M. Anderson | C1-S-D1 | 1062 | Sep-44 | Afloat as a breakwater at Powell River BC |
| 19 | Albert Kahn | C1-S-D1 | 1063 | Oct-44 | Abandoned and lost 1947 |
| 20 | Willard A. Pollard | C1-S-D1 | 1064 | Nov-44 | Sunk as a breakwater at Kiptopeke VA |
| 21 | William Foster Cowham | C1-S-D1 | 1065 | Nov-44 | Sunk as a breakwater at Kiptopeke VA |
| 22 | Edwin Clarence Eckel | C1-S-D1 | 1067 | Dec-44 | Scuttled 1946 |
| 23 | Thaddeus Merriman | C1-S-D1 | 1068 | Nov-44 | Afloat as a breakwater at Powell River BC |
| 24 | Emile N. Vidal | C1-S-D1 | 1069 | Dec-44 | Afloat as a breakwater at Powell River BC |
| Concrete Ship Constructors, Inc., National City CA | |||||
| 1 | Concrete No. 1 | B7-A2 | 634 | Apr-43 | Later YO 143 |
| 2 | Concrete No. 2 | B7-A2 | 635 | May-43 | Later YO 144 |
| 3 | Concrete No. 3 | B7-A2 | 636 | May-43 | Later YOG 40 |
| 4 | Concrete No. 4 | B7-A2 | 637 | Jun-43 | Later YOG 41 |
| 5 | Concrete No. 5 | B7-A2 | 638 | Jun-43 | Later YOG 42 |
| 6 | No name | B7-A2 | 1220 | Jul-43 | Later YO 145 |
| 7 | No name | B7-A2 | 1221 | Jul-43 | Later YO 146 |
| 8 | No name | B7-A2 | 1222 | Aug-43 | Later YOG 53 |
| 9 | No name | B7-A2 | 1223 | Aug-43 | Later YO 159 |
| 10 | No name | B7-A2 | 1224 | Sep-43 | Later YO 160 |
| 11 | No name | B7-A2 | 1225 | Sep-43 | Later YO 161 |
| 12 | No name | B7-A2 | 1226 | Oct-43 | Later YO 162 |
| 13 | No name | B7-A2 | 1227 | Oct-43 | Later YO 163 |
| 14 | No name | B7-A2 | 1228 | Nov-43 | Later YO 182 |
| 15 | No name | B7-A2 | 1229 | Nov-43 | Later YO 183 |
| 16 | No name | B7-A2 | 1230 | Dec-43 | Later YOG 82, afloat as a breakwater at Powell River BC |
| 17 | No name | B7-A2 | 1231 | Dec-43 | Later YO 184 |
| 18 | No name | B7-A2 | 1232 | Jan-44 | Later YO 185 |
| 19 | No name | B7-A2 | 1233 | Jan-44 | Later YOG 83 |
| 20 | No name | B7-A2 | 1234 | Feb-44 | Later YO 186 |
| 21 | No name | B7-A2 | 1235 | Feb-44 | Later YO 187 |
| 22 | No name | B7-A2 | 1236 | Mar-44 | Later YOG 84 |
| 23 | Carbon | B5-BJ1 | 2214 | Feb-44 | Later BCL 3049 |
| 24 | Barium | B5-BJ1 | 2215 | Mar-44 | Later BCL 3050 |
| 25 | Helium | B5-BJ1 | 2216 | Mar-44 | Later BCL 3051 |
| 26 | Nitrogen | B5-BJ1 | 2217 | Mar-44 | Later BCL 3052 |
| 27 | Radium | B5-BJ1 | 2218 | Apr-44 | Later BCL 3053 |
| 28 | Argon | B5-BJ1 | 2219 | Apr-44 | Later BCL 3054 |
| 29 | Cadmium | B5-BJ1 | 2220 | May-44 | Later BCL 3055 |
| 30 | Chromium | B5-BJ1 | 2221 | May-44 | Later BCL 3056 |
| 3` | Cobalt | B5-BJ1 | 2222 | May-44 | Later BCL 3057 |
| 32 | Iridium | B5-BJ1 | 2223 | Jun-44 | Later BCL 3058 |
| 33 | Lithium | B5-BJ1 | 2224 | Jun-44 | Later BCL 3059 |
| 34 | Magnesium | B5-BJ1 | 2225 | Jun-44 | Later BCL 3060 |
| 35 | Neon | B5-BJ1 | 2226 | Jun-44 | Later BCL 3061 |
| 36 | Nickel | B5-BJ1 | 2227 | Jun-44 | Later BCL 3062 |
| 37 | Phosphorus | B5-BJ1 | 2228 | Jun-44 | Later BCL 3063 |
| 38 | Sodium | B5-BJ1 | 2229 | Jul-44 | Later BCL 3064 |
| 39 | Sulphur | B5-BJ1 | 2230 | Jul-44 | Later BCL 3065 |
| 40 | Tellurium | B5-BJ1 | 2231 | Jul-44 | Later BCL 3066 |
| 41 | Tungsten | B5-BJ1 | 2232 | May-44 | Later BCL 3067 |
| 42 | Uranium | B5-BJ1 | 2233 | Jul-44 | Later BCL 3068 |
| 43 | Bismuth | B5-BJ1 | 2234 | Aug-44 | Later BCL 3069 |
| 44 | Bromide | B5-BJ1 | 2235 | Aug-44 | Later BCL 3070 |
| 45 | Hydrogen | B5-BJ2 | 2236 | Sep-44 | Later BCL 3071 |
| 46 | Calcium | B5-BJ2 | 2237 | Oct-44 | Later BCL 3072 |
| 47 | Antimony | B5-BJ2 | 2238 | Nov-44 | Later BCL 3073 |
| 48 | Cerium | B5-BJ3 | 2695 | Mar-45 | Later FMS 1 |
| 49 | Radon | B5-BJ3 | 2696 | May-45 | Later FMS 2 |
| MacEvoy Shipbuilding Corp., Savannah GA | |||||
| 1 | Concrete No. 6 | B7-A1 | 619 | Jan-44 | |
| 2 | Concrete No. 7 | B7-A1 | 620 | Feb-44 | |
| 3 | Concrete No. 8 | B7-A1 | 621 | Mar-44 | |
| 4 | Concrete No. 9 | B7-A1 | 622 | Apr-44 | |
| 5 | Concrete No. 10 | B7-A1 | 623 | May-44 | |
| 6 | Concrete No. 11 | B7-A1 | 903 | Jun-44 | |
| 7 | Concrete No. 12 | B7-A1 | 904 | Jun-44 | |
| 8-23 | No name | B7-A1 | 905-920 | Cancelled | |
| San Jacinto Shipbuilding Corp., Houston TX (later taken over by McCloskey & Co.) | |||||
| 1 | Concrete No. 29 | B7-A1 | 629 | Nov-43 | |
| 2 | Concrete No. 30 | B7-A1 | 630 | Nov-43 | |
| 3 | Concrete No. 31 | B7-A1 | 631 | Dec-43 | |
| 4 | Concrete No. 32 | B7-A1 | 632 | Dec-43 | |
| 5 | No name | B7-A2 | 633 | Cancelled | |
| 25-39 | No name | B7-A2 | 1304-1318 | Cancelled | |
| Barrett & Hilp, San Francisco CA | |||||
| 1 | Agate | B7-D1 | 1319 | Aug-43 | To US Army |
| 2 | Chromite | B7-D1 | 1320 | Sep-43 | To US Army |
| 3 | Flint | B7-D1 | 1321 | Sep-43 | To US Navy |
| 4 | Granite | B7-D1 | 1322 | Sep-43 | To US Navy |
| 5 | Graphite | B7-D1 | 1323 | Oct-43 | To US Navy |
| 6 | Gypsum | B7-D1 | 1324 | Oct-43 | To US Navy |
| 7 | Mica | B7-D1 | 1325 | Nov-43 | To US Navy |
| 8 | Bauxite | B7-D1 | 1326 | Jun-43 | Later IX 154 |
| 9 | Asphalt | B7-D1 | 1327 | Jun-43 | Later IX 153, lost off Saipan 1944 |
| 10 | Slate/Carmita | B7-D1 | 1328 | May-43 | Later IX 152, lost 1947 |
| 11 | Midnight | B7-D1 | 1329 | Mar-44 | Later IX 149, sold in China 1948 |
| 12 | Quartz | B7-D1 | 1330 | Apr-44 | Later IX 150, afloat as breakwater in Powell River BC |
| 13 | Bauxite/Silica | B7-D1 | 1331 | Jun-44 | Later IX 151, scuttled 1945 |
| 14 | Limestone/Corundum | B7-D1 | 1332 | Jul-44 | Later IX 164 |
| 15 | Feldspar | B7-D1 | 1333 | Aug-44 | Later IX 159, sold |
| 16 | Marl | B7-D1 | 1334 | Aug-44 | Later IX 160, sold in the Philippines 1948 |
| 17 | Barite | B7-D1 | 1335 | Aug-44 | Later IX 161 |
| 18 | Lignite | B7-D1 | 1336 | Sep-44 | Later IX 162 |
| 19 | Cinnabar | B7-D1 | 1337 | Sep-44 | Later IX 163, sold |
| 20 | Limestone | B7-D1 | 1338 | Oct-44 | Later IX 158, sold |
| 21-26 | No names | B7-D1 | 1339-1344 | Cancelled | |