| Castle Romeo | |
|---|---|
 Castle Romeo mushroom cloud | |
| Information | |
| Country | United States |
| Test series | Operation Castle |
| Test site | Bikini Atoll |
| Date | March 26, 1954 |
| Test type | Atmospheric |
| Yield | 11 Mt |
| Test chronology | |
Castle Romeo was the code name given to one of the tests in the Operation Castle series of U.S. nuclear tests. It was the first test of the TX-17 thermonuclear weapon, the first deployed thermonuclear bomb.
It was detonated on March 26, 1954, at Bikini Atoll of the Marshall Islands, on a barge moored in the middle of the crater from the Castle Bravo test. It was the first such barge-based test, a necessity that had come about because the powerful thermonuclear devices obliterated the small islands following detonation.