What you are seeing in this picture is a water mine, or as they referred to at the time, a “torpedo”. You can see the anchor and the chain, the barrel that was loaded with explosive and the trigger. A ship would bump against the trigger and detonate the mine. This one was taken from Mobile Bay during the Civil War.
In August of 1864 Mobile, Alabama remained one of the last ports in the Confederacy and outside of the trickle of blockade runners, its last line to the outside world. Mobile Bay was defended by three forts that could pound and attacking fleet into mincemeat. If that wasn’t enough the bay was seeded with mines (torpedoes). This would not dissuade the Federal forces.
Led by Rear Admiral David Farragut the US Navy, in a joint assault with the US Army, moved to close the bay. They were met by a CSA fleet and a general battle was commenced under the eyes of the three powerful forts. Having to contend with both the enemy fleet, forts and torpedoes Farragut issued his orders. Only one ship, the Tecumseh, fell victim to the mines, but they were still responsible for one of the lasting anecdotes of the war.
It was during this battle that Farragut reportedly told his officer, “Damn the torpedoes, full speed ahead!” Now, there is some doubt that he actually said it. He probably said something like it, but a lot of these famous sayings, especially ones that happen in the middle of a battle, tend to become more legend than reality. As a way to rally troops or motivate your co-workers, this saying is great in saying just go and do what you need to do, and deal with the consequences later.
The naval battle lasted about three hours. After after a number of weeks the forts all fell one by one. By the end of August 1864 Mobile Bay was securely in the hands of the Federals. The city of Mobile itself would be spared until the end o the war, but as a supply port it was out of the war.