The Moat

The Moat. Fort Jefferson. , It protected the fort walls from (1) heavy seas, and (2) enemy landings., Most of the moat wall was built in 1849-1851, but digging the moat to full depth, a task for prisoners, was not completed until 1873., Beginning in 1861, dozens of military prisoners were sent to serve their terms. The tale that sharks were kept in the moat to discourage escapes is pure fiction, almost. A prisoner named "Fat Charley” once brought a 10-footer into the moat as a curiosity. It lived two months. Actually, prison breaks were not uncommon, and a very few were successful., Natural Decay , From here you can see how pounding storm seas ravage the breakwater. The island's sand and shell move with wind and wave, and they also slide out from under heavy weight. As the fort walls rose higher and heavier, the sand moved, and foundations settled. In 1865 the engineers, fearful of adding more weight, decided to leave the second tier unfinished., Nearby are two massive blocks of wrought iron. They are side pieces for the gunports. When anchored in the masonry, they could resist enemy hits as well as muzzle blast from the fort gun they protected. But salt-laden moisture causes iron to rust, expand, and move the masonry around it. Behind every bulge you see in the walls, there's iron!, Wind, salt spray and rain scour away, exposed bricks and mortar. Rainwater seeps through the construction, dissolves lime and carries it away drop by drop to build cave-like formations. Look for them as you go.