The key to keeping a dry dock dry is the caisson shown here in our latest Dry Dockuseries video! Once we entered dry dock and verified we were lined up on the blocks, the caisson was brought back and we could drain the dock. #DryDockNJ #militaryhistory #maritimehistory #interestingthings #history #navyships #ships #usnavy #battleship #historicships #philly #museumsoftiktok #drydock #drydocking