Shipbuilders believed the Titanic was unsinkable because of its watertight compartments and doors. In the event of an accident, the captain could close these doors and prevent the boat from completely filling with water. The ship also was built to take on some water without sinking.
The state-of-the-art Titanic came equipped with 16 watertight compartments. Though shipbuilders believed that the ship could not flood, they predicted that it could remain afloat even if a few of the watertight compartments flooded. Within the walls were watertight walls, called bulkheads, meant to prevent the ship from entirely flooding.
Some compartments also had watertight doors. Once the captain activated these doors, they sealed shut and could not be opened. Shipbuilders believed these doors would help keep water located within a specific compartment in the event the compartment took on water. The ship's designers were so certain that the ship could not sink that they did not leave room for enough lifeboats for everyone on board.
After the Titanic hit an iceberg head on, water flooded the six forward compartments on the ship. Captain Edward J. Smith, realizing that the ship was taking on too much water, knew that it would ultimately sink. The watertight bulkheads should have prevented additional compartments from flooding, but they were not tall enough to contain all of the water and failed.