SS Sultana was a Mississippi River side-wheel steamboat that exploded on 27 April 1865 in the greatest maritime disaster in United States history. An estimated 1,800 of its 2,427 passengers died when three of the ship’s four boilers exploded and it sank near Memphis.
This disaster was overshadowed in the press by other recent events. John Wilkes Booth, President Lincoln’s assassin, was killed the day before.
The wooden steamship was constructed in 1863 by the John Lither-bury Shipyard in Cincinnati, and intended for the lower Mississippi cotton trade. Registering 1,719 tons, the steamer normally carried a crew of 85. For two years, it ran a regular route between St. Louis and New Orleans, frequently commissioned to carry troops.
The official cause of the Sultana disaster was determined to be mismanagement of water levels in the boiler, exacerbated by the fact that it was severely overcrowded and top heavy.
As the steamship made its way north following the twists and turns of the river, it listed severely to one side then the other. Its four boilers were interconnected and mounted side-by-side, so that if the ship tipped sideways, water would tend to run out of the highest boiler.
With the fires still going against the empty boiler, this created hot spots. When the ship tipped the other way, water rushing back into the empty boiler would hit the hot spots and flash instantly to steam, creating a sudden surge in pressure.
This effect of careening could have been minimized by maintaining high water levels in the boilers. The official inquiry found that the ship’s boilers exploded due to the combined effects of careening, low water level, and a faulty repair to a leaky boiler made a few days earlier.
Most of the new passengers were Union soldiers, chiefly from Ohio and just released from Conference prison camps such as Cahawba and Andersonville. The US government had contracted with Sultana to transport these former Prisoners of war back to their homes.
With a legal capacity of only 376, it was severely overcrowded. Many of the passengers had been weakened by their incarceration and associated illnesses. Passengers were packed into every available berth, and the overflow was so severe that the decks were completely packed.
Source: Military history