W19 (nuclear artillery shell)

The W19, also called Katie, was an American nuclear artillery shell, derived from the earlier W9 shell. The W19 was fired from a special 11 in howitzer. It was introduced in 1955 and retired in 1963.

Specifications
The W19 was 11 inch in diameter, 54 inch long, and weighed 600 lbs. It had a yield of 15–20 kilotons and was like its predecessor the W9, a gun-type nuclear weapon.

W23
The W19 nuclear system was adapted into a nuclear artillery shell for the US Navy's 16-inch (406 mm) main battery found on the Iowa-class battleships, the W23. Production of the W23 began in 1956 and they were in service until 1962, with a total of 50 units being produced.

The W23 was 16 inches (406 mm) in diameter and 64 in long, with a weight given variously as 1500 or in reference sources. As with the W19, yield was 15–20 kilotons.