During the seven days the Mortar Fleet of Com. David Dixon Porter fired on the forts of Jackson and St. Phillip in April of 1862 there were no accidents attributable to operator error.
The Seacoast Mortar, under windless conditions, required but an 11 pound charge of #7 cannon powder to attain the 4170 yard range that the two divisions of Mortar were anchored for. Due to headwinds from the North-East a 23 pound charge was used.
Farragut, who signed off on some of the ordnance stores requested for the Lower Mississippi operations, ordered Fuze No. 7 at fifteen seconds for the detonation of the 200 pound XIII inch mortar bombs. This proved to be too much time as most of the bombs dug themselves 18 to 22 feet in the soft ground before detonating.Thousands of rounds of XIII inch Mortar sell were fired at the forts.