There is a long a detailed discussion on Victorian Wars Forum on
Artillery pieces: 13" Seacoast Mortar. The discussion includes the evolution of the mortar into the U.S. arsenal as the results of observations made of use of the 13 inch mortars during the Crimean war. Lots of reference to the ACW and the deployment of the Mortars. Lots of reference for those who want to learn more. Some reference to IX Shell guns.
The discussion has been cut off by the moderators since the contributor isn't relating the material closely enough to the Victorian Wars. I sent the Author a pm and invited him to post there.
Here are two video's linked in the thread. We have all seen them before, but once is never enough.
[yt=425,350]Eox-jnTaEgk[/yt]
[yt=425,350]5v7bLf2ipmA[/yt]