This photograph shows just how much an LST could carry to the beach. Bear in mind that the deck below this one is also loaded, probably with armored vehicles for the initial assault.
"Invasion of Cape Gloucester, New Britain, 24 Dec. 1943. Crammed with men and material for the invasion, this Coast Guard- manned LST nears the Japanese held shore. Troops shown in the picture are Marines." PhoM1c. Don C. Hansen. 26-G-3056. (ww235.jpg).
Picture is from: National Archives and Records Administration