CREATE TABLE table_11552751_2 (ship_types_delivered VARCHAR(255))
What was the delivery date when s2 (lst) type, s2 (frigate) type, c1-m type was delivered?
    
SQL: SELECT 1 AS st_ship_delivery_date FROM table_11552751_2 WHERE ship_types_delivered = "S2 (LST) type, S2 (frigate) type, C1-M type"