Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_9 (tonnage VARCHAR, ship VARCHAR, builder VARCHAR, original_operator VARCHAR)

### Question ###
What is the Tonnage that has builder AG Vulcan, and the original operator NDL, and the ship, Prinzess Irene?

### Accurate SQL ###

SELECT tonnage FROM table_name_9 WHERE builder = "ag vulcan" AND original_operator = "ndl" AND ship = "prinzess irene"