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_23477312_1 (service INTEGER, train_name VARCHAR)

### Question ###
What's the service number of the Jammu Duronto train? 

### Accurate SQL ###

SELECT MAX(service) FROM table_23477312_1 WHERE train_name = "Jammu Duronto"