Task: Question Answering
Input (English): Context: The Caledonian Railway 179 Class (nicknamed Oban bogie) was a class of 4-4-0 steam locomotives designed by George Brittain for the Caledonian Railway (CR) and introduced in 1882. 
 Question: Which was the official year for the approval of Caledonian Railway 179 Class?
Output (English): 1882