Titanic could symbolise his family as he believes they are untouchable ( just as the society thought the titanic was ) until the inspector’s arrival gives them a rude awakening to reality. Dramatic irony is set to give a negative and unserious image of the character. Could foreshadow that an incoming iceberg ( the Inspector ) will break down portentous beliefs that mr birling upholds, fracturing the birlings tranquility and serenity.