What the rasping spark refers to in the Titanic?

In the context of the Titanic, the "rasping spark" refers to the sounds of distress signals and the frantic communication efforts made during the ship's sinking. It symbolizes the urgency and desperation of the crew and passengers as they attempted to call for help while the ship was going down. This phrase evokes the haunting atmosphere of the tragedy, highlighting the chaos and the fleeting hope for rescue.