Complex sentence: Contacting a large convoy on 25 October, "Cod" launched several attacks without success, with all her torpedoes expended she continued to shadow the convoy for another day to report its position.
Split into simpler sentences: Contacting a large convoy on 25 October, "Cod" launched several attacks without success. With all her torpedoes expended, she continued to shadow the convoy for another day to report its position.