Complex sentence: The new submarines are expected to be better armed than the "Collins" class, armed armed with long-range cruise missiles, which are not currently carried by the "Collins" class, as well as shorter ranged missiles and torpedoes.
Split into simpler sentences: The new submarines are expected to be better armed than the "Collins" class. It is anticipated that the new boats will be armed with long-range cruise missiles, which are not currently carried by the "Collins" class, as well as shorter ranged missiles and torpedoes.