Complex sentence: A machine which is Dual Modular Redundant has duplicated elements which work in parallel to provide one form of used on submarines of the Royal Navy employs duplicated central computing nodes, interconnected by a duplicated LAN.
Split into simpler sentences: A machine which is Dual Modular Redundant has duplicated elements which work in parallel to provide one form of redundancy. For instance: the Submarine Command System SMCS used on submarines of the Royal Navy employs duplicated central computing nodes, interconnected by a duplicated LAN.