Complex sentence: The Metropolitan Police also formed a Water Police Branch and at Devonport Dockyard the whole of that Branch lived on an old hulk which had at one time been commissioned as the Fifth-rate warship HMS Leda.
Split into simpler sentences: The Metropolitan Police also formed a Water Police Branch. At Devonport Dockyard the whole of that branch lived on an old hulk which had at one time been commissioned as the fifth-rate warship HMS Leda.