In 1870 the official returns identify 110 foreign trade ports in the UK. A hundred years later the oil terminals of Milford Haven, Sullom Vo and Orkney ranked high among British ports; reminders that the nature of trade and the state of cargo-handling technology are factors linking, or separating, transhipment needs and populations. The geographer James Bird, to whom anyone concerned with port history owes an enormous debt, in a detailed investigation of the history of all major British seaports, categorised his subjects under various headings. A variety of forms of port authority developed, all regulated by act of parliament, most of which were some type of public trust, with varying degrees of connection with municipal government, but a number were privately owned, principally by railway companies. Containerisation and new modes of discharging high volume bulk cargoes would rapidly render much of existing port provision, together with its associated workforce, redundant.