Buoyant trade in the decade after the Second World War was accompanied by the start of four dramatic changes in the way passengers and cargo were moved. The widespread use of road transport and then flying resulted in Glasgow Harbour losing virtually all of both its passenger services and the cargo trade with the Scottish islands and Ireland. The increasing introduction of car ferries caused the short sea trade to move to ports that offered the quickest crossing. Glasgow Harbour was simply too far away to compete for this new traffic.
The growing size of ships used to transport bulk cargoes such as iron ore dealt another body blow. For the Scottish steel industry to survive it had to make use of such large vessels. The cost of deepening the 30 km length of channel leading to Glasgow to cater for these ships was prohibitive. Thus a decision was taken to develop a new ore handling facility making use of the natural deepwater to be found in the Firth of Clyde. In June 1979 the jetty at Hunterston on the Ayrshire Coast was opened and the last ore carrier left Glasgow Harbour. The depth available at Hunterston is 29 meters.
The most significant change of all was the arrival of containerisation. Huge savings in time and cost could be made by moving goods in large steel boxes or containers and by the 1960s this form of trade was spreading throughout the world. To cater for the special ships used to carry containers a new container handling terminal was opened at Greenock in 1969.
The consequences of containerisation were massive reductions in the number of ships and the time they spent in port. Both reduced the need for docks and quays and they quickly declined. Thus throughout the 1970s quay after quay and dock after dock in Glasgow Harbour closed. Now the sites are redeveloped for uses far removed from the needs of shipping.
As the Clyde's ships returned to the natural deepwater of her lower reaches the wheel of sea-borne trade has turned full circle.