The growing tendency to provide large scale equipment for handling staple commodities makes it seem possible that in the future, despite the objection that it would deprive the ship owners of the advantage of competition, economic reasons will force the more general undertaking of services by dock owners and the acceptance of the position by ship owners. In the case of Manchester the powers giving the authority the exclusive right are coupled with the proviso that their charges to their customers must not provide more than a ten per cent profit, and it is a generally accepted principle of port finance that the several departments, viz., conservancy, facilities and services should each be separately self-supporting, though many exceptions to this rule may be found.
In some cases the two functions of conservancy and dock ownership are combined in one authority; in others, they are under separate ownership and administration. There is consider able difference of opinion as to which is the better system, but it is perhaps more generally held that more satisfactory co ordination can be secured, and therefore better efficiency and economy obtained when both functions are combined in the same authority. This is the case in most of the larger authorities of the United Kingdom, e.g., London and Liverpool. Examples of ports where the conservancy authority is separate from the dock owning authority are Southampton, Glasgow, Newport. There are cases also of which the following are examples—the East Coast rivers, the Tees, Tyne, Tay and Southampton—where the conservancy authority owns some docks, but other docks to a greater or less extent are provided either by the local railway company or by the local corporation. This entails a division of responsibility which it is sometimes complained leads to the neglect of the needs of trade.
Most ports endeavour to obtain sufficient land to establish industries in the immediate neighbourhood of the docks, and owing to the high cost of inland transport, and the fact that with most commodities the finished article weighs less than the raw material required to produce it, the tendency is continually to move industries more and more from inland centres to the coast in the immediate neighbourhood of the great ports, and when possible to obtain the economic advantage of establishment within the dock area to avoid the cost of intermediate railway or road haulage.
A problem in port economics which has always been the sub ject of much difference of opinion is the proper distribution of the burden as between the ships and the goods they carry. The principle generally accepted is that the burden should be divided as equally as can be between the two, but this has many excep tions. Some ports adopt the policy of making the charges on shipping very light with a view that thereby freights will be kept low, greater cargoes obtained, and the revenue recouped from the tonnage of those cargoes. Other ports hold the view that the incidence of the port charges on the total expenses of a voyage is so small that it cannot affect the freight, and low charges on goods encourage manufacturers and merchants to use the port. This is the policy of all the railway-owned ports whose dues on goods are not only fixed on a low basis but who frequently render services for less than cost, recouping the cost from the profits on railway haulage.
An important factor affecting the quantum of port and harbour dues is the nature and the cost of the works necessary under the particular physical conditions of each harbour. In the United Kingdom, owing to the great variation of tides, it is in most cases necessary for the efficient working of ships to maintain a constant level in the docks by impounding the water within lock gates (a notable exception is Southampton, which has been favoured by nature with four tides in the 24 hours, reducing the difference between high and low water to a few feet). The Pacific and Indian oceans and the Mediterranean sea on the other hand, with their low rise and fall of tide, enable their ports to dispense with such expensive equipment, and the great ports of these oceans, Sydney, San Francisco, Singapore, Marseilles, etc., are examples where the features of the port as left by nature have been almost entirely retained. For this reason the capital cost, as measured by the accommodation afforded, is much lower and is reflected in the lower scale of dues which can be imposed.