The following are some of the factors that will be important to study while research is being conducted into the feasibility of the construction of a harbour :

• The major purpose of the harbour : Is it to be built to export a particular commodity, e.g. a mineral that is to be mined in the area? Will it be to provide another facility for the fishing industry? Will it be used mainly for container shipping or for vehicle shipments? This type of question needs to be asked to establish the main purpose of the harbour as well as the type and size of vessel that will use the harbour. Once its purpose and teh type of ships expected to call have been established, the type of facilities within the harbour can be designed.
• The sustainability of the expected cargo volumes : Because the construction of a harbour involves such large expense, a constant flow of cargo must be assured for a long time. If only a small amount of cargo will move through the harbour, it might not be worthwhile to go to the expense of building it.
• A sheltered site for the harbour : As ships need to work cargo in calm conditions, harbours need to be constructed to give as much shelter from the swell. Although it is difficult to shelter ships from wind, the alignment of berths might be necessary to reduce the affect of the prevailing wind on ships berthed in the harbour and on cargo operations.

To ensure that the harbour is sheltered, it may be necessary to build a number of breakwaters, and some harbours are built out into the sea. Cape Town, Port Elizabeth, Ngqura and Simon’s Town harbours are examples of this type of harbour construction. They are known as Artificial Harbours.

Some harbours are built in a sheltered bay, lagoon or river mouth, and while short breakwaters might be necessary, the cargo wharves are built within the sheltered water area. Richards Bay, Durban, and Saldanha Bay are each built in a sheltered bay, while East London is built on a river. These are known as Natural Harbours.

• Size of the area to be developed for the harbour : This depends on the type and volume of cargo to be handled and the type of ship that is expected to call at the harbour. Mineral cargoes usually need large areas to keep the mineral before loading (this area is called the mineral stockpile); container terminals also are usually large in area, although those harbours handling a smaller volume of containers will obviously be smaller. If large ships are expected to call, there must be sufficient water area to turn these large ships. There should also be space for future expansion, and often the initial harbour plans include several possible stages of expansion for the harbour.
• Depth of water : This also depends on the size of ship expected to call. Deep-draughted ships will require an appropriate water depth, but if only small fishing vessels will call, the depth of water need not be as great.
• Flat land : For cargo to be stored (either in sheds or in open areas) and for rail or road networks large areas of flat land surrounding the harbour are required.
• Services (water, electricity) : For cargo handling equipment (cranes, mineral loaders, grain chutes, conveyor systems, pumps), large amounts of electricity are needed. All offices (including the vital port control centre) require electricity for their various electronic systems. Fresh water is also essential as ships often require tons of fresh water.
• Labour : A harbour requires workers of all levels of skills – from highly qualified engineers to supervise complex cargo loading machinery, building and harbour maintenance, and electronics systems, to lesser skilled people. Highly qualified and experienced seafarers are also required as harbour masters, pilots, tug engineers, and in other roles where they deal directly with the ships.
• Transport access : To move cargo to and from the harbour , adequate road and rail links are essential. Railway yards where trains are marshaled to carry the cargo to its destination are also needed, either at the harbour or close to the harbour. The large numbers of people employed in the harbour also need transport facilities close by.
• Finance : To build, operate and maintain a harbour costs a large amount of money. In some countries, the state operates all harbours and therefore the state will fund or subsidise harbour construction. Because of the large costs involved in harbour construction, careful planning is necessary to ensure that the construction project will be financially worthwhile, i.e. that the earnings from the harbour will pay back the costs of its construction within a reasonable time, and that earnings will cover operating costs.
• Ancillary Services : A harbour needs a large number of ancillary services, including pilotage, tug services, bunkering services, chandling services, waste disposal services, ship repair and engineering services, and others. The scale of these services depends on the size of operations in the harbour. A small fishing harbour will require all of these services (except pilotage and tug services), but on a smaller scale than a harbour like Cape Town or Durban where a full range of services extends to operations such as major ship repair and bunkering facilities.

To illustrate many of the above points and to trace the development of a major harbour, follow the history of Cape Town harbour in the next module.