Types of Pendulum Routes

Pendulum services involve a set of sequential port calls along a maritime range, commonly including a transoceanic service from ports in another range and structured as a continuous loop. They are almost exclusively used for container transportation with the purpose of servicing a market by balancing the number of port calls and the frequency of services. For instance, pendulum services between Asia and Europe have on average 8 to 10 containerships assigned and involve 8 to 12 port calls. Most transatlantic pendulum services have 6 to 8 containerships and involve 6 to 8 port calls. A pendulum service is fairly flexible in terms of the selection of port calls, particularly on maritime ranges that have nearby and competing ports grouped as regional clusters (e.g. North American East coast, Western Europe). This implies that a maritime company may opt to bypass one port to the advantage of another if its efficiency is not satisfactory and if its hinterland access is problematic. The shipping network consequently adapts to reflect changes in market conditions. The structure of pendulum service networks can take many shapes depending on factors such as the markets being serviced, trade imbalances and regulations:

• Symmetrical. Pendulum routes that involve a relatively similar number of port calls on the maritime facades serviced. Such a structure offers a good level of market coverage if the number of allocated vessels is sufficient, but with the drawback of longer cycle times.
• Asymmetrical. Involves fewer port calls along one of the maritime facades serviced. This can reflect several situations, including trade imbalances, cabotage constraints or export-oriented strategies. For instance, a maritime shipping company would be reluctant to offer several port calls along a facade within the same country (such as the United States) if cabotage regulations are present. It won't be able to ship containers between ports of the same facade, only pick or drop them. Trade imbalances are also reflective of asymmetrical pendulum services as traffic is collected along one facade and unloaded at a few major gateways accessing inland corridors of the other facade.
• Inter-hub. These services are almost similar to charter services as they directly connect major hubs or gateways. Their advantages are high capacity and frequency as well as lower cycle time, which can be offered when there is a substantial demand between the few ports serviced. They tend to involve the largest containerships available.