Pendulum services involve a set of sequential port calls along a
maritime range, commonly including a transoceanic service to ports
in another range and structured as a continuous loop. They are almost
exclusively used for container shipping 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 involving 8 to 12 port
calls. A service between Asia and the US West Coast would have 5 to
7 ships. 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 (e.g.
North American East coast, Western Europe). This implies that a maritime
container shipping 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
- Asymmetrical. Involves fewer port calls along one of
the maritime facades serviced. This is reflective of 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 carry domestic containers between ports of the same facade,
only pick up or drop them off. Trade imbalances are also reflective of
asymmetrical pendulum services as traffic is collected along one
facade and unloaded on the other range at a few major gateways accessing inland corridors.
- 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