Vessel bunching on the increase
From a network design perspective, for every weekly deep-sea liner service, one vessel would be scheduled to depart from an origin region each week. However, in the real world, a shipping line can have multiple vessels departing in the same week, on the same service. This can be caused by vessel delays, where a delayed vessel slides into the following week, vessel shortages where shipping lines deploy two smaller vessels to replace a larger vessel, or because of extra-loader vessels to cater to excess demand/cargo backlog. We term this phenomenon as “vessel bunching”, and it is defined as the number of sailings in a given week in excess of the number of weekly services; so if there are 17 sailings in one week, and there are 15 weekly services, “vessel bunching” equals 2, explains a Sea-Intelligence analysis.
It elaborates:
“To be able to discern trends, we have calculated vessel bunching as an average seen over a rolling 10-week period. For Asia-North Europe, this is shown in Figure 1. In the 8 years prior to the pandemic, there was a relatively low level of vessel bunching, whereas the pandemic caused an extreme increase. Towards the end of 2023, this had again almost normalised. However, the Red Sea crisis in 2024 has caused a new surge in vessel bunching, back to a level almost matching the pandemic peak.
“Higher vessel bunching creates a larger pressure on ports and terminals. While the offered capacity might be the same when seen over two weeks i.e., no vessel sailing in one week followed by two vessels sailing in the following week, having two vessels depart in one week and zero vessels in the second week, creates an extraordinarily high workload in one week and none in the second week. This clearly increases the risk of port congestion – and as a ripple effect, a similar crunch on the use of truck, rail, and barge capacity.
“Vessel bunching can therefore be seen as a proxy measure for the pressure on ports and the corresponding likelihood of congestion problems. As such, given the data, there is no indication that the pressure on ports is about to be alleviated.”
Source: Exim News Service: Copenhagen, Oct. 24