Port congestion
How congestion absorbs effective fleet capacity, the Sea-Intelligence and Linerlytica measures of the 2021 to 2022 peak, and its equivalence to a speed cut.
Port congestion is the accumulation of ships waiting for a berth, a pilot or a working gang beyond the time the service schedule allows. Its commercial significance is that it removes capacity from the market in the same way a fleet-wide speed reduction does, which makes the two economically comparable even though one is chosen and the other is not.
The 2021 to 2022 container cycle is the measured case. Sea-Intelligence put the share of global container fleet capacity unavailable because of delays at a peak of 13.8 percent in January 2022, against a 2011 to 2019 baseline of about 2.2 percent, falling to 7.9 percent by August 2022. Linerlytica measured physically congested tonnage peaking at about 4 million TEU, roughly 15.7 percent of a 25.3 million TEU fleet.
That absorption is why the boom years tightened the freight market even as carriers raised speeds: congestion was taking capacity out faster than the speed increase was putting it back. The full article will cover the causes, the measurement methodologies and their differences, the effect on schedule reliability, and the contractual treatment of waiting time under laytime and demurrage. See slow steaming and demurrage .