Port Operations10 November 20261:31

Just-in-time arrival, explained

Name: Just-in-time arrival, explained
Uploaded: 2026-11-10
Duration: 1 min 31 s
Description: Ships spend 15–22 days a year waiting for a berth. Just-in-time arrival turns that wait into slower steaming — and the savings are easier to model than to prove.

Ships spend 15–22 days a year waiting for a berth. Just-in-time arrival turns that wait into slower steaming — and the savings are easier to model than to prove.

Key points

Ships spend an estimated 15–22 days a year waiting for a berth (Global Maritime Forum, 2026).
Just-in-time arrival means the port confirms a berth time early enough for the ship to slow down instead of rushing to anchor.
Fuel burn rises steeply with speed, so a modest cut in speed removes a disproportionate share of the fuel.
Modelled savings run 4–14% per voyage for container ships (IMO GIA, 2022); measured results are often lower (Merkel et al., 2022).
The barriers are organisational, not technical: port and voyage-planning systems rarely share data, one disruption moves every window, and the saving itself is hard to measure.

About this explainer

Just-in-time arrival is one of the few emissions measures that needs no new fuel, no retrofit and no capital: the ship simply arrives when the berth is actually free, rather than racing to the anchorage and waiting there. This explainer sets out the mechanism — an arrival time confirmed early enough for the ship to slow down, and the steep relationship between speed and fuel burn that turns those saved hours into saved tonnes — and then the reasons it is still uncommon. Terminals, port authorities, lines, pilots and tugs work from systems that rarely connect to a shipowner’s voyage planning tools; a single weather or congestion event moves the window for everyone behind it; and because the faster voyage never happened, the saving is unusually hard to evidence. The closing figure is the condition for the rest: shared data, and measurement both sides trust.