Unit
hours
Mean completed berth duration per day for merchant vessels at the monitored US container gateways. Merchant vessel = AIS ship-type 70-79 (cargo) and 150 m or longer, which excludes tugs and workboats. AIS cannot distinguish container ships from bulkers, so this is a proxy for container traffic, not a measurement of it.
STATUS: WITHDRAWN · SINCE 1970-01 · RETURNS WHEN THE CONDITION BELOW IS MET
SUPERSEDED. Computed from the crew-set NavigationalStatus field and the old event state machine, both disproven 2026-07-30: the status field recorded 153 anchor events against 3,273 berth events because crews rarely set it, and the state machine split single calls into fragments on speed noise. Replaced by position-based detection in berthing.db — see tt001.gateway.* and berthing/METHOD.md. We will not serve data we cannot stand behind, so this page stays up but the numbers do not.
More on the practice: withdrawn data.
We watched it happen: our own AIS receivers (via the aisstream.io terrestrial network), our timestamps, our archive.
This address is permanent. If this figure is revised or corrected, the change is printed here with its size.
query_series, describe_series