Reading the metrics
What is dwell time in shipping? Container, vessel, and port dwell explained
Dwell time in shipping is how long something sits in one place at a port, and the trade uses that one word for three different clocks: vessel dwell, box dwell, and the ship queue. Vessel dwell is how long a ship sits at a berth, box dwell is how long an import container sits on the terminal, and ships waiting is a count of vessels queued offshore before a berth opens. The ship queue updates weekly and the Port of Los Angeles box-dwell report every business day; the national vessel-dwell series is archived.
Updated Oct 12, 2026
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Container dwell time means three different things at a port, and treating them as one number is how readers reach the wrong conclusion. Vessel dwell is how long a ship sits at a berth. Box dwell is how long an import container sits on the terminal after it comes off the ship. Ships waiting is a count of vessels queued offshore before they ever reach a berth. Same word, three clocks, each measured from a different point by a different source.
Vessel dwell: the ship at the berth
Vessel dwell at berth is the time a container ship spends tied up working cargo, from arrival at the berth to departure. The Bureau of Transportation Statistics built this one from Coast Guard vessel-position signals, the AIS transponders every ship broadcasts, and published a national average in hours for the largest US container ports. It is a ship metric, a read on how long the loading and discharge took. BTS ran the series from 2019 through June 2023 and then stopped, so every vessel-dwell figure on this site is an archived historical number, clearly labeled, never a reading for this week.
Box dwell: the container on the terminal
Box dwell, sometimes called container dwell, is the clock the trade actually means when it says dwell. It counts how long an import container sits in the terminal yard after discharge before it leaves by truck or rail. That is the number that drives free-time exposure, because a box sitting past its free days starts running up storage charges. There is no single free national feed for box dwell. The Port of Los Angeles is the exception that publishes it as data: every business day it posts how many import boxes are on its terminals and how long they have sat, in 0-4, 5-8 and 9-plus day buckets, and this site charts that on the Los Angeles import-container dwell page. Both San Pedro Bay ports also publish the rail-bound slice in the same shape, the boxes waiting on terminal for an on-dock train, which sits side by side on port rail container dwell at Los Angeles and Long Beach. Those are counts by age, not an average number of days.
Ships waiting: not a dwell at all
Ships awaiting berth is a headcount, not a duration. It is the number of container ships sitting at anchor or slow-steaming offshore because no berth is open yet. The Marine Exchange of Southern California has counted the San Pedro Bay queue since October 2020, and MARAD compiles the national picture that feeds the public table. It is the most current congestion signal on this site, updated weekly, which is why the homepage board leads with it. A long queue means ships are stacking up before the dock. It says nothing on its own about how long a box will then sit on the terminal.
Box dwell, live
- 9+ day share
The chart above is box dwell as the Port of Los Angeles reports it: the share of import boxes on its terminals that have sat 9 days or more. Right now that reads 16.4% of import boxes at 9+ days (8,903 boxes of 54,332 boxes). A rising share means more boxes are aging on the terminal, the pressure that shows up as demurrage exposure on individual bookings.
Reading the other two clocks
- Vessel dwell at berth
The archived chart above is vessel dwell, hours a ship sat at a US berth, and it stops in mid-2023. Read it as history, a record of how long ships worked cargo during and after the pandemic crunch, not a live gauge.
- Ships awaiting berth
The chart above is the live one, the count of ships waiting off LA/Long Beach this week. It tells you whether vessels are backing up offshore right now. Neither number is box dwell, and neither tells you what a specific container will do on the terminal. Keep the three apart and each answers a clean question. Blur them and you will read a two-year-old ship average as today's cargo delay.
The Dwell labels every dwell number with its exact clock and its source. It does not forecast congestion and it is not routing or fee advice. For how these clocks line up along the import chain, see from ship to your warehouse.
This guide covers the three PORT-side dwell clocks. Trucking has its own, unrelated dwell clock, the time a truck and driver wait at a shipper's or receiver's dock, which the industry calls detention: see dwell time in trucking.
Dwell also turns up on a single booking's tracking screen, as a date field rather than a clock: what the import dwell date means covers it, and container milestone tracking covers the other timestamps around it.
What makes these clocks move in the first place, ships bunching up on late schedules, boxes left in the yard, chassis, truck and rail shortfalls, strikes and storms, is covered cause by cause in what causes port congestion, with the clock that shows each one first.
Now look at the live data
Common questions
What does container dwell time mean?
It depends which clock you mean. Vessel dwell is how long a ship sits at a berth, box dwell is how long an import container sits on the terminal after discharge, and ships waiting is a count of vessels queued offshore. The trade usually means box dwell.
Is vessel dwell the same as container dwell?
No. Vessel dwell times the ship at the berth and is a ship metric. Container, or box, dwell times how long the container sits in the yard afterward and is the number that drives free-time exposure. They measure different things.
Where can I find current box dwell for LA/Long Beach?
The Port of Los Angeles publishes it every business day as a count of import boxes on its terminals by age (0-4, 5-8 and 9-plus days), which this site charts on the Los Angeles import-container dwell page. For the rail-bound boxes, both Los Angeles and Long Beach publish daily counts of containers waiting for an on-dock train, shown side by side on the port rail container dwell page.
Why does this site lead with ships waiting instead of dwell?
Because the ship queue is the freshest signal with national reach, published weekly for LA/Long Beach, Savannah and all US ports combined. Box dwell is published as data only by some ports, daily at Los Angeles, and the national vessel-dwell series was archived by BTS in mid-2023. The Los Angeles box-dwell and the LA and Long Beach rail pages sit beside the queue.
What is dwell time in logistics?
It is how long freight sits still at one point in its journey: a container on a marine terminal, a ship at a berth, a railcar in a rail yard or a truck at a loading dock. At a port it usually means container dwell, the days an import box sits on the terminal after it comes off the ship and before it leaves by truck or rail.
What does dwell time mean in shipping?
The time a ship, a container or cargo spends waiting in one place. For a ship it is the hours at the berth; for a container it is the days on the terminal; and the ship queue offshore is sometimes loosely called dwell too, though it is a count of waiting ships rather than a time.
How is container dwell measured?
Either as an average number of days a box sits on the terminal, or as a count of the boxes there now by how long each has sat. The Port of Los Angeles publishes the second kind every business day, currently 16.4% of import boxes at 9+ days (8,903 boxes of 54,332 boxes).