What actually goes wrong: two disruptions and one clock
A container rollover and a blank sailing are two different things a carrier can do to a booking, and free time is the fixed clock waiting at the other end, not a third disruption. A rollover is the carrier taking your booked container off its confirmed vessel and moving it to a later sailing, so the ship departs without it. A blank sailing is the carrier cancelling a scheduled sailing outright, so the departure does not run and every booking on it has to be re-planned. Free time is the allowance the carriage includes before charges start to accrue on a container: when it runs out, the US Federal Maritime Commission (FMC) frames the two charges that follow as demurrage, which accrues when a container exceeds free time on a marine terminal, and detention, charged for the extended use of the intermodal equipment.
Read together, the three are a map rather than a menu. A blank sailing is a common cause of a rollover, because the cargo booked on the cancelled sailing is exactly what gets rolled forward. And neither disruption adds a day to the free-time allowance. That allowance is fixed by the carrier's tariff and, for an import, starts counting when the box is discharged at destination, so a rollover or a blank sailing that lands the box later does not extend or shorten the clock. What a disruption does instead is squeeze the work that has to happen inside a window that does not move. On the import side, disrupted services bunch arrivals, so when the schedule resumes the desk clears customs, arranges trucking, and returns the empty against a compressed and often congested port. On the export side, a container already collected and packed that is then rolled or caught by a blank sailing can begin accruing detention at origin before it ever sails. None of these terms is redefined at length here; each links to its glossary entry.
Rollover, blank sailing, and the free-time clock at a glance
The first two rows are things a carrier does to your booking; the third is the fixed clock those disruptions run your shipment toward without ever extending. Read across each row for what the item is, where it sits, whose action it is, what it does to your schedule, and the desk's response. Every cell states a general property: no per-carrier value, tariff, fee, day count, or reliability figure is in the table, since those vary by carrier and route out below. The glossary link for each term is in the prose above, because table cells carry no links.
| Term | What it is | Where in the journey | Whose action | Effect on your schedule | What the desk does |
|---|---|---|---|---|---|
| Container rollover | The carrier bumps your booked box to a later sailing | At origin or a transshipment hub | The carrier's | The box waits for the next vessel and delivery slips | Detect it early, then accept the later sailing or rebook, and check a packed box for origin charges |
| Blank sailing | The carrier cancels the scheduled sailing, so it does not run | Before departure | The carrier's | Every booking is re-planned and the cargo is usually rolled forward | Rebook on another service or carrier, or accept the slip, and check a packed box for origin charges |
| Free time (the clock, not a disruption) | The tariff allowance before demurrage or detention begins | Destination for imports, from discharge; origin for export detention, from pickup | Set by the carrier's tariff, run by the desk | It does not extend because the carrier disrupted the schedule | Sequence clearance, trucking, and empty return inside the fixed window, and request extended free time at booking |
It is tempting to file a rollover, a blank sailing, and free time as three items on one list. They are not the same kind of thing. A blank sailing is a common cause of a rollover: when a carrier cancels a sailing, the cargo booked on it is what gets rolled forward onto a later vessel. The two are still different carrier acts, a rollover leaves your box behind while the vessel sails, a blank sailing cancels the sailing itself. And free time is the fixed clock waiting at destination, not a disruption of its own, and neither a rollover nor a blank sailing adds a day to it. Treating them as one flat list is what leads a desk to assume a rollover uses up free time, which it does not.
What a forwarder actually does about each
The response is different for each, and it starts before the delay shows up on a delivery report.
For a rollover, the first job is to catch it early, against the carrier's own tracking feed rather than a customer's phone call, because the sooner it is seen the more of the schedule can still be protected. Then the decision is whether to accept the later sailing the carrier has offered or rebook to hold the delivery date, and, if the container was already collected and packed, whether it is now accruing charges at origin while it waits.
For a blank sailing, the box has not necessarily moved yet, so the choice is whether to rebook onto a different service or carrier to protect the date or accept the slip and re-plan everything downstream of it. As with a rollover, a container already collected and packed needs checking for origin charges while it sits.
For the free-time clock, the work is sequencing: line up customs clearance, trucking, and the empty return so they finish inside a window that does not move, knowing that after a disruption arrivals bunch and the port congests, so every one of those steps takes longer than usual. The other lever sits back at booking, where you can decide whether to request extended free time rather than absorb charges later.
The mechanics one level down, how a claim is filed and how demurrage and detention are calculated and disputed, are not restated here. Those pages carry the charge story; the point on this page is that the clock they measure does not flex for a disruption.
How this plays out on your carrier
How a disruption actually plays out depends on the carrier you booked, and that is where the generic explanation stops being useful. Which carriers publish a loading guarantee or a rollable-cargo option, how each one's booking and tracking workflow first surfaces a rollover, and what each carrier's free-time tariff allows all differ, and none of that per-carrier detail is restated here.
Where it lives instead: rollover detection, the per-carrier compensation options, and automated rebooking are on the booking solution, which fans out to the individual carrier booking pages. Reliability-calibrated exception detection and the DCSA tracking visibility that surfaces a disruption early are on the tracking solution and the carrier tracking pages. The charge side, how demurrage and detention are calculated and challenged for the carrier and port you are dealing with, is on the demurrage and detention pages linked above. This section points; it does not repeat what those pages carry.
Where Expedion fits
On the desk, a disruption is a detection-and-replanning problem that repeats across carriers: spotting that a booking has been rolled, then deciding the next sailing against what each carrier is actually running. We run AI agents that detect a rolled booking against the carrier's tracking feed and re-plan the sailing across your carriers, with your team holding authorization and sign-off, alongside reliability-calibrated exception detection that flags the bookings worth looking at first. This carrier-side capability is in supervised production with design partners, not general availability. You can read how we handle booking and tracking in full.
Frequently asked questions
Is a blank sailing the same as a rollover?
No. A blank sailing is the carrier cancelling a scheduled sailing, so the departure does not run at all. A rollover is the carrier taking your booked container off its confirmed vessel and moving it to a later sailing, so the ship departs without your box. They are related, though: a blank sailing is one of the most common causes of a rollover, because the cargo booked on the cancelled sailing is what gets rolled forward.
Does a rollover use up my free time?
No, not directly. For an import, free time starts when the container is discharged at destination and runs on a fixed tariff allowance, so a rollover delays the arrival but does not extend or shorten that allowance. Two real effects sit underneath that. A container rolled at origin while already collected and packed can start accruing detention at origin before it sails. And when a disruption bunches arrivals and congests the port, the customs, trucking, and empty-return steps you have to finish inside that fixed window all take longer, which is where the pressure actually lands.
What can I do when my container is rolled?
Catch it early against the carrier's tracking feed, then decide between accepting the later sailing the carrier offers and rebooking to protect the delivery date. If the container was already collected and packed, check whether it is now accruing charges at origin. The per-carrier compensation options, such as loading guarantees and rollable-cargo products, and how a claim is filed sit on the carrier booking pages and the booking solution, not on this page.
When does the free-time clock start?
For imports, the allowance starts counting when the container is discharged from the vessel at destination. For exports, detention runs from the point you collect the empty for packing. The allowance itself is not standardised: it varies by carrier, port, direction, equipment type, and contract, and is published in the carrier's tariff, so the figure to plan against is the one on the tariff for your specific move, not a general number.
Where do demurrage and detention come in?
When free time runs out. The US Federal Maritime Commission frames it as demurrage accruing when a container exceeds its free time on the marine terminal, and detention being charged for the extended use of the equipment itself. How each is calculated, and how a charge is challenged, varies by carrier and port and is covered on the demurrage and detention glossary pages.