THE LOADED BOX · VSSI MONTHLY
January 2026 · Vessel Schedule Stability Index
The window held steady at the network level. A subset of voyages never settled.
Where in the planning horizon the window actually moved - and what that means for commitments still open.
Published May 05, 2026 · Framework TradeLanes VSSI Monthly v1.1 · Companion publication Safe-to-Gate Monthly January 2026
1. The Reading
The median cargo receiving window held within ±1 hours across the planning horizon - 137h at T-4w, 130h at T-0d, 136h at the final snapshot. The aggregate looks calm at the network level.
Volume tells a different story. The month produced 4,145 CRW revision events across 601 voyages. 56.7% of those events landed beyond T-7 - outside the 72-hour zone where exporters, terminals, and carriers usually fight over the window.
The window is still moving. What matters is where in the horizon it moves. Volatility sat outside the compression zone for most of the activity - in the mid-horizon planning window where commitments are being priced. The window became more visible. Whether it became more actionable depends on when the operator's commit deadline lands.
2. The Mechanism
Sustained Churn pattern · Terminal anchor
The mechanism in January 2026 is paired ERD and CY Cut activity. 50.1% of voyages with movement showed both fields revising together (co-moving) - the largest class in the dual-signal breakdown. Only 4.3% showed the two fields moving in opposite directions. The failure mode is sustained mid-horizon revision activity, not synchronization breakdown between the two signals.
And the activity was not evenly distributed. 5 of the Norfolk-adjusted top-activity voyages departed from USSAV Garden City, Savannah's primary container terminal. The mechanism is cross-carrier but terminal-specific.
The median at T-4w sat at 137 hours and finished at 136 hours. The shape on the chart is flat at the network level - the voyage-level activity is what shows the mechanism.
The three-element read
Contradiction. The median window held - and 601 voyages produced 4,145 revision events. The aggregate hides where the mechanism operates.
Operator implication. Plans committed at T-4w faced revision activity arriving between T-14 and T-3, inside the same horizon where rail commits lock and dispatch chains warm. The information arrived before the plan closed, but not before the commit chain opened.
Failure mode. Plan committed at T-4w. Mid-horizon revisions arrive in paired cascades at the terminal. The window moves forward. By T-3, the window the operator committed against no longer exists. EVER EXCEL 189E at USSAV (departure January 27, 2026) recorded 38 revisions - 1,416 hours of total absolute motion.
3. Key Metrics
Two metrics reinforce the same finding. Revision events are concentrated mid-horizon. Late-stage share - events landing inside 72h of ERD - sits below the mid-horizon mass.
| Metric | Value (this month) |
|---|---|
| Total events | 4,145 |
| Voyages with movement | 601 |
| Mean events per voyage | 6.9 |
| Beyond T-7 share of events | 56.7% |
| Inside T-3 share of events | 23.5% |
| Co-moving (paired ERD+CY) voyages | 50.1% |
| Diverging (opposite direction) voyages | 4.3% |
| Median window at T-4w | 137h |
| Median window at T-0d | 130h |
| Median window at final | 136h |
The breakdown matters more than the aggregate. Beyond T-14: 28.9%. T-14 to T-7: 27.8%. T-7 to T-3: 19.8%. T-3 to T-1: 8.0%. Final 24h: 3.0%. Post-ERD: 12.5%. The mass sits between T-14 and T-7 - the zone where rail commits and drayage dispatch are being finalized.
4. VSSI-P - Port-Level Snapshot
Where the mechanism operated
| Port | Vessels | Events | Late-stage rate | >7d stability rate | Band |
|---|---|---|---|---|---|
| Savannah (USSAV) | 145 | 1941 | 17.1% | 64.2% | High |
| Houston (USHOU) | 122 | 678 | 13.6% | 60.2% | High |
| Norfolk (USORF) | 106 | 749 | 42.6% | 38.5% | Elevated |
| Tacoma (USTIW) | 90 | 305 | 31.8% | 49.5% | Moderate |
| Oakland (USOAK) | 50 | 119 | 67.2% | 26.1% | Moderate |
| Los Angeles (USLAX) | 39 | 106 | 34.0% | 27.4% | Moderate |
| Long Beach (USLGB) | 34 | 287 | 19.9% | 64.1% | Elevated |
| New York (USNYC) | 23 | 69 | 33.3% | 43.5% | Moderate |
| Seattle (USSEA) | 20 | 63 | 19.1% | 77.8% | Elevated |
| Newark (USEWR) | 13 | 23 | 87.0% | 0.0% | Moderate |
Per-port observed patterns:
- Savannah (USSAV) - High. 145 vessels, 1941 CRW revisions. Late-stage (inside 72h) on 17.1% of events; longer-horizon stability movement (>7d) on 64.2%.
- Houston (USHOU) - High. 122 vessels, 678 CRW revisions. Late-stage (inside 72h) on 13.6% of events; longer-horizon stability movement (>7d) on 60.2%.
- Norfolk (USORF) - Elevated. 106 vessels, 749 CRW revisions. Late-stage (inside 72h) on 42.6% of events; longer-horizon stability movement (>7d) on 38.5%.
- Tacoma (USTIW) - Moderate. 90 vessels, 305 CRW revisions. Late-stage (inside 72h) on 31.8% of events; longer-horizon stability movement (>7d) on 49.5%.
- Oakland (USOAK) - Moderate. 50 vessels, 119 CRW revisions. Late-stage (inside 72h) on 67.2% of events; longer-horizon stability movement (>7d) on 26.1%.
- Los Angeles (USLAX) - Moderate. 39 vessels, 106 CRW revisions. Late-stage (inside 72h) on 34.0% of events; longer-horizon stability movement (>7d) on 27.4%. Below the eligibility threshold for primary ranking; observation provided for completeness.
- Long Beach (USLGB) - Elevated. 34 vessels, 287 CRW revisions. Late-stage (inside 72h) on 19.9% of events; longer-horizon stability movement (>7d) on 64.1%. Below the eligibility threshold for primary ranking; observation provided for completeness.
- New York (USNYC) - Moderate. 23 vessels, 69 CRW revisions. Late-stage (inside 72h) on 33.3% of events; longer-horizon stability movement (>7d) on 43.5%. Below the eligibility threshold for primary ranking; observation provided for completeness.
- Seattle (USSEA) - Elevated. 20 vessels, 63 CRW revisions. Late-stage (inside 72h) on 19.1% of events; longer-horizon stability movement (>7d) on 77.8%. Below the eligibility threshold for primary ranking; observation provided for completeness.
- Newark (USEWR) - Moderate. 13 vessels, 23 CRW revisions. Late-stage (inside 72h) on 87.0% of events; longer-horizon stability movement (>7d) on 0.0%. Below the eligibility threshold for primary ranking; observation provided for completeness.
Note on Norfolk. The Norfolk band reflects port-level voyage distribution. A subset of MAEU voyages at USORF shows CY Cut revisions that are not matched by terminal activity (noted in Safe-to-Gate Monthly Dec 2025, Section 4 methodology note). If that is confirmed against the terminal's record, a corrected band will be issued in a later edition.
5. Representative Vessel-Level Movements
Supporting sample · curated by the month's pattern · not a ranking
The following vessels illustrate how receiving windows moved in practice. Each card shows the voyage's identification, departure, revision activity, and the dominant pattern in the dual-signal space. The mix reflects the month's distribution - Sustained Churn voyages predominate, with one less-active case included for reference.
EVER EXCEL · USSAV · EGLV / 189E Departure: Jan 27, 2026 CRW revisions: 38 (20 ERD + 18 CY Cut) Total absolute magnitude: 1,416 hours Pattern: Sustained Churn - paired ERD+CY revisions See this vessel in Safe-to-Gate Weekly →
MSC PANTERA · USSAV · MSCU / XA549 Departure: Jan 03, 2026 CRW revisions: 26 (14 ERD + 12 CY Cut) Total absolute magnitude: 1,320 hours Pattern: Sustained Churn - paired ERD+CY revisions See this vessel in Safe-to-Gate Weekly →
MOL ENDOWMENT · USSAV · ONEY / 099W Departure: Jan 02, 2026 CRW revisions: 28 (14 ERD + 14 CY Cut) Total absolute magnitude: 1,296 hours Pattern: Sustained Churn - paired ERD+CY revisions See this vessel in Safe-to-Gate Weekly →
MSC NIOVI VIII · USSAV · MSCU / MZ552 Departure: Jan 02, 2026 CRW revisions: 29 (15 ERD + 14 CY Cut) Total absolute magnitude: 1,272 hours Pattern: Sustained Churn - paired ERD+CY revisions See this vessel in Safe-to-Gate Weekly →
ZIM VIRGINIA · USSAV · ZIMU / 154E Departure: Jan 04, 2026 CRW revisions: 28 (15 ERD + 13 CY Cut) Total absolute magnitude: 1,200 hours Pattern: Sustained Churn - paired ERD+CY revisions See this vessel in Safe-to-Gate Weekly →
6. What This Means for Planning
The decision horizon changes under this pattern.
When late-stage volatility dominates, exporters can buffer. Commit at T-4w, recheck at T-3, absorb the last-72-hour shift through reserved equipment and pre-booked appointments. The system is designed for that decision sequence.
When mid-horizon volatility dominates - and January 2026 sits at 56.7% of events arriving beyond T-7 - the buffer moves inside the commit window. The plan is moving while it is being committed. Rail commits, labor scheduling, and drayage reservations are placed against a window the schedule has not finished drawing.
The planning-horizon choice is no longer 'commit early at T-4w, recheck at T-3.' It becomes: wait for the voyage's trajectory to settle before committing, or accept that the commitment will be revised mid-flight. For a voyage already showing mid-horizon activity, the plan committed at T-4w will not be the plan that executes.
Cost is created when action is taken against a window that hasn't stopped moving. The window at T-4w is not a fiction. But if the same voyage is showing mid-horizon activity, every dollar priced against that T-4w window is priced against a plan that will be rewritten.
7. Bottom Line
January 2026 held its network-level shape - the median window stayed within ±1 hours across the planning horizon. Voyage-level activity, however, continued to move inside the planning window. The aggregate looks calm. The voyage-level signal does not.
The mechanism is paired mid-horizon revision activity, concentrated at USSAV Garden City. The window became more visible. Decision quality depends on when the operator's commit deadline lands.
Visibility improved. Decision quality did not - unless the commit horizon moves with the data.
TRADELANES · VSSI MONTHLY · JANUARY 2026
tradelanes.co
Appendix A - Measurement Layer
Band vocabulary. Stable - window held through execution. Moderate - window moved within planning tolerance. Elevated - window structure under stress. High - window not reliable for commitment. Used consistently across Safe-to-Gate Weekly, Safe-to-Gate Monthly, and VSSI Monthly.
Outcome classification. Compressed - final window narrower than original. Mixed - ERD and CY Cut moved in opposite directions. Late expansion - both shifts in the same direction past the planning tolerance. Moderate drift - small same-direction shift. Stable - window held within tolerance with no late-stage flag. Applied in strict precedence order; first match wins.
Sustained Churn. Voyage-level volatility pattern describing windows that keep moving through the planning horizon without settling. The classification thresholds live in the internal methodology appendix and are not published.
Late-stage qualifier. Inside 72h, inside 24h, or outside 72h, measured as the time between the latest revision event and ERD_final.
Methodology note. Analysis covers January 2026 U.S. departures with observable schedule revisions. 4,145 events across 601 voyages. VSSI-P bands computed from voyage-level distribution; classification thresholds live in the internal methodology appendix and are not published.
Carrier-terminal exclusion carry-forward. Maersk vessels at Norfolk's primary container terminal continue to show CY Cut revisions that are not matched by terminal activity - first noted in Safe-to-Gate Monthly Dec 2025 and still present. 5 MAEU/USORF voyages appear in residual top-activity lists with CY Cut activity that does not reflect underlying terminal behavior. These voyages are excluded from concentration findings and Norfolk band assignments in this edition. A fuller treatment will appear once the pattern is confirmed against the terminal's record.
Editorial update, Nov 2026: wording of the Norfolk methodology note clarified; no figures changed.