When Lake Huron freezes, the Detroit-Windsor corridor goes dark. This is the manifest I keep in the Kalamazoo vault: ice load thresholds, shutdown triggers, and the 14-week buffer that keeps the contract alive.
The Soo Locks close at 0.6m average ice thickness. Detroit-Windsor drops to 40% capacity at 0.3m. These aren't estimates—they're the numbers that shut down my Q4 shipments.
| Corridor | Shutdown Threshold | Buffer Activation | Reroute Target |
|---|---|---|---|
| Detroit-Windsor | 0.3m avg ice | 0.2m detected | Toledo–Sandwich rail |
| Soo Locks | 0.6m avg ice | 0.45m detected | Twin Ports–Thunder Bay |
| St. Lawrence Seaway | 0.8m avg ice | 0.6m detected | Hudson River terminal |
Kalamazoo warehouse B-7 holds 42 days of critical spares. Detroit yard holds 21 days. Windsor depot holds 14 days. When the ice hits 0.2m, Windsor becomes a ghost town—we pull everything to Detroit, then Kalamazoo.
| Location | Normal Stock | Ice Alert Stock | Critical Items |
|---|---|---|---|
| Kalamazoo B-7 | 42 days | 90 days | Hydraulic seals, bearing assemblies, control modules |
| Detroit Yard 4 | 21 days | 42 days | Fuel filters, transmission fluid, tire casings |
| Windsor Depot | 14 days | 0 (evacuated) | N/A |
From late December to mid-March, the corridor operates on countdown. Week 1: Windsor evacuation. Week 4: Detroit consolidation. Week 8: Kalamazoo lock-down. Week 12: Zero outbound movement. Week 14: Spring thaw confirmation.
Three parallel paths. Primary dies at 0.3m. Secondary dies at 0.6m. Tertiary survives to 0.9m—but costs 3.2x fuel and 4.1x transit time. I only burn tertiary when the alternative is total blackout.
| Path | Ice Limit | Transit Time | Fuel Cost Multiplier | Status |
|---|---|---|---|---|
| Primary (Detroit-Windsor) | 0.3m | 18 hours | 1.0x | Active |
| Secondary (Toledo-Sandwich) | 0.6m | 36 hours | 1.8x | Standby |
| Tertiary (Hudson fallback) | 0.9m | 96 hours | 3.2x | Reserve |