NOTE: Locks close in late December or early January and do not reopen until late March or early April.
The United States maintains and operates two of the seven locks on the Montreal-Lake Ontario section of the St. Lawrence Seaway. Keeping both locks running is critical because operability of the seaway segment is compromised by the closing of any of the locks.
Lock availability for the 2001 navigation season was approximately 99 percent if closure due to daylight-only navigation is excluded. Either or both of the locks was closed for the following times and reasons: structure-related (11 hours), vessel-related (46 hours), weather (13 hours), and other (4 hours).
|St. Lawrence Seaway System Availability||Sep-01||Sep-02|
|Percentage of time available for navigation||99.4||99.9|
|Percent change from same month previous year||0.00||0.50|
NOTES: System availability is hours actually available for use divided by hours which the lock is intended to be in operation. The locks are intended to be open 24 hours per day during the navigation season; however, locks may be closed early or late in the season for daylight-only navigation. Closure due to daylight-only navigation is excluded from this data.
Downtime at one lock constitutes downtime for the system.
Months during which the Montreal-Lake Ontario segment is open fewer than five days are excluded.
Data for the five locks operated by the St. Lawrence Seaway Management Corporation (SLSMC) of Canada are not included.
SOURCE: "Availability Performance Report," monthly issues; St. Lawrence Seaway Development Corporation (SLSDC), U.S. Department of Transportation.