The Portland Engineer District will close The Dalles navigation lock Tuesday May 24 at 6 a.m. to repair a gearbox that operates the mechanism for opening and closing the north leaf of the downstream gate. The lock is expected to reopen Saturday May 28 at 6 a.m.
However the Corps warns that it will not have a complete picture of the damage and needed repairs until the gearbox is opened and drained and a full assessment performed. The Corps expects to have this information on the morning of Wednesday May 25 and may announce an extension of the outage at that time to accommodate additional repairs.
The Corps believes that one or more bearings in the gearbox are failing. Bearing failure – which could occur without warning – could lead to more significant damage to other gate components and an unplanned extended repair outage.
This interim repair should allow the gearbox to function until the next regularly-scheduled maintenance outage in March 2012 when the Corps plans to replace it.