Presentation of this paper will be given as part of the SHORT COURSE: Miter Gates, Rolling Gates and Operational Machinery Process Design.
The recently published PIANC WG Report No. 154 covers international mitre gate design, operation, and maintenance. This presentation will summarize the current state-of-the-practice and best practices in mitre gate maintenance.
Mitre gates are critical components of locks for system reliability. The system reliability is strongly dependent on the successful long term operation of mitre gates. Maintenance is essential to reducing costly downtime and ensuring a long, successful life.
Starting with design, there are many features that can be included in how a mitre gate is constructed that can make future maintenance easier, less time consuming, and cheaper. Such features include easy-to-replace components (susceptible to wear and damage), accessibility to gate components with larger openings and ladders for maintenance personnel, and standardising replacement parts. Standardisation of river system mitre gate design helps to reduce part inventory, improves consistency in repair and replacement methods and reduces overall maintenance costs.
Methods of maintenance are also important. Smaller gates can be lifted out of place and worked on in-the-dry. Larger gates may require lock dewatering and jacking. Proper care to procedures and planning for these maintenance events is essential.
Debris and ice can cause operational and maintenance problems. High volume air bubbler systems have been used effectively to move ice and debris from the gate recess area such that the gate may fully move to recess position. High volume bubblers are also used across the lock chamber upstream of the gates to help limit ice movement into the chamber and gate area. Low volume air systems or propeller systems can be attached to the gates to prevent the buildup of ice on the gates. Permanent or portable steaming wands are used to cut ice from lock recess walls or gates.
Structural health monitoring, instrumentation, and inspection play important roles in proper maintenance of a mitre gate. When a problem is identified early, the resulting repair is often easier, less expensive, and less impacting to system performance than when a problem develops into a large and major issue.
In addition to components, the materials used to construct the gate components can have a significant impact on performance and longevity. Recent advances in bearing and composite materials have lead the way to better performance self-lubricating hinges as well as corrosion-resistant and lighter gates made of fiber reinforced polymers (FRP). These materials can reduce the amount of maintenance required for a mitre gate.