|Diagram from US Government|
The text for this diagram is:
Bear trap gates consist of two leaves. When in the lowered position, the upstream leaf overlaps the downstream leaf. The gate is raised by applying upper pool pressure to a chamber under the leaves. This pressure, sometimes supplemented with air or hydraulic cylinders, raises the dam gate. These gates generally retain a pool differential of 20 ft or less and are normally about 90 ft wide. They are ingeniously conceived but can prove difficult to maintain. Silt or sand deposits in or under the gates are particularly likely and may make it impossible to fully lower or raise the gates.
Ohio River, search for bear. This is one of those neat sites where I could spend soooo much time browsing.
|Cincinnati Views: Fernbank Engineering Article|
|Cincinnati Views: Fernbank Dam|
|Cincinnati Views: Fernbank Dam with heavy water flow|