This presentation includes a brief description of the parameters (forces, speed, flows, drags, friction, water densities, etc.) considered to define the relevant characteristics of the drive mechanism to open and close a 4000 tons Rolling Gate in five minutes. Also we will comment designs discussions and decisions to define relevant topics such as the sealing systems of the gate, flotation considerations, etc.
We will make a general description of the rolling gates components and their functions to have a comprehensive understanding of the system to operate the gates.
A Brief description of the Guidance, Bearing and Sealing system (GBS) to maintain the gate on the rails during its displacements, support the hydrostatic loads, and minimize the leakage of water through the borders of the gates.
We will comment topics such as the wire rope engineering selection factors that were changed during the design process.
Innovative electro-mechanical concepts has been implemented to modernize the tensioning system using load cell, sensors, and hydraulic cylinders to reduce any slacks of the wire rope. Other innovative concept is the Load Limiting Device (LLD) design to minimize the effect of high vertical forces, carried by the lower and upper wagons, than can be induced during seismic movement or loss of buoyancy of the gate due to a ship impact. A plow system has been implemented to remove any debris ahead of the lower wagons, which could be deposited over the rails.
Design considerations for easy maintenances or repair of lower wagons will be addressed.
In this presentation will be mentioned a test that was developed at University of Udine to evaluate the gate seal performance. To displace the rolling gates many forces has been identified to be overcome. These forces which some are relevant others has minimal effect during the displacement of the structure but not all them interact simultaneal. The most critical force to analyses correspond to the friction caused by the head differences and the effect of the difference on water salinity. There was a considerable friction on the wagons wheel and the rail contact surface basically due to the installations constrains. Innovative wire rope tensioning system will be describe. The tensioning mechanism required to eliminated any possible slack of the wire rope
During the design process particular decisions were made. The designer decided to select the “wheel Barrow” concept to the distribution of the positions of the wagons to carry the weight of the gate. Which consists in one lower wagon in the bottom at the front side of the gate. The supported wheel of the lower wagon are separated 1.6 meters and the wagon is located at the center of the gate. On the back side of the gate there is an upper wagon located on the top of the gate with wheels separated more than 10 meters. These wagons wheels carry approximately 15% of the total weight of the steel structure. The other 85% is supported with the flotation compartments.
Other of the concerns during the design process was the wear of the rail surface in the area of contact whit the wheels of the upper wagon at the recess entrance during the close position of the gate due to a small displacement of the center wall of the recces. To address this problem several alternative were analyzed.