The cantilever rolling gate

Abstract

The objective of this research is to design and evaluate a new type of rolling gate for the Western lock (Westsluis) in Terneuzen, for which all sensitive and heavily loaded mechanical parts are both easily accessible and located above water. Having all mechanical parts above water not only makes them easier to inspect and maintain, but it also makes them less prone to fouling or obstruction by debris. In this way, the risk of premature gate failure due to failure of wheels/rails is expected to be lower, increasing the overall availability during the lifetime of the lock.
Six variants are designed and evaluated using a qualitative Multi Criteria Analysis (MCA) and the Cantilever rolling gate is evaluated most feasible. The Cantilever rolling gate concept is a system in which all the rolling supports are located on an extension to the side of the gate. The gate is balanced by a counterweight and in a way 'hangs' in the gate chamber. The carriages are connected to the gate by hinges, which ensure the perpendicular horizontal movement of the gate in closed position to seal the lock against rubber profiles on the sill, gate chamber and recess.

Subsequently the Cantilever rolling gate is further elaborated at the case study location by means of structural calculations. The focus of the design calculations is on the load balance of the gate and supports in the longitudinal direction. To minimise the required extension of the gate chamber, the added cantilever length is kept as short as possible. To find the most optimal cantilever length, limits are defined regarding the minimum required force acting downwards on the carriages to maintain equilibrium and the maximum design capacities of the wheels and rails with respect to strength and fatigue.
Based on the performed calculations, the most optimal Cantilever rolling gate design for the Western lock in Terneuzen has the following properties; an added cantilever part with a length of 16.6 meters; a cantilever truss structure constructed of Circular Hollow Sections (69 t); a counterweight directly below the back carriage (1083 t); an 8-wheel front carriage and a 4-wheel back carriage.
The added cantilever structure of 16.6 m extends the gate part of 44.6 m by 37%. The designed cantilever rolling gate fits at the location of the case study, but the lock chamber and rails should be lengthened by 16.6 m to fit the extended gate.
Based on this research it is expected that the concept of a Cantilever rolling gate is technically possible. However, it is not yet certain whether the Cantilever rolling gate will also be feasible in practice. Some additional development is still required before the design can be considered fully technically feasible. For example, it is important that the horizontal force transmission and guidance is further evaluated. It is also recommended to calculate the actual availability and determine whether the difference in availability between the Cantilever rolling gate and the conventional rolling gate outweighs the cost.