Seite - 1558 - in Book of Full Papers - Symposium Hydro Engineering

what should be monitored and tested emerge directly from the practicability of establishing and maintaining the operational integrity of the various features of the dam system be it at the component level (or even further down to the elemental level, such as motor windings), or at the system level, or somewhere in between. Thus, beginning with the operational modes of water retention and water conveyance, and progressively resolving these system operational modes into their constitutive functional modes, it is possible to determine the overall operational integrity of the dam system and to establish that the dam is functionally safe. This can all be achieved on the basis of operationality without consideration of failure modes. 3.1 DERIVATION OF FAILURE MODES Failure modes can be derived directly from the operational modes of the system and its resolved parts. Figure 4 illustrates a spillway gate at the headworks module level comprising 10 components, and a functional analysis diagram that illustrates the operational modes of the various components in a self-explanatory way. Figure 4. Component level Functional Analysis Diagram of a spillway gate The function of the motor is to rotate the hoist drum and the failure mode of the motor is loss of rotation, with the effect that the hoist drum does not move. Functionality of the entire gate module is lost as a result and the obvious dam Side seal (wall) (10) Sill beam (8) Skin plate (5) Trunnion bearing (6) Edge seal (9) Lifting bracket with equalizer plate (4) Wire rope (3)Hoist drum (2) Drive motor (1) Strut arm (7) Side seal (wall) plate (11) Sill beam (9) Skin plate (5) Edge seal (10) Lifting bracket with equalizer plate (4) Wire rope (3) Hoist drum (2) Drive motor (1) Strut arm (8) ro ta te s W in ds ro pe in Appl ies t ensi le force to Transfers tensile force to Trunnion bearing (6) R o ta te s a ro u n dS u p p o rt s a n d p re v e n ts le a k a g e 1558