“…No doubt, idle discharges would at present be dispensed with on the stations shown in Table 2. At the same time, with a rather longer closure time for the guide vanes (i.e., converting to a higher transient irregularity), the maximum pressure in the penstock could be left unchanged or even reduced, as illustrated on the Khrama number 2;station [7]. As regards reliability of idle discharges, existing design standards take this into account, indicating that, for calculations of increased pressure from water hammer in a penstock feeding a number of turbines with idle discharges, failure of operation of idle discharge on one of the turbines has to be reckoned with [8].…”