I have one request the two SME teams should come from (SME-Motor & Electrical and SME-Recycle & Cooling) to do this following check. To learn and know how the cooling tower gear box could be damaged at the gear teeth.
I have comment to you that, the current operation regime to start the standby cooling tower must be revised and change (to run 2 fan, stand by one fan). If we decided to start the stand by fan at every week, the we prone to damage the gear teeth. Due to the highest torque is creating during start much more than normal speed. Then find the better way, such as to pressurize the gear box at 5 to -10 psi, to charge the dry air to prevent the moisture in oil at the unit that being shutdown shall be the solution for us.