The hunting gear in an electro-hydraulic steering system acts as a feedback controller responsible for maintaining the rudder's position. It achieves this by continuously comparing the desired rudder position (setpoint) received from the wheelhouse with the actual rudder position.

In control parlance, it operates as a closed-loop control system with the following functions:

• The hunting gear receives two input signals: The desired rudder position (set by the wheelhouse control) and The actual rudder position (measured by the rudder’s current position). It compares these signals to detect any error or difference.
• An error signal is generated if there is a difference between the desired and actual rudder positions. This signal causes the pump actuating lever to move, which adjusts the oil flow to the hydraulic cylinders, thereby correcting the rudder’s position.
• As the rudder moves to the desired position, the floating lever of the hunting gear also moves, feeding the corrected position back into the system.
• When the rudder reaches the desired position, the pump returns to the neutral position (no stroke), stopping the oil flow and keeping the rudder steady.
• If external forces, like waves, cause the rudder to deviate, the hunting gear will automatically detect the deviation and make corrections by adjusting the pump, similar to a controller in a closed-loop system.

The below sketch shows the operation of hunting gear.

• When the telemeter control receives the order for any movement from the wheelhouse, it moves one end of the floating lever to either side, depending upon the order. So it moves from position A to A’ as shown in the above sketch
• Movement of the floating lever will cause pump actuating lever to move from B to B’. This will start the pumping of oil and thereby the movement of rams.
• Once the rudder has accrued its desired position, it also moves the free end of floating lever to a new position i.e. from C to C’
• This movement of C to C’ will bring back the pump actuating lever to its original position i.e. from B’ to B. Thus, the pump is at no-stroke/ neutral position, causing the rudder to stay at its position.

If the standby pumping unit is motored, it means that the standby pump is rotating in the opposite direction to the operating pump, driven by the pressure generated by the operating pump. The following consequences may occur:

• Reduced Efficiency: The operating pump's output energy is wasted in rotating the standby pump, leading to reduced efficiency and slower rudder response.
• Motor Failure: The standby pump motor is designed to rotate in one direction. Running it in reverse can damage the ball bearings and ultimately lead to motor failure.
• Hydraulic System Instability: The opposite rotation of the pumps can introduce instability in the hydraulic system, leading to unpredictable rudder behaviour.

• Mechanical Locking: This method utilises a ratchet and pawl mechanism. The stationary ratchet is fixed with the motor casing while the pawls are mounted along with the pump coupling. When the pump is running, the pawl flies outwards due to centrifugal force and makes contact with the casing, which revolves with the coupling. When the pump stops, the pawls return to their normal position and engage with the ratchet teeth, thereby providing a positive lock against reverse rotation.

• Hydraulic Locking: This method uses a hydraulically operated bypass valve. While the pump is running, the bypass valve is closed due to hydraulic pressure from an auxiliary pump. When the pump stops, the pressure drops, causing the valve to open due to spring force. This blocks any oil flow from the operating pump to the standby pump, preventing it from motoring.