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9 Cards in this Set
- Front
- Back
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Steering motors
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The prime mover for the steering pumps. 125 HP electric A/C motors that turn at a constant 1800 RPM. They are horizontally mounted and coupled to the steering pumps.
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Steering pumps
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Pump hydraulic oil to the ram assemblies. Each pump is a motor driven, horizontally mounted, positive displacement, variable stroke, axial piston pump. The pump and motor sets (power units) are designed to be able to maintain pressure at approximately 2000 PSI through normal operating pressure is between 300-600 PSI.
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Trick wheel
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When engaged, the trick wheel will send a mechanical signal to the steering to control rudder locally from AFT steering. Normally, an electric signal from the bridge is used to control the rudder remotely.
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Differential control box
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Controls the stroke of the steering pump. An "ordered rudder position" signal from the bridge or trick wheel is compared to an "actual rudder position" signal from the follow-up assembly. The difference between the two signals operates internal components of the DCB which in turn operates the pump stroke control.
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Ram assembly
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Two rams (silver poles) are attached to the crosshead and move back and forth between two cylinders. Hydraulic oil pressure is applied to one cylinder on each ram (crisscrossed cylinder) to push the ram towards the other cylinder, turning the rudder.
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Crosshead
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Connects both rams to the rudder shaft.
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Emergency steering hand pump
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In the event that the power units cannot be used, such as a power failure, using hand pumps may turn the rudder. First, the oil must be aligned to bypass the pumps and to the hand-pumps. 30 turns of the hand pump will move the rudder 1 degree.
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Manual transfer valve
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Allows the operator to select which power unit, PORT or STBD, will operate the steering gear.
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Discuss the four methods of operation.
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Electronic signal from the Helm on the bridge
Mechanical linkage from the Trick wheels Mechanical linkage from the hand pump Jacking Wrench |
