Hydraulic Systems &= nbsp; &nbs= p; Chapter
21
Hydraulics= forms a powerful, efficient, and reliable method to power components aboard the ship. They also require prope= r care and operation.
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here are three hydraul= ic systems on the ship. The main system powers the bow thruster, windlasses, stabilizers, and the future crane. The steering and autop= ilot are the second system. The th= ird system steers the z-drive. Ea= ch system has sits own pump and reservoir to create completely independent systems. The systems are from= a homogeneous manufacture in each case to simplify component interoperation.<= o:p>
Hydraulic systems oper=
ate
under very high pressure and must be properly maintained. Routine maintenance is checking of
fluids, inspection for leaks or stress, monitoring for over-heating, and
observation for any abnormal sounds or operation. The systems require proper fluid, =
free
from any contamination. Any
contaminants can cause valve or control failure and can severely damage the
system as well as cause device malfunction. All service to the system must fol=
low
special procedures to prevent any contamination of the system. The rubber
hydraulic hoses and couplings should be inspected regularly for signs of
leakage or stress.
Primary Hydraulics
The primary hydraulic system powers the bow thruster, windlasses, stabilizers, and the future crane. See Figure 1 - Primary Hydraulic System. Th= e blue engine driven pump is mounted on the port aft end of the engines. It draws fluid from the blue reser= voir above the port side of the z-drive to pressurize the system. The lines from the pump have a tee= in the engine room for the attachment of the crane in the future. From there the lines travel throug= h the bilge to the control manifold mounted on the port wall of the mid-bilge, forward of the hatch.
The manifold received the pressure line and return l= ine from the pump and drives control lines for each of the devices. A load sense line from the manifol= d to the pump, engages the pump for the required pressure. Under direction from the controlle= rs on the helm, the valves in the manifold divert the pressure flow to each devic= e. The direction of each of the devic= es is controlled by the direction of the flow.&n= bsp; Each device has its own pair of lines from the manifold to control direction of operation. The b= ow thruster has an additional line from it to the return in the engine room fo= r a case drain.
Fluid returned from the manifold and the bow thruste= r case drain is cooled with sea water then returned to the reservoir. The hydraulic cooling provides a m= eans to cool the devices under control when in operation. This makes the hydraulic component= s much more resistant to heat build up in continuous operation.
Figure 1 - Primary Hydraulic System
![](3D"Hydraulics_files/image002.gif")
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Bow Thruster
The Wesmar 38 HP bow thruster is located in the bulb= ous bow and is plumbed through the forward bilge. A pair of hydraulic lines control = the direction of operation and a third line for a case drain returns cooling fl= uid taken from the drive lines to the engine room to the cooler and reservoir.<= /p>
Control for the bow thruster is via the turn Switch = on the helm console and a switch on the portable Mathers control unit. These controls wire to a controller mounted (where) [WW1] which drives the electrical lines to the control manifold. The attachment lines and seals in = the forward bilge should be inspected regularly for hydraulic or sea water leakage.
Windlasses
The Maxwell VWC 4500 windlasses are mounted on the f= ore deck and control the dispensing or retrieval of the anchor chain. Each windlass has its own pair of = lines from the control manifold. Th= e flow direction determines the rotation of the windlass. These lines run through the port s= ide of the forward bilge, then up the ship between the steel anchor locker bulkhead and the wood forward bulkhead in the forward stateroom. In the ceiling of the forward stat= eroom, it is routed into the chain locker and then to the windlass.
The windlasses are controlled from hand held units i= n the port side of the Portuguese wall. There is a control with a chain counter mounted on the helm for operation from the pilot house. These are wired (where) [WW2] and then to the control manifold.
Stabilizers
The Wesmar stabilizers are mounted within the bilge = keels on each side of the ship. The control manifold supplies a pair of lines that are tee= ’d to each of the stabilizers in the mid bilge under the stairs. The rotation of the fins is determ= ined by the direction of the hydraulic flow.
The stabilizers are controlled from a panel on the p= ort side of the helm ceiling console. These controls are wired to the stabilizer control box (where<= /a>[WW3] ). The control box uses the gyro sens= or input (really) [WW4] to control the stabilizers to counteract the rolling of the ship. The stabilizer control directs the manifold controller to move the fins as desired.
Crane (future)
The power connections for the crane can be connected= in the future to lines that have already been run from the engine room to the saloon ceiling where the crane will be mounted. These lines have not been connecte= d to eliminate any chance of a hydraulic leak in the saloon prior to this connection.
![](3D"Hydraulics_files/image004.gif")
When
the crane is connected, it will have it’s =
own
manifold to control the cable, slew, elevation, and extension of the crane.=
Steering Hydraulics
The hydra= ulic steering system supplied by Jastram is controlled by both the steering wheel driven helm pump and the Robertson auto pilot controller. The white engine driven pump on th= e port forward side of the engine pressurizes fluid drawn from the white Jastram t= ank on the aft engine room wall. = Pressurized fluid is fed to the auto pilot control valves on the aft wall of the engine room above the rudder piston. The autopilot control will direct the fluid in the desired direction of rudder movement. Fluid from the auto= pilot control, fluid returns to the reserve tank through a pressure splitter. The pressure splitter sends a small portion of the returning fluid to the helm pump fill. Overflow from the helm pump return= s to the reservoir. This system in= sures that the helm pump is always being filled and eliminates the need for a steering fluid reservoir above the helm station.
![](3D"Hydraulics_files/image006.gif")
Z-Drive Hydraulics
The z-drive is rotated via a hydraulic powered drive system. The blue hydraulic pu= mp mounted on the forward port side of engine draws fluid from the blue reserv= oir mounted above the z-drive. The pressurized fluid is sent from the pump to the rotation motor on top of the z-drive. After use, the fluid= is returned to the reserve tank. The rotation control diverts fluid in the des= ired direction through the pipes to the z-drive steering motor.