4A1. General description. The rudder of
the submarine is moved by hydraulic power.
Under normal conditions of operation the
steering system has its own source of power,
a motor-driven No. 5 Waterbury A-end pump,
and is therefore, except in emergencies,completely independent of the main hydraulic
system described in Chapter 3.
The principal control units are assembled
in the steering stand, located in the control
room. However, since there is an auxiliary
steering wheel in the conning tower connected to the steering stand controls by a
shaft, the submarine can be steered either
from the control room or from the conning
tower. To allow for every contingency, the
steering system is so planned that three different methods of steering, based on three
different sources of hydraulic power, are
available. They are designated as follows:
1. POWER, in which the hydraulic
power is independently developed by a motor
driven pump belonging to the system itself.
2. HAND, in which the hydraulic power
is developed in the telemotor pump by the
direct manual efforts of the steersman.
3. EMERGENCY, in which the hydraulic
power is supplied by the main hydraulic
system.
It should be emphasized that the rudder
itself is moved by hydraulic power in all three
cases; the only difference between these
methods is in the manner in which the power
is developed.
EMERGENCY power is used only when
the normal power (called simply POWER)
fails. HAND power is used only when silent
operation of the submarine is necessary to
prevent detection by enemy craft, or when
both the normal POWER and the EMERGENCY power from the main hydraulic
system have failed.
The submarine can be steered by all three
methods from either the control room or the
conning tower.
B. DESCRIPTION
4B1. General arrangement. A schematic
diagram of the steering system as a whole is
shown in Figure 4-1. The system may be
conveniently thought of as divided into four
principal parts:
a. The normal power supply system,
which consists of a Waterbury No. 5 A-end
pump, the motor which drives it, the control
cylinder, and the main manifold.
b. The steering stand, which consists of
the main steering wheel, emergency hand
wheel, telemotor pump, pump control lever,
change valve, emergency control valve, conning tower connecting shaft, and a clutch.
c. The main cylinder assemblies, which
consist of the cylinders and plungers and
the mechanical rudder-angle indicator.
d. The rudder assembly, which consists
of the connecting rods and guides, the crosshead, and the rudder itself.
Other units or features are considered in
Section 4B2e.
4B2. Detailed description. a. The normal
power supply system. 1. The Waterbury
pump. In normal operation, the hydraulic
power used by the steering system is developed by a Waterbury No. 5 A-end pump,
described in Section 2C. It is driven by a 15
horsepower electric motor at a constant speed
of about 440 revolutions per minute. The
pump turns in a clockwise direction as viewed
from the motor end of the shaft. Its speed is
constant, but the direction and angle of the
tilt-box change. These factors determine the
amount of oil pumped into the system to move
the rudder, and the direction in which it is
pumped.
2. The control cylinder. The function of
the control cylinder is to translate the movement of the main steering wheel, as the
80
Figure 4-1. Schematic view of steering system.
1) Fifteen-horsepower electric motor, speed 440 revolutions per minute; 2) magnetic brake; 3) brake release lever; 4) motor-driven Waterbury A-end
pump; 5) control cylinder; 6) steering system main manifold; 7) steering stand; 8) main steering wheel; 9) emergency steering wheel; 10) emergency
control valve; 11) telemotor pump; 12) pump control lever; 13) change valve; 14) conning tower connecting shaft; 15) port main cylinder, forward
end; 16) Port main cylinder after end; 17) starboard main cylinder, forward end; 18) starboard main cylinder, after end; 19) port plunger; 20) starboard plunger; 21) yokes for inboard connecting rods; 22) inboard connecting rods; 23) connecting rod bearings; 24) mechanical rudder-angle indicator
dial; 25) mechanical rudder-angle indicator pointer; 26) vent and replenishing manifold; 27) vent and surge tank; 28) main hydraulic system supply
manifold; 29) main hydraulic system return manifold; 30) line to main supply tank; 31) vent and replenishing line to supply tank; 32) gage; 33) relief
valve (48 pounds); 34) vent and replenishing line to stern plane Waterbury A-end pump.
81
steersman turns it left or right, into a corresponding upward or downward motion of
the control shaft, thereby changing the position of the tilt-box in the motor-driven Waterbury pump. This in turn varies the stroke
of the pistons inside the motor-driven pump.
It also determines the quantity and direction
of flow of the oil which is pumped to the
main rams. In this manner it controls the
output of the motor-driven Waterbury pump
in response to the adjustments made by the
steersman when steering by normal POWER.
The control cylinder assembly consists
of a pair of small hydraulic cylinders, opposed and axially in line, having in common
a single plunger which slides between and
through the cylinders. Bell-crank linkage
connects this plunger to the tilt-box.
Figure 4-2 shows the details of this unit.
The plunger (2) is a double-ended, solid steel,
cylindrical bar with a slotted center yoke
midway in its length. The yoke carries a steel
sliding block which engages the bell crank
(5) by a pin (4) fixed through the yoke. This
pin serves as a pivot for the bell crank, the
other end of which is keyed to a shaft (6).
Hydraulic oil under pressure from the
telemotor is delivered to the change valve and
is directed by it to one of the two ports (12).
Oil is forced out of the other port (12)
Figure 4-2. Cutaway of control cylinder assembly, with old-type centering spring.
1) Hydraulic cylinders; 2) plunger; 3) crosshead; 4) pin; 5) bell crank, 6) crankshaft; 7) double crank;
8) pump control shaft; 9) centering spring; 10) spring bracket; 11) pull-rods; 12) hydraulic ports; 13) metal
space ring; 14) packing; 15) packing gland; 16) packing-gland cap.
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by the plunger, back through the change
valve, and into the return side of the telemotor pump. As the plunger moves back and
forth between the cylinders, it turns the bell
crank, rotating the shaft a few degrees in
each direction. At the other end of the shaft,
a double crank (7) is fixed and, as the shaft
turns left or right, this crank moves the pump
control shaft (8). This shaft alters the angle
and direction of the tilt-box in the Waterbury pump. Figure 2-10 shows how the pump
control shaft is linked to the tilt-box in the
Waterbury pump.
The tilt-box is in the neutral position
(zero stroke of the pistons) when it is exactly
parallel to the cylinder barrel, that is, vertical.
As its position is controlled by the linkage
from the control cylinder, the tilt-box will
remain at neutral as long as no oil is being
directed by the steersman through the telemotor pump to either side of the control
cylinder.
As soon as the steering wheel is turned
left or right, a column of oil is sent to one
side of the control cylinder, moving the control shaft up or down and tilting the tilt-box
away from neutral. Unless the wheel were
then turned back exactly to its former position, the tilt-box could not return to neutral.
Therefore, in the absence of any other force,
the steersman, to restore the tilt-box to a
position of zero tilt would necessarily have
to find the previous position of the steering
wheel with the greatest precision otherwise
the motor-driven A-end pump would continue to pump oil and the rudder would continue to move.
In practical operation, such precision of
touch would be almost impossible to achieve,
and the steersman would be obliged to hunt
continuously for the neutral position of the
wheel in order to keep the boat on a straight
course. Therefore, some other means of
neutralizing, or centering, the tilt-box, must
be provided. Such a device is the centering
spring, a powerful spring connected into the
control cylinder assembly in such a way as
to hold the control shaft firmly in the intermediate or neutral position, until displaced
by a definite and deliberate effort of the
steersman. The instant this effort is discontinued, the control shaft returns immediately
to neutral. Thus it may be said that the centering spring provides a force which opposes
any motion of the control shaft away from
dead center.
For example, when the steering hand
wheel is turned to the left, the telemotor
pump immediately delivers oil into the left
side of the change valve. The change valve,
being in the normal POWER position, will
direct the oil to the left end of the control
cylinder. The control cylinder plunger is
moved, compressing the centering spring and
tilting the tilt-box. This allows the power
driven Waterbury A-end pump to deliver oil
immediately to the left side of its valve plate
and then to a pressure line leading to the left
side of the main steering manifold. Oil is
distributed by the manifold to the forward
starboard ram cylinder and the after-port ram
cylinder, moving their plungers (port plunger
forward, starboard aft) and causing the rudder to be moved to the left. As long as the
steersman has the wheel turned to the left,
the rudder will continue to swing to the left.
By partially returning the wheel to its former
position, the oil that was forced against the
control cylinder plunger will be removed
from the control cylinder, thus allowing the
centering spring to recenter the plunger and
tilt-box of the power-driven Waterbury A-end pump. Since the tilt-box has been returned to its neutral position, the pump will
discontinue delivery of oil and the rudder will
therefore remain at the designated rudder
angle.
Through mechanical linkage and hydraulic pipe lines, the control shaft is linked
with the steering wheel in an almost direct
connection. That is, any motion of the steering wheel will be instantaneously translated
into a corresponding motion of the control
shaft. Since this rule works both ways, the
resistance of the spring will be felt by the
steersman. When the steersman turns the
wheel in the opposite direction, the centering spring will return the control cylinder
plunger to neutral. This addition to the control system eliminates all necessity for the
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steersman to hunt for the zero, or neutral,
position.
Figure 4-2 shows one type of centering
spring, found on some older classes of vessels.
The spring (9) goes through a hole in the
brackets (10) and is seated in the yokes at
each end. The brackets are bolted rigidly
to the plunger crosshead (3). As this moves
either way from the center, the bracket on
this side will pull the pull-rod (11) along
with it. This rod, sliding freely in the opposite bracket, will pull on the far yoke,
compressing the spring, and causing it to
resist the motion.
On some of the later classes of submarines, the control shaft which extends through
the Waterbury A-end power-driven pump
has the centering spring attached to one end
of the control shaft, and the control cylinder
on the opposite end.
Figure 4-3 illustrates this type of installation. The pump control shaft (1) enters at
Figure 4-3. Motor-driven Waterbury A-end pump,
with new-type centering spring.
1) Pump control shaft; 2) housing for centering spring.
the bottom, connected to the tilt-box. The
centering spring and its actuating spindle,
against which the top end of the pump control
shaft bears, are contained in the tall, pipelike
housing (2) screwed onto the top of the
power-driven Waterbury A-end pump.
Figure 4-4. Steering system main manifold.
3. The steering system main manifold.
The steering system main manifold (Figure
4-4) consists of a multiple-port housing containing nine valves built into the body, and
eight ports which connect the main rams to
the sources of hydraulic power.
Figure 4-5 shows the location of the ports
as seen from a top view of the manifold. The
two end ports (1 and 2) are connected directly
to the Waterbury A-end pump. The four
ports nearest that end (3, 4, 5, 6) are connected to the fore and aft ends of the port
and starboard rams. The other two ports
(7 and 8) are supply and return ports for
auxiliary power, that is, either HAND or
EMERGENCY, whenever the motor-driven
Waterbury A-end pump is shut off.
Figure 4-5 also shows three of the valves.
All the valves have name plates indicating
their purpose. The two at the end nearest the
pump (9 and 10) are relief valves, placed in
the line between the power-driven Waterbury
A-end pump and the rams to prevent the
building up of excessive pressures. The valve
in the center (10) is the right rudder relief
valve; that nearest the power-driven Waterbury A-end pump (9) is the left rudder relief
84
valve. They are spring-loaded, and set to lift
at a pressure of 1,200 pounds per square inch.
The valve at the other end (11) is a hand
Figure 4-5. Diagram of steering system main manifold, top view.
1) Port to motor-driven Waterbury pump; 2) port to
motor-driven Waterbury pump; 3) port to after end
of port ram; 4) port to forward end of port ram;
5) port to forward end of starboard ram; 6) port to
after end of starboard ram; 7) port to auxiliary
power line, HAND and EMERGENCY; 8) port to
auxiliary power line, HAND and EMERGENCY; 9) left
rudder relief valve; 10) right rudder relief valve;
11) hand bypass valve; 12) vent valve.
bypass valve, used, when needed, to bypass
the hydraulic power by connecting the supply
and return lines from the power-driven Waterbury A-end pump directly to each other.
This bypass normally is closed.
Figure 4-6 is a bottom view of the manifold, showing the other six valves. These
are all cut-out valves, used to shut off their
corresponding ports. The four nearest the
power-driven Waterbury A-end pump, (9, 10,
11, 12) are called power cut-out valves. The
two at the left end (13 and 14), called hard
and emergency cut-out valves, are used to shut
off the two ports connected to the auxiliary
power lines.
Figure 4-7 shows the internal structure
of the valves. The hand bypass valve (1) on
top of the manifold is a disk-type valve. It
consists of a valve body or bonnet (6) containing a threaded traveling stem (7), its top
end squared to fit into the square interior of
the turn-nut (8), its lower end holding a
double ring (9) over which the valve disk
(10) fits. This disk, when screwed all the
way down, fits into the valve seat (11), closing
the valve. To open or close the valve, the
locking cap (12) is backed off a little with a
large hex-wrench, to free the turn-nut. Then
a small hex-wrench is applied to the top of
the turn-nut which, as it turns, rotates the
stem (7), causing it to travel up or down in
the bonnet, closing or opening the valve. The
upper and lower chambers (13 and 14) open
into two channels within the manifold body
which connect to the supply and return sides
of whatever source of power is being utilized.
Unseating the valve disk opens these chambers to each other, thereby bypassing the oil
directly from the supply to the return side
of the system. This valve, therefore, normally
is closed, that is, the valve disk normally is
screwed down into its seat.
The six cut-out valves on the underside
of the manifold, four of which (4 and 5) can
Figure 4-6. Diagram of steering system main manifold, bottom view.
1) Port to motor-driven Waterbury pump; 2) port to
motor-driven Waterbury pump; 3) port to after end
of port ram; 4) port to forward end of port ram;
5) port to forward end of starboard ram; 6) port to
after end of starboard ram; 7) port to auxiliary
power line, HAND and EMERGENCY; 8) port to auxiliary power line, HAND and EMERGENCY; 9) power
cut-out valve, forward-port ram; 10) power cut-out
valve, after-port ram; 11) power cut-out valve, after
starboard ram; 12) power cut-out valve, forward
starboard ram; 13) auxiliary power cut-out valve,
HAND and EMERGENCY; 14) auxiliary power cut-out
valve, HAND and EMERGENCY.
85
be seen in Figure 4-7, are structurally identical with the hand bypass valve described. The
nearest valve is shown partially cut away. In
each of these valves, the upper chamber (15)
leads into the port nearest it (17), while the
lower chamber (16) leads into one of the two
internal channels running lengthwise through
the manifold body. Thus, turning the stem
(18) to the right and seating the valve disk
(19) of any cut-out valve will blank, or cut
out, the corresponding port. These valves
normally are open.
The cutaway also shows the internal
structure of one of the relief valves (2). Here
Figure 4-7. Cutaway of steering system main manifold.
1) Hand bypass valve; 2) right rudder relief valve; 3) left rudder relief valve; 4) ram cut-out valves; 5) auxiliary power cut-out valves, HAND and EMERGENCY; 6) bonnets; 7) stem; 8) turn-nut; 9) double ring;
10) valve disk; 11) valve seat; 12) locking cap; 13) upper chamber, hand bypass valve; 14) lower chamber,
hand bypass valve; 15) upper chamber, cut-out valve; 16) lower chamber, cut-out valve; 17) ports above
corresponding cut-out valves; 18) stem of cut-out valve; 19) valve disk of cut-out valve; 20) ports to motor
driven Waterbury pump, supply and return; 21) disk of relief valve; 22) relief valve spring; 23) spring tension
adjusting nut; 24) relief valve locking cap. 25) packing-gland nut.
86
the disk (21), instead of being seated by turning the nut with a wrench, is held seated by
the loading spring (22). The spring tension
is adjusted by the adjusting nut (23), which
can be reached by removing the cap (24).
The two internal chambers of this valve, like
those in the hand bypass valve, open into the
channels leading to the power-driven Waterbury A-end ports. In practice, therefore, it
will be seen that the relief valves are simply
safety valves, kept closed by loading springs
and opened only by excessive oil pressure,
which is then able to bypass to the return
side of the manifold. Two such valves are
needed here, one on each side of the manifold,
because either line may become alternately
supply or return, depending on whether the
rudder is being turned left or right. Attached
name plates differentiate the valves.
Midway on the top of the manifold body,
at each side of the right rudder relief valve,
is a small vent valve (12, Figure 4-5), which
may be opened, when required, to vent air
which may have accumulated in the manifold.
b. The steering stand. The hydraulic
power which moves the rudder is directed by
the steersman from the steering stand, an
assembly which contains the control equipment for all three methods of steering,
POWER, HAND, and EMERGENCY (see .
Figure 4-8).
Figure 4-8. Control room steering stand.
1) Main steering wheel; 2) telemotor; 3) hand grip; 4) locking pin; 5) locking arm for steering wheel; 6) gear
box; 7) pump control lever, 8) telemotor shaft; 9) pump control shaft; 10) pump control shaft locking screw;
11) change valve; 12) change valve handwheel; 13) emergency control valve; 14) emergency control valve
handwheel (emergency steering wheel); 15) emergency control valve shaft; 16) clutch; 17) shaft to conning
tower steering wheel; 18) clutch handle; 19) locking bar for emergency control valve shaft; 20) emergency
control valve shaft locking arm; 21) vent valve on telemotor; 22) bed plate; 23) wing-nut clutch lock.
87
1. The telemotor pump. Since, in operation by normal power, it is the direction of
the motor-driven Waterbury A-end pump tilt-box that determines which way the rudder
moves (see Section 4B2a1), and since the
position of this tilt-box is controlled
by the movement of oil in the control
cylinder, it is clear that, to steer the submarine, some device is needed to drive that
oil in the direction required. The mechanism
must be one which will respond readily to
the steersman's touch, yet control accurately
the powerful pressures developed by the
motor-driven Waterbury A-end pump. Such
a device is the telemotor pump (2, Figure
4-8), the steering stand's main unit. The telemotor pump is actually a hand-operated Waterbury A-end pump. A bracket is fitted
externally to it and the pump control shaft
so that its tilt-box always tilts in the same
direction, though its angle, that is, the degree
of tilt, may be changed. Consequently, the
flow of oil depends solely on which way its
shaft is rotated. If a large handwheel is
fitted to this shaft, and the ports of the telemotor connected to opposite ends of the control cylinder, turning the wheel left or right
will then pump oil to one end or the other of
the control cylinder, which in turn tilts the
tilt-box in the motor-driven Waterbury A-end
pump, thus moving the rudder left or right.
Therefore, turning a wheel fitted to the shaft
of the telemotor pump will steer the submarine.
2. The main steering wheel. The main
steering wheel (1, Figure 4-8) is mounted
vertically at the after end of the steering
stand. It is used for both POWER and
HAND steering.
As HAND steering requires greater
effort, a retractable spring hand grip (3) is
built into the rim, which, during POWER
steering, may be kept folded in.
Figure 4-9. Cutaway of main steering wheel and steering stand gear box.
I) Main steering wheel; 2) locking pin (spring-loaded); 3) clutch jaw; 4) grease connection; 5) main wheel
drive shaft; 6) bevel gears; 7) conning tower steering wheel shaft; 8) telemotor drive shaft; 9) gear box
housing; 10) grease connection.
88
A spring-loaded locking pin (4) is built
into the hub, which when pulled out allows
the main steering wheel to be disengaged
from its shaft. This keeps the main wheel
from spinning uselessly when the submarine
is being steered from the conning tower.
Attached to the steering stand under the main
wheel is a locking arm (5) with a forked end
which can be swung out to keep the wheel
stationary when it has been disengaged. The
main steering wheel is connected to the telemotor pump through the gear box (6, Figure
4-8). This is shown partially cut away in
Figure 4-9.
Figure 4-9 illustrates the manner in
which the telemotor pump is connected both
to the main steering wheel (in the control
room) and the conning tower steering wheel.
The main steering wheel (1) is clutched
into the main shaft (5) by a jaw clutch. It
can be locked in either the clutched or de-clutched position by the spring-loaded locking pin (2). Keyed to the other end of the
shaft is the bevel gear (6).
The conning tower drive shaft (7) has
a similar bevel gear keyed to its lower end.
The telemotor pump drive shaft (8) also
is keyed into a bevel gear.
These three gears, are meshed to form a
gear train. Rotating the main wheel (1) will
therefore cause the gear on the end of the
telemotor pump shaft to rotate, but in the
opposite direction, due to the intermediate
(horizontal) bevel gear.
Of course, the vertical shaft leading to
the conning tower drive shaft also rotates
when the main wheel is turned, but a clutch
(see Figure 4-17) disconnects this stub shaft
from the conning tower driving shaft proper.
The gear housing (9) is lubricated
through the grease connection (4).
3. The pump control lever. In POWER
steering, as indicated above, the only function
of the telemotor pump is to move the control
cylinder plunger fore or aft; the actual work
of swinging the rudder is then done by the
power-driven Waterbury A-end pump. Since
the power-driven Waterbury A-end pump is
running at 440 revolutions per minute, a small
change in the position of its tilt-box produces
a large reaction at the rams, and fine and
exact control is therefore needed. Such control is effected by setting the telemotor
pump's tilt-box at a very small angle, the
minimum piston stroke, so that turning the
main wheel drives only a relatively small
volume of oil into the control cylinder.
However, in HAND steering, the pressure developed in the telemotor pump by
turning the main steering wheel, directly
actuates the main rams. Therefore, the rudder
is swung by the manual exertions of the
steersman. This means that, to achieve the
same fineness of control, there is no need to
pump relatively small quantities of oil
through the telemotor pump; on the contrary,what is wanted is a relatively large
volume of oil pumped to the actuating cylinder without too many turns of the wheel.
Therefore, the telemotor pump tilt-box should
be set at a large angle or maximum piston
stroke. This angle setting is done by means
of the pump control lever (7, Figure 4-8),
mounted on top of the telemotor pump, since
the maximum stroke allowed by the pump
control lever is determined by the bracket
connection.
This is shown in more detail in Figure
4-10. It must be emphasized again that the
tilt-box of a telemotor pump is always tilted
away from neutral, and always in the same
direction. For the steering system telemotor
pump there are only two angles, or settings,
POWER and HAND, shown by the name
plate (5) on the frame which holds the lever
(1). Moving the lever to one or the other
setting moves the pump control shaft (2),
which is linked to the tilt-box inside the telemotor pump(3). Whenever a tilt-box is
tilted away from the neutral position, the
stroke of the pistons changes-which is
precisely what causes pumping action. The
pressure of the oil against the piston will
tend to force the tilt-box to return to neutral.
This is particularly true when the angle is
large or when the tilt-box is set at the HAND
position. To prevent any change in angle of
tilt, the pump control shaft is extended up
into the lever frame, and a heavy locking
screw (4) is provided to clamp the control
89
shaft extension (6), notched for a positive
grip, in the desired position.
4. The change valve. Since there are
three methods of operating the steering
system, POWER, HAND, and EMERGENCY, a change valve (11, Figure 4-8) is
provided to open the lines being used, and
close, or blank off, the others. This valve is
mounted at the forward end of the steering
stand, by a pair of flanged ports connecting
directly to the pressure ports of the telemotor pump.
The change valve has six ports. A movable
internal mechanism enables the steersman to
select one of three different combinations of
ports, depending upon which one of the three
steering methods is in use.
The cutaway view (Figure 4-11) shows
how the operation of the change valve works.
Figure 4-10. Telemotor pump control lever.
1) Pump control lever; 2) pump control shaft; 3) telemotor;4) locking screw; 5) name slate; 6) control
shaft extension.
It is a piston-type, or traveling-nut-type valve,
the various combinations of outlets being
opened and shut off by a movable sleeve (1) as
it is raised and lowered by the handwheel (2)
This turns the shaft (3) a nonrising stem,
whose male threaded end (4) engages the
female threaded end of the sleeve. The sleeve
and the internal chamber of the valve body
(5) are accurately machined and lap-fitted to
each other so that the shutoff action of the
lands on the sleeve will be close-fitting. This
is further improved by phosphor-bronze collars which are soldered onto the lands, the
softer metal making a smooth, tight bearing
surface for the steel body of the valve. Note
that it is the sleeve that travels up and down,
Figure 4-11. Cutaway of change valve.
1) Sleeve; 2) handwheel; 3) shaft; 4) threaded end
of shaft; 5) valve body.
90
not the handwheel shaft, which merely turns
left or right. The thread used on the shaft
is a steeply pitched quadruple thread with a
rapid travel, which raises or lowers the sleeve
to the extreme limit of travel in three
quarters of a turn of the wheel.
The three possible positions of the wheel
are shown by a circular indicator plate
screwed to the spokes near the hub. A black
enameled strip of iron formed into an indicator and attached to the valve body shows
where the wheel should stop for each position.
Figure 4-12 is a diagram of the change
valve in all three positions, showing the relationships between the position of the sleeve and
the various oil lines entering the valve. Active
oil at high pressure from the emergency lines
of the main hydraulic system is shown in red;
active oil at low pressure in the telemotor
and control cylinder circuit is shown in blue.
At POWER, the sleeve is fully raised;
the telemotor pump ports (1) are connected
to the control cylinder ports (2), sending oil
at low pressure, developed by the steersman
in the telemotor pump, to the control cylinder.
At HAND, the sleeve is fully lowered;
the telemotor pump ports (1) are connected
directly to the auxiliary power ports of the
steering system train manifold (4) (see
Figure 4-6, ports 7 and 8), thus sending oil
developed by the steersman in the telemotor
pump, directly to the main rams.
At EMERGENCY, the sleeve is in the
intermediate position; all ports are blanked
off, preventing the high pressure oil (from
the main hydraulic system's emergency lines)
from reaching the telemotor pump and motorizing it.
WARNING. Always place the change
valve in the EMERGENCY position before
opening the emergency control valve. Failure
to do so may result in motorization of the
telemotor pump and serious injury to the
operator.
The three positions of the sleeve corresponding to POWER, HAND, and EMERGENCY, are shown diagrammatically in Figure 4-13. Oil from the supply side is shown in
red; return oil from a cylinder in blue.
Direction of flow is indicated by arrows. At
POWER, the sleeve (1) is at its uppermost
position (2); the telemotor pump ports are
connected to the control cylinder ports
through the sleeve channel; the ports to the
main rams are blanked off. At HAND the
sleeve is in the lowest position; the control
cylinder is bypassed, while the telemotor
pump ports are opened to the rams.
Figure 4-12. Diagram of change valve in three positions.
1) To telemotor; 2) to control cylinder; 3) emergency position; 4) to main steering manifold, HAND.
91
5. The emergency control valve. The
emergency control valve is mounted to the
left of the main steering wheel (looking forward from the wheel). It is shown at 13 in
Figure 4-8. Its function is to allow the flow of
oil from the main hydraulic system, in case
of failure of the steering system's own power,
and direct it to either side of the steering
system manifold (using the same lines as
those for HAND operation), from which it
goes to the rams. Like the change valve, the
emergency control valve is a piston-type, or
traveling-nut-type, valve with a nonrising
stem (see Figure 4-14). As the stem (1,
Figure 4-14) is turned left or right, it raises
or lowers the piston (2), opening either right
rudder or left rudder port to the supply port
(3) of the main hydraulic system, and thus
allowing the oil to flow to one side or the
other of the main steering manifold.
Details of the operating mechanism for
the emergency control valve are shown in
Figure 4-15. The stem is turned by a shaft
(8) connected through a pair of horizontally
mounted spur gears (6) to a handwheel (7)
the emergency steering wheel-mounted horizontally above the main steering wheel, at
about shoulder height. This handwheel has
RIGHT RUDDER stamped into its rim with
an arrow indicating how the wheel is to be
turned for that operation. This wheel functions as the steering wheel when the vessel
is being steered by EMERGENCY. Its position on the steering stand is shown at 14, Figure 4-8.
Figure 4-16 shows the emergency control
valve in each of its three positions, indicating
the relationship between the position of the
piston and the flow of oil to the rams. The
pressure side is shown in red, the return side
in blue.
At NEUTRAL, the piston is in the intermediate position. The ports (3 and 4) leading
to the steering system main manifold, and
thence to the main rams, are both blanked off
Figure 4-13. Schematic diagram of ports and lands in change valve.
1) Sleeve; 2) stop.
92
and the pressure from the supply port (1)
cannot reach them.
At RIGHT RUDDER, the piston has
moved to the bottom of its travel, the supply
port (1) is opened to the port (3) leading to
the after-starboard and forward-port rams; return oil from the after-port and forward-starboard rams comes in through the port (4) and
out through the return port (2).
At LEFT RUDDER, the piston is at the
top of its travel. Pressure from the supply
port (1) goes out through the port (4) to the
forward-starboard and after-port rams; return oil from the forward-port and after-starboard rams comes in through the port (3) and
goes out through the return port (2).
6. The clutch. Across the shaft of the
emergency control valve itself is the clutch
handle (18, Figure 4-8) which, through appropriate linkage, raises and lowers the positive
jaw clutch (16) located on the vertical
Figure 4-14. Cutaway of emergency control valve.
1) Nonrising stem; 2) piston; 3) supply port, from
emergency lines, main hydraulic system; 4) return
port, to emergency lines, main hydraulic system;
5) port to steering system main manifold and rams,
forward-port, after-starboard; 6) port to steering
system main manifold and rams, after-port, forward
starboard.
conning tower drive shaft (17) just under the
emergency handwheel spur gears. The clutch
handle is fitted with a locking bar (19) which
holds the emergency control valve shaft (15)
firmly in place. It is fastened by a spring
loaded locking arm (20) and a wing-nut clutch
lock (23).
Figure 4-15. Diagram of clutch and emergency steering wheel spur gears, clutch handle up.
1) Clutch handle; 2) linkage; 3) clutch; 4) shaft from
gear box; 5) shaft to conning tower steering
wheel; 6) spur gears; 7) emergency steering wheel;
8) emergency control valve shaft; 9) locking arm.
The function of this clutch is shown in
more detail in Figures 4-15 and 4-17. When
the handle is down (Figure 4-17), the clutch
is engaged to the emergency steering control
wheel, and the steering can be done by
POWER or HAND from the control room
steering stand, or by EMERGENCY from the
conning tower wheel. When the handle is up
(Figure 4-15), the clutch is disengaged and
steering can be done by POWER or HAND
from the conning tower, or by EMERGENCY
from the control room.
7. The conning tower steering shaft. The
conning tower steering shaft (7, Figure 4-9)
connects the steering stand to the conning
tower steering wheel.
As shown in Figure 4-9, the drive shaft
(7) from the conning tower steering wheel
ends in a horizontal bevel gear, the intermediate gear of a three-gear train (6). These
gears are contained in the gear box (9), an oil
filled housing located on the steering stand
93
Figure 4-16. Flow diagram of emergency control valve in three positions.
1) To main hydraulic system, supply; 2) to main hydraulic system, return; 3) to main rams, forward-port,
after-starboard; 4) to main rams, after-port, forward-starboard; 5) direction of rotation of emergency steering wheel for right rudder.
just forward of the main steering wheel (see
6, Figure 4-8). The conning tower steering
wheel is connected and disconnected by means
of the clutch, as described in the previous
section (see Figures 4-15 and 4-17).
c. The rams. The main cylinder ram assemblies, usually referred to simply as the
rams (port and starboard), transform hydraulic power into mechanical power to move
the rudder. Figure 4-18 shows their structure.
Each consists essentially of a pair of hydraulic
cylinders (1) opposed and axially in line, having in common a plunger (2), or ram, which
slides between and through them, and a hydraulic port(3) at each end into which oil
is admitted, to move the rams forward or aft.
At its center the plunger has a heavy yoke
(4) forged integral with it. This yoke has a
hole drilled into it to take the inboard connecting rod (5) which is locked into it at this
point by heavy locknuts, one on each side
of the yoke. The inboard connecting rod
slides through the bearings (6). Oil leakage
past the plunger is prevented by the packing
(10). Figure 4-20 is an exploded view of this
chevron packing, which shows clearly the
cross-sectional shape of the rings. This type
of packing is used in various hydraulic units
aboard the submarine. The entire ram assembly is bolted to the framework through
the brackets (7, Figure 4-18).
Mounted at the forward end of the ram
shown in Figure 4-18 is the mechanical rudder-angle indicator pointer (8), which shows
the angle of rudder deflection in degrees on
the indicator dial (9). Another rudder-angle
transmitter, electrically operated, is located
on the other ram (not shown). It transmits
the angle of deflection electrically to a rudder
Figure 4-17. Diagram of clutch and emergency steering wheel, clutch handle down.
angle indicator on the instrument board in the
control room. Figure 4-19 shows the packing
used in the main ram.
Figure 4-19. Packing used in main ram.
d. The rudder assembly. The rudder assembly is shown in Figure 4-21. The after
end of each inboard connecting rod (1) goes
into a guide (2) which is simply an open
ended cylinder containing a sliding member,
the guide piston (3). Through the guide piston, the inboard connecting rod is linked to
the outboard connecting rod (4). The guides
are located beyond the point at which the inboard connecting rods emerge, through watertight packing (5), from the pressure hull (6)
into the sea.
Since the guide pistons are not water tight, sea water is always present in the closed
end (7) of the guide cylinders. Therefore to
prevent a sudden build-up of water pressure
at this point when the guide piston moves
inward-a pressure which would tend to lock
the pistons against further movement-the
closed ends of the guide cylinders are connected to each other by a pipe (8) called the
equalizing bypass. This provides a free passage between the closed ends of the cylinders
for the sea water trapped behind the guides,
whenever the pistons are moved.
The two outboard connecting rods are
linked to opposite ends of the crosshead (9),
which actually swings the rudder. Through
the center pivot of the crosshead passes the
rudder stock (10), to which the rudder (11)
itself is attached. As the connecting rods are
pushed in opposite directions by the hydraulic pressure, they swing the crosshead, turning the rudder.
e. Other units. Besides the principal
parts already described, the steering system
also contains a vent and surge tank, a vent
and replenishing manifold, and several hand
cut-out valves located at various points in the
pipe lines.
1. The vent and surge tank. The vent
and surge tank is an oil reservoir that normally
Figure 4-20. Exploded view of chevron packing for
steering system main ram.
96
Figure 4-21. Diagram of rudder assembly and guides.
1) Inboard connecting rod; 2) connecting rod guide cylinder; 3) guide piston; 4) outboard connecting rod;
5) packing; 6) pressure hull; 7) forward (closed) end of guide cylinder; 8) equalizing line, or bypass; 9) crosshead; 10) rudder stock; 11) rudder.
is kept half full. It has three separate functions:
a) Venting. It vents air which has accumulated in the system. The tank is placed
at a level higher than the Waterbury pumps
and motor, allowing elimination of air and
replenishing of oil as well as thermal expansion of the oil in the inactive sides of the
Waterbury pumps and motor.
b) Replenishing. The vent and surge
tank provides replenishment of oil to the inactive side of the Waterbury speed gear,
replacing oil which has been delivered from
the case into the active system (see Section
2C4h).
Figure 4-22. Vent and replenishing manifold.
When the steering system is operating
under normal power furnished by the motor
driven Waterbury speed gear, oil is replenished from the case, or inactive, system into
the active system by means of replenishing
valves (see Section 2C4h). The reserve oil in
the vent and surge tank is used to make good
this loss, as well as other losses due to leakage
throughout the system. It is fed into the case
of the Waterbury speed gear by means of a
10- to 25-pound back-pressure. This back
pressure is received from the main supply
tank through the replenishing line since the
vent on the vent and surge tank normally is
closed. A relief valve mounted on the vent
and surge tank is set to lift at 48 pounds per
square inch.
c) Surges: thermal expansion. Oil circulated at high pressure throughout a hydraulic
system soon becomes heated and increases in
volume. For proper functioning, the system
must provide room for this expansion. The
vent and surge tank provides this room. As
the oil expands, the level in the tank rises, relieving the other parts of the system of the
strain which would otherwise be placed on
them if the increased pressure had no means
of escape.
The location of the vent and surge tank
in the steering system is shown schematically
in the piping diagram of the steering system
(27, Figure 4-1).
97
Figure 4-23. Cutaway of quick-throw, plug-type, hand
cut-out valve.
1) Handle; 2) stem; 3) packing; 4) line port; 5) valve
plug; 6) valve plug port; 7) setscrew.
Besides its function in the steering system, this tank, because of its convenient location, is also used to perform the same services
for the stern diving plane system. (see Chapter 5).
2. The vent and replenishing manifold.
The vent and replenishing manifold is a three-valve manifold (see Figure-22) installed in
the lines at the forward end of the steering
stand. It consists of three identical cut-out
valves whose structure and operate oral principles
are the same as the cut-out valves on
the steering system main manifold (see Section 4b2a3). Its internal mechanism is illustrated in Figure 4-7.
The two outer valves normally are closed,
except when it becomes necessary to fill or
vent the system. The center valve connected
to the control cylinder power line normally
is open.
The location of the vent and replenishing
manifold is shown in the schematic piping
diagram (26, Figure 4-1).
3. Quick-throw cut-out valves. Several
plug-type, quick-throw cut-out valves may be
installed at various points in the hydraulic
lines for the purpose of quickly shutting off
the flow of oil between the units in case of a
ruptured line or other emergency.
A cutaway view of this type of valve is
shown in Figure 4-23. The throw, or amount
of turn, of this valve stem is 90 degrees, or
a quarter-turn. The stem (2) has a squared
upper end fitting snugly into the hollow portion of the handle assembly ring, to which it
is secured by a hex-nut and washer screwed
down over the top of the stem. The lower,
threaded end of the stem is screwed into the
valve plug (5) and locked there by a small
setscrew (7), which can be seen in the illustration at the right of the threaded portion of
the stem. Running through the plug is a channel called the plug port (6). When this is
lined up with the two line ports (4), the valve
is OPEN. When the plug is rotated 90 degrees, this channel is at a right angle to the
line between the ports, and the valve is closed.
The cutaway view shows the valve in the
CLOSED position.
When these two cut-out valves are closed,
the motor-driven Waterbury is isolated from
the rest of the steering system. On later
classes of submarines, these valves have been
installed between the motor-driven pump and
main manifold.
C. OPERATION
4C1. Introduction. A detailed description
has just been given of the essential parts of
the hydraulic steering system. In this section
their operation is described. As has been indicated, there are three methods of steering,
called POWER, HAND, and EMERGENCY,
according to the source of hydraulic pressure
utilized. For clarity, a single rudder movement-from 0 degrees to 20 degrees right rudder-is described as it occurs in each method.
By so doing it is possible to show how each
unit, previously taken up in detail, functions
as part of the coordinated whole. The paths
taken by the oil are also shown.
98
Figure 4-24. Operation diagram of steering system by normal POWER.
1) Main steering wheel; 2) change valve; 3) 15-horsepower electric motor, speed 440 revolutions per minute; 4) motor-driven Waterbury A-end pump;
5) telemotor pump; 6) control cylinder; 7) plunger; 8) bell-crank shaft; 9) steering system main manifold; 10) port main cylinder, or ram, after end;
11) starboard main cylinder, or ram, after end; 12) inboard connecting rods; 13) line to main supply tank; 14) vent and replenishing line to supply tank;
15) gage; 16) relief valve (48 pounds); 17) vent and replenishing line to stern plane Waterbury A-end pump.
99
4C2. POWER steering. a. Explanation of
the diagram. Figure 4-24 shows the coordinated action of the system during POWER
steering. Direction of oil flow for right rudder
is shown by arrows. The power pump or high-pressure oil circuit is shown in heavy lines,
red for the supply side of the line, blue for
the return side. The telemotor pump or low-pressure circuit is shown in thinner lines, red
for the supply side, blue for the return side.
Areas and lines inactive during POWER
steering are shown in black. All colors and
directions shown are for right rudder. For
left rudder, or a return to a smaller angle of
right deflection, all arrows would point in the
opposite direction, and colors would be reversed in each circuit. Refer to each index
number on the diagram as it occurs in the
text.
b. Operation of the system on POWER.
The main steering wheel (1) is engaged in the
shaft clutch and locked into its shaft by the
locking pin.
The pump control lever mounted on the
telemotor pump is set at POWER and locked
there by the locking screw.
The change valve (2) is also set at
POWER.
The clutch handle is down.
The steering main manifold ram cut-out
valves are OPEN.
The various gages and levels are, checked
to make sure that the system is completely
filled with oil. The motor (3) which drives the
Waterbury pump (4) is started by pressing
the switch button at the control room steering
stand insuring that the switch on the steering control panel aft is in the ON position.
The system is now ready for operation
under POWER.
The submarine rudder is actuated by turning the large main wheel to right or left. Let
us suppose the submarine is running on a
straight course, the rudder indicator showing
zero degrees deflection. The steersman receives the order, "Right, 20 degrees rudder."
He turns the wheel to the right.
Its motion is transmitted through the
gear box to the telemotor pump (5), which,
drives oil at low pressure through the change
valve (2) into the control cylinder pressure
line. Oil is thereby driven into the after end
of the control cylinder (6), moving the plunger
(7) forward.
This swings the bell-crank shaft (8),
tilting the tilt-box in the motor-driven Waterbury A-end pump. Instantly its pistons pump
oil at high pressure through one side of the
manifold (9), into the forward end of the port
ram (10) and the after end of the starboard
ram (11). The port ram moves aft, the starboard ram moves forward; the connecting.
rods (12), pulled in opposite directions, swing
the crosshead and rudder to the right.
The steersman either holds the steering
wheel steady, or continues to turn it to the
right (depending on how swift a reaction is
needed) until the rudder indicator shows 20,
degrees right rudder. Then he turns the wheel
partially to the left, releasing the oil pressure.
The centering spring will then bring the control cylinder plunger to a neutral, balanced
position (see Section 4B2a), and recenter the
control shaft, neutralizing the Waterbury
pump's tilt-box and stopping any further
pumping of oil to the rams. This locks the
main cylinder rams or plungers in that position for as long as desired, holding the rudder steady at that angle.
But we have not yet followed the movement of oil in the system to the completion of
its cycle. Both the oil in the low pressure circuit from the hand-rotated telemotor pump
(5) and the oil at high pressure from the
motor-driven Waterbury (4) have a return
flow in their respective circuits.
We followed the oil in the low pressure
circuit until it reached and actuated the
plunger in the after control cylinder. It has
moved forward, driving oil out of the forward
end of the control cylinder, back through the
change valve, into the return port of the telemotor pump, completing its cycle.
We followed the oil in the high pressure
circuit from the motor-driven Waterbury A-end pump until it reached and actuated the
rams. The port ram has moved aft, and the
100
Figure 4-25. Operation diagram of steering system, by HAND.
1) Main steering wheel; 2) change valve; 3) electric motor, 15-horsepower, speed 440 revolutions per minute; 4) motor-driven Waterbury A-end pump;
5) telemotor; 6) control cylinder; 7) control cylinder plunger; 8) bell-crank shaft on control cylinder; 9) steering system main manifold; 10) port ram;
11) starboard ram; 12) inboard connecting rods; 13) line to main supply tank; 14) vent and replenishing line to main supply tank; 15) gage; 16) relief
valve (48 pounds); 17) vent and replenishing line to stern plane Waterbury A-end pump.
101
starboard ram has moved forward, driving oil
out of the opposite end of their main cylinders, back through the manifold (9) into the
return port of the motor-driven Waterbury
A-end pump, completing its cycle.
4C3. HAND steering. a. Explanation of the
diagram. Figure 4-25 shows he coordinated
action of the system during HAND steering.
Direction of oil flow for right rudder is shown
by arrow's. In HAND steering, the entire
steering action is accomplished by oil pressure developed in the telemotor pump by the
steersman's turning of the main steering
wheel. The supply side of the line is shown in
red, the return side in blue. Areas and lines
inactive during HAND steering are shown in
black. All colors and directions shown are for
right rudder. For left rudder, or a return to a
smaller angle of right deflection, all arrows
would point in the opposite direction, and
colors would be reversed. Refer to each index
number on the diagram as it occurs in the
text.
b. Operation of the system on HAND
power. The steering wheel (1) is locked into
its shaft by the locking pin. The retractable
hand grip is unfolded for use, at a right angle
to the rim.
The pump control lever on the telemotor
pump is set at HAND and locked there by
the locking screw.
The change valve (2) is also set at HAND.
The clutch handle is down.
The steering manifold (9) hand cut-out
and ram cut-out valves are OPEN.
The motor (3) and Waterbury pump (4)
are OFF.
The system is now ready for operation by
HAND.
The submarine is steered from the control
room-by turning the large main wheel right
or left. Let us suppose the submarine is running on a straight course, the rudder indicator
showing zero degrees deflection. The steersman receives the order, "Right, 20 degrees
rudder." He turns the wheel to the right. (The
wheel is much harder to turn under HAND
than under POWER, and must be turned
much farther to achieve the same degree of
rudder deflection.)
Its motion is transmitted through the
gear box to the telemotor pump (5) which
drives oil under pressure through the change
valve to one of the auxiliary power ports in
the manifold (9), into the forward end of the
port ram (10) and the after end of the starboard ram (11). The port ram moves aft, the
starboard ram moves forward and the connecting rods (12), pulled in opposite directions, swing the crosshead and rudder to the
right.
The steersman continues to turn the
wheel to the right until the rudder indicator
shows 20 degrees right rudder.
It is essential to understand that, in the
operation by HAND just described, the telemotor pump takes the place of the motor
driven Waterbury speed gear, supplying the
hydraulic power to actuate the rams and move
the rudder.
But we have not yet followed the movement of oil in the system to the completion of
its cycle.
The path of the oil has previously been
traced from the hand-rotated telemotor pump
until it reached and actuated the rams. When
the port ram has moved aft and the starboard
ram has moved forward, the oil is driven out
of the opposite ends of their main cylinders,
back through the manifold (9), out through
the other auxiliary power port, back through
the change valve, and into the return port of
the telemotor, completing its cycle.
4C4. EMERGENCY steering. a. Explanation
of the diagram. Figure 4-26 shows the coordinated action of the system during emergency steering. Direction of oil flow for
right rudder is shown by arrows. In emergency steering, the entire steering action
is accomplished by oil at high pressure from
the emergency lines of the main hydraulic
system. The supply side of the line is shown
in red, the return side in blue. Areas and lines
inactive during EMERGENCY steering are
shown in black. All colors and directions
shown are for right rudder. For left rudder,
or a return to a smaller angle of right
102
Figure 4-26. Operation diagram of steering system, by EMERGENCY.
1) Main steering wheel; 2) change valve; 3) electric motor, 15-horsepower, speed 440 revolutions per minute; 4) motor-driven Waterbury A-end pump;
5) telemotor; 6) control cylinder; 7) control cylinder plunger; 8) bell-crank shaft on control cylinder; 9) steering system main manifold; 10) port ram;
11) starboard ram; 12) inboard connecting rods; 13) emergency steering wheel; 14) spur gears; 15) emergency control valve shaft; 16) main supply
manifold, main hydraulic system; 17) main return manifold, main hydraulic system; 18) line to main supply tank; 19) vent and replenishing line to main
supply tank; 20) gage; 21) relief valve (48 pounds); 22) vent and replenishing line to stern plane Waterbury A-end pump.
103
deflection, all arrows would point in the opposite
direction, and colors would be reversed. Refer
to each index number on the diagram as it
occurs in the text.
b. Operation of the system on EMERGENCY power. The steering wheel (1) is disconnected from its shaft by pulling out the
locking pin in the hub, and then pulling the
wheel aft, disengaging it from the clutch jaw
on the drive shaft. The locking arm underneath the wheel is pulled up to a horizontal
position to hold one of the wheel spokes in
its fork, and locked in that position by inserting the pin under it.
The change valve (2) is set at EMERGENCY.
The clutch handle (1, Figure 4-15) is up,
the locking bar arm (9, Figure 4-15) is pulled
out and turned, allowing the shaft of the
emergency control valve to be turned.
The motor (3, Figure 4-26) is OFF.
The steering manifold (9) hand cut-out
and ram cut-out valves are OPEN.
The emergency steering valves in the
main hydraulic system main supply and return manifolds (16 and 17) are now opened
(see Chapter 3).
The system is now ready for operation on
EMERGENCY.
The submarine is steered from the control
room by turning the small emergency hand
wheel (13). Let us suppose the submarine is
running on a straight coarse, the rudder indicator showing zero degrees deflection. The
steersman receives the order, "Right 20 degree rudder." He turns the emergency steering wheel to the left.
Its motion is transmitted through the
spur gears (14) to the emergency control
valve shaft (15). This turns the nonrising
stem inside the valve, raising the sleeve and
opening the channel from the pressure line
of the main hydraulic system to one of the
lines leading to the auxiliary power ports on
the steering system main manifold (9).
Oil from the main hydraulic system will
then flow through the emergency control
valve to the manifold (9), into the forward
end of the port ram (10) and the after end of
the starboard ram (11). The port ram moves
aft, the starboard ram moves forward; the
connecting rods (12) swing the crosshead and
rudder to the right.
But we have not yet followed the movement of oil in the system to the completion of
its cycle. We have already traced the path of
the oil from the main hydraulic system until
it reached and actuated the rams. When the
port ram has moved aft and the starboard ram
has moved forward, the oil is driven out of the
opposite ends of the main cylinders, back
through the manifold (9) into the return port
of the emergency control valve, and out into
the return line to the main hydraulic return
manifold, completing its cycle.
WARNING. It is necessary to turn the
change valve to EMERGENCY before operating the emergency control valve. Turning the
change valve to EMERGENCY blanks off all
lines except the bypass ports around the telemotor pump, and thus protects the rest of the
equipment from the effects of the sudden entrance of oil at a pressure of 600 pounds to
700 pounds per square inch. Oil under high pressure will actuate various moving parts
accessible to it, motorize pumps, and may
cause various sudden, and possibly dangerous,
results to apparatus or personnel. Disconnecting the main steering wheel when changing
the system over to EMERGENCY, is an
added precaution.
4C5. Steering from the conning tower. The
conning tower has its own steering wheel
connected to the steering stand in the control room by a vertical shaft (see 7, Figure
4-9). Any of the three methods described
(POWER, HAND, or EMERGENCY) is
available from the conning tower wheel, depending on the position of the clutch. For
POWER or HAND steering from the conning tower, the clutch handle should be up
(see Figure 4-15). For EMERGENCY steering from the conning tower, the clutch should
be down (see Figure 4-17).