HNSA Crest with photos of visitors at the ships.
13
THE STEERING SYSTEM
 
A. INTRODUCTION
 
13A1. General. The rudder of the submarine is moved by hydraulic power. Under normal operation, the steering system has its own source of power, a motor-driven size 5 Waterbury A-end pump, and is, therefore, except in emergencies, completely independent of the main hydraulic system described in Chapter 12.

The principal control units are assembled in the steering stand, located in the control room. However, since there is a 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 are available, based on three different sources of hydraulic power. 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 steering stand 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 avoid 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
 
13B1. General arrangement. The steering system as a whole is shown in FigureA-20. The system may conveniently be thought of as divided into four principal parts:

a. The normal power supply system, comprising a Waterbury size 5 A-end pump, the motor which drives it, the control cylinder, and the main manifold.

b. The steering stand, comprising the main steering wheel, emergency handwheel, steering stand pump, pump control lever, change valve, emergency control valve, conning tower connecting shaft, and a clutch.

c. The main cylinder assemblies, comprising the cylinders and plungers and the mechanical rudder-angle indicator.

d. The rudder assembly, comprising the connecting rods and guides, the crosshead, on the rudder itself.

  13B2. Detailed description. The normal power supply system. The Waterbury speed gear. The actuation of the various hydraulically operated units on board a submarine often requires great precision of control and the transmission of power at variable speeds and pressures, without any sharp steps or graduations. The hydraulic machine used for many of these operations is the Waterbury speed gear, a mechanism which furnishes instant, positive, and accurate hydraulic power transmission.

The Waterbury speed gear may be used as a pump (converting rotary mechanical motion into hydraulic fluid displacement) or, with one important modification of internal structure, as a hydraulic motor (converting hydraulic fluid displacement into rotary mechanical motion).

 
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The type of Waterbury speed gear generally used as a pump is designated as a Waterbury A-end speed gear (Figure 13-1). The type used exclusively as a hydraulic motor is designated as a Waterbury B-end speed gear or Waterbury B-end hydraulic motor. The A-end type is in one special installation used as a hydraulic motor, but, since this is not generally the case, it will be convenient to describe the A-end type primarily as a hydraulic pump.

A-end and B-end speed gears are often used together to form a pair of power transmission units separated by any required length of hydraulic piping to suit the particular installation needs. So used, they receive rotary mechanical motion from an electric motor at one point and transmit it as fluid displacement any required distance, where it is reconverted into rotary motion with a positiveness and fineness of control that could not be achieved by the use of electric motors alone.

Waterbury A-end speed gear, used in the submarine hydraulic system primarily as a pump, is designated as size 5-A. Two sizes of B-end motors are used, designated respectively as 5-B and 10-B.

The Waterbury A-end pump is operated by a rotating shaft which may be driven either by an electric motor or by hand. Three motor-driven and three hand-driven Waterbury A-end pumps are used in a submarine: one of each type in the, steering system, stern plane system, and bow plane system, respectively. In operation by normal power, the two types are used in each system as a team; the motor-driven unit transmits oil or the power actuation of the system, while the hand-driven unit, fitted with a large handwheel and designated as a telemotor, or steering stand pump, transmits oil to a control cylinder to provide fine control of the output of the motor-driven units. The hand-driven unit is also used, alternately, to operate the system by hand whenever it is desired not to use the motor-driven pump.

Although the Waterbury A-end speed gear is activated by rotary motion, in principle it is actually a reciprocating multiple piston type of pump. It consists of a casing containing three basic elements:

  1. A socket ring, which holds the ball sockets of the seven or nine piston connecting rods arranged in a circle around the driving shaft.

2. A cylinder barrel, in which are bored the seven or nine corresponding cylinders.

3. A tilting box, which alters the angle and direction of the socket ring with respect to the cylinder barrel.

The socket ring and cylinder barrel are mounted on the drive shaft so that they rotate together. The socket ring is sea arranged that it can be made to rotate either parallel to the cylinder barrel or at an angle to it. Connected to the tilting box is a control shaft extending through the pump casing, which, when pushed up or down, determines the angle and direction of the tilting box.

Reference to Figure 13-1 will help to clarify the manner in which pumping action is obtained. The socket ring rotates within the tilting box on the radial and axial thrust bearing. As long as the tilting box is maintained in the vertical position, the socket ring and cylinder barrel rotate parallel to each other, and there is no reciprocating motion of the pistons within the cylinder barrel. However, when the tilting box is tilted in either direction away from the vertical, the socket ring no longer rotates in the same plane, as the cylinder barrel. This means that as a ball socket on the socket ring reaches that point in its rotation which is closest to the barrel, the piston belonging to it will be driven down into the corresponding cylinder, and then, as this same ball socket recedes to the point farthest away from the barrel, the piston will again be withdrawn.

The diagrams on the lower part of Figure, 13-1 showing the tilting box tilted away from the vertical, and illustrate the course of a single piston, whose motion we are able to follow as the socket ring turns through half a cycle (180 degrees).

As the piston rises to its uppermost position, it occupies a progressively smaller space in the cylinder until it reaches the point at which the socket ring and barrel are farthest apart. The partial vacuum which is produced in the chamber by the outward movement of the piston draws the fluid into the cylinder by suction.

 
146

Drawing illustrating the Waterbury speed gear internals.
Figure 13-1. Waterbury speed gear.
 
147

In the intermediate position, the piston returns into the cylinder and begins to displace the fluid accumulated there. At its lowest point, the piston occupies almost the entire cylinder. The expulsion of the fluid through the discharge port is now complete. The piston again rises from this position for the suction stroke. The repetition of these movements in sequence by all of the pistons results in a smooth nonpulsating flow of hydraulic fluid.

In normal operation, the hydraulic power used by the steering system is developed by a Waterbury size 5 A-end pump. It is driven by a 1.5-hp electric motor at a constant speed of about 440 rpm. The pump turns in a clockwise direction as viewed from the, motor end of the shaft. The pump's speed is constant; only the direction and angle of the tilting box change. It is these that determine the amount of oil that is pumped into the system to move the rudder and the direction in which it is pumped.

b. The control cylinder. The function of the control cylinder is to translate the movement of the main steering wheel, as the steersman turns it left or right, into a corresponding upward or downward motion of the control shaft, thereby changing the position of the tilting 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 that is pumped to the main rams. In this manner it controls the output of the motor-driven Waterbury pump in obedience to the actions of 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 plungers which slides between and through the cylinders. Bell-crank linkage connects this plunger to the tilting box.

On all later classes of submarines, the control shaft that 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.

  The pump control shaft enters at the bottom, connected to the tilting box. The centering spring and its actuating spindle, against which the top end of the pump control shaft bears, are contained in the tall, pipe-like housing screwed onto the top of the power-driven Waterbury A-end pump.

13B3. The steering ram cutout manifold. The steering ram cutout manifold 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.

The manifold is so arranged that the four center valves are power cutouts to the port and starboard rams from the main steering pump. The forward set of two valves and the after set of two valves are hand and emergency cutouts to the port and starboard rams when the power is furnished from the control room. A bypass valve at the top central part of the manifold, if opened, would bypass the main steering pump by connecting both sides of the pump together. This bypass normally is shut.

The manifold has two connections at the top which connect the manifold with the motor-driven Waterbury A-end pump. Of the lower four connections of the manifold, the two in the center are connections to the starboard ram. The remaining two connections, one forward and one aft on the lower part of the manifold, are hand and emergency connections from the control room.

The connections from the manifold to the port ram are at the foremost and aftermost part of the manifold. All the valves have attached name plates indicating their purpose.

The main cylinder ram assemblies, usually referred to as the rams (port and starboard), transform hydraulic power into mechanical power to move the rudder. Each consists essentially of a pair of hydraulic cylinders opposed and axially in line, having in common a plunger or ram that slides between and through them and a hydraulic port at each end, into which oil is admitted to move the rams forward or aft. The plunger has at its center a heavy yoke forged

 
148

Photos of the Steering stand.
Figure 13-2. Steering stand.
 
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integrally with it; the yoke has a hole drilled in it to take the inboard connecting rod which is locked into it at this point by heavy lock nuts, one on each side of the yoke. The inboard connecting rod slides through the bearings. Oil leakage past the plunger is prevented by the packing. The entire ram assembly is bolted to the framework through the brackets.

Mounted at the forward end of the ram is the mechanical rudder-angle indicator pointer showing the angle of rudder deflection on the indicator dial, which is graduated in degrees. An electrically operated rudder angle transmitter is located on the other ram. It transmits the angle of deflection electrically to a rudder angle indicator on the instrument hoard in the control room.

13B4. The steering stand. The hydraulic power that 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 13-2.)

a. The steering stand pump. Since, in operation by normal power, it is the direction of the motor-driven Waterbury A-end pump tilting box that determines which way the rudder moves, and since the position of this tilting box is controlled by the movement of oil in the control cylinder, it is clear that to steer the submarine, some device is needed which will drive that oil one way or the other as desired. The mechanism must be one that 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 steering stand pump, the steering stand's main unit. The steering stand 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 tilting 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, the ports of the pump connected to opposite ends of the control cylinder, turning the wheel left or right, will then pump oil to one or the other end of the control cylinder, which in turn tilts the tilting box in the motor-drivers Waterbury A-end pump, thus moving the rudder left or right. Therefore, turning a wheel fitted to the shaft of the steering stand pump will steer the submarine.

b. The main steering wheel. This wheel 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 handgrip is built into the rim. During power steering, this handgrip may be kept folded in. A spring-loaded locking pin is built into the hub; when pulled out, it allows the main steering wheel to be disengaged from its shaft.

This is provided to prevent the main wheel from spinning heedlessly when the submarine is being steered from the conning tower.

 
C. OPERATIONS
 
13C1. Power steering. When steering by power, (See Figures 13-3 to 13-7.) the following conditions are obtained:

a. The change valve in the control room is set for power steering.

b. The steering stand pump stroke control lever may be in any of the possible positions. Experience has indicated, however, that the most satisfactory position is with the pump at approximately three-quarters of a stroke.

  c. The main steering motor is running.

To illustrate the operation of the steering gear when steering by power, assume that it is desired to move the rudder from amidship to hard over left rudder. The steersman turns the steering wheel to the left, thereby turning the shaft of the steering stand pump which delivers oil through the change valve and one of the control cylinder lines to the after control cylinder; and oil from the forward control cylinder is forced back through

 
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Drawing of the valve being changed.
Figure 13-3. Change valve.

the other control cylinder line to the suction side of the pump.

Delivery of oil to the after control cylinder moves the control ram forward, thereby moving the main pump tilting box control shaft downward from neutral toward full stroke. This puts the tilting box in a position to deliver oil from the port side of the pump through the relief and cutout manifolds. Oil from the manifolds enters the lines to the forward starboard ram and the after port ram, moving the rudder to the left, while return oil from the forward port and after starboard ram is delivered to the starboard side of the pump or the suction side.

Drawing of the stroke being adjusted.
Figure 13-4. Stroke adjuster.

  Drawing of shifting steering control.
Figure 13-5. Shifting steering control.

For the purpose of maintaining the pump control shaft in neutral position when it is desired to hold the rudder angle constant, a spring-loaded centering device is mounted adjacent to the pump. This device consists of a compression spring enclosed in a cylinder and mounted on a spindle in such a way that if the spindle is moved in either direction, the spring is compressed and tends to return the spindle to its normal position. The spindle is connected to a lever mounted on the rocker shaft which operates the levers to the pump and control cylinders respectively.

When the desired position of the rudder is reached, the steering wheel must be brought

Drawing of steering wheel.
Figure 13-6. Steering wheel.

 
151

Drawing of operator starting control.
Figure 13-7. Starting control.

back to its original position to stop rudder movement, since there is no follow-up mechanism in this steering gear.

The power steering gear is protected by two relief valves, one installed in either side of the main relief manifold.

13C2. Hand steering. When steering by hand, (See Figures 13-8 to 13-12.) the following conditions are obtained:

a. The main Steering pump aft is stopped.

b. The change valve in the control room is set for hand operation.

c. The steering stand pump stroke lever

Drawing of operator starting control.
Figure 13-8. Starting control.

  Drawing of operator's hand on change valve.
Figure 13-9. Change valve.

is set in its aftermost position in order to obtain a maximum delivery of oil and therefore maximum speed of rudder travel under the condition of hand steering.

Again, assume that it is desired to move the rudder from amidships to the hard over left position. The steering wheel is turned left. Oil is delivered by the steering stand pump directly to the forward starboard ram and after port ram. The rudder moves to the left. Oil from the after starboard ram and the forward port ram returns to the suction side of the steering stand pump. The rudder moves so long as oil is delivered to the rams

Drawing of the stroke being adjusted.
Figure 13-10. Stroke adjuster.

 
152

Drawing of steering control being shifted.
Figure 13-11. Shifting steering control.

Drawing of steering wheel.
Figure 13-12. Steering wheel.

by turning the steering wheel and thus driving the steering stand pump.

13C3. Emergency steering. Provision is made for steering by direct delivery of oil to the main rams from the main hydraulic system. Oil is delivered from the main cutout manifold to the steering stand. The emergency steering control valve on the steering stand is a piston type control valve. Oil returns from this valve to the return and low-pressure side of the main cutout manifold. Movement of the control valve handwheel for right rudder causes the oil under pressure from the main cutout manifold to be

  delivered to the forward port and after starboard rams while at the same time, oil is returned from the after port and forward starboard rams through the control valve to the return side of the main cutout manifold. Movement of the control valve handwheel for left rudder causes the oil to be delivered to the after port and forward starboard rams while, at the same time, oil is returned from the forward port and after starboard rams through the control valve to the return side of the main cutout manifold.

When steering by emergency power, the change valve should be set in the emergency

Drawing of hand on starting control.
Figure 13-13. Starting control.

Drawing of hand on change valve.
Figure 13-14. Change valve.

 
153

Drawing of main cutout manifold.
Figure 13-15. Main cutout manifold.

position. The emergency cutout valves in the hand and emergency cutout manifold should be opened and the hand cutout valves should be shut. When the desired position of the rudder is reached, the handwheel must be brought back to neutral to stop rudder movement and to hold the rudder in the desired position. Arrangement is provided to connect the emergency control valve lever to the vertical steering shafting by a removable link, thereby making it possible to steer by the emergency system from the conning tower.

When emergency steering from the

Drawing of wheel with emergency steering pin.
Figure 13-16. Emergency steering pin.

  Drawing of emergency steering wheel.
Figure 13-17. Emergency steering wheel. conning tower, the handwheel control (in control room) must be disengaged. A clutch is provided for this purpose and must be engaged except when the link is connected for emergency steering from the conning tower. To steer by emergency from the control room, this removable link is not connected and the emergency steering control valve is moved by the handwheel. A locking pin is provided to hold the control valve in the neutral position when emergency steering is not being used. (See Figures 13-13 to 13-20.)

The electrical rudder angle indicating system is of the selsyn type. The rudder

Drawing showing emergency control valve lock.
Figure 13-18. Emergency control valve lock.

 
154

Drawing showing shifting of steering control.
Figure 13-19. Shifting steering control.

angle transmitter is located in the after torpedo room on the port side and is driven through a rack and pinion from the port steering ram connecting rod. There is one rudder angle indicator in each of the following locations: the bridge, the conning tower

  Drawing of emergency connecting link.
Figure 13-20. Emergency connecting link.

steering station, the control room steering station, the control room diving station.

A mechanical rudder angle indicator, driven also from the port steering ram connecting rod, is located in the after torpedo room.

 
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Version 1.11, 16 July 2010