Introduction. The definitions
contained in this chapter are exact meanings of the terms commonly used
in reference to the modern submarine and its operation. These terms and
explanations represent accepted interpretations and provide an understanding
of the functions of the equipment.
2Al. Surface condition. A submarine is in surface condition
she has sufficient positive buoyancy to permit running on her main engines.
2A2. Diving trim. The term diving trim designates that
condition of a submarine when it is so compensated that completing the
flooding of the main ballast, safety, and bow buoyancy tanks will cause
the vessel to submerge with neutral buoyancy and zero fore-and-aft trim.
2A3. Rigged for dive. A submarine is rigged for dive by
so compensating the vessel and preparing the hull openings and machinery
that the vessel can be quickly and safely submerged and controlled by flooding
the main ballast tanks, using the diving planes, and operating on battery-powered
2A4. Running dive. A running dive consists of submerging
a submarine while running on battery power.
2A5. Stationary dive. A stationary dive consists of submerging
a submarine without headway or sternway.
2A6. Quick dive. A quick dive consists of rapidly submerging
a submarine while running on main engines.
2A7. Submerged condition. This term designates a condition of
a submarine in which all fixed portions of the vessel are completely submerged
and the variable ballast is so adjusted that the submarine has approximately
neutral buoyancy and zero fore-and-aft trim.
2A8. Final trim.Final trim is the running trim obtained
after submerging, in which
the fore-and aft and over-all weights have been
so adjusted that the boat maintains the desired depth, on an even keel,
at slow speed, with minimum use of the diving planes.
2A9. Compensation.Compensation is the process of transferring
ballast, in the form of water, between the variable tanks, and between
the variable tanks and sea, to effect the desired trim.
2A10. Main ballast tanks. Tanks that are provided primarily to
furnish buoyancy when the vessel is in surface condition and that are habitually
carried completely filled when the vessel is submerged, except tanks whose
main volume is above the surface waterline, are known as main ballast
2A11. Variable ballast tanks. Ballast tanks that are not habitually
carried completely filled when submerged and whose contents may be varied
to provide weight compensation are known as variable ballast tanks.
Variable ballast tanks are constructed to withstand full sea pressure.
2A12. Negative tank. The negative tank is a variable ballast
tank providing negative buoyancy and initial down-angle. Submarines normally
will operate submerged in neutral buoyancy and without trim when the negative
tank is nearly empty. It is used to reduce the time required in submerging
from surface condition, to reduce the time required to increase depth while
operating submerged, and to prevent broaching when decreasing depth. It
may be blown or pumped.
2A14. Bow buoyancy tank. The bow buoyancy tank is a free-flooding,
tank with its main volume above the
normal surface waterline. It is located in the extreme bow of the vessel
and is formed of the plating of the superstructure. Its function is to
provide reserve surface buoyancy, emergency positive buoyancy in the submerged
condition, and to aid in surfacing.
2A15. Auxiliary tanks. The auxiliary tanks are variable
ballast tanks located at or near the submerged center of buoyancy, and
are used to vary the over-all trim of the boat.
2A16. Trim tanks. The trim tanks are the variable ballast
tanks nearest the bow and stern of the boat and are used to provide fore-and-aft
2A17. Normal fuel oil tanks. Tanks designed solely for containing
the engine fuel oil are known as normal fuel oil tanks.
2A18. Fuel ballast tanks. The fuel ballast tanks are designed
to be utilized as fuel oil tanks for increased operating range. When empty,
they may be converted to main ballast tanks, providing additional freeboard
and thereby increasing surface speed.
2A19. Expansion tank. The expansion tank, connected between
the head box and the compensating water main, admits sea pressure to the
fuel oil tanks. It receives any overflow from the fuel tanks resulting
either from overfilling the fuel system or from temperature expansion.
The bilges are pumped into this tank to prevent leaving an oil slick or
polluting a harbor.
2A20. Collecting tank. The collecting tank, connected
to the fuel oil tanks through the fuel transfer line, serves as a water
and sediment trap for the fuel oil being transferred to the fuel pump.
2A21. Clean fuel oil tanks. The clean fuel oil tanks are
storage tanks located within the pressure hull. They receive clean fuel
oil from the purifiers and are the supply tanks from which the engines
receive their clean fuel.
2A22. Poppet valve drain tank. The poppet valve drain tank
is located under the platform deck of the torpedo room immediately
below the breech of the torpedo tubes.
The air and water from the poppet valves, incident to the firing of torpedoes,
is discharged into this tank.
2A23. Fresh water tanks. The fresh water tanks contain
potable water for drinking, cooking, and certain sanitary facilities.
2A24. Battery fresh water tanks. The battery fresh water tanks
are storage tanks for the distilled water used in watering the main storage
2A25. Sanitary tanks. The sanitary tanks receive and store
the ship's sanitary drainage until conditions permit overboard discharge.
2A26. WRT tanks. The WRT, or water round torpedo, tanks
are variable ballast tanks, located in the forward and after torpedo rooms,
for flooding or draining the torpedo tubes.
2A27. Main vents. The
main vents are valves operated hydraulically,
or by hand, for venting the main ballast tanks when flooding. They are
located in the top of the risers of the main ballast tanks.
2A28. Emergency vents. The emergency vents are stop valves
in the vent risers near the tank tops and are used in case of damage to
the, main vents. They permit sealing the tank to prevent accidental flooding
and also permit blowing the tank if desired.
2A30. Riding the vents.Riding the vents is a surface
condition in which the main ballast tanks are prevented from completely
flooding by the closed main vents which prevent the escape of air.
2A31. Flood Valves.Flood valves are hinged covers at
the bottom of certain ballast tanks which may be opened to admit or expel
2A32. Flooding. Filling a tank through flood ports, open flood
valves, or other sea connections, is known as flooding.
a tank consists of expelling its contents by compressed air.
2A34. Pumping.Pumping a tank consists of using a pump
to transfer liquid from the tank to sea, from sea to tank, or from one
tank to another. The tanks must be vented during this operation.
2A35.Bow planes. The bow planes
are horizontal rudders, or diving planes, extending from each side of the
submarine near the bow.
2A36. Stern planes. The stern planes are horizontal rudders,
or diving planes, extending from each side of the submarine near the stern.
B. STANDARD PHRASEOLOGY
2B1. General. Standard phraseology
is the product of years of experience and has been developed to combine
precision, brevity, and audibility. The following procedures have been
approved for submarine communications, both airborne and over interior
communication systems. Strict adherence to these procedures increases the
speed of communications and reduces the chances of error and misunderstanding.
The standard phrases, developed for the various activities of a submarine,
are included in the chapter in which their use occurs.
bility and to minimize confusion. This is standard
for the service, and should be followed invariably.
The numeral "0" is spoken as "Ze-ro" for all numerical data except ranges.
In giving ranges, "0" is spoken as "Oh." When "00" occurs at the end of
a number it is spoken as "Double-oh."
Examples: "Bearing too ze-ro ze-ro." "Range fi-yiv oh double-oh."
a. Bearings and courses are spoken
Ze-ro or Oh (stress on both syllables of Zero)
FI-yiv (stress on first syllable)
Thuh-REE (stress on second syllable)
FO-wer (stress on first syllable)
2B2. Voice procedure. All
messages should be spoken clearly and loudly enough to be heard above the
noises and voices of the various compartments. Talk slowly and speak distinctly,
do not run words together. Make the listener hear all you say the first
time you say it.
2B3. Numerals. Exhaustive tests have demonstrated that numerals
should be spoken in the following manner to provide intelligi-
as three separate digits.
Examples: "Bearing ze-ro zero thuh-ree."
"Steer course wun niner six."
b. Speed and torpedo depths are spoken as two separate digits.
Examples: "Speed ze-ro six and wun half knots."
"Set depth wun too feet."
c. Angle on the bow is spoken as
a single compound number preceded by "port." or "starboard."
Example: "Angle on the bow port thirty fi-yiv."
d. Depth to keep, and bubble, or angle of the boat and angle
on the planes, are spoken as separate digits.
Example: "Six fi-yiv feet, too degree up bubble, too zero degrees
rise on the bow planes."
e. Time is spoken in standard Navy terminology .
Examples: "Ze-ro ze-ro thirty." "Ze-ro ate hundred." "Seventeen
thirty fi-yiv." "Ze-ro niner ze-ro fi yiv."
2B4. Messages. a. Messages over a telephone or talk-back normally
consist of two parts: 1) the call and 2) the text. There
should be no pause between these parts for acknowledgment by the receiver.
Example: "After room, open outer doors aft."
b. When it is necessary to prevent misunderstanding, the station calling
should identify itself immediately after the call.
Example: "Control, forward room: we heard a bumping noise along
the hull !"
2B5. Acknowledgment. a. Each message should be acknowledged by
an exact repetition. "Aye, aye" should not be used because it gives the
originator no clue as to whether or not the message has been understood
Example: Message. "After room, open outer doors aft." Acknowledgment.
"After room, open outer doors aft."
b. When an order has been executed,
that fact is communicated to the originating station. Example: Statement
of execution. "Conning tower, the outer doors have been opened aft."
Acknowledgment. "Conning tower, the outer doors have been opened aft."
c. When a question cannot be answered immediately, it is acknowledged
and the word "Wait" added. The question is answered as soon as the information
Example: Message. "After Engine Room, how are the bilges ?"
Acknowledgment. "After Engine Room, how are the bilges? Wait."
Reply, after the information is obtained. "Control, six inches of water
in the after engine room bilges." Acknowledgment. "Control, six inches
of water in the after engine room bilges."
d. If the acknowledgment shows that the message has not been heard
correctly, or if the originator himself decides to change the message,
he says, "Belay that," and gives the correct form.
e. A repeat is requested whenever there is any doubt concerning the
content of a message.
2B6. Emergency messages. In case of emergency, the station making
announcement calls, "Silence on the line." All other stations cease talking
until the emergency message has been completed.
2B7. Courtesy. The words "sir" and " please", and so forth, are
not used on interior communication circuits. On a combat vessel, courtesy
consists of making telephone messages as brief and efficient as possible.
C. COMMON ABBREVIATIONS
2C1. Acceptable abbreviations. In
the box below are given some of the most frequently used abbreviations.
They are time savers and should be used whenever possible. In the
interest of uniformity throughout the Service
they should be used exactly as they appear here.