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Taliani Test

A heat stability test for propellants and explosives.

Tamping

The act of charging or tamping a charge into a hole, with the aid of a tamping stick. Sometimes used loosely for “stemming” (q.v.). The action of compacting the explosive charge or the stemming in a blasthole.

Tamping Bags

Cylindrical bags containing stemming material and used in boreholes to confine the explosive material charge.

Tamping Pole

A wooden or plastic pole used to compact explosive charges or stemming.

Tank (military)

A military tank is an armored vehicle that has caterpillar traction and is armed with machine guns, cannon, rockets, or flamethrowers. It was developed by the British and first used (Sept. 1916) in World War I. In World War II tanks and tank tactics were greatly improved. The German army, using large numbers of tanks, overran Poland in less than a month. In mass tank battles on the plains of Europe and N Africa the tide often swung toward the side with the best tanks. Since World War II the basic features of tanks and tank tactics have remained unchanged, although there have been refinements. Tanks are vulnerable to recoilless weapons and various antitank missiles, but they remain indispensable, because of their mobility and versatile weaponry, wherever the terrain is suitable to their operation.

Tar (and pitch)

Tar and pitch, viscous, dark-brown to black substances, obtained by the destructive distillation of certain organic materials, e.g., Coal, Wood, and Petroleum. Although the terms tar and pitch are sometimes used interchangeably, pitch is actually a component of tar that can be isolated by heating. Tar, more or less fluid, is now used to produce Benzene and various other substances. Tar from pine wood is used to make soap and medicinals. Coal tar derivatives are used to make dyes, cosmetics, and synthetic flavoring extracts. Pitch tends to be more solid than tar and is used to make roofing paper, in varnishes, as a coal-dust binder in making fuel briquettes, and as a lubricant. Asphalt is a naturally occurring pitch.

Target Area

An area to be entered or breached, generally where a threat resides.

Telegraph

An electrically operated device or system for distant communication (the first ever invented) by means of visible or audible signals. The method used throughout most of the world, based in large part on the mid-19th-cent. work of Samuel F.B. Morse, utilizes an Electric Circuit set up customarily by using a single overhead wire and employing the earth as the other conductor to complete the circuit. In the telegraph's simplest form, an electromagnet in the receiver is activated by alternately making and breaking the circuit. Reception by sound, with the Morse Code signals received as audible clicks, is the basis for a low-cost, reliable method of signaling. In addition to wires and cables, telegraph messages are now sent by such means as Radio Waves, Microwaves, and Communications Satellites. Telex is a telegraphy system that transmits and receives messages in printed form. Facsimile is a system for transmitting and reproducing photographs and other graphic material by wire or radio.

Telephone

A device for transmitting and receiving sound, especially speech, by means of wires in Electric Circuits. The telephones now in general use are developments of the device invented by Alexander Graham Bell and patented by him in 1876 and 1877. A modern telephone transmitter, which is essentially a carbon Microphone, contains loosely packed carbon grains. When someone speaks into the telephone, the diaphragm vibrates, causing the carbon grains to be compressed and released. This motion varies the current flow in the associated electric circuit. The current, when transmitted to a distant identical instrument, causes the diaphragm in it to vibrate in response to the fluctuations induced by the nearby magnetic field. Telephone lines used include ordinary open-wire lines; lead-sheathed cables consisting of many lines; coaxial cables; and, most recently, glass fibers ( Fiber Optics). Coaxial cables and fiber-optic lines are placed underground, but other cables may be either overhead or underground. Long-distance transmission of telephone messages is often accomplished by means of radio and microwave transmissions. In some cases microwaves are sent to an orbiting communications satellites, from which they are relayed back to a distant point on the earth. Sophisticated services, including automatic switching systems, automatic dialing, call forwarding, and conference calling, have been developed in recent years.

Television

Television, transmission and reception of still or moving images by means of electrical signals, especially by means of Electromagnetic Radiation using the techniques of Radio. One of the most widely used image pickup devices, or camera tubes, is the iconoscope (invented by Vladimir Zworykin, 1923), which consists of a thin sheet of mica upon which thousands of microscopic globules of a photosensitive silver-cesium compound have been deposited. Backed with a metallic conductor, this expanse of mica becomes a mosaic of tiny Photoelectric Cells and Capacitors. The differing light intensities of various points of a scene cause the cells of the mosaic to emit varying quantities of electrons. The cells are left with positive charges in strengths proportional to the electrons lost. An electron gun, or “scanner,” passes its beam across the cells. As it does so, the charge is released, causing an electrical signal to appear on the back of the mosaic, which is connected externally to an amplifier. The strength of the signal is proportional to the amount of charge released. In the Vidicon, another type of pickup tube, the photoemissive mosaic is replaced by a photoconductive layer, resulting in increased efficiency. The scanning process, which is the essence of television accomplishment, operates as the human eye does in reading a page of printed material, i.e., line by line. A complex circuit of horizontal and vertical deflection coils controls this movement and causes the electron beam to scan the back of the mosaic 30 times per second. Two principal means of recording television programs for future use are video tape recording and kinescope. Video tape recording is similar to conventional tape recording except that because of the wide frequency range—4.2 megahertz (MHz)—occupied by a video signal, the effective speed at which the tape passes the recording head is kept very high. Sound is recorded along with the video signal on the same tape. Kinescope is a method in which programs are recorded on motion-picture film. Appropriate changes in the signal-carrying circuitry allow kinescopes to be played back from a developed negative as well as from a positive. Systems for recording television programs on discs have been recently developed. When a television program is broadcast, the varying electrical signals are amplified and used to modulate a carrier wave ( Modulation); the modulated carrier is usually fed to an antenna, where it is converted to electromagnetic waves and broadcast over a large region. The waves are sensed by antennas connected to television receivers, and the image is reconstructed essentially by reversing the pickup operation. The final image is displayed on the face of a Cathode-Ray Tube, where an electron beam scans the fluorescent face, called the “screen,” line for line with the pickup scanning. The tube's inside face glows when hit by the electrons, and the visual image is reproduced. Color television today uses as “element-sequential” system. Light from the subject is broken up into its three primary-color components (red, blue, and green), which are simultaneously scanned by three pickups. In the receiver the signals are brought together again. Each element, or dot, on the picture tube screen is subdivided into areas of red, blue, and green phosphors. Beams from three electron guns, modulated by the three color signals, scan the elements together in such a way that the beam from the gun using a given color signal strikes the phosphor of the same color.

Temperature

Temperature Coefficient

The relative change of a property (pressure, burning time) with the temperature.

Terminal Ballistics

The branch of ballistics which deals with the ultimate effect produced by a projectile.

Terminal Velocity

The constant velocity of a falling body attained when the resistance of air or other ambient fluid has become equal to the force of gravity acting upon the body. Sometimes called "limiting velocity."

Test Blasting Cap No. 8

Institute of Makers of Explosives No. 8 Test Detonator.

Tetryl

Sensitive explosive used especially in caps and boosters to detonate less sensitive explosives, and as the explosive filler in some types of projectiles.

Thermite

A high temperature producing mixture.

An incendiary composition consisting of 2.75 parts black iron oxide (ferrosoferric oxide) and 1.0 part of granular aluminum.

Thermocouple

Thermocouple, a temperature-measuring device formed by joining the ends of two strips of dissimilar metals in a closed loop, with the two junctions at different temperatures. Because the voltage that arises in this circuit is proportional to the temperature difference between the junctions, the temperature at one junction can be determined if the other junction is maintained at a known temperature.

Thermodynamics

The science of the mechanical action of heat, or the relationship of heat and mechanical energy, and the conversion of one into the other. Refers to the branch of science concerned with the nature of heat and its conversion into other forms of energy. Heat is a form of energy associated with the positions and motion of the molecules of a body ( Kinetic-Molecular Theory of Gases). The total energy that a body contains as a result of the positions and the motions of its molecules is called its internal energy. The first law of thermodynamics states that in any process the change in a system's internal energy is equal to the heat absorbed from the environment minus the work done on the environment. This law is a general form of the law of conservation of energy ( Conservation Laws). The second law of thermodynamics states that in a system the entropy cannot decrease for any spontaneous process. A consequence of this law is that an engine can deliver work only when heat is transferred from a hot reservoir to a cold reservoir or heat sink. The third law of thermodynamics states that all bodies at absolute zero would have the same entropy; this state is defined as having zero entropy.

Thermometer

Thermometer, an instrument for measuring temperature. A clinical thermometer consists of a small vacuum tube of uniform bore, with a temperature scale etched on its front. The tube is closed at one end and connected at the other with a chamber containing mercury or another liquid. When the chamber is heated, the fluid expands and rises into the tube.

Through-Bulkhead Ignition (TBI)

A means of transferring a detonation from one side of a bulkhead to the other without destroying the integrity of the bulkhead seal.

Thrust

The resultant force in the direction of motion produced by a rocket motor.

Thrust Chamber

Spray Cooling and protective flow of water over external area of thrust chamber during static firing.

Thruster

The thruster was designed to provide a force through a relatively short stroke. The device consists of a cylinder, piston and propellant cartridge.

Thunderstorm

A violent local atmospheric disturbance accompanied by lightning, thunder, and heavy rain, often by strong gusts of winds and sometimes by hail. The typical thunderstorm caused by convection occurs on a hot summer afternoon when the sun's warmth has heated a large body of moist air near the ground. This air rises and is cooled by expansion. The cooling condenses the water vapor in the air, forming a cumulus cloud. If the process continues violently, the cloud becomes immense; the summit often attains a height of 4 mi (6.5 km) above the base, and the top spreads out in the shape of an anvil as the transition to a cumulonimbus cloud occurs. The turbulent air currents within the cloud cause a continual breaking up and reuniting of the raindrops, building up strong electrical charges that result in lightning.

Titration

The determination of the concentration of acids or bases ( Acids and Bases) in solution by the gradual addition of an acidic solution of known volume and concentration to a basic solution of known volume, or vice versa, until complete neutralization (observable by the color change in an added indicator, such as phenolphthalein) has occurred.

TNT

Trinitrotoluene.

Torpedo

A missile designed to contain an explosive charge and be launched into water where it is selfpropelling and usually directable.

Tracer

Element of a type of ammunition (called tracer ammunition) containing a chemical composition which burns visibly in flight. Tracer is used for observation and adjustment of fire, for incendiary purposes, and for signaling.

Trajectory

Path of projectile, missile or bomb in flight.

Trajectory Chart

Diagram of a side view of the paths of projectiles fired at various elevations, under standard conditions. The trajectory chart varies for different guns, projectiles and fuzes.

Transducer

A device which changes one form of energy into another. A loudspeaker changes electrical energy into acoustical energy, for example. A transducer is a device that accepts an input of energy in one form and produces an output of energy in some other form, with a known, fixed relationship between the input and output. One class of transducers consists of devices that produce an electrical output signal, e.g., Microphones, Record-Player cartridges, and Photoelectric Cells. Other transducers accept an electrical input, e.g., Loudspeakers, light bulbs, and Solenoids. Transducers may be either active or passive. Active transducers require a source of energy in addition to the input signal to produce the output signal, whereas passive transducers require only an input signal.

Transformer

Transformer, an electrical device that transfers an alternating current or voltage ( Potential, Electric) from one Electric Circuit to another using Electromagnetic Induction. A simple transformer consists of two coils of wire electrically insulated from each other and arranged so that a change in the current through the primary coil will produce a change in voltage across the secondary coil. The ratio of the alternating-current (AC) output voltage to the AC input voltage is approximately equal to the ratio of the number of turns in the secondary coil to the number of turns in the primary coil. This capability for transforming voltages is the basis for a great many applications. Transformers are classified according to their use; power transformers ( Power, Electric) are used to transmit power at a constant frequency, audio transformers are designed to operate over a wide range of frequencies with a nearly constant ratio of input to output voltage, and radio-frequency transformers operate efficiently within a narrow range of high frequencies.

Transistor

Transistor, an electronic device used as a voltage and current amplifier, consisting of semiconductor materials that share common physical boundaries. The material most commonly used is silicon into which impurities have been introduced. In n-type semiconductors there is an excess of free electrons, or negative charges, whereas in p-type semiconductors there is a deficiency of electrons and therefore an excess of positive charges. Transistors are used in many applications, including radio receivers, electronic computers, and automatic control instrumentation (e.g., in spaceflight and guided missiles). Since the invention (announced in 1948) of the transistor by the American physicists John Bardeen, Walter H. Brattain, and William Shockley, many types have been designed. The n-p-n junction transistor consists of two n-type semiconductors separated by a thin layer of p-type semiconductor; the three segments are called emitter, base, and collector, respectively, and are usually sealed in glass, with a wire extending from each segment to the outside, where it is connected to an electric circuit. The transistor action is such that if the electric potentials on the segments are properly determined, a small current between the emitter and base connections results in a large current between the emitter and collector connections, thus producing current and amplification. The p-n-p junction transistor, consisting of a thin layer of n-type semiconductor lying between two p-type semiconductors, works in the same manner, except that all polarities are reversed. Also Integrated Circuits; Microelectronics.

Transition Elements or Transition Metals

Elements of group VIII and the b groups (I through VII) of the Periodic Table, characterized by the filling of an inner d or f electron orbital as atomic number increases. Many chemical and physical properties of these elements are due to their unfilled d or f orbitals. Transition elements generally have high densities and melting points, magnetic properties, and variable valence arising from the electrons in the d or f orbitals. These metals form stable coordination complexes, or complexions, many of which are highly colored and exhibit paramagnetism.

Transponder

An electronic device that receives a challenging signal and automatically transmits a response.

Transtainer

A low trailer for transportation of the rocket stages.

Transuranium

Elements Radioactive chemical elements with atomic numbers greater than 92 (Uranium). Only Neptunium (at. no. 93) and Plutonium (at. no. 94) occur in nature; they are produced in minute amounts in the radioactive decay of uranium. The transuranium elements of the Actinide Series were discovered as synthetic radioactive isotopes. Both American and Soviet scientists claim to have discovered independently the unstable transactinide elements 104, 105, and 106, and West German scientists reported discovering the unstable transactinide elements 107 and 109.

Trauzl Test

Method of determining relative energy available from an explosive material by measurement of the volume expansion of a lead block test.

Trigonometry

 

Trimonite

High explosive used as a substitute for trinitrotoluene as a bursting charge. Trimonite is a mixture of picric acid and mononitronaphthalene.

Trinitrophenol

Picric Acid.

Trinitrotoluene

(TNT) High explosive widely used as explosive filler in projectiles and by engineers; trinitrotoluol.

Trinitrotoluol

Trinitrotoluene.

Triple-Base Propellant

Propellant whose principal active ingredients are nitrocellulose, nitroglycerin and nitroguanidine. Propellant.

Triple Point

Intersection of the original shock wave, the reflected shock wave and the Maeh stem.

Trunkline

The line of detonating cord on the ground surface that connects detonating cord downlines.

Truss

Rigid frame between rocket tanks to hold electronic equipment.

Tube

The inner cylinder of a built-up gun, usually extending from the inner face of the breechblock to the muzzle.

Tubular Grain

A solid propellant grain in the form of a tube.

Twist

Inclination of the spiral grooves to the axis of the bore of a weapon. The degree of twist is the determining factor in the speed of rotation of the projectile.

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