271 lines
11 KiB
Plaintext
271 lines
11 KiB
Plaintext
ROCKETS AND CANNONS
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Rockets and cannon are generally thought of as heavy artillery.
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Perpetrators of violence do not usually employ such devices, because they are
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difficult or impossible to acquire. They are not, however, impossible to
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make. Any individual who can make or buy black powder or pyrodex can make such
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things. A terrorist with a cannon or large rocket is, indeed, something to
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fear.
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ROCKETS
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Rockets were first developed by the Chinese several hundred years before
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the myth of christ began. They were used for entertainment, in the form of
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fireworks. They were not usually used for military purposes because they were
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inaccurate, expensive, and unpredictable. In modern times, however, rockets
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are used constantly by the military, since they are cheap, reliable, and have
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no recoil. Perpetrators of violence, fortunately, cannot obtain military
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rockets, but they can make or buy rocket engines. Model rocketry is a popular
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hobby of the space age, and to launch a rocket, an engine is required. Estes,
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a subsidiary of Damon, is the leading manufacturer of model rockets and rocket
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engines. Their most powerful engine, the "D" engine, can develop almost 12
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lbs. of thrust; enough to send a relatively large explosive charge a
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significant distance. Other companies, such as Centuri, produce even larger
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rocket engines, which develop up to 30 lbs. of thrust. These model rocket
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engines are quite reliable, and are designed to be fired electrically. Most
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model rocket engines have three basic sections. The diagram below will help
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explain them.
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_________________________________________________________
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|_________________________________________________________| -- cardboard
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\ clay | - - - - - - - - - - | * * * | . . . .|c| casing
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\_______| - - - - - - - - - | * * * | . . . |l|
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_______ - - - thrust - - - | smoke | eject |a|
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/ clay | - - - - - - - - - | * * * | . . . .|y|
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/________|_____________________|_______|________|_|_______
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|_________________________________________________________| -- cardboard
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casing
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The clay nozzle is where the igniter is inserted. When the area labeled
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"thrust" is ignited, the "thrust" material, usually a large single grain of a
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propellant such as black powder or pyrodex, burns, forcing large volumes of
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hot, rapidly expanding gasses out the narrow nozzle, pushing the rocket
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forward.
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After the material has been consumed, the smoke section of the engine is
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ignited. It is usually a slow-burning material, similar to black powder that
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has had various compounds added to it to produce visible smoke, usually black,
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white, or yellow in color. This section exists so that the rocket will be
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seen when it reaches its maximum altitude, or apogee.
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When it is burned up, it ignites the ejection charge, labeled "eject".
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The ejection charge is finely powdered black powder. It burns very rapidly,
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exploding, in effect. The explosion of the ejection charge pushes out the
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parachute of the model rocket. It could also be used to ignite the fuse of a
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bomb...
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Rocket engines have their own peculiar labeling system. Typical engine
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labels are: 1/4A-2T, 1/2A-3T, A8-3, B6-4, C6-7, and D12-5. The letter is an
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indicator of the power of an engine. "B" engines are twice as powerful as "A"
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engines, and "C" engines are twice as powerful as "B" engines, and so on. The
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number following the letter is the approximate thrust of the engine, in
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pounds. the final number and letter is the time delay, from the time that the
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thrust period of engine burn ends until the ejection charge fires; "3T"
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indicates a 3 second delay.
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NOTE: an extremely effective rocket propellant can be made by mixing aluminum
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dust with ammonium perchlorate and a very small amount of iron oxide.
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The mixture is bound together by an epoxy.
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BASIC ROCKET BOMB
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A rocket bomb is simply what the name implies: a bomb that is delivered
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to its target by means of a rocket. Most people who would make such a device
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would use a model rocket engine to power the device. By cutting fins from
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balsa wood and gluing them to a large rocket engine, such as the Estes "C"
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engine, a basic rocket could be constructed. Then, by attaching a "crater
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maker", or CO2 cartridge bomb to the rocket, a bomb would be added. To insure
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that the fuse of the "crater maker" (see sect. 4.42) ignited, the clay over
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the ejection charge of the engine should be scraped off with a plastic tool.
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The fuse of the bomb should be touching the ejection charge, as shown below.
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____________ rocket engine
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| _________ crater maker
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V |
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_______________________________V_
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|_______________________________| ______________________
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\ | - - - - - -|***|::::| /# # # # # # # # # # # \
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\__| - - - - - -|***|::::| ___/ # # # # # # # # # # # \
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__ - - - - - -|***|::::|---fuse--- # # explosive # # )
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/ | - - - - - -|***|::::| ___ # # # # # # # # # # # /
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/___|____________|___|____|____ \_______________________/
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|_______________________________|
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thrust> - - - - - -
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smoke> ***
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ejection charge> ::::
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Duct tape is the best way to attach the crater maker to the rocket
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engine. Note in the diagram the absence of the clay over the ejection charge
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Many different types of explosive payloads can be attached to the rocket, such
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as a high explosive, an incendiary device, or a chemical fire bottle.
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Either four or three fins must be glued to the rocket engine to insure that
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the rocket flies straight. The fins should look like the following diagram:
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| \
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| \ <--------- glue this to rocket engine
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leading edge |
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-------> |
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| | trailing edge
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| | <--------
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\_____/
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The leading edge and trailing edge should be sanded with sandpaper so
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that they are rounded. This will help make the rocket fly straight. A two
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inch long section of a plastic straw can be attached to the rocket to launch
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it from. A clothes hanger can be cut and made into a launch rod. The segment
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of a plastic straw should be glued to the rocket engine adjacent to one of the
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fins of the rocket. A front view of a completed rocket bomb is shown below.
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fin | <------ fin
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| __|__ |
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V / \ V
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---------------| |---------------
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\_____/
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|o <----------- segment of plastic straw
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| <------ fin
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By cutting a coat hanger at the indicated arrows, and bending it, a
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launch rod can be made. After a fuse is inserted in the engine, the rocket is
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simply slid down the launch rod, which is put through the segment of plastic
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straw. The rocket should slide easily along a coathanger, such as the one
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illustated on the following page:
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____
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/ \
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cut here _____ |
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| / \
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V / \
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_________________/ \________________
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/ \
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/ \
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/____________________________________________\
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^
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and here ______|
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Bend wire to this shape:
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_______ insert into straw
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V
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____________________________________________
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\
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\
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\
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\
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\ <--------- bend here to adjust flight angle
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| <---------- put this end in ground
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LONG RANGE ROCKET BOMB
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Long range rockets can be made by using multi-stage rockets. Model
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rocket engines with an "0" for a time delay are designed for use in
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multi-stage rockets. An engine such as the D12-0 is an excellent example of
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such an engine. Immediately after the thrust period is over, the ejection
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charge explodes. If another engine is placed directly against the back of an
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"0" engine, the explosion of the ejection charge will send hot gasses and
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burning particles into the nozzle of the engine above it, and ignite the
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thrust section. This will push the used "0" engine off of the rocket, causing
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an overall loss of weight.
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The main advantage of a multi-stage rocket is that it loses weight as
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travels, and it gains velocity. A multi-stage rocket must be designed
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somewhat differently than a single stage rocket, since, in order for a rocket
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to fly straight, its center of gravity must be ahead of its center of drag.
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This is accomplished by adding weight to the front of the rocket, or by moving
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the center of drag back by putting fins on the rocket that are well behind the
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rocket. A diagram of a multi-stage rocket appears on the following page:
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/ \
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| C |
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| M | ------ CM: Crater Maker
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|___|
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| C | ------ C6-5 rocket engine
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/| 6 |\
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/ | | | \
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/ | 5 | \
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/ |___| \ ---- fin
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/ /| |\ \
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/ / | | \ \
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/ / | | \ \
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/ / | C | \ \
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| / | 6 | \ |
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| / | | | \ |
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| / | 0 | \ |
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|/ |___| \|
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| / \ |
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\______/ ^ \______/ ------- fin
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C6-0 rocket engine
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The fuse is put in the bottom engine.
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Two, three, or even four stages can be added to a rocket bomb to give it
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a longer range. It is important, however, that for each additional stage, the
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fin area gets larger.
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-= Exodus =-
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'94
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