Improvised Munitions Handbook (Improvised Explosive Devices or IEDs)

# Section 7
Miscellaneous

## 7.1 Clothespin Switch

A spring type clothespin is used to make a circuit closing switch to actuate explosive charges, mines, booby traps and alarm systems.

Materials Required
Spring type clothespin
Solid copper wire, 1/16 inch (2 mm) in diameter
Strong string on wire
Flat piece of wood (roughly 1/8 inch x 1 inch x 2 inches)
Knife

#### Procedure

1. Strip four inches (10 cm) of insulation from the ends of 2 solid copper wires. Scrape copper wires with pocket knife until metal is shiny.

2. Wind one scraped wire tightly on one jaw of the clothespin, and the other wire on the other jaw.

3. Make a hole in one end of the flat piece of wood using a knife, heated nail or drill. Tie strong string or wire through the hole.

4. Place flat piece of wood between jaws of the clothespin switch.

#### Basic Firing Circuit

When the flat piece of wood is removed by pulling the string, the jaws of the clothespin will close completing the circuit.

Caution: Do not attach the battery until the switch and trip wire have been emplaced and examined. Be sure the flat piece of wood is separating the jaws of the switch.

#### A Method of Use

## 7.2 Mousetrap Switch

A common mousetrap can be used to make a circuit closing switch for electrically initiated explosives, mines and booby traps.

Materials Required
Mousetrap
Hacksaw or file
Connecting wires

#### Procedure

1. Remove the trip lever from the mousetrap using a hacksaw or file. Also remove the staple and holding wire.

2. Retract the striker of the mousetrap and attach the trip lever across the end of the wood base using the staple with which the holding wire was attached.

Note: If the trip lever is not made of metal, a piece of metal of approximately the same size should be used.

3. Strip one inch (2-1/2 cm) of insulation from the ends of 2 connecting wires.

4. Wrap one wire tightly around the spring loaded striker of the mousetrap.

5. Wrap the second wire around some part of the trip lever or piece of metal.

Note: If a soldering iron is available, solder both of the above wires in place.

#### How to Use

This switch can be used in a number of ways—one typical method is presented here.

The switch is placed inside a box which also contains the explosive and batteries. The spring loaded striker is held back by the lid of the box and when the box is opened the circuit is closed.

## 7.3 Flexible Plate Switch

This pressure sensitive switch is used for initiating emplaced mines and explosives.

Materials Required
Two flexible metal sheets: one approximately 10 inches (25 cm) square one approximately 10 inches x 8 inches (20 cm)
Piece of wood 10 inches square by 1 inch thick
Four soft wood blocks 1 inch x 1 inch x 1/4 inch
Eight flat head nails, 1 inch long
Connecting wires
Adhesive tape

#### Procedure

1. Nail 10 inch x 8 inch metal sheet to 10 inches square piece of wood so that 1 inch of wood shows on each side of metal. Leave one of the nails sticking up about 1/4 inch.

2. Strip insulation from the end of one connecting wire. Wrap this end around the nail and drive the nail all the way in.

3. Place the four wood blocks on the corners of the wood base.

4. Place the 10 inch square flexible metal sheet so that it rests on the blocks in line with the wood base.

5. Drive four nails through the metal sheet and the blocks to fasten to the wood base. A second connecting wire is attached to one of the nails as in step 2.

6. Wrap adhesive tape around the edges of the plate and wood base. This will assure that no dirt or other foreign matter will get between the plates and prevent the switch from operating.

#### How to Use

The switch is placed in a hole in the path of expected traffic and covered with a thin layer of dirt or other camouflaging material. The mine or other explosive device connected to the switch can be buried with the switch or emplaced elsewhere as desired.

When a vehicle passes over the switch, the two metal plates make contact closing the firing circuit.

## 7.4 Metal Ball Switch

This switch will close an electric circuit when it is tipped in any direction. It can be used alone for booby traps or in combination with another switch or timer as an anti-disturbance switch.

Materials Required
Metal Ball 1/2 inch (1-1/4 cm) diameter (see note)
Solid copper wire 1/16 inch (1/4 cm) diameter
Wood block 1 inch (2-1/2 cm) square by 1/4 inch thick
Hand drill
Connecting wires
Soldering iron & solder

Note: If other than a 1/2 inch diameter ball is used, other dimension must be changed so that the ball will rest in the center hole of the block without touching either of the wires.

#### Procedure

1. Drill four 1/16 inch holes and one 1/8 inch hole through the wood block as shown.

2. Form two “U” shaped pieces from 1/16 inch copper wire to the dimensions shown.

3. Wrap a connecting wire around one leg of each “U” at least 1/4 inch from the end and solder in place.

4. Place metal ball on block so that it rests in the center hole.

5. Insert the ends of the small “U” into two holes in the block. Insert large “U” into the remaining two holes.

Caution: Make sure that the metal does not touch either “U” shaped wire when the switch is standing on its base. If the ball does touch, bend wires outward slightly.

#### How to Use

Mount switch vertically and connect in electrical firing circuit as with any other switch. When tipped in any direction it will close the circuit.

Caution: Switch must be mounted vertically and not disturbed while completing connections.

## 7.5 Altimeter Switch

This switch is designed for use with explosives placed on aircraft. It will close an electrical firing circuit when an altitude of approximately 5000 feet (1-1/2 km) is reached.

Materials Required
Jar or tin can
Thin sheet of flexible plastic or waxed paper
Thin metal sheet (cut from tin can)
Adhesive tape
Connecting wires

#### Procedure

1. Place sheet of plastic or waxed paper over the top of the can or jar and tape tightly to sides of container.

Note: Plastic sheet should not be stretched tight. A small depression should be left in the top.

2. Cut two contact strips from thin metal and bend to the shapes shown.

3. Strip insulation from the ends of two connecting wires. Attach one wire to each contact strip.

Note: If a soldering iron in available solder wires in place.

4. Place contact strips over container so that the larger contact is above the smaller with a very small clearance between the two.

5. Securely tape contact strips to sides of container.

#### How to Use

1. Connect the altimeter switch in an explosive circuit the same as any switch.

2. Place the explosive package on airplane. As the plane rises the air inside the container will expand. This forces the plastic sheet against the contacts closing the firing circuit.

Note: The switch will not function in a pressurized cabin. It must be placed in some part of the plane which will not be pressurized.

## 7.6 Pull-Loop Switch

This switch will initiate explosive charges, mines, and booby traps when the trip wire is pulled.

Materials Required
2 lengths of insulated wire
Knife
Strong string or cord
Fine thread that will break easily

#### Procedure

1. Remove about 2 inches of insulation from one end of each length of wire. Scrape bare wire with knife until metal is shiny.

2. Make a loop out of each piece of bare wire.

3. Thread each wire through the loop of the other wire so the wires can slide along each other.

Note: The loops should contact each other when the two wires are pulled taut.

#### How to Use

1. Separate loops by about 2 inches. Tie piece of fine thread around wires near each loop. Thread should be taut enough to support loops and wire, yet fine enough that it will break under a very slight pull.

2. Fasten one wire to tree or stake and connect end to firing circuit.

3. Tie a piece of cord or string around the other piece of wire a few inches from the loop. Tie free end of cord around tree, bush, or stake. Connect the free end of the wire to the firing circuit. Initiation will occur when the tripcord is pulled.

Caution: Be sure that the loops do not contact each other when the wires are connected to the firing circuit.

Other uses: The switch minus the fine thread may be used to activate a booby trap by such means as attaching it between the lid and a rigid portion of a box, between a door and a door jamb, and in similar manners.

## 7.7 Knife Switch

This device will close the firing circuit charges, mines, and booby traps when the trip wire is pulled or cut.

Materials Required
Knife or hack saw blade
6 nails
Strong string or light rope
Sturdy wooden board
Wire

#### Procedure

1. Place knife on board. Drive 2 nails into board on each side of knife handle so knife is held in place.

2. Drive one nail into board so that it touches blade of knife near the point.

3. Attach rope to knife. Place rope across path. Apply tension to rope, pulling knife blade away from nail slightly. Tie rope to tree, bush, or stake.

4. Drive another nail into board near the tip of the knife blade as shown below. Connect the two nails with a piece of conducting wire. Nail should be positioned so that it will contact the second nail when blade is pulled about 1 inch (2-1/2 cm) to the side.

Note: Check position of nails to knife blade. The nails should be placed so that the knife blade will contact either one when the rope is pulled or released.

#### How to Use

Attach one wire from firing circuit to one of the nails and the other to the knife blade. The circuit will be completed when the tripcord is pulled or released.

## 7.8 Improvised Scale

This scale provides a means of weighing propellant and other items when conventional scales or balances are not available.

Materials Required
Pages from Improvised Munitions Handbook
Straight sticks about 1 foot (30 cm) long and 1/4 inch (5 mm) in diameter
Thread or fine string

#### Procedure

1. Make a notch about 1/2 inch (1 cm) from each end of stick. Be sure that the two notches are the same distance from the end of the stick.

2. Find the exact center of the stick by folding in half a piece of thread the same length as the stick and placing it alongside the stick as a ruler. Make a small notch at the center of the stick.

3. Tie a piece of thread around the notch. Suspend stick from branch, another stick wedged between rocks, or by any other means. Be sure stick is balanced and free to move.

Note: If stick is not balanced, shave or scrape a little off the heavy end until it does balance. Be sure the lengths of the arms are the same.

4. Make a container out of one piece of paper. This can be done by rolling the paper into a cylinder and folding up the bottom a few times.

5. Punch 2 holes at opposite sides of paper container. Suspend container from one side of stick.

6. Count out the number of handbook pages equal in weight to that of the quantity of material to be weighed. Each sheet of paper weighs about 1.3 grams (20 grains or 0.04 ounce). Suspend these sheets, plus one, to balance container on the other side of the scale.

7. Slowly add the material to be weighed to the container. When the stick is balanced, the desired amount of material is in the container.

8. If it is desired to weigh a quantity of material larger than that which would fit in the above container, make a container out of a larger paper or paper bag, and suspend from one side of the stick. Suspend handbook pages from the other side until the stick is balanced. Now place a number of sheets of handbook pages equal in weight to that of the desired amount of material to be weighed on one side, and fill the container with the material until the stick is balanced.

9. A similar method may be used to measure parts or percentage by weight. The weight units are unimportant. Suspend equal weight containers from each side of the stick. Bags, tin cans, etc. can be used. Place one material in one of the containers. Fill the other container with the other material until they balance. Empty and refill the number of times necessary to get the required parts by weight (e.g., 5 to 1 parts by weight would require 5 fillings of one can for one filling of the other).

## 7.9 Rope Grenade Launching Technique

A method of increasing the distance a grenade may be thrown. Safety fuse is used to increase the delay time.

Materials Required
Hand grenade (improvised pipe hand grenade, section 2.1, may be used)
Safety fuse or fast burning improvised fuse (section 6.7)
Light rope, cord, or string

#### Procedure

1. Tie a 4 to 6 foot (a meter) length Rope of cord to the grenade. Be sure that the rope will not prevent the grenade handle from coming off.

Note: If improvised grenade is used, tie cord around grenade near the end cap. Tape in place if necessary.

2. Tie a large knot in the other end of the cord for use as a handle.

3. Carefully remove safety pin from grenade, holding safety lever in place. Enlarge safety pin hole with point of knife, awl, or drill so that safety fuse will pass through hole.

4. Insert safety fuse in hole. Be sure that safety fuse is long enough to provide a 10 second or more time delay. Slowly release safety lever to make sure fuse holds safety lever in place.

Caution: If safety lever should be released for any reason, grenade will explode after regular delay time (4–5 seconds).

Note: If diameter of safety fuse is too large to fit in hole (step 4), follow Procedure and How to Use of Time Delay Grenade, section 6.9, instead of steps 3 and 4 above.

#### How to Use

1. Light fuse.

2. Whirl grenade overhead, holding knot at end of rope, until grenade picks up speed (3 or 4 turns).

3. Release when sighted on target.

Caution: Be sure to release grenade within 10 seconds after fuse is lit.

Note: It is helpful to practice first with a dummy grenade or a rock to improve accuracy. With practice, accurate launching up to 100 meters (300 feet) can be obtained.

## 7.10 Bicycle Generator Power Source

A 6 volt, 3 watt bicycle generator will set off one or two blasting caps (connected in series) or an igniter.

Materials Required
Bicycle generator (6 volt, 3 watt)
Copper wire
Knife

#### Procedure

1. Strip about 4 inches (10 cm) of coating from both ends of 2 copper wires. Scrape ends with knife until metal is shiny.

2. Connect the end of one wire to the generator terminal.

3. Attach the end of the second wire to generator case. This wire may be wrapped around a convenient projection, taped, or simply held against the case with the hand.

#### How to Use

1. Connect free ends of wires to blasting cap or squib leads.

Caution: If drive wheel is rotated, explosive may be set off.

2. Run the drive wheel firmly and rapidly across the palm of the hand to activate generator.

## 7.11 Automobile Generator Power Source

An automobile generator can be used as a means of firing one blasting cap or igniter. (Improvised Igniter, section 5.2, may be used.)

Materials Required
Automobile generator (6, 12, or 28 volt) (an alternator will not work.)
Copper wire
Strong string or wire, about 5 feet (150 cm) long and 1/16 inch (1-1/2 mm) in diameter
Knife
Small light bulb requiring same voltage as generator (for example, bulb from same vehicle as generator)

#### Procedure

1. Strip about 1 inch (2-1/2 cm) of coating from both ends of 3 copper wires. Scrape ends with knife until metal is shiny.

2. Connect the A and F terminals with one piece of wire.

3. Connect a wire to the A terminal. Connect another to the G terminal.

Note: The F and G or C terminals may not be labeled; in this case, connect wires as shown. The F terminal is usually smaller in size than the C or G terminal.

4. Wrap several turns of string or wire clockwise around the drive pulley.

#### How to Use

1. Connect the free ends of the wires to the light bulb.

2. Place one foot on the generator to secure it in place. Give the string or wire a very hard pull to light the bulb.

Note: If not successful at first, rewind string and try again several times. After repeating this operation and the bulb still does not light, follow step 4, How to Use.

3. If light bulb lights, follow steps 1 and 2 of above, How to Use, connecting free ends of wires to blasting cap or igniter instead of to light bulb.

4. If light bulb does not light after several pulls, switch leads connected to F and G terminals. Repeat above How to Use, steps 1 to 3.

## 7.12 Improvised Battery (Short Lasting)

This battery is powerful but must be used within 15 minutes after fabrication. One cell of this battery will detonate one blasting cap or one igniter. Two cells, connected in series, will detonate two of these devices and so on. Larger cells have a longer life as well as greater power.

Materials Required | Source
--- | ---
Water |
Sodium hydroxide (lye, solid or concentrated solution) | Soap manufacturing Disinfectants Sewer cleaner
Copper or brass plate about 4 inches (10 cm) square and 1/16 inch (2 mm) thick |
Aluminum plate or sheet, same size as copper plate |
Charcoal powder |
Container for mixing |
Knife |
One of the following:
Potassium permanganate, solid | Disinfectants Deodorants
Calcium hypochlorite, solid | Disinfectants Water treating chemicals Chlorine bleaches
Manganese dioxide (pyrolucite) | Dead dry cell batteries

Note: Be sure sodium hydroxide solution is at least a 45% solution by weight. If not, boil off some of the water. If solid sodium hydroxide is available, dissolve some sodium hydroxide in about twice as much water (by volume).

#### Procedure

1. Scrape coating off both ends of wires with knife until metal is shiny.

2. Mix thoroughly (do not grind) approximately equal volumes of powdered charcoal and one of the following: potassium permanganate, calcium hypochlorite, or manganese dioxide. Add water until a very thick paste is formed.

Caution: Avoid getting any of the ingredient on the skin or in the eyes.

3. Spread a layer of this mixture about 1/8 inch (2 mm) thick on the copper or brass plate. Be sure mixture is thick enough so that when mixture is sandwiched between two metal plates, the plates will not touch each other at any point.

Note: If more power is required, prepare several plates as above.

#### How to Use

1. Just prior to use (no more than 15 minutes), carefully pour a small quantity of sodium hydroxide solution over the mixture on each plate used.

Caution: If solution gets on skin, wash off immediately with water.

2. Place an aluminum plate on top of the mixture on each copper plate. Press firmly. Remove any excess that oozes out between the plates.

Caution: Be sure plates are not touching each other at any point.

3. If more than one cell is used, place the cells on top of each other so that unlike metal plates are touching.

4. When ready to fire, clean plates with knife where connections are to be made. Connect one wire to the outer aluminum plate. This may be done by holding the wires against the plates or by hooking them through holes punched through plates. If wires are hooked through plates, be sure they do not touch mixture between plates.

## 7.13 Improvised Battery (2 Hour Duration)

This battery should be used within 2 hours and should be securely wrapped. Three cells will detonate one blasting cap or one igniter. Five cells, connected in series, will detonate two of these devices and so on. Larger cells have a longer life and will yield more power.

If depolarizing materials such as potassium permanganate or manganese dioxide cannot be obtained, ten cells without depolarizer, arranged as described below, (step 4) will detonate one blasting cap.

Materials Required | Source
--- | ---
Water |
Ammonium chloride (sal ammoniac) (solid or concentrated solution) | Medicines Soldering fluxes Fertilizers Ice melting chemicals for roads
Charcoal powder |
Copper or brass plate about 4 inches (10 cm) square and 1/16 inch (2 mm) thick |
Aluminum plate same size as copper or brass plate |
Wax and paper (or waxed paper) | Candles
Wire, string or tape |
Container for mixing |
Knife |
One of the following:
Potassium permanganate, solid | Disinfectants Deodorants
Manganese dioxide | Dead dry batteries

Note: If ammonium chloride solution is not concentrated (at least 45% by weight) boil off some of the water.

#### Procedure

1. Mix thoroughly (do not grind) approximately equal volumes of powdered charcoal, ammonium chloride and one of the following: potassium permanganate or manganese dioxide. Add water until a very thick paste is formed. If ammonium chloride is in solution form, it may not be necessary to add water.

2. Spread a layer of this mixture, about 1/8 inch (3 mm) thick on a clean copper or brass plate. The layer must be thick enough to prevent a second plate from touching the copper plate when it is pressed on top.

3. Press an aluminum plate very firmly upon the mixture on the copper plate. Remove completely any of the mixture that squeezes out between the plates. The plates must not touch.

4. If more than one cell is desired:

1. Place one cell on top of the other so that unlike metal plates are touching.
2. Wrap the combined cells in heavy waxed paper. The waxed paper can be made by rubbing candle wax over one side of a piece of paper. Secure the paper around the battery with string, wire or tape. Expose the top and bottom metal plates at one corner.

#### How to Use

1. Scrape a few inches off each end of two wires with knife till metal is shiny.

2. Clean plates with knife until metal is shiny where connections are to be made.

3. Connect one wire from the explosive to a copper or brass plate and the other wire to an aluminum plate. The connection can be made by holding the wire against the plate. A permanent connection can be made by hooking the wire through holes in the exposed corners of the plates. The battery is now ready for use.

Note: If battery begins to fail after a few firings, scrape the plates and wires where connections are made until metal is shiny.

## 7.14 Armor Materials

The following table shows the amount of indigenous materials needed to stop ball type projectiles of the 5.56 mm, .30 caliber, and .50 caliber ammunition fired from their respective weapons at a distance of 10 feet (3 m).

| Thickness of Materials
Inches | Centimeters
--- | ---
Indigenous Material | 5.56 mm | .30 caliber | .50 caliber | 5.56 mm | .30 caliber | .50 caliber
7.62 mm | 12.70 mm | 7.62 mm | 12.70 mm
Mild steel (structural) | 1/2 | 1/2 | 3/4 | 1-1/4 | 1-1/4 | 2
Mild aluminum (structural) | 1 | 1 | 2 | 2-1/2 | 2-1/2 | 5
Pine wood (soft) | 14 | 22 | 32 | 36 | 56 | 82
Broken stones (cobble gravel) | 3 | 4 | 11 | 8 | 11 | 28
Dry sand | 4 | 5 | 14 | 11 | 13 | 36
Wet sand or earth | 6 | 13 | 21 | 16 | 33 | 54

Note: After many projectiles are fired into the armor, the armor will break down. More material must be added.