U.S. Army Special Forces Guide to Unconventional Warfare (11 page)

a. Description.

1. This delay is composed of a hollow metal rod or bamboo filled with wet beans, rice or peas. The tube is inverted and placed in the center of a ring of igniter material and a small vial of water or acid is tied to the tube. When the wet beans expand, they lift and topple the tube, thereby spilling the acid or water onto the igniter causing combustion.
   
2. This tipping delay may be used with a variety of igniters. They are easily prepared, and give fairly accurate delay times. This delay should not be used at temperatures near or below 32° F. when water is used as the initiator due to freezing. The following water actuated igniters listed in chapter 3 can be used with this mechanism: Sugar—Sodium Peroxide (0203), Aluminum Powder—Sodium Peroxide (0204) and Silver Nitrate—Magnesium Powder (0208). The delay may be used with concentrated sulfuric acid to initiate the above igniters and the following acid activated igniters: Sugar-Chlorate (0201), Fire Fudge (0202), and Match Head (0205). This delay may be used with the Glycerin—Potassium Permanganate Igniter (0206).
   

b. Material and Equipment.

c. Preparation.
The pipe or tube may be made of any material. It must be closed at one end and flat at the other in order to stand vertically. A large glass test tube is ideal for this purpose.

1. Using some string or rubber bands, attach the small vial to the larger tube. Attach the vial near the top with the open end of the vial pointing up and the open end of the tube down.
   
   
2. This assembly should stand up without toppling over. If it appears unsteady, move the vial downward slightly. A final adjustment may be required when the delay is filled with the required materials.
   

d. Application.

1. Rice will usually give delays of about ten to twenty minutes. Peas and beans will usually give delay times up to 4 or 5 hours. Whichever is used it must be first tested to determine the delay time for the tube that will be used.
   
2. To use this device, tightly pack the piece of pipe or bamboo with rice, peas or beans depending on what delay time is required. Add enough water to completely moisten the beans and quickly pour off the excess water. Place the pipe open end down, and immediately fill the small vial with water or concentrated sulfuric acid, depending on which igniter is being used.
   
   
3. Place a quantity of the igniter mixture in a ring around the delay assembly. Make the ring of such diameter that when the tube falls over, the acid or water from the vial will spill onto the igniter mixture.
   
4. Place incendiary material where the flame from the igniter will start it burning.
   
5. Another way in which the tipping delay can be used is to fill the small vial with glycerin instead of water or acid and then spread potassium permanganate crystals in a ring around the delay. When the glycerin is spilled onto the crystals, combustion will occur and ignite the incendiary material. The glycerin igniter will not work in temperatures below 50° F.
   
6. It is recommended that this device be tested at the same temperature at which it is to be used.
   

a. Description.

DISSOLVING
TIPPING DELAY

CORROSIVE
TIPPING DELAY

1. This device consists of a vial of initiating liquid supported by a tripod. One of the legs which supports the vial of liquid is dissolved by a fluid. The center of gravity of the structure changes and the structure topples over. The contents of the vial spill onto an appropriate igniter mixture and combustion occurs.
   
2. This corrosive or dissolving tipping delay may be used with a variety of igniters. However, it should not be used at temperatures near or below 32° F. when water is used as the initiator due to freezing of the water.
   
3. The following water actuated igniters listed in chapter 3 can be used with this mechanism:
   

   Sugar—Sodium Peroxide (0203), Aluminum Powder—Sodium Peroxide (0204) and Silver Nitrate—Magnesium Powder (0208). The delay may be used with concentrated sulfuric acid to initiate the above igniters and the following acid activated igniters: Sugar-Chlorate (0201), Fire Fudge (0202), and Match Head (0205). This delay may be used with the Glycerin—Potassium Permanganate Igniter (0206)‘
   

b. Material and Equipment
.

c.
Preparation
.

1. Make a tripod out of three sticks, taping them together at the top. Two legs should be the same length; the third should be about 2—3 inches shorter.
   
2. Tape to the short leg, either a stick of hard candy, piece of heavy bare copper wire, steel nail, or steel wire, adjusting the length so that the wire leg stands almost vertically.
   
   
3. The finished tripod should have a distance of about 4—5 inches between any two legs.
   
4. To the top of the tripod, on the short leg, firmly tape or tie the small 1-fluide ounce capacity vial, open end up. Make certain that the tripod still stands upright after attaching the vial. The distance between legs may have to be varied to keep the tripod barely standing upright.
   

d. Application.

1. To use the delay device, insert the leg of the tripod which has the candy, wire, or nails into a glass or porcelain bowl. Fill the vial at the top of the tripod with either water, concentrated sulfuric acid, or glycerin, depending on which igniter is being used. Spread a quantity of the proper igniter material in a ring around the tripod, placing it where the spilled initiating liquid is certain to contact it. Fill the glass or porcelain bowl with the prescribed liquid for dissolving the leg of the tripod in the bowl. For hard candy the liquid is water; for copper wire the liquid is concentrated nitric acid; for steel nails the liquid may be either concentrated hydrochloric acid, or a saturated solution of cupric chloride.
   
2. No definite delay times can be established for these delays because of factors such as temperature, solution concentration, and imperfections in the leg of the tripod. Prior to use, test the device under conditions expected at the target. The following table should be used merely as a guideline of expected delay times for the various materials.
   

   Delay material	Delay time
   Hard candy plus water	5—10 minutes
   Copper wire plus concentrated nitric acid	2—5 minutes
   Copper wire plus nitric acid diluted with an equal volume of water.	45—60 minutes
   Steel wire or nails plus concentrated hydrochloric acid.	24 hours to 7 days
   Steel wire or nails plus cupric chloride 10 minutes to solution.	5—6 hours.

3. The delay time will vary greatly with only moderate changes in temperature. Do not use this type of delay mechanism where accurate delay times are required.