1226 
Summary of results. 
For Multiole Cnarge Tyoe 1A, at 15 ft. distance, the Mach zone extends 50 degrees either 
sige of the 0 degree direction and the maximum pressure, momentum and energy in this zone are 
140%, 158% and 212% resoectively of the corresconding values at the same distance froma normal 
charge with equal weight of exolosive. The 2¢ 1b, Multiole Charge 1A thus oroduces at 15 ft, a 
maximum pressure, momentum and energy equal to those from normal charges of weights 7 1bs., 5 1bs. 
ana 5.25 IDs. rescectively, i.e. this Multiole Charge has the explosive efficiency of a normal 
Charge containing at least double its own weight of explosive. 
For Multicle Charge Tyoe 18, at 15 ft. distance, the Mach zone extends 100 degrees sither 
side of the 0 dejree direction. The charge has highest explosive efficiency in the directions 
between 60 and 80 degrees where the maximum oressure, momentum and energy are 140%, 135% and 1353 
resoectively of the corresoonding values at the same distance from a normal charge with equal 
weight of explosive, ise. Multiole Charge Tyoe 18 oroduces at 15 ft. In the directions between 
60 and 80 degrees a maximum oressure momentum and energy equal to those from normal charges of 
weights 7 Ibs., 4 lbs. and 3.5 Ibs. resoectively. 
For Multiole Charge Tyce 2, at 15 ft. distance, the Mach zone extends from about 50 to 
100 aegrees. The Charge has highest exolosive efficiency at about 75 degrees where the maximum 
oressure, momentum and energy are 165%, 155% and 195% resoectively of the corresponding values at 
the same distance from a normal charge with equal weight of 2xplosive, i.e. Mu)tiple Charge Typ2 2 
produces at 15 ft. in the 75 degree direction a maximum pressure, momentum and energy equal to 
those from normal charges of weights 11 los., 5 Ibs. and 5 lbs, resoectively. 
Conclusions. 
A further trial has been carried out on the Multiole Charge Effect using a new method of 
initiating the charge by means of cordtex. °ressure measurements have been made at four different 
distances ana in various directions ffom three tyoes of Multiple Charge each consisting of two 
141d. TN.T. demolition charges. A 2k 1D. T.N.T. Multiole Charge gives within a cone of 
50 degrees semi-vertical angle a maximum oressure, momentum and energy equal to that from normal 
charges of weight 7 Ibs., 5 Ibs. and 5.25 lbs. respectively. 
The effect is found to be closely connected with the Mach wave effect, 
Reference. 
(1) "The Multiple Charge Effect", by A.G, Bcoker and C. Harrington, 
