Tactical Use
Phosgene was first used in cloud attacks in December, 1915. These attacks continued for about nine months and were then gradually replaced, to a large extent, by gas shell attacks. Phosgene was first found in German projectiles in November, 1916. These shell were known as the D-shell. Besides pure phosgene, mixtures of phosgene and chloropicrin, phosgene and superpalite, and phosgene and diphenylchloroarsine have been found.
Fig. 26.—Interior of a Shell Dump.
The English introduced the use of projectors in the Spring of 1917. They have a decided advantage over shell in that they hold a larger volume of gas and readily lend themselves to surprise attacks. As the Germans say, “the projector combines the advantages of gas clouds and gas shell. The density is equal to that of gas clouds and the surprise effect of shell fire is also obtained.”
Toward the close of the war, the Germans made use of a mixture of phosgene and pumice stone. A captured projector contained about 13 pounds of phosgene and 5½ pounds of pumice. There seems to be some question as to the value of such a procedure. Lower initial concentrations are secured; this is due, in part of course, to the smaller volume of phosgene in the shell containing pumice. Pumice does seem to keep the booster from scattering the phosgene so high into the air, and at the same time does not prevent the phosgene from being liberated in a gaseous condition. This would indicate that pumice gives a more even and uniform dispersion and a more economical use of the gas actually used.
Owing to its non-persistent nature (the odor disappears in from one and a half to two hours) and to its general properties, phosgene really forms an ideal gas to produce casualties.