Mortar, chemical, stokes

Delivery systems were also improved. As early as 1920, experiments with the barrel of the Stokes Mortar enlarged the bore to 4.2 in. in diameter, which increased the range of the mortar from 1100 to 2400 yards. By 1928 this new improved mortar became the standardised weapon for the delivery of toxic chemical agents, as well as smoke and high explosives.7... 

Stokes Mortar The 4 in. Stokes mortar developed for chemical agent delivery was first fielded by the British in September 1915 at Foos, and was in wide use by the Somme battles of 1916 this represented the first use of projectiles filled with lethal chemicals in World War I. Chemical artillery shells (or projectiles ) and mortars remained in chemical arsenals throughout the twentieth century. During World War I, the Germans produced chemical agent-filled projectiles for 77, 105, and 150 mm artillery pieces,... 

The 4 in. Stokes mortar developed for chemical agent delivery, first fielded in September 1915 at Loos this represented the first use of projectiles filled with lethal chemicals in World War I. 

Fig. 1.31 From left to right a Livens container (phosgene), a 4 Stokes (Mortar Bomb (chloropicrin) and a 6" shell (mustard gas), found buried at Bramley in 1987 (reproduced with permission of the Chemical Defence Establishment, Porton Down). They all exhibit an advanced state of corrosion.

Fig. 2-11. A complete Stokes mortar with ammunition and accessories for firing. Photograph Chemical and Biological Defense Command Historical Research and Response Team, Aberdeen Proving Ground, Md.

Fig. 2-17. An experimental 4.2-in. chemical mortar, showing (1) the standard, (2) the barrel with the shock-absorbing mechanism, and (3) the tie rods connecting the standard to the baseplate. This weapon differed from the Stokes mortar, its predecessor, in that it was easier to set up and it was rifled the spiral grooves can be seen on the inside of the barrel at its muzzle. Photograph Chemical and Biological Defense Command Historical Research and Response Team, Aberdeen Proving Ground, Md.

During the 1930s, the CWS stockpiled the chemical weapons used by World War I ground forces in preparation for a future war. These were primarily Livens projectors, Stokes mortars, and portable cylinders. In addition, there were chemical shells for 75-mm, 105-mm, and 155-mm artillery pieces (Figures 2-22 and 2-23). 

Nitrostarch was used as an explosive because it did not use the same precursor chemicals as TNT or amatol. The Trojan Powder Company at Allentown, Pennsylvania, produced up to 1,720,000 pounds per month. It was used in the 3-inch Stokes mortar and in hand grenades. DuPont also made a form of nitrostarch called grenite. Nitrostarch is a flour-based explosive often mischaracterized by EOD persoimel as a flour-filled inert round instead of a high-explosive round. 

A 1923 list sets the war reserve CWM at, White Phosphorus 500 tons. Titanium tetrachloride 100 tons. Phosgene 192 tons, Mustard Gas 60 tons. Chlorine 200 tons, Chlorpicrin 40 tons. .. Shell 4 Stokes Mortar, complete 188,000, Livens Projectors 25,000, Shell, L.P. complete 40,000, Cylinders, chemical, portable 25,000, Candles, smoke 75,000, Candles, toxic 15,000, Candles, lachrymatory 25,000, Arsenious oxide 100 tons. .. Sulphur monochloride 2,000 tons. .. Hexochlorethane 100 tons. While this is substantial and frightening, it is considerably less than the material known to have been on hand at the end of the war, particularly the shells and smoke candles. The author believes that the balance was buried or dumped at sea during the years following World War I. 

At the end of World War I, there were four million shells in the United States inventory. World War I ordnance such as the Livens projectile and Stokes mortar were outmoded by World War II, resulting in burials and dumping. Leaking ordnance was a continual problem. Add to that the 1,343,728 World War II chemical bombs, and the 13,550,613 World War II chemical mortar rounds not used in World War II, and the probability of substantial buried chemical weapons becomes a certainty, in addition to the tremendous numbers of currently stockpiled ordnance. Also, even current inventory ordnance would have an occasional leaking or damaged munition. In addition, experimental ordnance, grenades, rockets, candles, spray tanks, smoke pots, and cylinders are also burial candidates. Where is the question state and local regulators need to repeatedly ask. 

Military sites often span several wars or decades. The constant improvement in the weapons of war may suddenly render a particular ordnance item obsolete. A timeline should be constructed for major changes in ordnance and then the site should he considered against that backdrop. The advent of the Dahlgren gun, breach loading caimon, chemical weapons, modern mortars, airplane-deployed bombs and the demise of smaller guns such as the 3-in. Stokes, 75-mm or larger 30-caliber ammunition in rifles in favor of 22-caliber bullets should be considered as these events would be motivation to dispose of substantial quantities of obsolete ordnance. 

Bottom photos of ordnance typically found in old munitions ranges Left top to bottom 3.5-inch rocket 2.5-inch bazooka. Right top to bottom 81-mm illumination mortar 3-inch Stokes chemical mortar 60-mm high explosive mortar. 

After completion of the preliminary testing, tests of the EDS-1 with containers and munitions filled with the chemical agents phosgene (CG), sulfur mustard (HD), and sarin (GB) took place between late November 1999 and November 9,2000. For phosgene, 11 items were tested four cylinders and seven 4-inch Stokes mortars. For mustard, 14 items were tested two cylinders, seven 4.2-inch mortar rounds, and five 4.5-inch projectiles. For sarin, one steel cylinder containing 1.3 pounds of agent was tested (U.S. Army, 2000). 

The 4.2-inch mortar was the culmination of attempts to improve the 4-inch British Stokes Brandt (SB) mortar. With American-made SB mortars and with shell and propellants purchased from the British after World War I, the CWS sought to obtain increased range, accuracy, and mobility. By 1924, experiments under the direction of Capt. Lewis M. McBride (later colonel) produced the rifled 4.2-inch chemical mortar with a range of over 2,000 yards, and by the end of World War II this distance had been doubled. ... 

For the baseplate of the Stokes mortar it had been feasible to have a steel cup, bolted to an oak plank. But recoil from the new 4.2-inch barrel soon pounded this type of baseplate into splinters, and a forged steel baseplate had to be produced. Finally in 1928, after several years of experimentation, model Ml 4.2-inch chemical mortar was ready for service. ... 

Photo 8.4 Top 81-mm illumination mortar shell. Middle 3-inch Stokes chemical mortar. (Note most WWI mortars had no fins and may be mistaken for pipe. Bottom 60-mm high-explosive mortar. Fuses are often buried separately from ordnance items, contain impact-sensitive explosives, and are generally brass or aluminum, undetectable with magnetometers. Photo by Alvin Harris... 

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