In Their Words

75mm Shell Fragment

Shells specifically designed for poison gas delivered deadly payloads of phosgene, Lewisite, mustard gas, or any number of toxic substances. Pictured at right is a fragment of a 75mm shell. Shells such as these were commonly fired by American soldiers from the French 75mm Field Gun, a type of artillery widely used by the A.E.F. due to the shortage of American artillery.
A white band can be seen running around the lower circumference of the shell fragment. Driving bands were used to spin the shell by engaging the rifling groves within the barrel of the artillery piece that fired the shell. The spin created by the driving band caused the shell to rotate like a football and thus enabled it to travel farther and have greater accuracy.

Colored bands were used to identify the shell by the type of gas it carried. A series of one to three bands was typically painted around the upper circumference of a shell, with each color indicating a different classification of gas. White bands always indicated a shell contained a lethal chemical agent such as phosgene. Shells with red, white, and yellow bands were filled with agents classified as “suffocants.” A shell with only red bands indicated that it carried lachrymatory or vesicant (the “blister gasses”) chemicals, such as tear or mustard gas. Finally, yellow or purple bands indicated a smoke or incendiary payload.

The second image depicts a cross-section of a chemical shell prior to detonation. A chemical agent in liquid form was filled into the interior of the shell then sealed in by the attachment of the bursting charge and fuse housing. Once launched the fuse would time down and then trigger the explosive charge, in turn blowing open the shell and rapidly heating the liquid agent and then dispersing it as its gaseous counterpart. Since such shells were not truly designed with explosive power in mind, only enough explosive material was used to open the shell and convert the liquid chemical to gas. The walls of the shells that carried gas were also thinner than normal explosive shells, which also contributed to the small amount of explosive required by the shell.
This particular shell was recovered by museum staff from the Bois de Lalval at Cantigny, France in May 2007.

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