Smoke Shells are special munitions fired by Long Tom, Sniper and Thumper artillery. Rather than armed with an explosive warhead, these shells create billowing clouds of obscuring smoke at the target location. The potential to create literal a "fog of war" on the battlefield can be used to hide troop movements and other actions from the enemy.
Smoke shells follow all normal rules of unguided artillery. Each shot fills one hex and the adjacent hexs with Heavy Smoke that rises 2 levels high and lasts until the end of the third round after fired.
- Tactical Operations, p. 356, "Smoke Artillery/Arrow Missiles"