A direct hit at close ranges from a 105-mm gun or a 25-pounder has usually knocked out the tank or the crew, regardless of the point of impact. High-explosive shells are always useful against personnel in the open and in light shelters. Flashless powder is highly desirable, especially for medium and heavy artillery, which are the favorite targets of dive bombers, strafing fire, and enemy batteries. Weapons have been difficult to detect at a distance when using this type of propellant. The use of separate-loading ammunition places any weapon at a disadvantage during action against armored vehicles.

The Germans give much attention to the effect of the tropical sun on their munitions and weapons. All ammunition other than small arms ammunition is especially packed for the Tropics. All munition cases are so marked. Normal charges for tropical use are calculated at an average temperature of 77° Fahrenheit.

Caissons have been found to be one of the best means of stowing ammunition, because they both protect the ammunition and make it readily available and mobile.

Protection is needed because of the vulnerability of shells and fuzes piled on the ground. The explosion of stacked ammunition set afire by an aircraft cannon wiped out in one instance two Bofors crews. It is true that stacked ammunition can be dug in for protection against shell fire and air attack. However, the mobile operations of the desert give little time for digging protective pits for ammunition--in fact, there is hardly ever sufficient time to dig slit trenches for personnel. Protection at the guns cannot be given by trucks, because they are too conspicuous and vulnerable to be allowed to remain at gun positions as ammunition carriers. Dumped ammunition can seldom if ever be saved in the sudden moves of armored action. Caissons are the British solution to all these difficulties.

The British use artillery trailers between the 25-pounder gun and its prime mover. Two trailers are also coupled behind a prime mover to form the ammunition section. Each trailer can carry 32 rounds of 25-pounder ammunition and fuzes, plus some extra space for a small amount of supplies. These loaded trailers are dropped near the gun positions and give some protection against air attack and shelling, serving the same purpose as horse artillery caissons.