Unit of fire

[Kingfish]

G'morning gents,

Recently I've been reading 'Guadacanal, The first offensive' by John Miller. In it he repeatedly uses the term "unit of fire" when referring to ammo supply, either from a battalion level ("Every battalion initially hauled two units of fire from the ammo dump") or for a whole invasion force (.."by 16 April the invasion force had on hand 10 units of fire for field and seacoast artillery, and 15 units for anti-aircraft artillery"..)

So what is a unit of fire? Is it equal to the default number of rounds you get with a CM Spotter?

Thanks in advance

[Slapdragon]

Unit of fire is a very useful but nebulous term since it represents how much firing a group (like a battalion of infantry or a battery of howitzers) can do, but it is quite variable. Luckily, most armies will standardize the term.

In normal terms, a unit of fire is the amount of ammunition needed to sustain action for x amount of time assuming full engagement but not assuming armageddon style firing off of rounds. So, a modern U.S. armored division carries 3 units of fire, and a unit of fire in ammunition enough to fight twenty four hours at a standard tempo.

At Guadalcanal, with the supply problems caused by the loss of the battle of Savo Island, the relatively weak position of the Navy, and the like, having multiple units of fire on hand was important because troops were forced to fight without ressupply for days and even weeks.

Unless I did more research, I could not guess what the time x was for a unit of fire at that time, but you can just assume that the numbers are balancing numbers, allowing you to compare ammunition stocks for different units that have very different logistics characteristics.