Search is out to lunch, so I can’t tell if this has previously been addressed.
Often enough I have read about in literature or seen in movies the issuance of the command “Fire for Effect” given to artillery once they are on target.
I don’t know what this means; I can only imagine that it must mean something to the effect of “keep lobbing enough arty on them that they keep their heads down.”
When artillery fire is called for, the requestor typically provides a set of map coordinates to be hit. The gunner then fires a shot or two, the requestor calls back and tells him how much he missed by. If it was close, he’ll say something like “move 100 meters north and fire for effect”. If not, he’ll give a correction and the gunner will try again. The first few shots are just for aim, the rest for effect – to blow stuff up.
Just a final detail. Field Artillery is emplaced in 4 to 8 gun batteries. The spotting or ranging rounds mentioned by aramis are fired usually by only one gun in the center of the battery. After the Forward Observer is sure the spotting rounds are landing on target he initiates the Fire for Effect Phase. Then every gun in the battery fires until the Effect is achieved.
Just a bit about Adjusting Fire. The Forward Observer (FO) can give adjustments to the artillery unit’s Fire Direction Center (FDC) through a few different frames of reference.
From the Observer, and the arty unit has to know where the FO is, then they do the math. The FO calls the location of the target as a grid location AND azimuth from the FO, or merely an azimuth and distance from his position, then makes adjustments Left, Right, Add, or Drop based on the line drawn from him to the target. He doesn’t have to know where the arty is.
Shift From a Known Point Good if there are preplanned targets in an area.
Once the first round impacts, the FO corrects by no less than 30 meters. “ADD 200, RIGHT 100” would send the next round 200 meters further from the FO in line with the target, and 100 meters to the right of that line. The last spotting round does not have to be on target, the FO can say “ADD 50, FIRE FOR EFFECT”. The Effect is spelled out early in the Fire Order, when the target is described (“Troops digging in”, “Tanks in the Open”, “Tanks in the Treeline”). This allows the FDC to select the appropriate explosive and fuzing for the desired destruction. The FDC selects the numbers of guns to fire based on the target and other missions, and may tell two four guns to fire. If the desired effect is not achieved by the fire mission, the FO can give a damage assessment and request a REPEAT of the fire mission.
Herein lies a lesson. Never, ever, EVER use the word “REPEAT” in military radio communications, use “SAY AGAIN”. Transmissions have a nasty habit of bleeding over into half frequencies that may be used by someone else, and you don’t want that someone else to be an FDC that is not on target yet.
DISCLAIMER: This is from memory, and I was not an FO or cannon-cocker. But we had to know this stuff in Stinger.