View Full Version : american maps/artillery

11-05-2008, 10:34 PM
anybody have any links relating to how an american field officers map would be read and exactly what information would be radioed back to the artillery batteries?

11-06-2008, 12:57 PM
I'd suggest you find some period army/artillery training manuals on the subject. While I don't know where the specific one you want may be found, there are a variety of on-line sources of manuals, and NYC should very definitely have a library that's been designated as a federal repository -- and as such, should have access to most, if not all, 1940's War Department manuals.

Carl Schwamberger
11-07-2008, 07:40 AM
I can answer that one partially. The techniques I was trained in in the early 1980s were not far removed from those of the 1940s. I have some of the refrences for the 1940, but the question covers a large ammount of information. I'll give a brief from memory. Then you can use that to direct some specific questions.

Usually a grid was overlaid on the map, either commonly printed on it or occasionally drawn in where the prefered military type maps were not availble. The 'grid' is sumply a system of XY coordinates like you practiced in geometry or algebra class. The grid lines we used were in one thousand meter increments. A target or any other point on the ground was located by reading the distance 'Up' or north from the nearest horizontal line and 'Right' or east from the nearest vertical line.

So you wish to locate a road interection. You find the grid lines to the left and below the target and read the numbers printed for them on the map, say '20' for the hotizontal line and '04' for the vertical line. Simply to locate the general area of the road intersection the numbers would be read "2004". We added in a third and sixth digits as a standardization convention, so it would be read as "200040". To locate the target to a accuracy of 100 meters you measure up from the horizontal line and add that measurement in 100 meters increments, and the same for the 'Right' measurement. That is if the road intersection is 300 meters north of the horizontal line and 600 meter right of the vertical line then the location is read as: "203046". Locating to a accuracy of ten meters requires adding two digits to the location. So 370 meters up and 620 meters right would read "20370462". This location system can be made as fine grained as you like. We never used more than a eight digit grid location for artillery targets. For survey of battery locations or Registration points the survey teams would use ten or twelve digit locations in their measurements.

If there was no grid for the maps we could in theory use the Lattitude and Longitude. We never trained with this and it was only casually refered to in the classroom . The common alternate to the Grid location method was to use survey techniques to identifiy a point accurately in relation to the cannon battery. Ideally that point would be located near the center sector of the batterys range and right/left limits. In the 1940s the US Army refered to this as a "Base Point" The observer would use that point as a refrence to locate with simple geometry the target in relation to the battery. We were trained in two different techniques for this. One technique used the observers position as the starting point for the calculation, the other used the Base Point or an previously designated target as the start point. For several technical reasons it was slightly faster to use the latter technique than the Grid location, if the Base Point or previous target had been shot at accurately.

The core of the communication between the observer and the battery or larger formation, was the 'Call for Fire'. This was given in a standardized but flexible format. The first part was identification of the battery being called and the observer, and would be in a simple code if on the radio. ie: "Red One this is Red One Alpha". Since the US artillery usually had several observers and batterys on the same radio frequency or telephone circut definative ID was essential. Next came the target location, that gave the indivduals responsible for finding the direction and range to the target a start in their task. Then came a brief description of what the observer first wanted to do. This usually boiled down to "Fire for Effect" or "Adjust Fire". In the first case the observer wanted the target attacked with the appropriate ammunition, in the second case the observer wanted a single shot fired to check the accuracy of the targets location. After that came a brief target description, a remark about the ammunition recomended, and last 'Special Instructions'.

We abreviated the Call for Fire by using Standards. These were items that were most common. In the case of Ammunition the default was High Explosive. If the observer did not give a projectile request or recomendation then the battery automatically fired HE. The same for fuze. The Special Instructions part was used only when required & otherwise not included.