Section 40.—Range-Cards and Range-Marks.
1. Range-Card.—A range-card is a device for giving ranges to various points in a field of fire for use in attack or defence. Range-cards should be prepared by fire-unit commanders for their own use and for use by N.C.O.’s and observers. When possible, the best way to prepare a range-card is to use a piece of a large scale map of the country on which to draw the range circles and direction lines. There will usually be more time for preparing range-cards in defence than in attack, and consequently range-cards prepared for defensive positions will as a rule be more elaborate than those made for use in attack.
Fig. 44.—Simple Range-Card for Attack.
Note.—The distances on the left are those from the enemy’s position. Those on the right in brackets are only for the range-taker’s information, and should not be shown on the card to avoid confusion.
2. A Simple Range-Card for Attack.—[Fig. 44] shows a rough example of a simple range-card made for use in attack over the ground shown in the left sector of the sketch in [Fig. 47], from which it will be seen that the objects on the range-card are taken. This has been done to make the example more practical and interesting. The ranges are supposed to be taken from the cross-roads at X to a series of prominent objects on or a little to either side of the line of advance. The distance of each of these points from the enemy’s position (2,000 yards away) is carefully noted, and thus ranging during the attack is greatly facilitated. The range of the enemy’s position from intermediate points can also be more easily estimated by back-reckoning.
Fig. 45.—Simple Range-Card for Defence.
Note.—The point from which ranges are taken should always be described clearly on the card to facilitate setting it.
3. A Simple Range-Card for Defence.—[Fig. 45] shows a rough example of a simple range-card made for use in defence. The ranges in this case are supposed to be taken from the point A immediately south of the church. The direction line from A to the church is drawn thicker than the other lines to facilitate “setting” the range-card in the same manner in which a map is set. When the card is set for the point from which ranges are taken—which is noted on the card—by pointing the thick direction line on the church, the other direction lines will indicate the ranges of the other points marked on the card.