Heavy Field Howitzers 1914-1915 (Part IV)
Armies of the First World War
Ballistics
In addition to being considerably lighter than contemporary guns of the same calibre, howitzers of the early 20th century were inherently more accurate. In experiments conducted in that era, artillery shells fired at a certain point on the ground invariably fell within an oval centered on that point. (The long axis of the oval ran along an imaginary line running from the artillery piece to the target.) All other things being equal, the ovals created by guns were roughly twice as long as the ovals created by howitzers. As both kinds ovals were roughly equal in width, this meant that the ovals formed by guns were substantially larger than the ovals formed by howitzers. At the same time, the chances of a howitzer achieving a direct hit on the point-of-aim were at least twice as good as those of a gun.1
The inherent accuracy of howitzers made them especially useful for firing against linear targets, such as trenches, that were perpendicular to the direction of fire. That is to say, shells fired from a group of howitzers arrayed along a line would tend to fall along a parallel line. Even under field conditions, these lines could be remarkably even. For example, on the last night of the battle of Paardeberg (26 February 1900), a British naval officer described the explosions of the shells of a salvo fired by a battery of four 6-inch howitzers as “falling in a line across the laager at regular intervals.”2
In situations where the exact distance between a howitzer and its target could be determined, the inherent accuracy of howitzers could be turned to advantage. This was particularly true in siege warfare, where the slow pace of operations, the fixed location of targets, and the presence of military surveyors made such information relatively easy to come by. In situations where the precise location of a target remained unknown, the value of inherent accuracy fell. Some experts even went so far as to argue that, in the absence of high-quality range finding, inherent accuracy was a major handicap. (Shells that fell in the wrong place with great reliability, after all, were less dangerous to an imprecisely located enemy than shells sprinkled randomly over a larger area.)
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A typical experiment of this type was described in an article published by an officer of the U.S. Army in 1916. Using data from the practice firing of 3-inch (76mm) guns and 4.7-inch (120mm) howitzers, the author calculated the number of shells from each type of weapon that had to be fired in order to hit a standard infantry trench at a given range. E. D. Scott, “Field Artillery Fire”, The Field Artillery Journal, Vol. VI, No. 3, July/September 1916, page 400.
T.J. Jeans (editor), Naval Brigades in the South African War, 1899-1900, (London: Sampson Low, Marston & Company, 1901), page 79