The development of rockets led to the organization of another type of artillery battalion for the field army. The 4.5-inch rockets, originally produced for use on aircraft, were tested as artillery in the Pacific in 1943 and in Europe a year later. Artillerymen in the Pacific rejected them, but when the First Army reorganized a 105-mm. howitzer battalion with the 4.5-inch rockets in November 1944 and employed them a few times in the Hurtgen Forest, First Army commander Lt. Gen. Courtney H. Hodges reported “excellent results.” Artillerymen, however, disliked the rocket’s inaccuracies and the smoke and flash that gave away its position. A shortage in artillery ammunition, however, spurred increased use of rockets. A tank battalion in the Third Army also employed the rockets briefly and reported that the morale effect was good.
In 1944, a table of organization and equipment (TOE) for the rocket battalion was developed, authorizing the unit thirty-six multiple rocket launchers in three batteries (twelve per battery). Each battery had three rocket platoons, and each platoon four rocket sections. This organization was later changed to two rocket platoons, each platoon having six rocket sections. The tables authorized the battalion to be truck-drawn. In practice, rocket field artillery battalions were to be used as War Department reserve units and attached to an army or task force as necessary. Rockets were most effective in attacking area targets, relieving the artillery of massing battalions.
Because of large probable errors, rockets could not be used on pinpoint targets or in close support of ground troops. Of the six battalions organized under the TOEs during the war, only two served overseas but neither saw combat.
When the Army adopted the triangular division, it eliminated the fixed field artillery brigade with its organic elements. The new arrangement of four self-contained battalions proved more responsive in providing artillery support to the division’s maneuver elements. Corps artillery, however, retained the fixed brigade organization. The corps artillery brigade in 1940 consisted of a headquarters and headquarters battery, two 155-mm. howitzer regiments, one 155-mm. gun regiment, and an observation battalion. The number of field artillery weapons in the brigade was seventy-two. No action to correct the deficiencies of the fixed organization occurred until 1942, when General McNair reviewed the structure of the nondivisional units and recommended that artillery be organized into self-contained battalions that could be allocated to an army and then further attached to corps as necessary. The corps could then vary the number and types of units attached to the divisions to meet the requirements of the situation. The units were also to be capable of being combined into task forces to carry out specific missions.
In place of the regiment, McNair recommended the artillery group—a tactical headquarters with limited administrative capabilities and a variable number of administratively self-contained attached battalions. This concept had already been used to a certain degree in the organization of nondivisional armor units. Artillery officers also had previously advocated grouping two or more batteries, battalions, or regiments to perform a common mission. Temporary grouping of units for counterbattery fire, long-range fire, or reinforcement of division artillery had been routine.
In December 1942, the War Department authorized the separate battalion arrangement for nondivisional field artillery units and a group headquarters and headquarters battery for every three to four battalions. The fixed field artillery brigade disappeared, and the new brigade (only a headquarters and headquarters battery) was authorized for the control of three to four groups. Except for a few brigades of heavy artillery at the field army level, however, field artillery brigades were seldom seen. Groups instead were usually attached directly to the headquarters and headquarters battery of the corps artillery, as it was not generally considered necessary for an army to maintain tactical control of field artillery units. The principal missions of nondivisional artillery were the neutralization or destruction of hostile artillery (counterbattery fire), destruction of hostile defenses, long-range interdiction fire, and reinforcement of division artillery fires. Instead of the fixed corps brigade, the new headquarters, corps artillery, commanded by a brigadier general, had only a headquarters battery and an observation battalion assigned to it. Flexible groups with varying numbers of battalions were attached as needed.
The transition from regiments to groups was slow because considerable time was required to structure the battalions into administratively self-sufficient units and because the reorganization of units already in combat was difficult. Except for the units in combat, however, the reorganization was accomplished in 1943, and the first TOE for the group headquarters and headquarters battery appeared in April of that year. The TOE authorized the unit eleven officers and seventy-eight enlisted men, provided the bare essentials for exercising tactical control of its attached battalions, and gave the group two liaison airplanes for observation. The TOE for the headquarters and headquarters battery, field artillery brigade, authorizing it an aggregate strength of 103 in 1944, was similar to that of the group. The groups and brigades were not originally designed to function administratively, but combat experience showed the necessity of their doing so, and they were later augmented by supply and administrative personnel.
Because the War Department delayed implementation of the group organization for those units already in combat, the new field artillery groups that deployed from the United States to North Africa fought alongside the fixed brigades already serving there. The divisions had already been streamlined under the triangular structure, and any additional support had to come from corps level. Because the corps artillery in the theater was limited in flexibility under the fixed brigade structure, the new groups and their battalions were used almost exclusively as a pool from which the divisions drew additional field artillery support. When the battle area shifted to Italy, the use of the field artillery group changed little. Its capabilities were not fully met or tested even though it was performing its limited functions well. The fixed field artillery brigade continued to function as corps artillery, but all newly arriving nondivisional field artillery units were organized under the new concept. By March 1944, all the regiments of the fixed corps artillery brigade in Italy were reorganized under the new system. Although the reorganization provided a uniform structure for the artillery for the first time in combat, in actuality, the intent of greater flexibility was not immediately realized.
By the time the nondivisional field artillery units were fighting in western Europe, their organization was standardized and their role more defined. One reason for the field artillery group’s success was that, unlike its earlier service in North Africa and Italy, the units had ample time to train together. The centralized employment of nondivisional artillery gave way to decentralization, although in some instances the former was preferred. Such flexibility would not have been possible under the old fixed corps artillery brigade structure. For example, in July 1944, when the First Army launched an attack to break out of Normandy, the VIII Corps Artillery was centralized in order to act as a “direct pressure force” in the early phases of the corps effort. But on 1 August, the four groups of the VIII Corps Artillery were decentralized by attaching them to divisions in order to render the divisions the most effective support.
The group headquarters was the organization that provided the corps artillery commander the capability of employing his resources in the most effective and flexible manner. It could perform as a second corps artillery fire direction center, as a control headquarters for field artillery attached or in direct support of a task force, as a subordinate tactical headquarters of the corps in controlling battalions with similar missions, and as a tactical headquarters to assist the division artillery headquarters when several nondivisional artillery battalions were attached to the division. The group’s flexibility, both in tactics and in organization, enabled the artillery commander to meet his requirements.
One defect in the group structure was the lack of continuity of command. Mindful of the problem, the War Department in 1944 issued Circular 439, advocating that battalions serve with specific groups, if feasible, to enhance the continuity of command and to improve morale; however, by the time the circular reached the theaters, the commanders had become too accustomed to enjoying the group’s flexibility and in most instances opted not to make any substantive changes in their routine.
The group organizational concept had limited use in the Pacific, where divisions played a more important role than corps. As a whole, the nature of jungle warfare, the limited size of island operations, and the policy of defeating Germany first restricted employment of field artillery there. Army nondivisional field artillery units within the Pacific area were almost nonexistent until 1944. When the 32d Infantry Division participated in the Buna operation on New Guinea, the division artillery remained in Australia on the premise that artillery other than pack howitzers could not be used and that Buna could be taken without field artillery support by using air support and infantry mortars. The assumption was an error, and support had to be obtained by borrowing artillery from the Australian 7th Division. Although nondivisional Army field artillery units were not used on Guadalcanal, the XIV Corps Artillery commander coordinated the artillery battalions of the Americal, 25th Infantry, and 2d Marine Divisions to maximize field artillery support. From this point on, field artillery played a more important role in the Pacific. While the groups were few in number, they contributed significantly to the effective support of the maneuver units. In the campaign on Okinawa in 1945, the employment of nondivisional artillery was widespread because of the large number of such units available on a fairly large battle area with strongly organized defenses and because of the growing awareness of the value of artillery support. In the battle for Manila the same year, primarily Army field artillery, tanks, and tank destroyers cleared the city.
Triangularization of the divisions had led to the use of task-organized formations for flexibility, and this concept was subsequently extended to nondivisional units. By the end of the war, task forces or regimental combat teams (RCT), whereby combat and support units were grouped temporarily around an infantry unit to perform a particular mission, were employed more and more. A typical one might include an infantry regiment, a 105-mm. howitzer battalion, a combat engineer company, a medical collecting company, and a signal detachment. Other units could be attached or detached as necessary. The flexible nature of the RCT in adapting to terrain and combat conditions made it particularly useful, and the grouping could be discontinued when the mission was over.
On the Battlefield
Advancements made during World War II in target location played an important role in the success of field artillery employment. Methods for locating targets included sound and flash ranging; ground and aerial observation; photo interpretation; prisoner of war, military intelligence, and “shell rep” (report on enemy shells fired on Allied positions) analyses; radar sightings; and other intelligence means. Except for radar, all had been used in World War I.
The tables of organization authorized the field artillery observation battalion in the corps artillery two sound and flash batteries in addition to its headquarters and headquarters battery. In September 1944, the War Department authorized additional observation battalions at the army level in Europe, where they were normally deployed by battery to support divisions. Of the twenty-six observation battalions active on 30 June 1945, nineteen were in Europe, four in the United States, and three in the Pacific. When a corps operated as a unit, the observation battalion was to maintain centralized control of its batteries. When the divisions in the corps acted independently, the observation batteries were to be detached from the corps to support the divisions. Additional support in 1944 in Europe came from the field army observation battalions. More success was achieved with centralized control in stabilized conditions than with decentralized control during periods of rapid movement. The observation battalions were supposed to provide their own position and target area survey and to tie into a general control survey net provided by topographical engineers. Artillery survey requirements were underestimated, however, and the observation battalions had to improvise to achieve higher order survey control in the field. After the war, the tables added separate survey platoons to each battery. In the latter stages of the war in Europe, some antiaircraft radars were made available to observation units. The radars were used for obtaining better weather data and for battlefield surveillance at night. Flash ranging was only about one-tenth as successful as sound ranging in Europe because of adverse terrain and weather conditions and inadequate flash-ranging equipment. Observation battalion commanders reported that German use of flashless powder neutralized the value of flash ranging and that the Germans used flares as camouflage for their artillery. Civilian experts also considered the Army’s sound-ranging equipment about ten years behind commercial equipment used by oil companies, and newer sets were developed during the war. Sound ranging, however, was often the best source for counterbattery intelligence, and target locations by sound were invaluable in confirming locations determined by other means.
Ground observers included forward observers, those in the observation battalions, and those in teams manning surveyed observation posts. In Europe, most targets were located by map coordinates, and forward observers adjusted the majority of the artillery fire missions. Men in static observation posts conducted only a limited number of fire missions because many of the observers had insufficient training and little experience in the conduct of observed fires.
Artillery commanders were insistent that the number of forward observers not be less than one per tank or rifle company, including those in reserve, about forty per division. Maintaining enough forward observers was a difficult problem. When they were furnished on the basis of one per infantry or tank company, the direct-support artillery battalion sometimes found it necessary to send as many as twelve observers. But forward observer sections were not included in the infantry division TOEs until after the Normandy invasion (three forward observers in each direct-support battalion). The Army had authorized them for some time in the armored division, although not in the quantity needed, and other personnel in the artillery battalions had to perform the function. In addition to the forward observer himself, an officer, the tables authorized each forward observer section one wireman and one radioman for communications. Two forward observer sections were needed per battery, but the tables only authorized three per battalion. The medium battalions needed between four and six forward observers, but were only authorized one per battalion. Some units maintained a forward observer pool, made up of the younger battalion officers and run by roster to ensure coverage. The physical strain on these officers was great because their casualties were high. Most battlefield promotions in field artillery units serving in Europe were awarded to enlisted men serving as forward observers. It was reported that personnel using forward observation methods, usually by map coordinates, adjusted up to 95 percent of observed fires during the war.
A key link between the forward observer sections and fire-support resources was the liaison officer. Each direct-support battalion maintained one liaison officer with each battalion in its supported infantry regiment. The liaison officer’s primary functions were to plan fires in support of infantry operations and coordinate target information. A large number of direct-support battalion fire missions resulted from communications through fire-support channels. Forward observers would funnel target information through the liaison officer to the battalion fire direction center (FDC), which, when supplementary fires were needed, could request additional fire support from higher echelons. Corps and division artillery, as well, passed missions down to the direct-support battalion FDCs. When the supported infantry regiment went into reserve, the direct-support artillery battalion usually stayed on line to furnish supplementary fire for other direct-support artillery battalions as necessary.
Aerial observers supplemented the ground observers in locating targets and adjusting artillery fire. The Hero board had recommended aerial observers as an integral part of the artillery, but airplanes did not become organic equipment until 1942. With the virtual separation of the air arm from the ground forces in that year, the need became more acute. In late 1941, the War Department, influenced by reports from observers and by news items about the war in Europe, had authorized field testing of aircraft for artillery observation and approved the addition of aerial observers in field artillery TOEs published the following year. Each field artillery headquarters, from battalion through corps artillery, included an air observer section, with two aircraft and their pilots, along with maintenance personnel, vehicles, supplies, and equipment. No observers were authorized, but were obtained by using other officers and sometimes enlisted men in the organizations. An artillery air officer was later added to the artillery staff of each group, brigade, division, corps, and army to advise the respective commanders in all matters pertaining to aerial observation. In Europe, infantry and airborne division air observers usually operated from a common airfield, resulting in centralized control of air observation at the division. Most individual battalion requirements were met by closely coordinating and scheduling flights. Nondivisional battalions attached to field artillery groups operated in a similar manner. Centralization resulted in more efficient coverage, facilitated economical use of aircraft and personnel, and was more suitable for proper maintenance and service of the aircraft. Armored divisions, on the other hand, operated air observation sections at the battalion level because of the rapid movement of the divisions during combat. Their air sections did operate on a common channel, however, so that any unit was free to obtain information from any aircraft. Air superiority and the fact that the U.S. Army field artillery had organic air observation were key reasons why the U.S. field artillery dominated the European battlefield.
Aerial observation for adjusting artillery fire, as well as for other missions, also proved invaluable in the Pacific. Lush vegetation and mountainous terrain at times hindered the ground and air observers’ view, but generally much of the fighting occurred along the shore and in other relatively open areas. As in Europe, the sections usually operated under centralized control. Navy bombers provided assistance, although their relatively high speeds often made observation difficult. The Army Air Forces also provided artillery adjustment and observation in both theaters with high-performance aircraft for medium and heavy battalions. Difficulties in communications and a lack of knowledge of field artillery gunnery on the part of the observers caused most of the problems in the inability of high-performance aircraft to complete artillery adjustments.
The use of aerial reconnaissance photographs in conjunction with maps and firing charts were of tremendous value and provided a high percentage of artillery targets. Field artillerymen began taking an interest in aerial photography with the development of cameras that could capture large areas without undue distortion. While recognizing the usefulness of such pictures for reconnaissance purposes, field artillerymen were more interested in producing photo maps to use for firing charts. In the North African campaign of 1942, it became apparent that American facilities for producing aerial photographs were inadequate, even though the British in the same theater were making excellent use of such pictures in intelligence work. But American expertise in this area steadily increased, and by 1943 in Sicily the Army Air Forces were providing aerial photography support at the army level. At the corps artillery fire direction centers, photo interpretation teams confirmed sound and flash locations and targets reported from other sources. Army air observers also took some aerial photographs, which were especially useful when inclement weather grounded Army Air Forces planes. Most commanders, however, believed that they could not replace the Army Air Forces photographs, which covered areas deep into enemy territory. Poor visibility over jungle areas, a lack of wide-area photographs (making it necessary to piece a useful picture together from many photographs), and poor reproduction facilities often limited the use of aerial reconnaissance photographs in the Pacific. But when these problems did not exist, aerial photography was even more valuable in the Pacific than elsewhere as suitable maps were unlikely to be available.
Radar, which was still in its infancy, was tested in Europe from late 1944 through the end of the war. The results were limited partly because the sets, not designed for the purpose of spotting field artillery targets, were extremely heavy and partly because of wet weather. The XV Corps found them extremely useful, and by February 1945, 9 percent of the corps artillery missions were based upon radar findings. Most commanders felt that the possibilities of using radars would be increased through the development of small portable sets.
The study of shell craters to determine the direction and range of enemy artillery had fallen into disuse before the war. In December 1942 in Tunisia, Capt. George Morgan of the 32d Field Artillery Battalion became interested in the subject and compiled a personal reference manual. Later, while serving as the assistant counterbattery officer in II Corps, he combined the results of his research with those of two British armies and subsequently produced a manual that influenced the use of “shellreps” in the entire theater. These reports usually contained pertinent information on impact areas as well as the time and direction of the shelling; when possible, they also included the number of shells and any duds, the type of target, and the amount of damage. They were extremely useful in confirming locations made by sound, photographs, and other means.
Other means of locating targets were coordinated at corps level. Reports from prisoner-of-war interrogation teams, spies, friendly civilians, and other sources were compared with photographs and sound, radar, and shelling reports to give accurate target locations.
The development of improved gunnery techniques and standardized training for all field artillery units, including those of the Marine Corps, contributed to the ability of field artillery to deliver effective massed fire support. The evolution of centralized fire control was one of the most significant improvements in the branch. The policies and procedures in fire direction developed at the Field Artillery School during the interwar years proved basically sound and were generally followed by all Army and Marine field artillery units in Europe and the Pacific.
The high degree of centralized control reached during the war permitted maximum use of prearranged fire. Division artillery was most effective against enemy infantry in the open, and secondly in blinding enemy observation, preventing the movement of reserve troops, and assisting in counterbattery fire. Continuous fire was always possible by moving only part of the artillery, keeping the rest firing in positions until the displacing batteries were ready to resume action. The heavier corps and army artillery reinforced the divisions and provided their conventional roles of counterbattery fire, interdiction missions, destruction of hostile defenses, and fire on rear areas. As General Hodges later remarked, “Of the principal arms that could be brought to bear directly on the enemy, infantry, armor, and air were seriously handicapped by the weather and terrain. Through all, however—day and night, good weather and bad—the flexibility and power of our modern artillery were applied unceasingly.”
When lack of time precluded use of prearranged fire, it was necessary to develop a rapid means of massing all available firepower. While there were several procedures, the most common was the “serenade.” Only corps, division, or group artillery commanders could authorize serenades, which were controlled entirely by radio. Commanders had to ensure that the target warranted the expenditure of ammunition and that the map location of the target was accurate enough to achieve the desired result. Missions were fired “when ready,” or a time was designated for all battalions to fire on a target simultaneously. A better known method was “time on target” (TOT). Procedures were similar to those of the serenade, but the missions were controlled chiefly by telephone, and the rounds for all units were to land on the target at the same time. The TOT required frequent synchronization of time and the determination of flight time for all projectiles.
The introduction of the proximity fuze, commonly referred to as the pozit or VT (variable time) fuze, during the German counteroffensive in the Ardennes in December 1944 greatly increased the effectiveness of artillery fire. Unlike a time fuze, it required no setting and contained a tiny electronic device that caused the shell to explode when it came near the target. Although employed more extensively by antiaircraft artillery, it was used by field artillery to burst shells at an ideal height over enemy trenches and foxholes. Considerable concern was expressed because of the danger to air observation posts, and its use was restricted to daylight hours.
After nearly six years of warfare, the Germans surrendered in May 1945, and the War Department redirected its efforts toward winning in the Pacific. But World War II ended abruptly in August after the atomic bombs were dropped on Hiroshima and Nagasaki, ushering in a new era of warfare. Field artillery had been a decisive factor in the Allied victory, prompting Third Army commander General George S. Patton, Jr., to later remark: “I do not have to tell you who won the war. You know our artillery did.”