Tanks as Artillery: A Secondary Role of Armor

M4 tanks of the 755th Tank Battalion in Pietramala area, Italy, firing an indirect artillery mission, 1 October 1944.

by Captain Alexander M. Haig Jr., et al

The following material is a reprint of Chapter 2 of a Research Report entitled A Secondary Role of Armor—Tanks as Artillery by Captain Alexander M. Haig, Jr., Captain Sidney W. Achee, Captain John T. Harmeling, Captain Cheney L. Bertholf, Jr., and Captain Joseph J. Addison, Committee 10, Armor Officer Advanced Course, The Armored School, Fort Knox, Kentucky, 1952-1953, which was published by The Armored School in April 1953. The entire report examined the use of tanks as artillery in World War II and Korea and then examined the then-current doctrine to determine how effective it was and what changes could be made to improve the doctrine. Only that portion dealing with World War II has been reprinted here since that is the period that we are dealing with in this series.

In the discussion that follows, an understanding of the term “indirect fire” is essential. For the purpose of this study “indirect fire” is to be interpreted to indicate artillery type fires which may or may not be observed and are surveyed and controlled through fire direction centers. The subject discussion is frequently misdirected to include normal defilade tank fire, directed by an observer. The latter is an essential subject in tank training and an accepted employment for tank armament.

The question of the feasibility of utilizing tanks in the indirect fire role arose during World War II. In some cases, armored officers felt that their units were being misemployed when required to fire indirect missions. In other cases, particularly in lower echelons, the cry was, “I am not being trained for this mission.”

Research on this subject has been limited in the past. This committee found only two related efforts to resolve this question. The first was a staff study by a board of officers conducted at the Armored School on 30 January 1951. The second was a research study on indirect fire in the Korean Conflict completed by Committee 10, the Advanced Class of the Armored School, completed in June 1952. Both studies provided valuable assistance to the efforts of this committee.

Because of the limited research done in the past on indirect fire by tanks, extensive investigation was demanded. Unit records, After Action Reports, and Intelligence Summaries of World War II provide historical testimony. In addition, questionnaires were sent to armor commanders throughout the Army and the nature of the replies attests to the pertinence of the study.

The tank is defined as a track-laying vehicle with sufficient armor to protect the crew from small arms, artillery fragments and some high-velocity projectiles, and possessing a cannon and one or more machine guns as armament. These three characteristics—mobility, armor protection and firepower—when properly exploited, produce the shock action for which tanks were built. Historically, the tank has been able to influence the battle most when armored commanders have gone “hell-bent” for their objectives, thereby getting the most out of the mobility built into the tank. On other occasions, in certain tank-versus-tank actions, the side whose tanks had the heaviest armor plate won the battle. In either case, the skillful tank crew always fires all weapons which could help in the accomplishment of the mission, whether it be exploitation or a slugging match. As tanks and tank guns have become larger, the ranges have increased, thereby permitting the tank to rely less on its defensive armor, and more on its offensive gun. This does not imply that successful commanders of armor have neglected the full development and use of mobility on the battlefield.

As a result of the tactical situation, there have been many occasions when, for any one of a number of possible reasons, tank forces were not, and indeed, could not be used in their primary role. As a matter of fact, by November 1943, WD [War Department] Training Circular 125 had been published for the guidance of our armored units in the field. This circular outlined methods of employment of tanks as artillery, and its provisions had been affected in most units by the end of the year.

One of the earliest documented examples of tanks or tank destroyers used in an artillery role is that recorded in a report from the Artillery Section, Headquarters VI Corps, dated 15 October 1943. The 776th Tank Destroyer Battalion was assigned to Division Artillery, 34th Infantry Division, on the basis of one company of twelve 3-inch guns to each light battalion. The commanding general of 34th Division artillery was very well satisfied with the results obtained. Provisions were made for the massing of fires from all thirty-six guns on call. The positions occupied were such that the battalion could have been massed for employment in its primary role in a very short time.

From the 16th to the 29th of November 1943, a G-3 Training Board from Army Ground Forces headed by Colonel Stovall, visited the 1st Armored Division for the purpose of interviewing officers on the subject of Armored Command activities. Major General Ernest N. Harmon, then commanding the 1st Armored Division, stated in an interview that:

Greater emphasis must be placed on indirect fire from tanks. Tanks must have the necessary instruments and be trained to fire indirect fire effectively. In the 1st Armored Division we have placed all platoons, all companies, all battalions, in the fire direction centers of the artillery battalions and of the division artillery. In many cases when tanks could not be used as such we have used them as artillery to help infantry over ground impassable for tanks.

But, still according to General Harmon, “tankers must be imbued with the idea of fighting direct-fire” and “tanks must fire direct fire and be capable of indirect fire. The artillery must fire indirect fire and be capable of direct fire.”

Another of the officers interviewed on this occasion was Brigadier General, then Colonel, Hamilton H. Howze, commanding the 13th Armored Regiment. It was Colonel Howze’s opinion that all medium tanks should be equipped for indirect fire. The tanks in his regiment were so equipped by placing on improvised brackets the machine gun panoramic sight.

On December 24th of the same year, the 701st Tank Destroyer Battalion was attached to the 1st Armored Division Artillery. Each tank destroyer battalion had an organic survey section, but in essence it was not much different otherwise from the tank battalion. On the date mentioned, the companies of the 701st operated from the Artillery Fire Direction Center by means of telephones. For observed fire, the battalion reconnaissance platoon provided forward observers. The organic loads of ammunition were left intact, so that the battalion was prepared to move out in its primary role. Since there had not been many opportunities for the battalion to operate in its primary role, the men felt that it had been of great benefit to them to be able to fire in the secondary role. They felt that they learned a great deal by being so employed, and it gave them confidence in their ability to meet any situation that might arise.

During December 1943, another Army Ground Forces Board headed by Colonel Devore visited ground forces units in contact with the enemy, among which was the 751st Tank Battalion. The ideas on tanks used in a secondary role of this battalion commander differ from those previously outlined.

This battalion has fired some indirect fire missions along the lines as mentioned in War Department Circular 125. That was when the battalion was in support of the 36th Division at Altavilla near Paestum. We used the same system that is used for mortar fire by lining on stakes. However, the artillery asked me to get my battalion out of the way as it was drawing enemy fire on their positions. I do not believe in teaching artillery methods of indirect fire as the times that the tanks can be used for such missions are very few.

In response to a letter to unit commanders from Army Ground Forces concerning tanks and tank destroyers used as artillery, the commanding officer of Headquarters, 2nd Armored Group, stated that both the 755th and the 757th Tank Battalions had been too busy reorganizing to undertake training in their secondary role. However, in January 1944, the 755th had sent several officers and enlisted men to an artillery school at 6th Field Artillery Group; and the 757th, in February of that year, received one week of instruction from an artillery officer in indirect fire methods. Each company spent one day on the range, firing as artillery. All concerned felt that it was beneficial to both crews and observers. In training, excellent results were obtained by means of welding machine gun panoramic sights to the tops of the turrets.

General Harmon, who, as has been indicated, had strong views on this subject further stated in July 1944 that:

The use of tank and tank destroyer units on a secondary mission to reinforce artillery has been effectively used in past operations while in static positions both for observed and unobserved fire. Experience has proven the soundness of their use in this manner and the desirability of giving adequate training in this type of fire.

The general continued with the recommendation for the issue of one Command Post and Fire Direction Set and one Survey Set as issued to Field Artillery Battalions, to each tank and tank destroyer battalion headquarters.

Lieutenant Colonel J. R. Pritchard, commanding the 68th Armored Field Artillery Battalion in July 1944, was also interviewed on the subject of tanks and tank destroyers used as artillery. Based on his experience, he advised that tanks should be placed in position as a platoon, with each platoon acting as a firing battery, with battery executive and five-gun sections. The platoon should register on a common base point and numerous check points. Tank fire, in Colonel Pritchard’s opinion, should be used for reinforcing artillery fire, deepening artillery fire, and for harassing missions. For communications, there should be a direct wire from the tank company commander to the artillery battalion fire direction center. The company commander should be on a party line to his platoons, and the platoon commander on a party line to his tanks. The tank crew members should then be using headsets only, in order to free their hands and ensure an uninterrupted flow of information.

A combat lessons report from Headquarters 2nd Armored Group in October 1944 contains some very interesting notations on methods and procedures. In July 1944, the medium tank companies of the 751st Tank Battalion were divided, intra-company, into two combat elements. Two platoons were employed as artillery under the direction of the 894th Tank Destroyer Battalion during an operation in support of an anti-aircraft artillery brigade, which had been given an infantry mission in a defensive sector. The 2nd Armored Group was to furnish armor support to the brigade. Since, prior to this, there had not been much need for this unit to be used as artillery, training had been neglected, and the personnel were inexperienced in artillery techniques. Necessary training was given to the crews while on the line by artillery officers. Each tank was dug in by means of a tank-dozer, so that the maximum range of 75-mm gun was 12,000 yards, and maximum depression cleared the minimum range. The observation posts and the fire direction center were manned by personnel from the 894th Tank Destroyer Battalion, and wire was used between each tank and the fire direction center. Ample ammunition was on hand. As an example, in the last ten days of July, the 751st Tank Battalion fired 13,158 rounds of HE; 1,400 rounds of APC [armor-piercing canister]; 700 rounds of WP [white phosphorous]. Most often, the ranges varied from 7,000 to 10,000 yards. On occasion, TOT [time-on-target] missions were fired with great effectiveness. The artillery tanks were left in place and the personnel from the rest of the company were rotated. This procedure dispensed with relaying the guns every few days. However, arrangements were made for the artillery tanks to revert to their primary mission of close support of the infantry whenever necessary.

The use of tanks as artillery was not confined to the United States Army. As an example of such use by our Commonwealth Allies, this excerpt from a report by the 18th New Zealand Armoured Regiment is cited:

… early December 1944, when 8th Army was held up before Faenza and R. Lamone, tank units were frequently employed for days at a time in indirect fire roles. This account deals with a squadron of 18 New Zealand Armoured Regiment—the methods employed, the task allotted, and the results achieved.

The first time this regiment was so employed, they laid down a barrage across the Sangro to support another regiment. Before Faenza, “C” Squadron was given a mission of harassing the enemy, and they were assigned a number of targets in their area. Each target was to receive one round every two minutes during the entire night, each tank firing in turn on its assigned target. Fifty rounds per gun per night was the ammunition allotment. On one occasion when the daylight target was an enemy occupied house at a range of over 5,000 yards, one of the tank guns placed three rounds in succession through the doorway of the house. During a two-week period, “C” Squadron fired about 6,000 rounds. Quite frequently, they engaged targets at ranges in excess of 10,000 yards. The conclusions drawn by the author of the report, Major General H. L. Birks, RAC, are:

Tanks must be level and near a supply route.

They must have alternate positions, since two days of unmolested fire is the maximum.

On flat country, observation and correction must be made from the air.

Approximately four times the ‘contact’ rate of ammunition is used.

Tanks are not artillery, and their use as such is justified only by the results.

By the time of the Normandy invasion, the practice of using tanks and tank destroyers in an artillery role when the occasion arose, was already well established.

Late in September 1944, VII Corps had crossed into Germany in the vicinity of Aachen and was in front of the Siegfried Line. VII Corps included the 1st and 9th Infantry Divisions, the 3rd Armored Division, and the 4th Cavalry Group. In addition, the 634th, 635th, and 899th Tank Destroyer Battalions were firing in support of Corps Artillery.

From 29 December 1944 to 4 January 1945, Company A, 781st Tank Battalion was attached to the 753rd Tank Battalion for operations. Each platoon was employed as an artillery battery to assist the fires of the task force artillery. At the time, the tanks were attached to the 79th Infantry Division, which was withdrawing from the vicinity of Strassburg. On 5 January 1945, Company A moved to Hoerdt for indirect fire missions which were coordinated through the 935th Field Artillery Battalion. This company had some tanks with 75s and some with 76s. The 75s were surveyed in and given fire missions; the 76s were surveyed in, but on this occasion, had no fire missions.

At this time, the 781st Tank Battalion was attached to the 100th Infantry Division and was being held in division reserve. On 1 March, the 3rd Platoon of Company A, a platoon of Company B, a platoon of Company C, and the Assault Gun Platoon fired indirect fire missions in support of the 374th Field Artillery Battalion. The 1st Platoon of Company C and the Assault Gun Platoon continued on the indirect fire mission through 13 March.

The 2nd Platoon of Company D moved to Bitche on 16 March to fire in support of Battery D, 926th Field Artillery Battalion. During the rest of March and April, the 781st Tank Battalion supported the advance of the 100th and the 103rd Infantry Divisions, ending at Garmisch-Partenkirchen on 30 April 1945.

These examples were selected from a number of similar reports, inasmuch as they are typical of the tank and tank destroyer operations in France and Germany.

Opportunities for the use of armor in mass were highly limited in the war in the Pacific. No land masses with suitable maneuver room were involved during the various island campaigns that were fought by our forces engaged against the Japanese. Our allies were as interested as we were in all tactical developments, and their observers and inspectors visited our forces for the purpose of reporting to their own governments on the latest innovations.

In 1945, Major John B. Robinson, Royal Canadian Armoured Corps, submitted a report to his superiors entitled, “Report on U.S. Amour in the Ryukyus (Okinawa) Campaign.” In this report, Major Robinson outlined the technique that had been developed on Leyte. Since the Japanese had retreated into the rugged hill country, the tanks could not be used in their primary mission of infantry support. Consequently, the tank units were organized into tank-artillery battalions under division artillery control for the purpose of reinforcing artillery fires. Each platoon was organized as a four-gun firing battery, with the fifth tank held in reserve. Each company then became the equivalent of a battalion and was attached to a field artillery battalion. The artillery was responsible for the selection of positions, survey, and all fire direction. Two-way communication was provided by means of radio and wire, and all fires were observed and corrected by the field artillery forward observers. Targets assigned to the tank-artillery units were as distant as 11,000 yards. Each tank retained its basic load of ammunition intact, except in case of grave emergency.

Once again, we see that the tank gun represented too much fire power to be allowed to remain idle.

On Okinawa, tanks saw little use as artillery, because the infantry did not outrun their artillery support, and there were opportunities for tank units to be maneuvered.

It would seem that Major Robinson and our own after-action reports differed on the number of times that tanks on Okinawa were employed as artillery. In their report dated 2 August 1945, the 20th Armored Group mentions occasions when it was necessary for the amphibious tanks to act as supporting artillery from defiladed positions until the field artillery battalions were landed. In the same reports, but on another page, there is mention made of medium tanks used in an artillery role.

Indirect fire by tanks was employed on many occasions with uniformly excellent results. By this method, massed fires are easily delivered and easily shifted as desired. Direct fire from turret defilade with an observer near the crest was also effective.

It is of interest to note that at various times during the Okinawa campaign, the 20th Armored Group contained the following units, which were placed in support of or attached to various infantry divisions as the situation changed:

Amphibious Tractor Battalions

536th

715th

718th

728th

773rd

788th

Amphibious Tank Battalions

708th

776th

780th

Medium Tank Battalions

193rd

706th

711th

763rd

On the basis of the units assigned, and missions performed, the 20th Armored Group certainly qualifies as an authoritative source.

Towards the end of the fighting in Europe, the Army War College sent form letters to various field commanders at theater, army, corps and division level, requesting opinions on the composition of the postwar army. One of the questions dealt with the status of tank and tank destroyer units in that army. It is an historical fact that the tank destroyer branch was dissolved, and its missions were given to the armor branch. Particular attention should be given to the emphasis placed by a number of higher commanders on the capabilities which the postwar armor branch must have. Two officers who had a great deal of command experience during World War II made remarks which were fairly typical of the answers received by the Army War College. Lieutenant General Lucien K. Truscott, Jr., Commanding General of Fifth United States Army, said, “Both tanks and tank destroyers should be trained as artillery. They must be equipped and trained for use as artillery as a secondary role. Major General Willis D. Crittenberger, Commanding General of IV Corps, said, “The gunners of Armor and the Tank-Destroyers should be thoroughly trained in artillery firing methods.”

The results of the conferences held after the war are known to all. We now have one Armor branch which incorporates the experiences and ideas concerning organization of all our armored commanders into a homogeneous body, which is prepared to perform a wide variety of missions.

The conclusions to be drawn from our experiences in World War II with regard to tanks used in an artillery role are obvious. No commander of a tank unit has ever advocated that tanks are mobile artillery pieces. Most are in agreement that the proper primary mission for the tank is one which will exploit to the fullest its mobility, permitting the armor protection and the immense firepower to assist in the accomplishment of that mission. This is what is meant by “shock action,” and is the only justification for spending hundreds of thousands of dollars for each vehicle. But, for that very reason—the one of high cost—it is very unprofitable for the tanks and tankers to remain idle simply because the situation prevents their “proper” employment. This is the conclusion reached by the many commanders who used their tanks to reinforce artillery when the occasion demanded or permitted. In addition, it was common practice for the tanks, and tank destroyers, to be located that they could be readily massed for employment as armor.

Ammunition supply and communications were two more considerations affecting the use of tanks in a static position. Each vehicle was left with its basic load of ammunition at all times except in emergency. Wire was strung from tank to tank in order to ensure rapid transmission of fire orders. Necessary survey was accomplished by people well qualified, either field artillery or, in some cases, tank destroyer personnel.

The question of morale is worth mentioning at this point. A number of the commanders who have written concerning the subject, state that the feeling of the soldiers in their units was that they were glad to be contributing to the overall effort. Let us not deny to the soldier the opportunity to destroy the enemy whenever the situation permits.

In summation, based on experience in World War II only, the tank as we now know it, represents fire power which must under all circumstances be employed to further the accomplishment of missions assigned, regardless of terrain and weather, and the tactical situation.

M4 medium tank in indirect artillery fire role.

 

M10 gun motor carriage in indirect artillery fire role.

M10 gun motor carriage in indirect artillery fire role.

M4 medium tank (105mm) in indirect artillery fire role.