The Organizational Reforms of December 1938

Battalion: An Organizational Study of United States Infantry

The estate of the late John Sayen has graciously given the Tactical Notebook permission to serialize his study of the organizational evolution of American infantry battalions. The author’s preface, as well as previously posted parts of this book may be found via the following links:

In light of the deteriorating world situation and the resultant willingness of Congress to pass larger military appropriations, the War Department believed that it could afford to pad Colonel McNair’s extremely austere organizations with additional men. Combat organizations could now be designed more on a basis of what was desirable than on what was affordable.

In this vein the War Department issued new organization tables for a division of about 15,000. This was much larger than what (soon to become a Brigadier General) McNair had proposed but it would be fully motorized and far “leaner” and more nimble than the square division that it would replace. In terms of size, there was much less distinction between the War Department’s and McNair’s infantry regiments. The regiment which the War Department mandated, even at its full war strength and with all its attached chaplain and medical personnel, totaled 2,542 officers and men or only about 140 more than what McNair had recommended.¹

Rifle squads and platoons were again shuffled. The Infantry Branch was sure it had been on the right track when it increased the rifle squad to 12 men (eight in peacetime) in its December 1936 review. This permitted the deletion of the awkward rifle sections while maintaining the platoon at an acceptable size. Since 12 men were considered too many for a corporal to handle, a sergeant would lead the new squad and a corporal would assist him.

The larger squad promised to be much less brittle than the older seven, eight, or nine-man organizations. Senior officers well remembered that the eight-man AEF squads had required frequent reorganization in response to the constant attrition that whittled away their strength. This resulted in personnel turbulence that sapped unit cohesion at its most vital point. Since the minimum doctrinal size of a squad was six men, a twelve-man squad could function without reorganization even after losing up to half its members. Three twelve-man squads could form a greatly simplified three-element 40-man platoon that even a hastily trained wartime lieutenant should be able to command effectively.

For armament, the rifle squads would only carry M1 rifles. M1903 rifles, with one BAR per squad, would serve until enough M1 rifles became available. Rifle squads would be highly mobile since no squad member would be so heavily loaded as to be unable to move long distances at a walking pace or “double time” for short stints. Rifle platoons would also carry no crew-served weapons, lest the weight and ammunition requirements of these devices reduce the platoon’s mobility and their manning requirements cause a reduction in rifle squad strength.²

The new rifle company (see Appendix 4.2) would include crew-served weapons but would concentrate them in its headquarters rather than distribute them among its platoons. To accommodate the new weapons, the company headquarters would expand to a platoon and would serve as a weapons platoon in all but name.

The company headquarters portion of the new unit still followed the conventional pattern except that in wartime it would have two command elements. The larger one (under the company commander) would control the company as a whole while the smaller (under the headquarters platoon commander) directed the two weapon sections. The balance of the company headquarters constituted two weapon groups and the rear services group.

One of the weapon groups was a light mortar section armed with another Hotchkiss-Brandt mortar, the 60mm M2. This weapon replaced the 47mm, which had finally been deemed to be too light. The 60mm mortar, as originally designed for the French Army, had nearly twice the range of the 47mm (1,900 yards vice the 47mm’s 1,000 yards) and could fire a shell with about three times the effective casualty radius (15 yards or so). Like the 47mm, it could also launch pyrotechnics.

At the same time, the 60mm was much heavier than the 47mm mortar it replaced. The tube, the baseplate, bipod, and accessories of the 60mm mortar weighed 50 pounds and constituted a two-man load, whereas the 20-pound 47mm mortar could by carried by one man. Individual 60mm rounds were also was much heavier than 47mm. A five round box of 60mm ammunition weighed about 18.5 pounds and a five-man mortar squad could carry, in addition to the mortar, no more than six boxes (30 rounds) or enough for perhaps 90 seconds’ firing at the maximum rate. By contrast, the same five-man squad could carry 96 rounds of 47mm.

The mortar section would normally operate within 500 yards of the company’s front line. It was expected that cover would almost always be available within this zone. Visual or voice communication with other company elements should always be possible and the mortars should be able to observe and engage targets facing all or most of the company’s front line. Though the mortar section had only two squads, it was issued a third mortar for use by its mortar squad ammunition bearers in “defensive” situations when tactical movement was not required.

The other weapon section was the BAR/LMG section, with two seven-man squads, each operating two BAR. The LMG section was intended to follow the leading rifle platoons to deliver flanking (and hopefully) enfilading fires across its own or an adjacent company’s front in either the offense or defense. It could also deliver supporting fires through gaps between platoons. Both LMG squads would normally be used together and would rarely if ever be attached out to the rifle platoons. There were now only two LMG squads per company, as compared to six in the 1935 regiment and the regiment Colonel McNair had designed. However, it was expected that this reduction in automatic firepower should be offset by the replacement of the BAR by the M1919 LMG.

This M1919 LMG could offer greater accuracy and stability and two to three times the BAR’s effective rate of fire. However, an LMG squad could operate only one M1919 at a time. The other would be kept in reserve for defensive situations. Because its weapon sections could only hand carry their primary weapons and a very limited supply of ammunition, each rifle company would include a light truck (at first, a commercial-type 1.5-tonner) to carry its spare crew-served weapons and ammunition. When the enemy was not in close proximity, it would carry the primary weapons as well.³

The resulting rifle company, though larger that what General McNair would have preferred, was better armed, and offered more tactical independence and flexibility than any previous company. Its standard for tactical mobility at the company level was that all weapons and equipment had to be light enough to be hand carried over extended distances and varying terrain at a walking pace. However, (unlike at platoon level) the men carrying the crew served weapons and ammunition would not have to be able to “double time” and it was understood that they would have had to rest more frequently. The LMG and mortar sections comprised a de facto weapons platoon and established the company as the smallest tactical unit that could generate its own base of fire. They gave the company commander a tool with which he could influence the battle even after all his rifle platoons had been committed.

The old machine gun company had been expanded into a heavy weapons company, charged with giving close support and protection to the rifle companies (see Appendix 4.3). “Close support,” meant acting as the battalion’s base of fire while “protection” included protecting the battalion’s flanks, assembly areas, and bivouacs by fire. As had been the case in the 1935 experimental motorized regiment, the new company was oriented around its two platoons of water-cooled Browning .30 caliber M1917A1 heavy machine guns (HMG), augmented by an antitank platoon (air-cooled .50-caliber machine guns) and a platoon of 81mm mortars.

Although the weapons company commander was responsible for the supply, training, and administration of his entire company, in battle he normally controlled only his two HMG platoons. The antitank and mortar platoons worked directly under the battalion commander. Although the HMG platoons continued to perform largely as they done had in the First World War, the presence of LMG’s in the rifle companies allowed them greater flexibility to position themselves further back from the front line.

HMGs continued to operate in pairs. In the offense, they covered the flanks of the battalion and directly supported the rifle companies with flanking or overhead fire. They also protected the battalion’s objective, once it had been seized, from enemy counterattack. They could deliver antiaircraft fire as well. Although overhead fire was seldom practiced during peacetime for safety reasons, each HMG platoon did include a fire control corporal to direct the platoon’s indirect and overhead fire.

In the defense, the HMGs would cover the battalion’s front line with a barrier of flanking enfilade fire that an enemy would have to cross in order to reach the battalion’s positions. This is still a standard defensive tactic. Like the rifle company’s M1919-equipped LMG squads, each HMG squad actually had two guns. One was for “normal” use when tactical mobility was necessary. The second was reserved for “defensive” situations where the squad would be stationary and its four ammunition bearers would be free to man it. This extra gun, plus water and ammunition for the primary gun, would be carried in the squad’s light truck.⁴

The battalion antitank platoon was armed with two M2 Browning .50-caliber machine guns. These could be used singly or in pairs to cover the most likely armor avenues of approach. Although M3 37mm antitank guns were entering service, they could not be hand carried and thus exceeded the mobility parameters laid down for battalion level weapons. Even so, the .50-caliber was by now regarded as too light for antitank work and the Army was contemplating its replacement with a 20mm or 25mm weapon on a wheeled carriage that could be hand drawn.

A debate over whether to concentrate the regiment’s 81mm mortars into a single company or to divide them among the battalions was resolved in favor of dividing them. Although the concentration of mortar fire made possible by the former course of action could be very desirable in many circumstances, the Chief of Infantry was adamant that concentration of fire was really the province of the artillery. Infantry weapons should distribute their fires along the front so as to fill the gaps left by the artillery and other supporting arms.

The new mortars (both 60mm and 81mm) were regarded as by far the most significant additions to the infantry’s armory. They were much more effective than the old Stokes mortars and rifle grenades at attacking trenches, shell holes, and other below ground positions that were relatively immune to flat trajectory weapons like rifles and machine guns. It was against the small targets, such as machine gun nests, that could stop the infantry’s advance and which the artillery might easily miss that the Chief of Infantry believed that the new mortars should be used.

Infantry mortars were not there to duplicate, compete with, or even to supplement the artillery but to complement it. They would focus on the “detail” work for which the artillery was less effective and/or economical, especially given the lack of rapid and reliable communications that bedeviled infantry-artillery cooperation. The new mortars would operate well forward. The 60mm mortars would be within 500 meters of the front line and the 81mm within 1,000.

The mortars could be in defilade but their observers had to be able to see all or most of their sector and then communicate with the mortars by voice or hand signal. This was because the Army had adopted a deliberate policy of not issuing radio or telephone equipment to its infantry mortar units. Although the Army acknowledged that telephone communication between the mortars and their observers could be useful, it feared that wire or radio equipment would encourage placement of the mortars too far from the fighting for them to be really effective. If wire and radio communications were available they could be better used to call in the regiment’s supporting artillery.

The whole point of having mortars was to reduce dependence on such communication means, which, under battle conditions, could be very unreliable. In addition to directing fire, the mortar observers (usually platoon or section leaders) chose their targets, in accordance with what they could see of the situation plus any guidance contained in their current operation orders and what they knew of the battalion’s mission. They did not normally take calls for fire from front line rifle units. They had to be close enough to see the action and to know where friendly troops were and where and when they needed help.

The new battalion headquarters detachment (see Appendix 4.4) was extremely austere. The staff consisted only of a lieutenant colonel battalion commander, a major serving as both executive officer and operations officer, and one lieutenant who combined the roles of adjutant, intelligence officer, and headquarters detachment commander. A supply officer from the service company and a communication officer from the regimental headquarters company were normally present as well. The staff received enlisted support from the headquarters section of the headquarters detachment. The intelligence section furnished trained scouts plus a topographical draftsman. An ammunition or pioneer section provided ammunition carrying parties. These would be especially important when the weapons carriers could not get ammunition close enough to the mortars or machine guns they supported for the crews to move it the rest of the way without assistance. Instead of a communication platoon, there was only a message center section. All other battalion communicators would come from a battalion section of the communication platoon in the regimental headquarters company.

Although the battalion was clearly the infantry’s basic fighting unit, a battalion would still depend heavily upon its parent regiment for most of its supply, communication, medical, and administrative needs. Regimental headquarters did have, more or less, a full staff and, if authorized, a regimental band. Enlisted support for the regimental headquarters would come from the headquarters company headquarters and the intelligence platoon. The former provided a mess team and five (four in peacetime) commercial Ford Phaeton five-passenger sedans with drivers. One of these sedans was for the company headquarters’ own use. Attempts to armor the Phaeton were unavailing but its light weight contributed considerably to its mobility since it was easy to push when it got stuck.⁵

The antitank platoon gave the regimental commander an antitank reserve that was fully motorized but not radio equipped. It was not as large as the eight-gun company that General McNair had recommended, but its six 37mm M3 antitank guns could augment the three battalion antitank platoons. In 1939 and 1940 the War Department was able to pare an officer and ten men from this platoon without greatly affecting its efficiency.⁶

The largest element of the headquarters company was the communication platoon. The four sections that it provided to the regimental and battalion headquarters were all similar, except that the regimental section included its own message center. All four sections, however, had wire and radio/visual subsections. The battalions took full control over their communication sections, once they were attached, but the regimental commander retained authority to order them to install certain regimental wire lines in order to expedite the setup of the overall wire net.

Additionally, the section of a battalion not in enemy contact might be ordered to install wire lines for the regiment. In the defense or in a deliberate attack, a battalion would normally maintain two telephone stations, one at the battalion command post, and one at an observation post (usually manned by intelligence platoon personnel) co-located with the observers from any artillery that might be directly supporting the regiment. In addition to voice traffic, buzzer phones (of which the regiment had five) might be used to transmit CW messages over telephone lines. Occasionally, phone lines might be extended to the rifle and weapons companies of one battalion but additional telephones would have to be borrowed from regiment in order to implement this. In a rapid advance, a battalion might bring forward one phone line with which to connect itself to its parent regiment.

For radios, the regimental section carried two 179-pound, 15-mile ranged SCR-171s for communicating with division level and higher headquarters and three 76-pound five-mile ranged SCR-131s for communicating with the SCR-131 held by each battalion section. Both the SCR-171 and SCR-131 sets transmitted in CW (Morse code) only and were hand generator powered. However, the regiment was also, and for the first time, issued with man-packed battery powered voice radio sets. These were SCR-195s and with all its accessories and spare parts kit each one weighed 91 pounds. However the load that an operator actually had to carry was only 26 pounds.

The SCR-195 could transmit up to 4.5 miles in ideal conditions though practical ranges were only about three miles in dry weather or two miles in wet. It was not capable of CW transmission nor could it transmit within SCR-131 or 171 frequency ranges. Each regimental or battalion section was allowed two SCR-195s (for a total of eight in the regiment). One SCR-195 from this pair, with its operator would accompany the regimental or battalion commander while the other would be given to a remote station such as in an observation post, at the head of a march column, or with the point company during an advance.⁷

Communication security was already posing difficulties since encryption and decryption was slow with CW systems and generally impossible with voice systems. The M-94 cipher device, for example, which equipped battalion and regimental message centers, could only encrypt/decrypt one word per minute, though if the division field code or air-ground liaison codes were used the speed increased to about three words per minute. CW transmission was the fastest. A telegraph/buzzer phone could process up to 30 ten-word messages per hour. A radiotelegraph set (SCR-131 or 171) was good for 15 to 20 messages per hour but a voice radio was only two thirds as fast.

Visual signals were even slower and depended on good weather. A lamp could transmit ten messages per hour; signal panels only three per hour. All traffic except telephone conversations (which were supposed to be limited to tactical matters) had to be written in triplicate on the appropriate forms and routed through the regimental or battalion message centers. The message center chief usually selected the means of transmission since he knew best what was available. Messengers (some of them motorcycle equipped) remained an important communication means at all echelons but especially in the rifle and weapons companies, which still had neither telephones nor radios.⁸

Editor’s Note: The format of the many appendices to this work fit poorly with Substack. For that reason, I have placed them on a PDF file that can be found at Military Learning Library, a website that I maintain.

For Further Reading: Readers wishing to delve deeper into the issues discussed in this post will find much of interest in the Infantry Conference Report of Committee on Organization, June 1946, as well as in issues of the Infantry Journal and the Infantry School Mailing List published in the late 1930s.

1. US Army Adjutant General Table of Organization T/O 7-11 “Infantry Regiment, Rifle (Motorized)” (Washington DC 6 December 1938)

2. US Army Adjutant General Table of Organization T/O 7-17 “Infantry Company, Rifle” (Washington DC 6 December 1938); Major General George A. Lynch, “Some Reflections on Infantry Material and Tactics” Infantry Journal July 1938 pages 292-300 and “The Tactics of the New Infantry Regiment” Infantry Journal March-April 1939 (Washington DC) pages 98-113

3. “Toy or Tool?” Infantry Journal July-July 1936 (Washington DC) pages 359-360 and Captain Harold G. Sydenham, “The Infantry Mortars” Infantry Journal May-June 1939, pages 224-227

4. US Army Adjutant General Table of Organization T/O 7-18 “Infantry Company, Heavy Weapons (Motorized)” (Washington DC 6 December 1938); “Loads of Infantry Vehicles” Infantry School Mailing List July 1940 pages 217-260; and The General Board, United States Forces European Theater Study No. 15 “Organization, Equipment, and Tactical Employment of the Infantry Division” page 8

5. “Squad Cars T-1 and T-2” Infantry Journal May-June 1936, page 253

6. US Army Adjutant General Table of Organization T/O 7-12 “Infantry Headquarters and Headquarters Company, Regiment, Rifle (Motorized)” (Washington DC 6 December 1938)

7. “The 1939 Infantry” Vol XVIII July 1939 pp. 243-275; “Loads of Infantry Motor Vehicles” Vol XX July 1940 pp. 217-260; “Infantry School Reference Data” Vol XXII July 1941 pp. 191-220; all are from The Infantry School Mailing List (The US Army Infantry School, Fort Benning Georgia).

8. “Infantry School Reference Data” The Infantry School Mailing List July 1941 pages191-220 and “Command Post Operations” Infantry School Mailing List February 1940 pages 77-95.