AAA Ground Recognition Signals

The following comments from the commander of the U.S. 5th Armored Division on the proper use of ground recognition signals were published in “Antiaircraft Artillery Notes,” No. 5, November 22, 1944.

Subject: Use of Ground Recognition Signals
Source: AA Section, Headquarters Twelfth Army Group

The following extract is taken from AAA Situation Report No. 98, First US Army:

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“a. The following is quoted from a letter received at this headquarters from the Commanding General, 5th Armored Division:

“‘1. At approximately 1630, 2 November 1944, nine to twelve P-38s approached the CP of the 47th Armored Field Artillery Battalion located in a group of buildings about fifty (50) yards south of paved highway one mile southeast of ROETGEN (K-919273). After circling the CP twice, the three lead planes broke out of the circle and flew off in the direction of ROETGEN. The next three planes made a diving attack of the CP, dropping six bombs. ******* The 440th AAA thereupon fired six recognition flares, at which the remaining planes pulled out of dive without dropping bombs and dipped their wings and left the area.*******

“‘3 ******* AA did not fire on planes, other than recognition flares.’

“b. The AAA complied strictly with standing instructions, by firing flares and withholding fire of their weapons. The friendly A/C, recognizing the signal and the lack of fire from the ground, immediately ceased the attack. This exemplifies the manner in which such incidents must be handled.”

 

Air Ground Liaison Panel Codes

A diagram showing some typical layouts of ground-to-air signal panels from the U.S. War Department’s Handbook for Combat Air Intelligence Officers, Army Air Forces Air Intelligence School, Harrisburg, Pennsylvania, March 1944.

Air Ground Liaison Panel Code
 

Signals Intelligence in Operation Torch

The following report on Allied signal intelligence during Operation Torch and the campaign in North Africa is reproduced from “Intelligence Lessons from North Africa, Operation Torch” by the Office of Assistant Chief of Staff, G-2, Allied Force Headquarters, March 1943.

C. SIGNALS INTELLIGENCE (Y).

20. Any review of the lessons learnt in this campaign in the functioning of Signals Intelligence (British: Wireless Intelligence, generally known as Y) can be divided into three parts:

a. Before landing,
b. After landing and
c. General.

It is proposed to consider the subject under these three heads.

21. Before Landing.

The outstanding lesson learnt was the need for dispatching complete units in the first follow up and not dividing them into roughly two halves between convoys 2 .and 3. This precaution had been taken to avoid the risk of the total loss of the unit, but it is now seen that by dividing the unit or units among several ships of the same convoy the same insurance against total loss is achieved. The advantages are that in the early stages of any campaign the maximum amount of Y cover is necessary as no other day to day source of intelligence exists, and also that the enemy being less security minded when his plans are interfered with, more is given away, all of which may be of exceeding value as the campaign develops. Considerable pressure would have to be exercised on the branch responsible for loading tables, but the advantages of a complete Y unit to the formation commander are such that the highest priority for its inclusion entire should be obtainable.

22. After Landing.

a. Assignment.

As 5 Corps did not land in the first follow up, the Corps Y unit (B-type Section) was attached to 78 Div H.Q. This arrangement worked extremely well, and the smallness of the Div I Staff was compensated by one of the I.O.’s of the Section estimating the value of Y intelligence in terms of I(a). Whenever the same problem arises, it is recommended that the Corps B-type Section be attached to the senior Division acting in quasi Corps role until such time as Corps H.Q. have landed. This is preferable to keeping the unit back until Corps H.Q. have landed partly for the reasons mentioned in para. 21 and partly because no Y unit can produce intelligence the moment it sets up house. This is due to the necessity for sorting the traffic heard (since all major wireless bands are full of’ traffic, much of which can be, heard even when the transmitter is many hundreds of miles away). The two mobile D/F trucks now part of every B-type Section have a considerable part to play in this preliminary sorting process.

b. B-type Section (1942).

The revised B-type Section (1942) is an undoubted improvement on the 1941 edition. This has only been partly evident so far, as the Section with 5 Corps is on the old establishment as regards personnel and transport but on the new one as regards equipment. Had the Section been completely on the new establishment it would undoubtedly have produced more; if not better, results. The strain on too few operators coping with increased sets has resulted in a certain amount of: sickness-due to overkeenness on their part.

c. Communications.

The need for adequate communications facilities between all Sections of the Y Service cannot sufficiently be stressed. Y must be provided with its own W/T communications as quite apart from the need for passing intelligence (in high grade cypher) it cannot function properly unless technical information is continually passing between all its units and I(s) at higher levels. The normal Signals channels can sometimes cope with the intelligence side, rarely with the technical information which is often required in the form of “question and answer”.

A further point is that communication should be authorized from the start with G.H.Q. of adjacent theater or theaters. Owing to special cyphers for Y intelligence issued to this H.Q. not being made available to G.H.Q. Middle East, much valuable assistance from Mideast in the early stages could not be received.

d. Siting of Units.

The siting of Y units provided many difficulties owing to the mountainous nature of the ground. Not until recently has a general move forward of higher formations taken place so that the problem has constantly been where to site units so that they fulfill their two main functions

(1) of taking the traffic required.

(2) of passing it in shortest time to the Intelligence Branch of the formation to which assigned.

The only general answer possible is that units may have to be sited near a lower formation than is customary, reporting over their own links to the higher formation to which they belong. (The alternative of a Signal Center does not work well in practice as the lines are usually overloaded no matter what priority is assigned to Y units.)

23. General.

The following points of a more general application are grouped together for convenience though not necessarily inter-related.

a. Inclusion of ‘veterans’.

An immense advantage would accrue in any future operation by the inclusion of personnel from units with battle experience on the strength of new units first coming out. Experience counts more in Y work than is generally realized. A judicious interlarding with Mideast personnel in units fresh from home would have been of great value in this operation.

b. I a Training for I.O.’s.

Y I.O.’s trained in U.K. need to be more Ia minded. A detailed Order of Battle knowledge is an invaluable asset to any I.O. and more stress on this might be laid. It is also necessary for the Y I.O. to know what is, and is not, important to Ia so that his choice of information to pass back immediately may be right. So much of the intelligence produced by Y is ‘scrappy’ (due to difficulties of reception, new or only partially broken codes and the like) that the selection of the right ‘straw’ to indicate the wind is not always apparent. It is recommended therefore: that all I.O.’s in Y should at some period — preferably after being Y trained — serve an attachment of some weeks duration at Ia of a formation, preferably Corps or Division.

c. Intelligence School.

Soon after the start of any operation such as this provision should be made at G.H.Q. for a small “Intelligence School” to read all logs from Y units in the theater, to produce wireless network diagrams from them to check callsigns serial and row changes and generally to be responsible for the longer term W/T I. Sections in the field have little opportunity for more then short term W/T I and in times of battle practically none at all. Investigation into map reference systems, code systems, and the like cannot be undertaken locally but must be done centrally. This is a very real need and should be catered for in any future operation. This party should normally arrive simultaneously with the Army A-type Section.

d. Pool of Reinforcements.

An adequate pool of reinforcements should be drawn up and included in all future operations. In this theater only two W/T I Other Ranks were provided and were absorbed soon after landing leaving no reinforcements whatsoever. On the Signals side the scale is also too low and requires reconsideration. Any loss of personnel through enemy action or sickness is immediately reflected in the operational output of the unit. The ideal solution would be the dispatch of one complete B-type Section over and above those assigned to Corps. This unit could then relieve Corps Sections in rotation either in whole or in part and provide all grades of reinforcements as required.

e. American Y Units.

All the above remarks have been confined to British units as the participation of complete American units in this theater has not yet materialized. The American Section with British W/T I personnel has acquitted itself well in spite of many handicaps due to faults inherent in the general organization of American field Y units. This subject is one however which needs to be investigated at a higher level and a joint American-British Committee might well at some later stage be charged with examining the problem in the light of British experience and American difficulties.

24. Conclusion.

In the main the plans made, the training of the units and the results achieved have been entirely satisfactory. The improvements suggested above are chiefly concerned with detail and should without undue difficulty be capable of realization.

25. I.S. Staff at Army H.Q.

It is considered that only one I(s) Staff Officer is needed at Army H.Q. until the arrival of the A-type Section.

26. Water Trailer for A-type Special Wireless Section.

A-type Special Wireless Section has a strength of 54 all ranks and only sixteen 2-gallon containers to hold drinking water. For technical reasons, the section is often sited in remote areas where the problem of obtaining drinking water is great.

It is considered that a water trailer is essential for the section.

 

VHF Ground-to-Air Radio

A somewhat fanciful illustration from a U.S. equipment manual showing the VHF Ground-to-Air Radio Set AN/CRC-1 being used by ground forces to call in air support.

VHF Ground-to-Air Radio

When assembled for operation, Radio Set AN/CRC-1 may be used as a ground-to-air command set to transmit information from ground troops to combat aircraft relative to strategic ground targets against which strafing or bombing action is desired.


 

De-Mechanized Warfare

From Combat Lessons No. 6:

De-Mechanized Warfare

In a gesture of protest against the trend toward complete mechanization, the wire team shown at work in the accompanying photo picked up an idle buggy in a front-line town, conscripted a “liberated” horse, and set off to salvage much-needed wire. The horse is garbed becomingly in an air-ground recognition panel. Despite an enthusiastic report on the project, no change in T/O and E is contemplated by the War Department.

De-Mechanized Warfare -- U.S. Signal Troops in Horse and Buggy