Field Artillery Journal - Jan 1937

Embed Size (px)

Citation preview

  • 7/31/2019 Field Artillery Journal - Jan 1937

    1/83

    27TH YEAR OF PUBLICATION

    THE FIELDARTILLERY

    JOURNALJANUARY-FEBRUARY, 1937

    AND NOW THE AUTOGIRO

    BRIGADIER GENERAL LESLEY J. McNAIR

    THE ITALIAN ARTILLERY IN ETHIOPIA

    LIEUTENANT COLONEL JOHN S. WOOD

    FIVE DECISIVE DAYS

    COLONEL CONRAD H. LANZA

    PUBLISHED BIMONTHLY BY

    THE UNITED STATES FIELD ARTILLERY ASSOCIATION

  • 7/31/2019 Field Artillery Journal - Jan 1937

    2/83

    January-February, 1937

    CONTENTS

    A Message from the Chief of Field Artillery ........................................................ 3

    From a Wartime Recruiting Poster (frontispiece) ............................................... 4

    And Now the Autogiro ........................................................................................... 5By Brigadier General Lesley J. McNair, U. S. Army

    Two Views on Transport

    Horse vs. Motorat Night ............................................................................... 18

    By Colonel Edward N. Wentworth, FA-Res.Horse vs. MotorRecruits............................................................................... 19

    By Captain Creswell G. Blakeney, FA

    Who in the Driver's Seat? ...................................................................................... 22By Captain Joseph I. Greene, Inf.

    The Italian Artillery in Ethiopia (digests) ............................................................ 27By Lieutenant Colonel John S. Wood, FA

    United States Field Artillery Association.............................................................. 34

    Five Decisive Days .................................................................................................. 37By Colonel Conrad H. Lanza, FA

    Digest of Field Artillery Developments ................................................................. 66

    Christmas Problems, C & GSS.............................................................................. 67

    Request for Old Standards .................................................................................... 67

    Knox Trophy Award, 1936 .................................................................................... 69

    Talking Shop ........................................................................................................... 71

    ROTC Units ............................................................................................................ 72

    A Letter from Thorvald ......................................................................................... 73

    ReviewsPeriodicals ............................................................................................. 74

    Books ....................................................................................................................... 75

    Departments

    Thanks to These................................................................................................. 76

    Titles of Essays Received .................................................................................. 77

    Some Forward Observations ............................................................................ 78

    Military Books ................................................................................................... 80

    AUTHORS ALONE ARE RESPONSIBLE FOR STATEMENTS CONTAINED IN THEIR ARTICLES

  • 7/31/2019 Field Artillery Journal - Jan 1937

    3/83

    27TH YEAR OF PUBLICATION

    VOL. 27 No. 1

    JANUARY-FEBRUARY, 1937

    THEFIELD ARTILLERY

    JOURNALCopyright 1937, by

    The United States Field Artillery Association

    Patron Saint of Artillery

    PUBLISHED BIMONTHLY FOR

    THE UNITED STATES FIELD ARTILLERY ASSOCIATION

    BY MONUMENTAL PRINTING COMPANY

    32D STREET AND ELM AVENUE

    BALTIMORE, MD.

    Editorial Office, 1624 H Street, N. W., Washington, D. C.Michael V. Gannon, Captain, Field Artillery, Editor

    Entered as second-class matter August 20, 1929, at the post office atBaltimore, Md., under the Act of March 3, 1879

    Published without expense to the government

    The Field Artillery Journal pays for original articles accepted

  • 7/31/2019 Field Artillery Journal - Jan 1937

    4/83

    THE U. S. FIELD ARTILLERY ASSOCIATION1624 H Street, N. W., Washington, D. C.

    Please enroll me as a member of the Association and as a subscriber to TheField Artillery Journal. I inclose $3 for subscription and dues.

    Name ................................................................................................................................

    Rank and Organization...................................................................................................

    Street.................................................................................................................................

    City ......................................... State ..............................................................................

    ARTICLE II OF CONSTITUTION

    "The objects of the Association shall be the promotion of the efficiency of the Field

    Artillery by maintaining its best traditions; the publishing of a Journal for disseminatingprofessional knowledge and furnishing information as to the field artillery's progress,development, and best use in campaign; to cultivate, with the other arms, a commonunderstanding of the powers and limitations of each; to foster a feeling of interdependenceamong the different arms and of hearty cooperation by all; and to promote understandingbetween the regular and militia forces by a closer bond; all of which objects are worthy andcontribute to the good of our country."

    Please change my address

    from ..................................................................................................................................

    to .......................................................................................................................................

    ...........................................................................................................................................(Signature)

    ...........................................................................................................................................

  • 7/31/2019 Field Artillery Journal - Jan 1937

    5/83

    An autogiro is undergoing a tryout in the work of the Field Artillery

    School at Fort Sill. No one can foresee clearly the full possibilities of this

    new machine as an auxiliary to the ground troops. For the field artillery

    particularly, it should facilitate reconnaissance, liaison, battlefield

    surveillance, and observation of fire. Only time will tell, but our hopes are

    high. The decision that air photos, rather than fire-control maps, be usedin survey operations, has influenced our gunnery practices. The

    reorganization of the infantry division presents problems pressing for

    solution. We look ahead to progress.

    More realistically we see that the radio, even with its ever-improving

    devices, can not yet displace the wire-telephone; nor has the runner been

    outmoded as a means of communication. While motors have come to us in

    large numbers, we still have the horse and mule doing valiant service. Nosystem of fire control has yet been devised superior to direct observation.

    The cannoneer still has muscles to exercise, and brains with which to

    control his mechanical servants, which are not yet his masters, and never

    can be.

    However, it is safe to make one assumptionthe field artillery will

    achieve its mission, the fire support of infantry and cavalry, by mastering

    and practicing its lessons, rather than by giving these but perfunctory

    attention while awaiting the improbable moment when battles can be wonby pushing buttons. "There is no royal road to national defense," said the

    late Secretary of War, Honorable George H. Dern. "You cannot purchase

    it with gadgets,"nor can battles be won thereby.

    I have been pleased to note, from the reports of the various boards

    which inspected entries in the 1936 Knox Trophy Contest, that our lessons

    are being well learned.

    UPTON BIRNIE, JR.,Major General, United States Army,

    Chief of Field Artillery.

    To the Officers and Soldiers of theField Artillery

  • 7/31/2019 Field Artillery Journal - Jan 1937

    6/83

    Photoby

    U.

    S.

    SignalCorps

    FROMAWARTIMER

    ECRUITINGPOSTER

  • 7/31/2019 Field Artillery Journal - Jan 1937

    7/83

    THE FIELD ARTILLERY JOURNALVOLUME 27 JANUARY-FEBRUARY, 1937 NUMBER 1

    And Now the AutogiroBY BRIGADIER GENERAL LESLEY J. McNAIR, U. S. ARMY

    IGHTEEN years have elapsedsince the Armistice. Warequipment of today makes that of

    the World War appear quite outmoded.It is a striking fact, however, that thereare few items of modern equipmentwhich were not in use, or at least in

    being, during that war. Motorization,mechanization, all types of airplanes,and balloons, for example, were incommon use at that time. Postwar typesembody many improvements anddevelopments, but distinct innovationsare rare: progress has been by evolution,rather than revolution.

    But today the Army is face to face

    with something really newtheautogironew in its interesting military

    possibilities, and new in its original andexceedingly clever application ofaerodynamic principles. The Air Corpshas purchased two Kellett autogiros, onea YG-1 and the other a YG-1A: and,after acceptance tests, has placed themachines, with Air Corps pilots, at thedisposal of the ground arms, for servicetests.

    The autogiro was invented by SenorJuan de la Cierva, a brilliant Spanishengineer, whose first machine was builtin 1920. His earlier experiences with

    airplanes were not altogether happy,

    KELLETT AUTOGIRO YG-1A

    Note the inclination of the rotor axis. The propeller axis also is inclined, so as to pass through the center ofgravity of the giro as a whole

    5

    E

  • 7/31/2019 Field Artillery Journal - Jan 1937

    8/83

    THE FIELD ARTILLERY JOURNAL

    KELLETT AUTOGIRO YG-1A

    The rotor blades are folded back for transport by road or for storage. Note the horizontal tail surfacesopposing airfoils, which set up a couple to counteract the propeller torque

    and he was impressed by the inherentfaults of the type. He sought greatersafety in flying. It is the irony of fate that,at the age of forty-one and after bringinghis brain-child through the most trying

    period of its development, he met deathrecently in a modern transport airplane.

    Our new autogiros have flyingcharacteristics which appeal especially tothe artilleryman. The minimum speed instill air is about 16 miles per hour. When

    flying into a wind of this or a greatervelocity, they can hover above a selected

    point. The maximum speed is 130 milesper hour, and the cruising speed 105miles per hour. They can land in a smallspace, since the roll on landing is almostnila few feet. Descent, either with orwithout power, may be varied at willfrom a long glide to the vertical.

    In a take-off in still air, the machines

    can clear an obstacle 50 feet high at adistance of 300 feet from the startingpoint. The jump take-off, now underdevelopment, permits an initial vertical

    rise, predicted as great as 200 feet, beforebeginning normal flight.*The giro permits rapid and wide

    changes of speed; it is capable ofexceedingly sharp turns; it can dive andloop; and, in general, has no smallassortment of acrobatics, with

    possibilities as yet unexplored.These characteristics and other features

    of the giro point to interesting possibilitiesin its tactical employment. Its landing and

    take-off capabilities permit the giro tooperate in close touch with the supportedground units. In addition, the rotor bladescan be folded back parallel to the fuselage,for transport by road, which would permitthe giro actually to march with

    *The jump take-off was under development byCierva in England at the time of his death, and itsinvention is credited popularly to him. Actually,

    however, the original conception and elaboratecalculations establishing its practicability were thework of an AmericanMr. R. H. Prewitt, a youngalumnus of Purdue University and now ChiefEngineer of the Kellett Autogiro Corporation.

    6

  • 7/31/2019 Field Artillery Journal - Jan 1937

    9/83

    AND NOW THE AUTOGIRO

    a column if desired. The small minimumflying speed should permit a rapid,

    detailed reconnaissance by giro moreeffectively than by any other means,either air or ground. The giro has takenaloft a telephone wire and establishedcommunication with the ground from analtitude of two thousand feet. Visualsignaling, giro-ground, is readily

    practicable.Thus the giro is under consideration

    for a field of usefulness now filled by theobservation airplane and the captive

    balloon. Some comparison of the threemeans is appropriate. Statements in thisconnection are of course purely relative;moreover, they are subject to revision asexperience with the giro is accumulated.

    The balloon now is the quickest andmost accurate means of air observation offire. It permits the use of a field glass, andhas wire communication with the ground.

    However, it is a large, visible, andvulnerable target. It is sensitive to

    weather conditions, a wind of 25 milesper hour affecting its usefulness. Itrequires a large ground establishment,and its mobility is limited.

    The airplane has high speed, whichdiminishes its vulnerability. In addition, itcan defend itself by machine-gun fire. Ithas a large radius of action in observationand reconnaissance; and its view can bevertical, favoring accuracy. Its speed,vibration, and wings handicap vision; afield glass cannot be used.

    The giro affords better vision than doesthe airplane, owing to the absence ofwings, and to its lesser speed andvibration. The practicability of using a fieldglass from it is yet to be determined. Themachine itself is less visible in the air thanthe airplane. Since the present type of giro isunarmed, it is reasonable to assume that

    THE AUTOGIRO IN FLIGHT. NOTE THE CONING OF THE ROTOR BLADES .

    7

  • 7/31/2019 Field Artillery Journal - Jan 1937

    10/83

    THE FIELD ARTILLERY JOURNAL

    its operation, except at night, would beconfined largely to friendly territory.

    However, a larger typeand there is nobasic reason to doubt its practicabilitycould be armed readily. Armament,coupled with the giro's inherentmaneuverability, would change thisaspect completely. Like the airplane, thegiro is less subject to the weather than the

    balloon.The comparative effectiveness of the

    three means in observing fire undertactical conditions is yet to bedetermined, although there is reason to

    believe that the giro would be superior atnight. It appears that, for reconnaissanceof targets and hostile terrain, the airplanewould be superior to the present giro: butthat the giro would be decidedly superiorin reconnoitering friendly terrain and forcommand and courier purposes. The girois the most easily concealed on theground.

    Merely as a short-range forecast, andassuming that the giro proves serviceable,it is not difficult to visualize the

    possibility of its replacing the balloonlargely, if not entirely, and theobservation airplane in a degree as yetindeterminate.

    The giro is intriguing to both thelayman and the technician, even in thesedays of ceaseless wonders. Aside fromthe widespread interest which themachine has aroused, the principlesembodied are important in appraising itsvalue and possibilities. There are somemisconceptions in this respect.Consequently, a brief explanationasnontechnical as possibleof the basicfeatures seems in order.

    It is seen from the cuts that the girohas a fuselage and undergear of thefamiliar type; it carries an engine and a

    propeller. There are no wings in theordinary sense; but the fuselage carriescertain tail surfaces and a rudder, whichstabilize the machine and facilitate

    turns. The distinctive feature is a largerotor, mounted abov the fuselage and

    consisting of three equally-spacedblades or wings. In flight, the rotorrotates freely with its axis, due toairflow. It is to be noted that the planeof the rotor is not perpendicular to thatof the propeller, but is inclineddownward to the rear, for reasonswhich are explained later.

    The propeller is connected directlywith the motor, and the pilot can connectthe rotor also by means of a clutch. In

    preparing to take off, the brakes of thegiro are set, and the motor and propellerstarted. The pilot engages the rotor,which thus is brought to speed. He thenreleases the rotor and the brakes, andopens the throttle. The rotor continues tospin for the moment. The propellermoves the giro forward. The airflowthus created maintains the rotation of therotor; and, as the giro gains speed on the

    ground, the rotor also gains speed andsoon lifts the machine into the air. Itmay be remarked that the rotor could bestarted from rest by taxiing the girdaround the field, but the method would

    be slow and hence impracticable. Thusin flight, the motor-driven propellermoves the giro, while the air-driver rotorsustains it.

    AUTOROTATION

    Among the array of phenomena whichare at work constantly during theoperation of the giro, perhaps none isquite so difficult to grasp as that of therotor's rotation without a visible source of

    powertermed autogiration, or morecommonly autorotation. An understanding of autorotation is the key toappreciating the giro's behavior, so that it

    is necessary to make a special effort toexplain the phenomenon.

    On seeing the giro in flight, one isapt to jump to the conclusion that the

    8

  • 7/31/2019 Field Artillery Journal - Jan 1937

    11/83

    AND NOW THE AUTOGIRO

    rotor rotates in the same manner as awindmill. Actually, the rotor and the

    windmill rotate in opposite directions, sothat the windmill is hardly a suitableanalogy. If the rotor were a windmill, itwould hold the giro on the ground, insteadof lifting it.

    Before going into the reasons for thiscondition, it seems best to demonstrate thefacts convincingly and practically, in orderto clarify the problem.

    The cuts show two forms of modelrotors home-made, but satisfactory forthe purpose. Each consists of a handle witha pivot at the end, on which is mounted arotor, free to spin in an airflow. No. 1, withfour blades, is essentially a windmill. The

    blades are pitched at about 15 degrees with

    respect to the plane of rotation. No. 2 hasblades formed as efficient airfoils, like the

    wings of an airplane. The pitch is zero.Both forms are pitched in the samedirection. It is apparent then, that, if eitherof the rotors is to lift or sustain, it mustrotate so that a blade in its uppermost

    position or when nearest to the fan movesaway from the reader. Rotation in thisdirection only is autorotation, properlyspeaking. Rotation in the oppositedirection is antiautorotation.

    Our interest in such rotors is to subjectthem to airflow and see what happens. Thisis accomplished readily by holding them invarious positions before an electric fan as asource of airflow equivalent to that obtainedin flight. The position of rotor No. 1

    Photo by U. S. Signal Corps

    MODEL ROTOR NO. 1A windmill: capable only of antiautorotation. Pitch of blades about 15 degrees with respect to the plane of

    rotationAirflow A: Corresponding with that in flight with power

    9

  • 7/31/2019 Field Artillery Journal - Jan 1937

    12/83

    THE FIELD ARTILLERY JOURNAL

    Photo by U. S. Signal CorpsMODEL ROTOR NO. 2

    Formed blades of zero pitch; capable of autorotationAirflow B: Corresponding with that in flight (descent) without power

    before the fan gives a direction of airflowdesignated as airflow A; that of rotor No. 2,as airflow B. Airflow A approximates thatobtaining with the giro for all directions offlight with power. Airflow B is thatobtaining in vertical descent without power.

    With rotor No. 1, having flat bladespitched at about 15 degrees, autorotationcan not be obtained with either airflow Aor airflow B, or any intermediate airflow;there is antiautorotation only. Even if therotor is spun initially by hand in thedirection of autorotation, and then issubjected to airflow, it stops quickly andantiautorotation sets inand, for airflow

    B especially, at high speed. The reasonlies in the excessive pitch of the blades.

    With rotor No. 2, having formedblades of zero pitch, there is autorotation.

    If the rotor is placed at rest before the fan,with any airflow between A and B, itautorotates invariably. However, if it isspun by hand in the direction ofantiautorotation and then is placed beforethe fan, it continues to rotate in thisdirection at apparently the same speed asit autorotates.

    A third rotor, similar to No. 2 but withblades pitched at slightly less than threedegrees, also was tried. It gave onlyantiautorotation, on account of the pitch.

    As a result of these demonstrations, itis concluded that

    First, in order to secure autorotation,

    the pitch of the blades must be small.The fact that autorotation is notobtained with these small models at a

    pitch around three degrees by no means

    10

  • 7/31/2019 Field Artillery Journal - Jan 1937

    13/83

    AND NOW THE AUTOGIRO

    fixes the limit at less than this value.Actually, with the giro, autorotation is

    obtained with a pitch as great as fourdegrees or moretheoretically over tendegrees under ideal conditions. In thecase of the YG giros, the pitch is about2 degrees.

    AIRFOIL IN AN AIRFLOW

    Second, in order to secureautorotation, there must be a componentof airflow upward through the rotor; andthe greater the component, the faster isthe rotation. This fact accounts for theinclination of the plane of the rotor ofthe giro with respect to the axis of the

    propeller, noted previously; otherwise,flight would be impossible. It followsthat the upward component of airflowthrough the rotorand hence the rotorspeedcan be increased in two ways:for a given direction of airflow, byincreasing the velocity of airflow; and,for a given velocity of airflow, byaltering the direction of airflow from A

    toward B.In view of the foregoing presentationof the practical aspects of autorotation, itis interesting to examine in a general waythe reasons for the demonstratedconditions:

    As a preliminary, it is well first torefer to the fundamental principlesrelating to an airfoil subjected toairflow. The airfoil is inclined to theairflow as indicated. The movement ofeither the air or the airfoil sets up a force

    perpendicular to the airflow, known asthe lift: and a force parallel to theairflow, known as the drag. These forcesare present in the cases of both thewings of an airplane and the blades ofthe giro's rotor. In fact, the rotorfrequently is referred to as a rotatingwing.

    The blades of the rotor pass through a

    succession of positions with respect to thedirection of flight, because of the rotationof the rotor and the inclination of the

    plane of rotation. It is sufficient to

    consider two positions: First, theadvancing blade, extending directly to theright side and moving forward with thegiro; and second, the retreating blade,extending directly to the left side but

    moving rearward. Other positions of theblades could be studied similarly. Thefigures show the conditions sufficientlyaccurately for the purposes of thisdiscussion. Movement under full power isassumed.

    Consider the advancing blade. The cutshows a section of the rotor blade, whichis one foot wide and 20 feet long. The

    plane of rotation is inclined slightly, withthe rotor axis perpendicular to it, asindicated. The blade is pitched withrespect to the plane of rotation. Wp is thecomponent of airflow due to the forwardmovement of the giro, in the direction offlight, under the thrust of the propeller.Wr is the component of airflow due to therotation of the rotor, parallel to the planeof rotation. Wp and Wr give a resultantairflow in the direction indicated, whichcreates a drag in the same direction and a

    lift perpendicular to it. The resultant ofthe lift and drag is the airforce acting onthe blade at this point of its length. Theresultant airforce

    11

  • 7/31/2019 Field Artillery Journal - Jan 1937

    14/83

    THE FIELD ARTILLERY JOURNAL

    THE RETREATING BLADE OF THE ROTORA section of the blade acted upon by autorotative airforces

    is slightly behind the axis of the rotor, sothat the airforce developed here isantiautorotative, and acts to retard theautorotation which is indispensable inflight. However, it can be seen that, forsections of the blade nearer the axis of therotor. Wr is less than that shown, and theresultant airflow therefore is more inclinedwith respect to the chord of the airfoil; that

    is, the angle of attack is greater than that

    shown. An increase in the angle of attackmoves the resultant airforce forward towardthe rotor axis; and, for sections sufficientlynear the rotor axis, the resultant airforce isahead of the rotor axis, so that its action isautorotative. Thus,the outer portion ofthe advancing bladeis acted upon byantiautorotative

    airforces, and theinner portion byautorotative airforces.This condition has

    been establishedconclusively by test.

    THE ADVANCING BLADE OF THE ROTORA section of the blade acted upon by antiautorotative airforces

    Consider theretreating blade. Thesection of the bladehas its leading edgeto the rear, and it

    moves in a directionopposite to that offlight. The rotor axis

    is inclined as for the advancing blade, and

    of course the blade again is pitched abovethe plane of rotation. Wp has the samedirection and intensity as for the advancing

    blade. Wr, parallel to the plane of rotation,opposes the movement of the

    12

  • 7/31/2019 Field Artillery Journal - Jan 1937

    15/83

    AND NOW THE AUTOGIRO

    blade, just as for the advancing blade.Thus, Wp and Wr have almost opposing

    directions, while they are almost in thesame direction for the advancing blade.The resultant airflow is as indicated, witha decidedly greater angle of attack, but oflesser intensity, than for the advancing

    blade. The resultant airforce acting on theblade is much less than for the advancingblade; and, since it is ahead of the rotoraxis, it is autorotative. For sections nearerthe rotor axis, Wr is less than that shown,and the angle of attack is even greater; sothat the airforces acting on the retreating

    blade are autorotative throughout itslength.

    The lift is a maximum for positionsnear the advancing blade, and aminimum for positions near theretreating blade.

    For positions of the blades other thanadvancing and retreating, the airforces are

    predominantly autorotative. If the

    autorotative and antiautorotative airforcesacting on the blades in their variouspositions be considered collectively, theirresultantor algebraic summust bezero; for otherwise the speed of the rotorwould change until a constant speed wasestablished. If, for example, theautorotative airforces predominated, therotor would speed up, increasing Wr forall positions of the blades. This increasewould decrease the angle of attackthroughout, decrease the autorotativeairforces, and increase the

    antiautorotative airforces. These changessoon would stop the acceleration of the

    rotor, which then would rotate at aconstant speed under those particularconditions. It is true that the speed ofmovement and other conditions of flightchange the airforces acting on the rotor

    blades, but the effects are compensatingin such a degree that the resulting changein the speed of the rotor is slight. The girois designed so as surely to giveautorotation and adequate lift, and therotor speed throughout the range of flyingconditions undergoes remarkably littlechangesomething of the order of ten

    percent.

    FLEXIBILITY OF THE ROTOR

    Thus far the rotor has been consideredas though the blades were attached to theaxis rigidly. Actually, the blades are freeto fold upward like an inverted umbrella,the position of each blade in flight being

    controlled by the forces acting upon it ateach instant. The lift due to the airflowacts to raise the blade, except of coursewhere the lift is negative. The centrifugalforce due to rotation tends to held the

    blade horizontal. The necessity of thisarrangement lies in the variations of thelift to which a blade is subjected as itrotates. It has been shown that the lift isgreater on the side of the advancing blade(right) than on the side of the retreating

    blade (left). If the rotor blades were fixedto the axis rigidly, one effect of the

    FLEXIBILITY OF THE ROTOR

    The forces acting upon the advancing and retreating blades, combined so as to show the lift of the rotor asa whole

    13

  • 7/31/2019 Field Artillery Journal - Jan 1937

    16/83

    THE FIELD ARTILLERY JOURNAL

    differential in lift would be to roll thegiro sideward (to the left). Thus the

    hinges of the rotor blades provide aflexible rotor, and incidentally relievestructural stresses in the blades. Thesituation is shown generally in thefigure. Each blade rises until the lift is

    balanced by an equal component of thecentrifugal force acting on the blade.The other component of the centrifugalforce is balanced by tension on the

    blade. The resultant of the tension onthe blades is the lift of the rotor as awhole, and is balanced by the weight ofthe giro; except, in some positions,when the rotor lift is augmented by avertical component of the propellerthrust.

    The figure is somewhat misleadingunavoidably so. Since, as stated

    previously, the lift is greater on theright than on the left side, it would benatural to expect the right blade to be

    more "coned" than the left, as shown inthe figure. Actually, however, themaximum coning is when the blade isto the left front, and the minimumconing when the blade is to the rightrear. The condition is due to the factthat the rotation of the rotor changesthe position of a blade before the lift

    produces its full effect; in other words,coning lags behind lift. It may be addedthat the resultant lift of the rotor as awhole is not exactly on the axis asshown, although not far from it.

    Since the airforces acting on a bladeare changing throughout the cycle ofrotation, it follows that the coning alsois changing constantly. In short, a bladerevolves about the axis, rising andfalling with the varying lift. Thismovement of the blade perpendicular tothe plane of rotation is called flapping.

    CONTROLThe control it might be called

    steeringof the giro is remarkably

    logical, simple, direct, and effective.Control is primarily by tilting the rotor

    axis. Although the rudder and tailsurfaces are valuable aids in control,they are not strictly necessary for this

    purpose.

    Control in the vertical plane withpowerdiving and climbingis bytilting the rotor fore and aft through atotal of some 11 degrees, in quite thesame general fashion as for theautomobile in the horizontal plane. The

    figure shows the giro as for level flight.Its attitude with respect to a horizontalline is a general one for rectilinearflight: for climbing, it is inclinedupward along the line of flight; and indiving, it is inclined downward alongthe line of flight. In this attitude, thegiro may be said to be in balance, dueto its design. There are three forcesacting in the vertical plane, the thrust ofthe propeller, the lift of the rotor, and

    gravity. The design is such that, forrotor position A, all three forces actthrough the center of gravity, as shown,or sufficiently nearly so for the purposeof this discussion. Hence, so far asconcerns the vertical plane, the giro isin rotational equilibrium; there is nomoment acting to disturb its attitude;and the only movement is that oftranslation along the line of flight,

    parallel to the propeller thrust.If the rotor is elevated to position B.

    it is seen at once that the rotor lift nolonger passes through the center ofgravity, but is in front of it; the othertwo forces are unchanged in thisrespect. The result is that the rotor liftsets up a moment which turns the noseof the giro upward, and the machineclimbs. If the rotor is held elevated, the

    flight is curved, concave upward; and ifcontinued sufficiently, the result is aloop. Or the rotor may be held in

    position B only until the desired

    14

  • 7/31/2019 Field Artillery Journal - Jan 1937

    17/83

    AND NOW THE AUTOGIRO

    CONTROL OF THE GIRO IN A VERTICAL PLANERotor position A is that for rectilinear flight in whatever direction; rotor position B, that for curvilinear

    flight in climbing; and rotor position C, that for curvilinear flight in diving

    direction is attained, and then returned toposition A. The result then would berectilinear climbing.

    Similarly, position C gives a dive,either rectilinear or curvilinear,

    depending on how long the rotor is heldin position.If the motor fails or is cut out in flight,

    descent must follow; and autorotation ismaintained by the airflow due to descent.The descent may be either vertical orgliding, according to the attitude in whichthe machine is placed by the control. If aglide, the necessary propulsion is

    provided by a component of the force ofgravity. It has been found by test that thespeed of descentthat is, the verticalcomponent of the giro's total speedvaries with the inclination of the descent.

    If the glide is such as to give a horizontalspeed of about 40 miles per hour, thevertical speed is the minimum possibleabout 9 miles per hour. If either a greateror a lesser horizontal speed is obtained,

    the vertical speed is greater than 9 milesper hour. In any case, the vertical speedof landing without power is sufficientlysmall to obviate danger. The long glidingrange permits reaching a suitable placefor landing in case of engine failure. Thevertical speed of descent of the giro instill air is somewhat too great for a gentlelanding, so that some forward speed

    preferably is introduced just beforetouching the ground, in order to soften thelanding.

    Control in turns is quite similar tothat in the vertical planeby tilting

    15

  • 7/31/2019 Field Artillery Journal - Jan 1937

    18/83

    THE FIELD ARTILLERY JOURNAL

    CONTROL OF THE GIRO IN TURNSJust before a turn. The rotor is tilted laterally tothe position shown in full lines, but the machine hasnot yet responded, and is not in rotationalequilibrium

    The giro has responded to the lateral tilting of therotor, and is in the turn. It has banked so as toreestablish rotational equilibrium

    the rotor laterally through a total angle ofabout seven degrees. In the left figure, thegiro is in straight-away flight, just before

    a turn. The rotor is tilted laterally to theposition shown in full lines. The resultingchange in the direction of the rotor lift hastwo effects: It sets up a lateral componentwhich draws the giro bodily to one side;and it sets up a moment which rotates themachine laterally until equilibrium isreestablished. The side-slip is resisted bythe tail of the fuselage, which turns themachine, aided by the rudder if used. Therotation banks the machine automatically.The attitude after the turn is begun isshown in the right figure.

    THE HELICOPTER

    In connection with the giro, it is ofinterest to mention the helicopter, lest thetwo types of aircraft be confused. Thegiro decidedly is not a helicopter,although both types have rotors. Thegiro's rotor is air-driven; that of the

    helicopter is motor-driven. The airflow inthe case of the giro is upward through therotor; in the case of the helicopter, it isdownward.

    The inception of the helicopter datesback to the fifteenth century, long beforethe airplane appeared. Many helicopters

    have been built, but none has provedpractical nor come into use. Mechanicaland structural complications havecharacterized all constructed to date. The

    perfect helicopter would permit eitherswift or stationary flight. While thehelicopter has not been successful thusfar, it is not accepted in all quarters thatthe type is impracticable. *Only recentlyMr. W. Laurence LePage has advocated ahelicopter with a flexible rotor and directcontrol, but without a propeller. Forwardmovement would be by inclining the rotorforward, it being estimated that a speed of150 miles per hour could be obtainedwith an inclination as small as about eightdegrees.

    THE FUTURE OF THE GIRO

    The first successful airplane flight waswell over thirty years ago. It was success

    at least in man's age-long struggle toimitate the flight of birds; it

    *Journal of the Franklin Institute, October, 1936.

    16

  • 7/31/2019 Field Artillery Journal - Jan 1937

    19/83

    AND NOW THE AUTOGIRO

    electrified the world. There began at once aperiod of feverish activity in developing

    the new machine. A decade later came theWorld War, which intensified such effortsas nothing else could have done. It mightwell be that the elapsed years actually areequivalent to fifty years of normal peacetime development in this respect. Thus it isclear that the airplane has reachedmaturity; untold millions of treasure have

    been spent on it, including private capitaland direct and indirect aid by governments.A host of master minds have concentratedon it, and are still at work, spurred byworld-wide competition.

    A world full of scientific wonders hasfound special pride in the airplane. Whatis this upstart which has come along tochallenge the very fundamentals of theairplane? Why bother when the airplaneis filling so admirably the needs of aircommerce? Can it hope to matchmuchless excelthe perfection of the modern

    airplane? The giro indisputably is thecreature of a brilliant mind, a mindthoroughly familiar with the airplane. Thegiro is a reality, not a theoretical dream; italready is past the blueprint stage. It isidle, however, to compare the young giroof today with the sleek, perfectedairplane. People once smiled at thehorseless carriage. Shall we now dolikewise, when a wingless (in theordinary sense) flying machine appears?

    It is apparent that the giro isaerodynamically complexmore so than

    the airplanebut this complexity doesnot extend necessarily beyond the realm

    of engineering and design. Thedevelopment thus far has required a greatamount of costly research and test, andmuch more still is needed. The effort upto now has been confined tocomparatively small groups, andconducted as private enterprises.Recently, however, the National AdvisoryCouncil for Aeronautics has interesteditself, and is contributing helpfully. While

    progress has been marked andencouraging, it has been slow.

    The problem of the giro should beapproached primarily by considering itsessential principles, without unduestress on its present design, limitations,and defects. Does the giro offersomething worth while which theairplane has not? If the answer is yesor even possibly yesthen the Federalgovernment should put its might

    squarely behind this struggling infant,and push its development. The answershould be found in a period of yearsnot decades.

    We of the military now are about tomeet this strange, new bird which hascome among us. We now have theopportunity of participating in adevelopment which has dramatic

    possibilities. We must not forget,however, that the giro is only a boy, andwe should neither expect nor demand thata boy do a man's work.

    17

  • 7/31/2019 Field Artillery Journal - Jan 1937

    20/83

    Two Views on Transport

    Horse vs. MotorAt Night

    BY COLONEL EDWARD N. WENTWORTH,FA-Res.

    HE trend toward motorizing allbranches of field artillery is ratheralarming when one considers that

    in future wars the amount of nightmovement will be even greater thanduring the World War. Despite thegreater speed of motor units for

    movements over long distances, horseswill continue to be more rapid thanmotors within the division area, becauseof the better vision in the dark whichhorses possess as compared tochauffeurs.

    Striking evidence of this waspresented in a skeletonized field artillerybrigade problem which was carried on atCamp McCoy, Wisconsin, by the 161st

    FA Brigade this past summer. Theexercise involved a situation in which afrontal attack on the enemy positionindicated too great a sacrifice, and thedivision commander decided to attackfrom the flank. This necessitated themovement of the provisional artillery

    brigade, from their supporting positionsfor the frontal attack, to a new areawhere they could cover and support theflank attack.

    A reconnaissance by detachmentsdown to and including batteries for the

    purpose of selecting positions andcompleting survey operations, wasinvolved. The batteries were to be ledinto position under cover of darkness,and support the attack at daylight on themorrow. In the reconnaissance, ahandicap was experienced in themotorized organizations, because of the

    absence of motorized vehicles that couldgive the personnel thorough and quickaccess to all parts of the terrain. Themounted detachments were able to go

    through wooded areas, under cover,without disclosing their positions bydust. They therefore could make athorough study of the positions withconsiderably more speed than could bemade by the motorized units.

    The night occupation of position

    included one regiment equipped with abattery of horse-drawn artillery, oneregiment equipped with a battery oftractor-drawn artillery, and a thirdregiment equipped with a battery oftruck-drawn artillery. The firing

    batteries were left at rear echelons, thehorse-drawn being approximately threemiles and a quarter from the position to

    be occupied, the tractor-drawn about

    two miles and a half from the positionto be occupied, and the truck-drawnabout two miles and a quarter from itsgun position. All movements werewithout lights.

    At nine o'clock it was dark enough sothat orders were issued to bring up theguns. Word was sent to the horse-drawnregiment by mounted messenger, and toeach of the other two regiments by amessenger in an automobile. The horse-

    drawn unit, despite the fact that nearlytwo miles additional, going and coming,had to be traveled, was in position tenminutes before the truck-drawn unitsarrived, and about eighteen minutes

    before the tractor-drawn units arrived.A number of variable factors entered

    into the situation, such as the fact thatthe horse-drawn units were manned byROTC candidates who showed high

    enthusiasm, but who were as unfamiliarwith the horses as the horses wereunfamiliar with their drivers. This lackof acquaintance between horses

    18

    T

  • 7/31/2019 Field Artillery Journal - Jan 1937

    21/83

    TWO VIEWS ON TRANSPORT

    and drivers undoubtedly served to slow upthe operations somewhat more than would

    have been the case had the ROTC beenusing the horses regularly. On the otherhand the ROTC students were on theirmettle and full of enthusiasm to equal theregular soldiers in a tactical exercise.

    One is impressed with the knowledge,as a result of this experience, that horsessee better in the dark than men, and thatin the distances involved in divisionartillery movements, horses will givequicker support after dark than motorizedvehicles. In this exercise, the trucks andtractors were able to move over bad roadswhile, for part of the distance, the horseequipment had to move over secondarysand roads. This made the relative speedof the horses even more striking.

    Another factor involved in thesituation is the amount of noise. Anofficer, not of the brigade, who wentahead to an outlying OP some two

    thousand yards in advance, reported thathe could hear the tractors moving intoposition very clearly and well in advanceof the time they got into position, whereashe was unable to hear either the horses orthe trucks. Secrecy of movement is betterobtained with animal than with tractor

    equipment, unless the latter are improvedgreatly before another war.

    It is difficult to visualize any areawhere combat will be encountered, inwhich a motor vehicle could be inventedto take a reconnaissance party orindividual over any and all terrain in thesatisfactory manner that a horse does. Wehave many vehicles that can take

    personnel and materiel up to the area, butnone that can make a thoroughreconnaissance expeditiously. In futurewars decisions will have to be made morequickly, for movements will be muchmore rapid than in the past, owing to themechanized units. Reconnaissance willhave to be far more hasty, and a poorreconnaissance, which does not enablethe party to select the best OP's and

    positions, will be sacrificing an advantagewhich is rightfully theirs, whether thesituation be offensive, defensive, or amere security measure. It is just as

    important as ever that the artillery of theinfantry division, supporting the troopsthat meet the first shock of combat, havefacilities for the most efficient and rapidreconnaissance, the greatest degree ofmobility by night, and the best facilitiesfor secret movement.

    Horse vs. MotorRecruitsBY CAPTAIN CRESWELL G. BLAKENEY, FA

    F we could take two groups ofrecruits and assign one to a horse-drawn and one to a motorized battery;

    then, at the end of a given time, it shouldbe possible to answer the question ofwhether, in this motor-conscious age, it is

    easier to train truck drivers or pairdrivers. To all intents and purposes suchan experiment has been worked outduring recent ROTC camps attended by

    the advance-course students of PrincetonUniversity.

    Before their arrival in camp thesestudents had received a certain amount ofinstruction with both horses and motors. Assophomores and juniors they had an average

    of two hours "drill" each week in equitationor driving. They had studied motors fromthe theoretical side for one term. Allcould drive passenger cars. In other

    19

    I

  • 7/31/2019 Field Artillery Journal - Jan 1937

    22/83

    THE FIELD ARTILLERY JOURNAL

    words, these "recruits" certainly knewmore about horses, but probably no

    more about motors, than the averageincrement one might expect onmobilization.

    In the years prior to the summer of1936 about one-fourth of the instructiontime was given over to animal transport.This, in general, included themanagement of the pair and team,maneuvers limbered, short marches,

    practical harness adjustment, stable

    management, and care of animals. Theanimals and materiel of a regular batterywere used in this instruction. At the endof the first three weeks of camp, by dailyrotation of duties among the students,they were able to perform the duties ofthe various mounted individuals of a

    battery.

    At the beginning of the fourth week theunit marched from Madison Barracks toPine Plains, a distance of twenty-twomiles, with some difficulty, but withal, itcould make the trip. The next step in theinstruction was a hike of about sevenmiles, the pitching of a shelter-tent camp,and return to camp. This was accomplishedwith considerable fatigue to allhorses,students, and instructors alike.

    The camp finale was an overnightproblem involving a six-mile march, anoccupation of a position, a movementforward under cover of darkness to anew position, and return to camp aftersupporting a simulated attack at dawn.The six-mile march was made with somediscomfort, because of dust; theselection and occupation of the positionwas done in good style. The horses weretaken to water twice during the day, amatter of half a mile each day. Thecannoneers performed their duties in

    firing while the drivers were lookingafter the animals. The displacementforward was to be made at nine o'clock.

    In order to insure proper harnessing, thedrivers began to harness well before

    darkness had fallen. So that by the timethe movement had been made, the picketline stretched, unharnessing done, andthe animals fed, it was late beforeanyone was able to get any sleep at all.When the battery had returned to campthe next morning everyone wasthoroughly tuckered out.

    As for the summer of 1936, it was thefirst year the unit was equipped with a

    completely motorized unit of light fieldartillery with high-speed adapters for theguns. During the first three weeks incamp, again about one-quarter of theinstruction was given in motor transport,

    but much time was saved because themotors did not have to be harnessed andunharnessed, so that more stress could

    be laid on the duties of motor officers.During this time each student was givenan opportunity to drive all types ofvehicles and also to drive a truck with agun towed behind it. Instruction wasgiven, too, in maneuvers limbered, inconvoy rules, in maintenance and shopwork, and in the actual care which atruck driver must give his vehicle.

    At the end of this three weeks' periodinstead of the command moving to PinePlains, it remained at Madison Barracksand a daily march was made for service

    practice and ROP's. Student officersconducted the marches, and they and thedrivers were rotated daily. This routinewas interrupted for a 150-mile march toLake Placid, where camp was made forthe night and the vehicles cared for. Thefatigue of the day was so slight thateveryone was able to attend a dance. Thereturn trip was made the following day.During the entire march each student

    drove about fifty miles. Whereas thedriving was generally good, there was anoticeable improvement toward the end of

    20

  • 7/31/2019 Field Artillery Journal - Jan 1937

    23/83

    TWO VIEWS ON TRANSPORT

    each stint in the equal spacing betweenvehicles and the consequent uniform

    travel of the tail of the column.For the final overnight exercise thesituation required a thirty-mile march,followed by the same tactical situationand movement forward as for the

    previous year's horse exercise. As thiswas the culmination of the training, itgave an excellent idea, to those who hadseen both problems operate, of therelative efficiency of the two types oftransport, as far as the ability of thestudent drivers to function wasconcerned. The drivers performed theirduties nearly to perfection. The gunswere dropped in their proper positionswith despatch; the vehicles were taken tothe truck park and hidden mostsatisfactorily; fifteen minutes beforedarkness fell and the battery was tomove forward, the drivers were alertedand the motors turned over; all was quiet

    and orderly in coupling the guns, inmoving out, and in establishing the

    battery in its forward position; andeveryone was bivouacked at the guns ortruck park in short order. All of this indecided contrast to the days of horses. Inthe morning, the daylight firing wasdone and the battery returned thetwenty-five miles to Madison Barracks,where the vehicles were thoroughly

    cleaned before the men were released atnine-thirty. No one was tired and therewere no frayed tempers.

    During the course of the secondthree weeks' instruction the batterymarched a total of 910 miles. Therewere no lost vehicles; there was noaccident (not even a fender lost its

    paint); at no time was anyoneexcessively fatigued. The opinion ofthose charged with the instruction was

    that, as far as the transport wasconcerned, the drivers were able to

    handle the motor equipment onehundred percent more efficiently thanthey could horses. More was expectedof the unit and more was accomplished,with less fatigue. As an experiment asto how prospective drivers will react tomotors or horses it would seem well

    proven that a body of men can betrained more quickly to handle amotorized battery in all itsramifications than a horse-drawn one.Further, it shows that a motor driver,although not permanently assigned to atruck, can be trained to operate andcare for it over good roads and bad in arelatively short time.

    But from the standpoint of trainingreserve officers it would seem that acertain amount of training with horses isstill necessary. About half of the regulararmy division artillery is organized as

    horse-drawn; there is the horse artillerywith the cavalry division; pack artilleryhas been proven very much worthwhile;and there is no better way to make areconnaissance than on horseback. Inconsequence, as a matter of all-aroundtraining, instruction in both types oftransportation must be given to a certain

    percentage of the students studying to bereserve officers. As yet we can not afford

    to put all of our eggs in one basket andneglect either horses or motors. This dualtype of training can be given best atROTC institutions where, at the collegeor university, the students have anopportunity to work with horses and atthe summer camp they can use motors asthe means of transportation. Thus our

    prospective reserve officer will be able tostep into any type organization to whichhe may be assigned.

    21

  • 7/31/2019 Field Artillery Journal - Jan 1937

    24/83

    Who In The Driver's Seat?BY CAPTAIN JOSEPH I. GREENE, INFANTRY

    F our army should suddenly beexpanded to meet an emergency, itsmotor vehicles would be numbered

    in hundreds of thousands. For every

    one of these vehicles there must be adriver, and preferably, an assistantdriver also. It is thus worth our while toconsider what our sources of driverswill be, what degree of driving abilityour potential drivers may already

    possess, and what further training theywill need.

    At first thought the problem mayseem slight. There are 26,000,000registered vehicles in the United States,

    every one of which somebody drives.As some hasty statistician hascalculated, there are six vehicles apiecein our country for an army of 4,000,000men.

    On the other hand, the statement isoften made, and sincerely, by thosewho have supervision over the trainingof peacetime military drivers, that ayoung man who has never driven a car

    makes a better driver than one who hashad previous experience. This, as weshall soon see, is a broad statement, andis based on grounds that fit neither ourideas of emergency training nor themotor civilization of our nation.

    It is not difficult, however, toascertain what our situation would beas regards military drivers if warshould come at any time in the nearfuture. There are plenty of dataavailable; we have only to examinethem. We can gain the clearest picture,

    perhaps, by making several

    comparisonsnot only a comparisonbetween wartime and peacetimemilitary drivers, but also between bothof these and civilian drivers in general.

    In addition, we should consider in briefthe probable differences betweenmilitary vehicles in war and in peace,and between these and the general runof vehicles on our highways, since thisis a pertinent factor affecting drivers.

    First, we may dispose of the possibilityof making military drivers from men whohave never driven a motor vehicle. The

    points in favor of doing this are simplythat drivers thus trained learn the right

    way of doing things from the beginning,and have nothing to unlearn. This maywell be true. But here we immediately runcounter to the fact that in many parts ofthe nation today it would be hard to findmen of military age who have neverdriven a car of some kind. Even in the

    poorer districts, where the per-capitaownership of automobiles is low, therewas no dearth of boys at the beginning of

    the C.C.C., who had driven enough tobelieve they could qualify for a truckdriver's rating. In few camps were lessthan 25 percent willing at least to try outfor the jobs, and in many camps somethree-quarters thought they had a chance.Except for a small number of veterans,C.C.C. personnel consisted of youths of21 or younger. Any war army wouldconsist of men above 21, hence all themore likely to have had drivingexperience of some kind. The

    possibility, therefore, of selecting andtraining all wartime military drivers from

    22

    I

  • 7/31/2019 Field Artillery Journal - Jan 1937

    25/83

    WHO IN THE DRIVER'S SEAT?

    among only those without drivingexperience of any kind is difficult to

    imagine as practicable.But there are much better reasons fordismissing this idea entirely. A table ofmotor vehicle registration for 1935,

    published in the U. S. Governmentmonthly magazine, Public Roads,* forAugust, 1936, shows 3,655,705registered trucks and tractors. (Thetractors form a very small part of thewhole. Well over half of the total ismade up of trucks of 1-ton capacity orlarger.) According to the World

    Almanac, there are more than a millionmen gainfully employed as drivers andchauffeurs. These we may look upon ina measure as professionals. But there arestill more than 2,500,000 persons whomwe may call amateur truck drivers.Certainly there is a driver for everyregistered truck.

    How great a part of all these drivers,

    professional and amateur, really knowtheir business well enough to becomecapable military drivers in short order, itis impossible to say. Of the milliondrivers listed as gainfully employed,

    probably one in three works for acompany or corporation that operates afleet of vehicles. To hold such jobs ahigh order of driving ability is required.Commercial firms of the present dayrealize fully that motor vehicles form a

    big item in dollars and cents. They notonly require efficient and reasonablycareful driving but also expertmaintenance. They are fully awake tothe necessity for thoroughly traineddriving and maintenance personnel. Thattheir standards are high in both regardsis borne out by a reading of anyautomotive industrial journal, and by thefact that the ratio of accidents to

    taxicabs, busses, and commercial trucks

    is lower than it is for privately ownedpassenger cars. Many commercial firms

    require, for example, a rigid physicalexamination for all drivers, and manyare putting into effect the most modernmethods of testing driving ability.

    Of the 2,500,000 who drive trucks butare not primarily engaged in driving toearn a living, it is surely reasonable toestimate that one in ten is a fair driver.This group contains many farmers whoown and run their own trucks, and allthose such as plumbers, electricians, andrepairmen, with businesses too small toinclude a hired driver as such.

    Thus, of what we have termed theprofessional type of driver, we haveroughly 350,000, and of the amateurtruck drivers, some 250,000, whom wecan reasonably expect to drive withsome degree of experience. This total of600,000, it is worth noting, comprisesonly one driver in 43, when all the

    registered motor vehicles in the UnitedStates are taken into consideration.This great body of trained drivers is

    a potential source of military drivers inany emergency. It is true that our

    policy is to avoid disrupting civiliancommercial affairs any more than wecan help, in time of war. But it is not to

    be supposed that the mere fact that aman is a capable, highly trained, bus,truck, or taxi driver will be a bar toenlistment or grounds for draftexemption. Moreover, if an army needssuch men, it will work no greathardship if the commercial world ingeneral must replace them by lessqualified drivers, capable, however, oftraining to a similar degree ofefficiency. If an emergency army took300,000 drivers from their civil

    pursuits that would be only 9 percent of

    all the truck drivers in the nation, and alittle more than 1 percent of the driversof all kinds. And even if we assumethat all members of an army of

    *Publication of the Bureau of Public Roads,Department of Agriculture.

    23

  • 7/31/2019 Field Artillery Journal - Jan 1937

    26/83

    THE FIELD ARTILLERY JOURNAL

    4,000,000 were drivers of registeredvehicles, 85 percent of all drivers would

    still be left in civil life. Women, menbelow and above military age, andunemployed drivers would soon make upthe difference to the business of thenation.

    It seems likely, therefore, that therewould be no lack of drivers if war shouldcome. In fact, obtaining experienceddrivers in an emergency period will beeasier than in time of peace. In time of

    peace few good drivers with steady jobsenter the enlisted ranks. Even in years of

    business depression, an experiencedmotor vehicle driver seeks, and oftenobtains, work upon Government projectsat somewhat higher scale of pay than hewould be certain of getting as a soldier.The C.C.C. truck-driver grades are onlyone example. Hence it is that there are notmany young men among peacetimerecruits who already know reasonably

    well how to drive and take care of a truck.All in all, then, we are likely to bemuch better off as to trained driving

    personnel for a wartime army than, forexample, as to trained machine gunners.Whatever their experience, of course,drivers brought into the army will needfurther training in military ways ofdriving. It is not to be expected thatwartime drivers will jump into trucks andaway to battle. But even if an emergencywere so great as all that, it would be wellwithin possibility to find enough driversto operate the vehicles with fair efficiencyfrom the start. In the summer of 1935,when, in maneuvers, the army began touse modern trucks in large numbers,remarkable results were achieved withdrivers inexperienced in militarymovements.

    But are the conditions of military

    driving actually so much more difficultthan those of civil traffic as it runs uponour highway by day and by night? It isdoubtful. Indeed, except for the one

    factor of enemy activity, military drivingwill be done under conditions that are

    generally much better than those of dailytraffic.In the first place, the condition of

    vehicles will be much better. During anextensive traffic survey in New Jerseyin 1933*, the ages of 239,000 truckswere noted. The table shows what wasfound.

    Age

    Percent

    of TotalLess than 1 year .......................... 3.91 year .......................................... 14.12 years ........................................ 18.23 years ........................................ 16.94 years ........................................ 18.05 years ........................................ 9.66 years ........................................ 6.57 years ........................................ 5.08 years ........................................ 2.99 years ........................................ 1.710 years ...................................... 1.110 to 20 years ............................. 2.1

    There were 35 trucks more than 20years old. The average age of trucks wasalmost 4 years. These figures, from a

    populous industrial State, can be taken asfairly representative of the country atlargeif anything, a little above theaverage. They speak only generally, of

    course, of the average condition of the239,000 trucks, or of the condition of anyage group. But that can be guessed by anyone who drives his own car, and takeseven a little pride in keeping it in shape.

    If war came, the army might have anumber of four-year-old vehicles. Theywould be in good condition, however,

    because they would have had the excellent

    *The report was made by Mr. L. E. Peabody,Senior Highway Economist, Division of HighwayTransport, Bureau of Public Roads. Department ofAgriculture. The data in the table appeared in PublicRoads for April, 1935.

    24

  • 7/31/2019 Field Artillery Journal - Jan 1937

    27/83

    WHO IN THE DRIVER'S SEAT?

    maintenance that obtains in the army intime of peace.

    But by far the greater part of ourvehicles would be new. Indeed it isprobable that in the event of war wecould get new vehicles as fast as wecould organize units to use them. Theexisting stocks alone of suitablecommercial vehicles would give us anexcellent start.

    There is other plain evidence, too, toshow that military vehicles under almostany conditions are kept up better thanthe average car. Of more than a millioncars inspected in Pennsylvania, a year ortwo ago, 40 per cent needed brake repairwork. In another State, four cars out offive had glaring or insufficientheadlights.

    These figures are typical of the carsthat we pass daily on the road, but not ofmilitary vehiclesin peace or in war.Maintenance may slump during an

    extended campaign, but in our motorcivilization, and in a militaryorganization, drivers' maintenance,higher maintenance and inspection, unitreplacement, or even vehiclereplacement, will prevent military motorvehicles ever reaching the state ofneglect that is all too common innonmilitary automobiles. In general, thedrivers of an emergency army will havemuch better vehicles to drive than theydrove before they put on uniforms.

    And vet the performance of the greatmass of vehicles comprising daily trafficis truly remarkable. The 26,000,000vehicles of the United States eachaverage 8,000 miles of travel per year.

    In time of war, the military drivermay drive farther than that in a year'stime. But much of his driving will beunder better conditions, not only as

    regards condition of vehicle, but also asregards risk from his own or his fellowdrivers' carelessness. In spite of the greatnumbers of automobile accident

    fatalities that occur each year in theUnited States, only one recorded

    accident of any kind occurs in each200,000 miles of vehicle travel. Andonly one fatal accident occurs in each5,000,000 miles of vehicle travel. (Thevehicles of the country travel about650,000,000 miles per day. Thesurprising thing, when the figures arecarefully studied, is that more accidentsdo not occur.)*

    These things are true in spite of thefact that requirements in the differentStates as to driver's examinations varywidely, and that States with thoroughlaws thoroughly enforced are fewindeed. Taking the United States ingeneral, with these few exceptions, thehalf-blind, the deaf, the aged, theyouthful, the decrepit, the drunken, thereckless, the careless, the inexperienced,and even the half-witted, have smalltrouble obtaining drivers' licenses where

    one is even required.In any conceivable military force,however, drivers will, like all soldiers,

    pass a physical examination beforeacceptance into the service. They willcome from a limited age group, whichfor the most part will eliminate driversof less than 21. (The accident rateamong youthful drivers is far higher thanin any other age group.) Furthermore,soldiers selected as drivers will have to

    pass special drivers' tests based onmodern, scientific methods of driverselection.

    The wartime military driver, then,will drive a better vehicle, with lesschance of accident in the ordinary sense,than the man behind the wheel on any

    busy highway.Moreover, he is also subject to uniform

    *Editorial Note: Yet it has been said thatautomobile accidents, from 1920 to 1935, cost thiscountry more casualties than all four of its majorwars.

    25

  • 7/31/2019 Field Artillery Journal - Jan 1937

    28/83

    THE FIELD ARTILLERY JOURNAL

    training, discipline, and control. Athousand vehicles moving down a

    highway, all driven by men who havehad at least a brief training in doing thesame things in the same way, have afar better chance of arriving atdestination intact, or with a minimumof difficulty, than a thousand civilianvehicles whose drivers may havealmost as many different notions of theway to drive. Standard safe drivingdistances, and standard rules of theroad are two of the most importantfactors in this regard.

    We must bear in mind, however, thatmuch wartime driving will be off themain highways on country roads andcross-country routes. Furthermore, the

    best of highways may become torn byshells and bombing. Driving under theseconditions must be learned byexperience, and it is here that men whohave been used to driving over similar

    ground in civil life will show to bestadvantage. The country truck driver, thelumber haulers, the contractors'employees who have learned how tomaneuver their loaded vehicles overrough detoursthese will have the bestgroundwork of experience for the mostdifficult army driving. Those who have

    been more used to highway and citydriving will have to learn by training and

    by experience.From experience also must comeproficiency in driving under conditionsof battle itself. But here, surely, longcivil experience tempered by brief armytraining should be of greater value than a

    brief period of military training withoutany previous experience.

    We may conclude that in case of warthe following will be true:

    (1) There will be great numbers ofexperienced drivers from which to selectour military drivers.

    (2) Many of them will have hadexperience in driving over poor roads

    and rough terrain.(3) All drivers from civil life willneed at least a brief training in militarymethods, but enough will be capable ofhandling vehicles with a minimum of

    practice and trainingor even with noneat allif that should be necessary in agreat emergency.

    (4) It will not be practicable to trainmilitary drivers from men who havenever driven before. It will take too longeven if it should be possible to find suchmen in adequate numbers.

    (5) In general, military driving isdone under better conditions than incivil life. The one important exceptionis on and near the battlefield or underhostile air attack. But vehicles will bein better condition, and standardmethods of maintenance and drivingwill obtain.

    The gist of all we have said may besummed up about as follows: What weshall need as emergency driver trainingis not an elementary course in drivingand drivers' maintenance, but intensivetraining in correcting the bad drivinghabits of experienced drivers and inadapting the experience of such men tothe special conditions of militarydriving. Since we shall need manydrivers at once, there must be a rapid

    process of elimination, which will putthe best men in drivers' seats as soon as

    possible, and keep a supply of gooddrivers continuously ready to take thewheels of new vehicles as they are

    procured. This process must also dropout the "in-and-out Sunday drivers" andall others whose ability does not comeup to the mark. Instead of having toofew, we are sure to have more drivers

    than we need. We must be prepared touse modern methods of testing andselecting in order to pick the best.

    26

  • 7/31/2019 Field Artillery Journal - Jan 1937

    29/83

    The Italian Artillery in Ethiopia(DIGESTS BY LIEUTENANT COLONEL JOHN S. WOOD, FA)

    S time goes on the magnitude ofthe Italian effort in Ethiopia

    becomes more apparent. An ideaof the difficulties encountered and of theefforts required to overcome them may begained by a study of artillery employmenton the Eritrea and Somalia fronts. Thesefronts will be considered in turn, for they

    present marked differences in terrain,

    forces involved, and tactics employed.ERITREA EXPEDITION*

    1. TERRAIN

    The terrain confronting the northernItalian columns consisted of a high

    plateau extending parallel to the coast at amean height of 2,000 meters and cut bydeep and rugged valleys. The few roadsand trails followed the main ridge along

    the center. They were wide enough forfairly easy going along the levels butbecame only mule or foot paths in thevalleys. The principal one, the so-calledimperial highway, was no more than amediocre dirt road with no maintenance.

    Nevertheless, in dry weather on theflats, travel was generally simple, evenfor motor vehicles, owing to the ease ofmoving across country and ofimprovising trails. In the valleys and on

    the slopes, however, movement wasalmost always difficult and requiredspecial measures or the construction ofroads.

    Both truck and tractor columns wereable to move and maneuver closely inrear of the troops, particularly whenfurnished with the assistance of an escortof foot troops, as was normal. Packartillery was always able to move where

    needed and even the truck units nearly

    always found some way to advance.Observation was excellent from the

    many high points and isolated hillsoverlooking the plain, air observationrarely being needed.

    There was no lack of both surface andground water. The latter is found at shallowdepth, sometimes even constituting anobstacle to motor movement.

    From an artillery standpoint, thegenerally favorable conditions ofmaneuver, the absence of naturallimitations to fire, and the excellent

    possibilities for observation andsignalling favored a large-scaleemployment of every type of field piece,except the heaviest calibers. Naturally,the exceptional conditions and the gravedifficulties of supply required specialmeasures in the organization of troops

    and trains and in manner of theiremployment.

    2. ORGANIZATION.The artillery plans and preparations for

    the expedition were based on theforegoing considerations, the need forlight, fast units, and the absence of enemyartillery. A reorganization of unitsincluded motorization to the greatest

    possible degree with a considerablereduction of battery personnel andmateriel. The number of guns was cutdown to conform to the possibilities ofammunition supply; the trains of pack

    batteries were motorized; truck-drawnbatteries were reduced to three pieces;and the reserve artillery was given thefastest trucks available.

    The peacetime artillery of three nativebatteries (65/17 guns*) and three

    *The usual Italian system of describing artillery.In general, the top figure represents the caliber inmillimeters and the lower figure the length incalibers.

    27

    A

    *L'artiglieria nella guerra Italo-Etiopica, by Gen.GavarelliRivista Di Artiglieria E Genio, September,1936.

  • 7/31/2019 Field Artillery Journal - Jan 1937

    30/83

    THE FIELD ARTILLERY JOURNAL

    companies of foot artillery for manningthe frontier forts was finally augmented

    and so organized as to provide:Four native pack mule battalions ofthree batteries (65/17 or 75/13), one foreach native brigade.

    Three native tractor and truckbattalions of three batteries (77/28).

    Two truck-drawn battalions of threebatteries (105/28) manned by Italiannationals.

    Four native fortress artillery groups oftwenty-four batteries, together with a likenumber of national groups. These groupsdisposed of 400 pieces of various calibers(120, 105, 77, 75, 76) intended for theforts in being and those to be constructed.

    From Italy were received themotorized battalions of the generalreserve artillery and the organic artilleryof the divisions constituting theexpeditionary force, together with thenecessary cadres to complete the colonial

    units.In order to provide a solid defensiveorganization for the colony, three lines offortified posts were constructed along 300kilometers of front on the southwestfrontier. These were capable of all-arounddefense, and were provided with fifteento thirty days' supply of ammunition,food, and water. They were mannedchiefly by artillery (82 batteries of 320

    pieces) and a truck transport pool wascreated to facilitate the movement andreinforcement of these units. This systemof posts was pushed forward during theadvance into Ethiopia to provide

    protection for the occupied areasanextremely difficult and laborious task.

    As an experiment, two especiallymobile motorized battalions of 77/28were organized for close-supportmissions in any terrain. The guns were

    knocked down into suitable loads andtransported on light trucks, supplemented

    by small mountain tractors and trailers forsupply and for movement in and around

    the battery positions. The battalioncombat and field trains were truck units.

    Owing to the impossibility of securing allthe required motor equipment, the utilityof these motor pack units could not befully determined.

    A groupment of battalions (100/17 and149/13), motorized, arrived from Italy toconstitute the general reserve artillery.

    3. TRAINING.

    By means of schools, tacticalexercises, and firing practice, the whole

    expeditionary artillery was rapidly madefamiliar with the following principles ofemployment:

    a. The necessity and possibility ofpushing immediately in rear of theinfantry ready for prompt action in orderto utilize the artillery superiority to theutmost degree. Hence: Careful selectionand reconnaissance of routes; provisionof special means to overcome terrain

    difficulties; assignment of engineer andinfantry detachments as escorts tofacilitate artillery movement.

    b. Fire action in close support of theinfantry. Hence: Liaison detachmentswith each infantry battalion at least;observation well forward; sure means oftarget identification and preparation offire (charts and maps); simple but surecommunication (maximum use of visualsignalling).

    c. Decentralization of command andof firing units, but with the possibility ofcentralization by even the highestcommander when necessary. Hence: Each

    battalion in direct support of a designatedinfantry unit with priority of fire missionsin its zone of action, but incommunication with the higher artillerycommander for other missions:continuous forward reconnaissance by

    both battery and higher commanders, toinsure prompt displacement behind theadvancing infantry.

    Owing to the special conditions of

    28

  • 7/31/2019 Field Artillery Journal - Jan 1937

    31/83

    THE ITALIAN ARTILLERY IN ETHIOPIA

    terrain and the enemy weakness in artilleryand air forces, battery positions were

    selected further forward near theirobservation posts, and were closely groupedto simplify the organization of command,communication, and fire. In these forwardareas each battalion and isolated battery hadto provide strong all-around machine-gundefense of its positions.

    Air observation was planned andprovided but was not much employed inthe actual operations. It was rarelyneeded, except for the indication oftargets and a limited amount ofsurveillance.

    The corps topographic sections and thearmy map section, together with acolonial topographic section organized

    prior to their arrival, were practiced inrapid preparation and distribution ofcharts and maps. The work of thesesections, in conjunction with the airphotosections, was particularly effective and

    valuable during the entire advance.4. OPERATIONS

    a. First phase.The information of the enemy at the

    beginning of active conflict in Octobergave no indication for any particularapportionment of the reserve artillery. Itwas finally assigned to columnsaccording to the roads available.

    Hardly a round was fired during the

    initial advance, which was made in threecolumns:

    The west column (2d Corps) to Adua(Adowa);

    The center column (Eritrean Corps) toEnticcio;

    The east column (1st Corps) toAdigrat.

    The difficult marches, however, furnisheda large-scale test of the maneuverability

    of the new artillery units, both pack andtruck. The truck-drawn units were able tofollow closely, except those of the centercolumn, which were held up by

    impassable mountain terrain about thirtykilometers north of Enticcio. Had infantry

    and engineer detachments been furnishedduring this period it is certain that nodelay would have occurred in the artilleryadvance. The light trucks and the tractors,

    particularly, demonstrated exceptionalmaneuvering power over difficult ground.

    As soon as the first objectives wereattained, the fortress artillery was broughtforward to man the second and thirddefensive lines of the newly occupiedterritory. Within a few days twenty

    batteries had arrived as a nucleus of thisdefense.

    b. Second phase.The long advance to the Macalle-

    Tembien-Tacazze line, over increasinglydifficult and little-known country, gaveadditional evidence of themaneuverability of the truck-drawnartillery. The native battalions of 77/28and 105/28 followed immediately behind

    the infantry and were soon joined by thebattalions of 149/13.

    As before, the defensive batteries weremoved forward promptly, fifteen of them

    being used along the line ofcommunications in the Macalle sectoralone.

    c. Third phase.After the relief of General di Bono and

    the assumption of command by Marshal

    Badoglio, the operations took on a newcharacter and a new tempo. The enemy hadconcentrated two strong forces, one underRas Mulugueta south of Amba Aradam, theother under Ras Cassa south of Tembien.

    In this situation, almost all of thetruck-drawn artillery was concentratedin the vicinity of Macalle as a generalreserve under the army commander. Twogroupments, a total of eleven battalions

    and thirty-four batteries, were formed.Some of these were brought forward byforced marches of 500 kilometers infour or five days, over the few

    29

  • 7/31/2019 Field Artillery Journal - Jan 1937

    32/83

    THE FIELD ARTILLERY JOURNAL

    trails, or across country under extremelydifficult conditions.

    The artillery action in the ensuingbattle of Enderta in February was intense,continuous, and often decisive. In thedouble envelopment of the strong andextensive Amba Aradam position, the gap

    betwen the two corps was particularlydangerous. Two or three battalions of themotorized reserve artillery were attachedto each corps for protection of the outerflanks, the remaining five battalions beingdisposed centrally in front of Amba so asto cover the front of both corps and withneutralization and interdiction missionsalong the entire strong enemy fronttogether with the particular mission of

    protecting the corps' inner flanks.Battalions were massed close to their

    observation posts and the infantry lines,prepared for close defense, and joined bya very complete communication net toinfantry and higher artillery commanders.

    A gridded map, 1/50,000, was widelydistributed to both infantry and artilleryfor location of targets and preparation offire.

    The fire throughout was prompt, sure,and effective. After a rapid but intense

    preparation by all the artillery, theinfantry began its long advance,constantly supported and protected by the

    batteries, which were particularly activein breaking up counterattacks. Frequentdisplacements were required, many ofthem of six or seven kilometers. In thefive days of this battle which routed theEthiopian forces, the artillery fired 26,000rounds, half being expended by thereserve artillery.

    About half of the reserve artillery wasnow sent to Scire and Tembien for actionagainst the remaining enemy forces. Themovements were made by forced marchesand with great rapidity. One battalion of149/13 moved 550 kilometers in threedays over practically trackless country.

    d. Fourth phase.In the latter part of March, the

    Ethiopians were reported concentrating

    their best troops around Ascianghi for alast stand. These forces were believedto possess artillery in considerableamounts which were later found to be

    From Revista Di Artiglleria E Genio

    ITALIAN NATIVE TROOPS IN ETHIOPIA WITH 65-mm. ACCOMPANYING GUN

    30

  • 7/31/2019 Field Artillery Journal - Jan 1937

    33/83

    THE ITALIAN ARTILLERY IN ETHIOPIA

    much exaggerated. For this reason, everyeffort was bent toward providing for the

    advance of particularly mobile units ofreserve artillery to supplement theorganic division pack artillery whoseeffectiveness was now much reduced bythe loss of a disturbingly large number ofits animals.

    The zone of advance was moredifficult than any yet encountered. Onone stretch of 50 kilometers there werethree mountain passes at least 3,000meters high traversed only by mule orfoot paths. All available troops, includingthe greater part of the artillery personnel,were set at work constructing a road.Fifteen days were allowed for itscompletion but the task was abandoned astoo long after a week or so of labor.

    The approach of the rainy season andthe increasing enemy activity called for aspeedy advance. A route was selectedover which the artillery was to be dragged

    or carried. A groupment of reducedbattalions of six to nine pieces, accordingto the number of light trucks available,was formed. Pieces were disassembledinto transportable loads. The whole effortof this groupment was directed towardmoving the guns of four battalions.Another groupment was formed by the

    personnel of the other five battalions ofthe reserve artillery with the mission of

    assisting the movement of the guns andcarrying out the necessary reconnaissanceand preparations for their immediateemployment in the new zone. In spite ofthe rains, by the end of March, a weekahead of the time expected, two battalionsof 100/13 were in position, and renderedinvaluable assistance in breaking up theenemy attack which began on April 1st.Similarly, in the subsequent advance onAddis Ababa, the artillery was present,ready to support the infantry on everyoccasion.

    * * * *

    The northern operations presentedmany features of special interest to the

    artilleryman. Particularly noteworthy werethe maneuverability of truck-drawn units,the appearance of motorized pack artillery,the utilization of fortress artillery to protectthe zone of communications, thedetermination to keep the guns inimmediate touch with the infantry in allsituations, and the insistence on having ahighly mobile artillery mass of maneuverin hand under the immediate control of thecommander-in-chief.

    SOMALIA EXPEDITION*

    1. TERRAIN.The lower Somala plain extends from

    the coast for hundreds of miles intoEthiopia, wooded and flat, covered withthorny busha "spiny fog of green"during the wet season; parched, dusty,and yellow during the dry months.Traversed only by native trails and by a

    few sluggish streams, this vast territoryoffers a formidable obstacle to anyadvance.

    In such a country, the impossibility oflocal supply, even of water, necessitatedlong lines of communications and strictsubordination of operations to themaintenance of these lines. Tactically, thelimited possibilities of orientation,communication, observation, andmaneuver, together with the necessity forconstant security measures on all sides,constituted a peculiarly difficult problem.

    On the higher plateau, four or fivehundred miles inland, the terrain becomessimilar to that of the great centralhighland described in the account of thenorthern operations. Rather open incharacter, broken by rugged hills and

    *Le nostre operazioni nell' Africa Orientale-Rivista di Fanteria, January, 1936. L'impiego dell'-

    artiglieria nella Somalia, by Major Petroni and Capt.BarengoRivista di Artiglieria e Genio, July-August,1936. Impressioni di guerra sul fronte Somalo, byMajor PetroniRivista di Artiglieria e Genio, April-May 1936.

    31

  • 7/31/2019 Field Artillery Journal - Jan 1937

    34/83

    THE FIELD ARTILLERY JOURNAL

    deep valleys, with few roads or trails, itpresented only the usual difficulties

    encountered in mountain country.2. TRANSPORT.

    The few dirt trails existing at thebeginning of hostilities were soonchurned up into clouds of dust in dryweather, and seas of mud in the wetseason, by the constant stream of trucksfloundering along them. Nevertheless,

    both troops and supplies were brought up,in spite of the fact that four or five hours

    were often required to move a singlekilometer ahead. Naturally, the roadswere improved as time went on, but itmust be remembered that the distanceswere great and road material extremelylimited. The distances from the port ofMogadiscio to the various advanced baseswere from 300 to 1,000 kilometers.

    Truck transport was used from thecoast to the combat zone, camels and

    pack mules from there forward. Of these,the mule was considered superior.

    3. TROOPS.

    Prior to the border incident at Ual Ualin 1934 the troops in Somalia consisted ofa few Arab-Somali battalions