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"Reading a Japanese Map" from Tactical and Technical Trends

The following WWII U.S. military report on Japanese military maps was originally published in Tactical and Technical Trends, No. 47, June 1, 1944.

[DISCLAIMER: The following text is taken from the U.S. War Department publication Tactical and Technical Trends. As with all wartime intelligence information, data may be incomplete or inaccurate. No attempt has been made to update or correct the text. Any views or opinions expressed do not necessarily represent those of the website.]
 

READING A JAPANESE MAP

A map is taken from the body of a dead Japanese officer -- what does it represent? The ability to read and interpret such a map on the spot may mean the difference between victory and defeat.

a. General

In many ways, Japanese maps, although generally similar to our own are puzzling. The symbols upon them frequently resemble ours, but often are strange, and again, familiar but having a different meaning from ours. A broad-leafed tree, for example, is represented by in both systems, but -- suggestive of an apple hanging on a branch -- means an orchard tree (or "private soldier"); is a spring, a foundry and a statue; elongate the zero into capital O, and "statue" becomes "isolated tree." The symbol for a road (more than three meters wide) is two parallel lines but if the lower line is broken it discloses that significant military detail, "Road impassable to carts," and , "Road under construction" differs from an 18-foot country road. The Japanese symbol for a railroad rather suggests a canal. The military symbols are even more confusing, as they seem to be a badly digested combination of the American and German systems -- for example, an observation post in German is ; in Japanese, a battalion OP is ; an AT gun in German is ; a Japanese rapid fire gun . Occasionally, a few curious figures are found, as in a photostat of an ex-British area marked with a symbol , apparently meaning "airport", although the character suggests a rapid-fire gun or a battalion OP, and the usual airport symbol is . Later in this article, military symbols will be discussed in more detail.

In view of these differences, it is believed worth while to examine Japanese maps and both their topographical and military symbols with a view of presenting in a condensed form enough information to enable a combat officer with little time or energy for detailed study to grasp the essentials of any Japanese map that would be likely to fall into his hands. Much has been deliberately omitted -- the symbols for fences, for example, are limited to those having military significance -- stone walls that provide bullet-proof protection and bamboo fences and "living tree" hedges that may either give cover or hide the terrain beyond. Hereafter is shown a number of the more frequent Japanese terrain symbols. Several types of terrain are illustrated by cuttings from un-retouched maps such as figure 1, which shows an urban area, part of Kyoto sheet, and figure 2 cut from another part of the sheet are flat rice-lands. Ordinary countryside and mountainous areas are mapped in figures 3 and 4. On page 43 is a selection of military symbols, and figures 5, 5A, and 6 are examples of actual Japanese combat maps from Attu and Guadalcanal, reproduced as faithfully as possible.

Many Japanese maps are printed in an eye-straining small type. When working with a Japanese map, even in a good light, a 4-inch magnifying glass is extremely useful. For the benefit of American readers, the printed maps here illustrated are enlarged to almost twice their original size. It will be noted that these maps show an extraordinary amount of detail -- far too much to try to memorize. Symbols might be found that represent a prefectural office, district (gun, pronounced "goon"), municipal, village, MP, police, revenue, monopoly and meteorological offices; a factory, foundry, granary, lime kiln, lumber yard, metal works, powder magazine, store house, temples of various faiths and an "orthodoxy bell tower" -- whatever that may be. Practically anything anyone might wish to locate is shown, except a comfort station. Occasionally symbols are thrown in which may be obvious to a Japanese but not to a westerner, without the usual careful explanation -- in Japanese script -- on the margin. Finally, symbols may vary with the scale of the map, with one set for a 1 to 50,000 and another for 1 to 200,000. Only the more useful symbols are therefore included.

COMMON JAPANESE MAP SYMBOLS

[Common Japanese Map Symbols]

*From figure 6, Guadalcanal
*It is frequently very difficult to distinguish between a badly printed "masonry wall" symbol and a "wooden fence." The "wall" is apt to have white spaces.
**Inverted picks indicate abandoned mine.
***Frequently looks like simple cross lines.

b. Japanese Topographical Maps

(1) General Observations

Japanese official topographical maps are published on standard scales 1 to 10,000, 1 to 20,000, 1 to 50,000, and so on. As the 1 to 50,000 is the most usual, and employs the standard symbols, parts of maps in this scale are here reproduced for illustration. Sometimes the scale will be stated at the bottom as a fraction in Arabic numerals, sometimes not. However, there is a distance scale at the bottom of the sheet in meters and ri, the Japanese "statute mile," actually a one-hour walk, or league, of approximately 2.5 U.S. miles. The meter scale is recognizable by its marking in thousands, and by the Japanese character at the left, which in small print is apt to look like an asterisk. The meter-scale is apt to be on top, the ri-scale below. From the meter scale, the mathematical scale of the map may be quickly calculated by the following method: A meter is approximately 39 inches. Therefore, measure off from the metric scale a convenient number of thousand-meter units to correspond with the inch-scale of the ruler, multiply the thousand-meter units so measured by 39,000 and divide by the number of inches spanned. For example, in the scale below as shown on a Japanese map, the total length of the metric scale, including the fraction-scale, to the left of zero, is four inches; therefore 5,000 meters equals 4 inches; 1,000 meters equals 39,000 inches; 39 x 5,000 = 195,000; divided by 4 the result is 48,750, or approximately 50,000; hence, the scale is 1 to 50,000.

[Map Scale]

Somewhere, the contours will be marked in Arabic numerals -- a typical example, the sheet used in figure 4, has the 100-meter contours in heavy lines, and intermediate unnumbered lighter lines representing 120, 140, 160 and 180-meter contours are printed in finer lines. As to symbols, on the left there may be a column of symbols which is frequently helpful although explained in Japanese. However, as will be noted in the following discussion of the map of Kyoto, occasional unexplained symbols occur.

(2) Map of a City

Figure 1 represents the NE portion of the city of Kyoto, situated on the largest Japanese island, Honshu, southwest of Tokyo, and about 25 miles north of the important port of Osaka. Three miles northeastward lies the beautiful lake of Biwa (Biwa Ko) from which Kyoto draws water through a gravity tunnel large enough to accommodate market boats. The city was the ancient capital of Japan and has many historic shrines and temples. Today it is one of the centers of silk, embroidery, weaving, porcelain and lacquer industries which ten years ago supported a population of over a million. Upon the map, a reference grid has been drawn, the lines lettered from north to south and numbered from west to east. It may be read quite simply, down and to the right. Distances south of lettered lines are indicated by numbers. For instance, the bath-tub-shaped symbol of the prefectural office is at E.8, 1.9. A question may be raised as to why a city is included in such an article as this, but plenty of fighting has occurred in cities, and it may be convenient to be able to recognize and direct gun-fire quickly on such strategic points as telephone exchanges or power sub-stations.

[Figure 1: City Map (Kyoto)]
[click to enlarge]

Following the double-track (electric) railroad, possibly of 4 foot 8 1/2 inches European gauge, that enters the grid from the northeast, it will be seen that the right-of-way crosses two 18-foot roads, one of which leads to a local station. Westward, at A.9, 6.2 will be seen the single dark line of a three-foot, push-cart path, which joins the road just west of the depot and, running SW parallel to the tracks, till, as it crosses a small branch of the Biwa Lake Canal it connects with another 18-foot road. This branch canal enters the map at D.6, 7.0 and circles northwest to A.1, 4.3 thence southwestward to B. 8, 1.3. In its course, it apparently passes under the small stream at A.7, 5.5 in a siphon or over it on an aqueduct--it is difficult to say. At B.1, 2.9 and further on, siphons or culverts are also indicated. Returning to the railroad, and 18-foot road at B.4, 6.1, the road winds eastward, crossing the double tracks apparently on grade. South of the road are dry-rice-field symbols and a small embankment.

The railroad proceeds southwest to another station, north of which at B.9, 5.2, is the cog-wheel symbol of a factory. The light shading of the houses indicates light construction, heavier shading, heavier construction, not population density. At C.7, 4.5 will be seen the thin capital X of a police station. Just east of the terminal is the swastika symbol of a Buddhist temple. South of the terminal at E.0, 4.6 will be seen the circle of some sort of a local city office, and SW of the office at E.4, 4.3, the "little boy" symbol that indicates a school. Near the terminal there should be a post office, and one will be found at E.8, 5.6 with the line-and-T-in-a-circle symbol indicating that there is telephone and telegraph service as well. A telegraph-and-post office will be found at H.6, 1.9 next to a school. No example of the "envelope" symbol has been found. The "city hall" (inner and outer rings) will be found at G.4, 3.6 and at H.6, 1.4 west of a school, may be made out the star representing "regimental & defense Hq.," perhaps an armory. There are several items of interest in the E, F, 6, 7 quadrangle, including an obvious triangulation station numbered 102.6 or 102.6 meters elevation, a Shinto "heavenly gate" shrine-symbol just above it, the three-tined-pitchfork symbol of an imperial tomb just south of "0" in 102.6. At E.9, 6.8 is a small black square symbol for which no interpretation is known. In the quadrangle below is another odd symbol, like a carpet tack, point up, in an inverted U which may be a grave monument (the tack) in an enclosure, the inverted U.

At the northwest corner of the grid, a high-tension power line enters the city, terminating at a power-house (converter?) in a rice field. (In the diagonally opposite corner of the grid at G.8, 6.4 is another powerhouse). Four quadrangles south, at E.2, 1.2, in the middle of a city block un-built on the north, the telephone symbol, somewhat like a desk-set, may be found -- probably an exchange. At F-1, 1.6 is a Y-shaped symbol of unknown meaning. An isolation hospital can be identified at A.8 on line 5. If the top line were double, the shield-and-cross symbol would indicate a general hospital.

In the center of the city is an imperial palace -- the building not shown, perhaps for religious reasons -- two large, walled enclosures, set among groves (the "bird-in-flight" symbols) and the whole park surrounded by a tree-crowned embankment or a moat -- it is difficult to tell which. There is a temple-lantern (small circle-with-four-arms) at E.5, 3.5. In the street half way between F and G, a streetcar line with station, runs east and west. Careful inspection of the map shows no iron-cross (or crossed dumb-bell) symbol of a jail. The toy-Christmas-tree symbol of a court of appeals may be found at F.6, 3.2, south of the car line. There is no symbol for a fire-engine house, although some of the circles might house fire fighting equipment. The circle surmounted by three small vertical lines in the south-west corner of the large park F.2, 2.5, is interpreted as "government office, domestic." A tiny statue-symbol may be picked out at F.8, 4.5, just diagonally south-west of the cogwheel factory symbol. West of the statue is the diamond-shaped symbol of a tax office. Clearly marked at F.2, 3.6, east of the park is the cross of a church, and what seem to be two others—missions perhaps -- may be seen faintly at F.4. 1.1, just above the street car station. Resembling a sheaf of wheat, the symbol for a bank may be found at 2.9 just above the H line. Across the small brook that runs out of the grid at A.0, 2.4, may be seen two bridge symbols, one at A.7, 2.7 of a type not explained in the margin, but from its heavy inking, probably of masonry; the other, at B.8, 3.2 might be masonry or steel, as the characters for masonry and steel bridges are almost identical. At the bottom of the map at H.6, 5.1 will be seen a small Buddhist temple with several out-buildings, perhaps shrines, facing the street and car-line, enclosed on the north and east by a masonry wall; and, on the top of the cut bank on the south side, an embankment planted with a hedge of trees -- much useful information packed in a very small space. The Japanese cartographer is thorough.

An examination was made of a map of the harbor-front area of Yokohama to determine whether a figure of such an industrial and shipping section should be included. Practically nothing was discovered of military value not discussed elsewhere.

(3) Flat Country-Side

In figures 2 and 3, are shown two fairly representative types of countryside -- 2, flat rice lands bordering on the lake, Biwa Ko, near Kyoto, and a small coastal village, 3, with an anchorage and hills behind.

Figure 2 presents a very tricky problem in map reading that will make an expert look twice -- the problem of the difference between a dike and a dry stream. Pick up the double-track railroad on line G at 1.5 and follow it north-east over an 18 foot road, through rice fields dotted with pine trees to the westward, and crossed by a three-foot cart track on a small embankment. At F.2, 1.5 will be seen a small family burial plot with a marker. The railroad now crosses another push-cart track, which to the westward, follows the line of a small drainage ditch. Crossing a highway and an 18-foot country road, the line disappears under what appears at first glance to be a stream bed. The faint parallel marks of a tunnel do show up under a glass. The embankment may be recognized by the tiny arrow-head-shaped dots pointing outward, and by a road on top. There is, however, another line of faint dots north of the road symbol, and further on, on what might be mis-read as the opposite bank of the "stream" is another double row of dots. The correct reading is an embankment, with two ridges on each side of it, perhaps the elevated, dry bed of an old canal, but in any event, a military obstacle providing defilade, a protected parapet, and an excellent place to dig in machine guns or AT weapons.

[Figure 2: Japanese Countryside Map]
[click to enlarge]

In the village that is strung out along the highway paralleling the railroad, may be noted the - a postal-telephone-telegraph office, a village office, and between them a Buddhist temple. Next the town hall is a survey marker showing 96.77 meters elevation, and just above the "6", a police station. East of the police station is an oval suggesting a sub-prefectural office. North of that is a Shinto shrine, and beyond the shrine, a recognizable chimney with smoke coming out of it, attached to a good-sized building of very light construction -- perhaps some sort of a drying shed. In the fields at D.4, 5.2 is an "isolation hospital" -- here probably not isolation but a small local hospital perhaps of a few rooms for lepers or insane patients -- and just above it the half-a-cog-wheel symbol of a small watermill. The presence of the water mill -- possibly a "fileature" for reeling silk and the shed-and-chimney suggests that the latter may be a building in which cocoons are kept. High and low-tension power lines may be noted east of the railroad, distinguished by the two dots, sometimes looking like a cross-bar of the high tension line. Numerous drainage ditches and small, diked-in ponds without any outlet would suggest very flat land and a high water-table, which is in fact the case as the lake is a very short distance off the map to the west. One feature on the map is the presence of vegetable gardens, indicated by shading at B.1, 5.0 or B.2, 7.0. These gardens are apt to be surrounded with fences or trees and provide cover for snipers. At line B.0, 5.0 the railroad crosses another double embankment, and beyond, before it reaches the railway, a fill is indicated by the outward-pointing dashes. It is not high. If it were, the height would be marked as at F.8, 1.7, and again on the embankment at E.3, 6.0, where the figure "9.1" (meters?) appears.

A curious symbol looking like single and double road-barriers can be seen at the road fork, B.8, 8.3 and others occur at the northern and eastern exits of the village at C.8, 3.7. These do not fit any Japanese symbol shown on the symbol list printed on the map sheet, and are believed to be some indication of road width, tentatively, six and twelve meters. Another unknown very small symbol, perhaps a tiny, circular pond, can be seen at the right of the road "barrier" at C.6, 3.9.

At D.2, 4.8 can be seen two symbols that appear to be mounds, perhaps ancient burial mounds. This may well be as the area has been settled for thousands of years. Inside the pencil circle at F.6, 3.4 may be seen dots suggestive of the tea-symbol, three dots in a triangular pattern. Tea "gardens" however, are apt to be planted on hills. None has been identified on this map, nor the tiny "K" symbol of mulberry trees. The zig-zag dot-and-dash lines such as may be found at C.8, 1.3 are village boundaries.

(4) Hilly Country-Side

Turning to the hill-country area, figure 3, we find an attractive seaside village near Kaimondake (Mt. Kaimon) at almost the southern tip of Kyushu, one of the main islands of Japan proper. A small anchorage is indicated in the bay by an incomplete anchor. Inland, the pine-covered hills rise sharply to the 1,200 foot saddle-back west of the lake, which is marked as having an elevation of 126 meters. It must be a picturesque country, as just off the map about four miles rises the almost perfectly symetrical, 3,000-foot peak of Mt. Kaimon, evidently an extinct volcano of the circular, pointed "Fuji" type. Along the water-front may be noted, reading around to the left from the point, on line E at 7.7, a small-boat ferry, indicated by a figure of a boat; a rocky shore, the post office, and an improved highway following the shore line to the road fork leading inland. Here, at the shore line, may be noted two oddly-shaped symbols like three flowers in a bowl, indicating mineral springs. There is another north-east of the lake. Just west of the second spring, at D.1, 6.6 will be found the terminus of a 3.5-foot gauge railroad (standard for Japan), under construction -- two parallel lines joined at intervals by bars, Just above the spring is a small tunnel, with another a short distance further on, before the railroad crosses the highway on a bridge. A path continues from the turn of the road along the shore.

[Figure 3: Japanese Hilly Countryside Map]
[click to enlarge]

Following west from the bay on the road running inland, a hospital can be noted to the south, before the second settlement is reached. This is apparently not an organized village, as it lacks a post-office, village hall, or any sort of temple or school--which is quite unusual. The settlement clusters around the building marked with the horizontally-divided-diamond sign listed in TM 30-480, p. 281 as a "monopoly bureau factory" -- perhaps tobacco -- although no example of this symbol has been observed on the Japanese symbol sheets studied in the preparation of this article.

South of the road opposite the police station is a rice field, the double upright marks on a base being a variation of the usual parallel-line rice symbol -- certainly one of the characters one would expect to find entirely standardized. There is nothing noteworthy in the second village.

Following any path uphill to the northward, it may be noted that the 300 and 200 meter contours are marked, but not the 100, with the intermediate contours lightly printed. The odd little three-line symbol means "waste land." At "300", between C and D in the 1 column is a well-marked cliff or escarpment. Along the steep bluff that surrounds the little lake may be seen broad-leaf tree symbols and a few K-shaped mulberry trees.

It is to be noted that no Buddhist shrines appear on this map or in the general area. There seems to be a tendency for the townspeople to be Buddhist, and the old-fashioned country people to cling to the ancestor-worship of the Shinto faith.

(5) Mountain Terrain

Figure 4 shows a more mountainous section of the same general area. As many of the Japanese mountain maps are a monotonous tangle of contours with little detail of interest, an area south and west of figure 3 was selected to illustrate the Japanese portrayal of mountain topography.

[Figure 4: Japanese Map, Mountain Terrain]
[click to enlarge]

Beginning with the tip top of Mt. Kaimon in the extreme south-west corner, an odd symbol is immediately encountered -- the downward-pointing line starting from the circle just below the survey bench-mark, 924.0. Obviously it must be a flagpole, statue, or marker -- but it is not. Two inconsistencies are to be noted -- one, that the bench-mark, which should represent the highest point is not in the circle, or obvious top-contour; second, that the line points downward from the circle; and finally, a detail revealed in the original map only by a glass, the line is actually an arrow, with its head inside the circle. The fact of the matter is, that the circle represents a tiny hollow, probably the remains of the old crater, and the arrow is used to call attention to it. This data is explained in an appropriate marginal note on the original, but an arrow-circle is apt anywhere to mean a depression. The arrow at C.8, 3.9, however, merely connects the Japanese lettering above, beginning with the cross in the square, which is a place-name.

Another unusual item may be noted in four types of contour lines -- "numbered," "measured intermediate," "intermediate," and "helping." The first two are obvious; the intermediate, with broken contours may be seen just south of "120" at E.8, 1.2, and "helping" at C.7, 2.5 where an "intermediate" contour fades into a "helping." Making it more complex, a practically identical faint dotted line apparently indicates some sort of an enclosure, as in the F, G, 2, 3 quadrangle.

Vivid chasm symbols occur at H.8, 3.4 and along the stream that runs south from F, between 5 and 6, and an equally illustrative "crumbling cliff" at B.6, 1.7. At the same point an operating mine is indicated by the crossed miners' picks, upright. If reversed, the mine would be closed. The shaded circle indicates silver -- an open circle would be gold. (Gold mines occur a few miles further north, off the map.) It must be a small mine, since no improved road goes near it nor does the high-tension power line which crosses the center of the map send in a feeder cable. There are about thirty houses in the nearby camp giving some idea of the number of hands employed in the diggings. Just east of the settlement, the small circles of different sizes without tree-trunk stems probably show a cut-over area suggestive of mine props. At F.0, 4.5 is a grove of mulberry trees, and a shallow, swampy pond appears at C.3, 4.6. From the crest of the flat topped hill at D.2, 6.2, dotted lines expanding northeast probably indicate divisions between crops or types of vegetation. Large slide-tracks are indicated by fine, straight lines cutting across the contours, not shown on these illustrations.

c. Military Maps

(1) General

Military maps, naturally, are far simpler than topographical sheets. For example, the military railroad symbol is the same as our own rather than the complex civilian symbol. This simplification is offset by a somewhat illogical and very complex set of military symbols -- see page 43. The following instructions to map makers has been highly condensed from a translation of "The Applied Tactics of the Japanese Army."

*          *          *

(a) General Instructions

The title of the map is written on top (from right to left) and the date in smaller print underneath.

Lakes, ponds, streams and also the disposition of Japanese forces are colored blue, enemy dispositions in red.

The location of commanders is shown by the headquarters symbol.

The location of an artillery OP is not necessarily shown if close to the guns.

The position of the same units at different times is indicated, when necessary, by unshaded and shaded symbols. [It is thought that the shaded symbols indicate the last position occupied.]

Road spaces and intervals of marching troops are drawn as far as possible to scale.

(b) Deployment

The disposition of outposts, the positions, and that of the reserves, to the patrols and sentry posts must be indicated in detail. The outpost line of resistance must be indicated by a continuous line in blue.

(c) Defense

The direction of a counterattack (on a hostile force) is indicated by an arrow.

In the map of a defensive sector, the direction of the anticipated main hostile attack will be differentiated from subordinate attacks, and both types of anticipated attacks indicated by red arrows. If main attacks are anticipated in two or more directions, both will be indicated, but the more important attack clearly specified.

(d) Deployment for Attack

In a meeting engagement, it is necessary to indicate clearly the line of battle, and whether the attack will be piecemeal or coordinated.

To indicate the enemy situation when attacking an organized position, the probable and actual situation will be shown. The probable situation will be indicated as such.

(e) Artillery Positions and Preparation

Enemy lines and probable artillery positions will be shown, also the direction of both our own [Japanese] and hostile attacks, and our own front line. Main fire direction zone will be shown; position of all unit commanders, OP's, ammunition trains, routes leading to forward positions, routes of advance and if necessary, means of concealment, positions of artillery observers and the communication net will be indicated. When a change of position is anticipated, the route to be taken and the time will be indicated.

On maps showing artillery preparation, the type of gun, the number of batteries, and the area to be covered by fire will be indicated. The preparatory fire prior to the infantry advance and that to be delivered thereafter will be indicated.

*          *          *

(2) Military Symbols

Military symbols are particularly confusing since they do not always follow a well-thought-out pattern as do our own, or the German. A "unit," for example, is ; an infantry unit, , but a field artillery unit is represented by the symbol for a gun whereas the expected symbol would be , a character which represents not an artillery unit, but a field artillery ammunition train. The arrow generally associated with "machine gun," when combined with the gun symbol into , means not machine-cannon, but long-range field gun. These discrepancies could be multiplied indefinitely. It must be clearly understood, and never forgotten, that to read Japanese symbols by combining them according to a reasonable and natural system may lead to highly erroneous, and even dangerous, conclusions. A symbol must be either known, or if not known, interpreted with extreme caution. Of over 300 symbols listed in "Applied Tactics of the Japanese Army," some of those believed to be the more useful to a field officer are listed below, together with the abbreviations used on maps. Like the symbols, they are at times illogical and confusing.

Common Japanese Military Symbols and Abbreviations

[Common Japanese Military Symbols]

*The symbol is not "artillery unit," but, "field artillery ammunition train." The symbol is irregular -- compare, "Tank am train," below.
**Symbol shown on map of Shemya Island.

Abbreviations*

Abbreviations sometimes used instead of symbols are usually in English letters, but the Japanese are often careless in the matter of capitalization.

A      Army, also field artillery
AAAntiaircraft artillery and/or AA position
BBrigade
bBattalion
biAInfantry battalion gun unit
cCompany, troop, battery
DDivision
FThe enemy -- foe, foeman (cf. Feind--German)
FcAir squadron (Japanese, not enemy)
(F, in combination, loses its "enemy" significance)
FeAHeavy artillery
FMAir unit
GImperial guards
HHowitzer
HAAA gun
HMAAA machine cannon (artillery)
HMGAA machine gun
iInfantry
iAInfantry gun unit
iBInfantry brigade
iHInfantry mortar
iKInfantry cannon (gun)
iRInfantry regiment
KCavalry (cf. Kavallerie--German)
LGLight machine gun -- (cf. leicht--German)
LMLight trench mortar unit (not light trench mortar)
MMortar -- also ammunition section (platoon)
also used as adjective "Medium." (cf. Mörser--German)
MAMachine cannon unit
MGMachine gun unit
MMMedium trench mortar unit
MWGrenade discharger, rifle (cf. Minewerfer--German)
PEngineers (cf. Pioniere--German)
PWArmored car unit
RRegiment
RiARegimental gun unit
RStRegimental ammunition train
SIndependent -- see figure 7, PS = Independent engineer units, in company areas 1 and 2; (Note: S = "independent." Always follows unit abbrev.) Also, march casualties collecting unit; also, heavy (cf. schwer--German) used as adjective -- see below.
SAHeavy (U.S. medium) field artillery
SeShipping, as in SeP, below
SePShipping engineers regiment, see Tactical and Technical Trends, No. 43 p. 9, Japanese Use of Military Barges par. c.
SMHeavy trench mortar unit
StAmmunition train
TARapid-firing gun unit
TASIndependent AT unit
TKTank unit -- also Tank
TLSignal company, wire (telephone or telegraph) unit
TPMechanised unit
ZChemical warfare unit
ZidAutomatic gun unit

*Where interpretations or abbreviations differ from those in current TM's (as in "LM") the former represent the most recent revisions.

Unit Designations

Roman numerals -- battalions
Arabic numerals -- other units

Example -- III 2i - 3d Battalion, 2d Infantry; 18 P - 18th Engineers.
Note -- on figure 7, will be found in the company areas -- the symbol with ( PS) meaning of the unnumbered Independent Engineers, which is two squads out of the 16 squads of the unit. As there are 16 squads in a company, the Independent Engineer unit was a company.

(3) Two Examples of Japanese Combat Maps

Two examples of Japanese combat maps are shown in figures 5 and 6, with interpretations in figure 5A, and (c) below. The first represents a small island near Attu, the other a Japanese sketch of an American position on Guadalcanal.

(a) Shemya Island

In figures 5 and 5A are shown the map of an island believed to be Shemya, one of the several tiny Semichi Group which lies just east of Attu. It was apparently held by the 1st, 2d and 4th companies of a Japanese battalion, and fortified to cover an expected attack from the south, supported by airplanes from the eastward. The script at the top reads, "S Island Garrison Unit Distribution Sketch." Under the island, the text is, "Zone of expected enemy landing;" and at the right, "The battalion will place its strong-point on the southern edge of S Island and will annihilate the enemy at the shore which (when it?) will attempt to land. Second Lieutenant Odajima." Lt. Odajima was presumably an adjutant.

The symbols are rapidly sketched, and in some cases, do not conform to official examples. Machine guns are indicated, for instance, by not the regulation .

Moreover, the communication net, shown by the solid and waved lines forming a rough diamond, are extremely deceptive, forcibly illustrating the point previously made that Japanese map symbols can not be read by a non-expert in the light of pure reason or logical deduction. The regulation symbol for a telephone line is a thin, solid line, interspersed with the telephone symbol. The symbol for a radio net is dotted lines and radio symbols. Here we have the solid line marked not by the of the telephone, but by the of the radio. Furthermore, the wavy line, immediately suggestive of radio vibrations, is marked with the telephone symbol not the radio character. The explanation apparently is, that the maker of the original map rapidly ruled in the radio-net lines without bothering to make them dotted, being sure that those who used the sketch would interpret the solid line correctly because they connect radio symbols. The waved, running line connecting the telephone symbols represents not radio vibrations but, "insulated wire."

The light lines running out to sea among the off-shore wire entanglements are believed to indicate a shelving beach, suitable for hostile landing craft, but may be submerged obstacles. In the oval of the 1st Co. defense area is an unaccounted for inner shaded oval corresponding to what may be the topmost contour. It may mean shelter area. The usual interpretation of such a symbol is "billeting area." At several points on the map are symbols that are quite similar to our own searchlight symbol, , placed where AA searchlights might possibly be expected. These are also quite deceptive, as they mean, "occupied position." No searchlight symbol appears on the map. The symbol for AAC artillery position may indicate the presence of one gun, or more. At the bottom of the map, below the broad arrow, main-expected-attack symbol, colored red in the original, is the letter F meaning enemy -- Feind (German). No meaning is known for the faint, originally red, large character at the right resembling the figure 3. It may be an accidental scrawl.

[Figure 5: Japanese Combat Maps]
[click to enlarge]

[Figure 5A: Japanese Combat Maps]
[click to enlarge]

(b) Guadalcanal Map

Figure 6 is a very careful copy of an original Japanese sketch of the American position on the Lunga River in Guadalcanal. Unfortunately, the original was too faint for photographic reproduction. The key to understanding this situation is the light curved line at 47,500--49,500 which is the "Front line of friendly (Japanese) units," drawn originally with a blue pencil. The American positions were in red. Obviously the terrain is rather rough, with a "cliff" marked at 49,300--49,150 and patches of long grass scattered through the jungle. Three antiaircraft positions are indicated, as well as numerous small defense areas with what appear to be slit trenches -- two actually inside the Japanese front line. The emplacement symbol is the usual symbol for "field artillery protective works." For heavy artillery, the line would be doubled. The "jungle" symbol is not shown in the lists of Japanese symbols available, or in TM 30-480 but the symbol given in figure 6 will shortly appear in a revised training manual. The "A three meals and B one meal," see below, is presumed to refer to the type ration carried by the assault troops. "A" ration is rice, "B", hardtack. Some of the circles which are scattered over the area were colored red and some were not, possibly indicating unoccupied or alternate positions.

[Figure 6: Japanase Guadalcanal Map]
[click to enlarge]

(c) Translation of Japanese Characters on Guadalcanal Map

1. Time of assault 22.17 (10.17 PM).

2. "A" ration, rice, three meals; "B" ration, hardtack, one meal.

3. Material for construction of airfield has been landed at this point. This is the best anchorage in this island since it is protected from the wind.

4. Transmitting station.

5. Grassland -- used as dummy airfield provided for hostile bombing.

6. HYO -- Leopard.

7. Cliff.

8. Power plant No. 2.

9. Remains of reef (across the river).

10. There are fording areas at various places. Flow of river is somewhat rapid. Light river-crossing equipment must be carried.

11. KUMA -- Bear.

12. SHISHI -- Lion.

13. Lunga River.

14. Runway.

15. Shelter for fighter planes.

16. Two pieces of 12-cm howitzers (literal trans).

17. Both banks are 2 to 6 meters above water level. River bed is sand and gravel.

18. This hill, 20 to 30 meters in elevation, is flat at the top and commands the area to the north.

19. This hill is 20 to 30 meters in elevation. From it may be seen the airfield. The grass of the lowland is a little over shoulder high.

 
 


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