Paragraph
Components   .................................................................................................		75
Panoramic telescope 32 (Rbl. F. 32)   .............................................................		76
Stereoscopic director 36 (Kdo. Gr. 36)   .........................................................		77
Auxiliary director 35 (Kdo. Hi. Gr. 35)   .........................................................		78
Azimuth and elevation indicators   ....................................................................		79
Fuze setter   ....................................................................................................		80
On-carriage wiring   .........................................................................................		81
Aiming circle   .................................................................................................		82
Range finder model 34   ...................................................................................		83
Surveying rod   ................................................................................................		84
Plotting rules   ..................................................................................................		85
Battery commander's telescope   ......................................................................		86
Care and preservation   ..................................................................................		87

75. COMPONENTS.

a. The fire control equipment consists of the stereoscopic director 36 (Kommandogerät 36), or the auxiliary director 35 (Kommandohilfsgerät 35); the azimuth and elevation indicators; the fuze setter; the necessary on-carriage wiring; and the cables.

b. When the stereoscopic director is available, it transmits data electrically to the indicators and fuze setter. These have dials, each containing 3 concentric circular rows of 10 lamps each. The data are indicated by the lighting of lamps and matched by operating the gun until the 3 blackout indexes of each of the 2 indicators and the fuze setter cover the lighted lamps. The gun is then alined on the target indicated by the director.

c. When the auxiliary director is used, slant range is obtained from a separate 4-meter range finder (information not available) and is manually set into the director. The computed values are read off on dials and scales visible in the sides of the director and then telephoned to the gun crew.

d. Information is not available on the cables used to connect the directors with the guns.

76. PANORAMIC TELESCOPE 32 (RBL. F. 32).

a. Description of Panoramic Telescope 32 (Rbl. F. 32).

(1) The panoramic telescope used for orienting with the stereoscopic director is the Rundblickfernrohr 32 (figs. 86 and 87). The telescope is clamped in the telescope holder on the top of the recuperator. The holder is located at the pintle center of the mount.

Figure 86 — Panoramic Telescope 32 (Rbl. F. 32) in Telescope Holder

(2) The panoramic telescope (fig. 88) is a 4-power, fixed focus type with a field of view of 9 degrees. The line of sight may be raised or lowered by rotation of the angle of site knob. The angle of site scale is graduated from 100 mils to 500 mils (300 mils is normal). The angle of site micrometer is graduated in mils from 0 to 100 mils. The azimuth scales on the vertical barrel of the telescope are graduated in 100-mil intervals; the upper scale, 0 to 64; the lower scale, 0 to 32. A knurled portion permits adjustment. The center index is locked in place by a lug at the front of the telescope. The azimuth micrometer includes 2 scales graduated in mils from 0 to 100 mils. The index between the scales is fixed. It is believed that one scale is used for setting in corrections and the other for setting in fine azimuth values. A throw-out lever is provided for rapid setting in azimuth. A locking lever locks the azimuth micrometer in any setting. The reticle pattern is shown in figure 87.

Figure 87 — Panoramic Telescope 32 (Rbl. F. 32) — Rear View

(3) The telescope holder is of conventional design. It is welded to the top of the recuperator and is in the vertical plane through the axis of bore. It is also at the pintle center. The telescope holder lever operates a cam which engages a notch in the body of the telescope. Two screws with jam nuts permit adjustment in azimuth of the telescope in the holder.

Figure 88 — Panoramic Telescope 32 (Rbl. F. 32) — Front View

77. STEREOSCOPIC DIRECTOR 36 (KDO. GR. 36).

a. General. The stereoscopic director 36 (Kommandogerät 36) (figs. 89 to 95) is the standard director used with the 8.8 cm. Flak 36. It is a combined stereoscopic range finder and director, supported on a pedestal which has three leveling feet and two suspension arms for securing to front and rear bogies for travel. The bogies are similar to those used for carrying the gun mount.

Figure 89 — Stereoscopic Director 36 (Kdo. Gr. 36)

Figure 90 — Stereoscopic Director 36 (Kdo. Gr. 36) — Range Finder Removed from Director

b. Range Finder (Em. 4m. R. (H)).

(1) The 4-meter base stereoscopic range finder (Raumbildentfernungsmesser (Höhe)) adapted for height finding has magnification of 12x and 24x and a range scale reading from 500 meters (550 yd) to 50,000 meters (55,000 yd). It is clamped by two rings to the director for use and in travel is carried in a chest fitted with hand grips.

(2) A device for obtaining approximate height is fitted on the right end of the range finder tube. This consists of an arm pivoted at one end and engraved with a scale of ranges. A series of parallel lines graduated to the value of height are engraved on the disk to which the arm is pivoted. As the instrument is elevated, the disk carrying the scale rotates with the instrument. The arm, however, remains vertical, and the height line corresponding to the range on the range arm indicates target height (fig. 91).

Figure 91 — Stereoscopic Director 36 (Kdo. Gr. 36) — Height Scale

(3) Two tracking telescopes are fitted on the range finder tube to the right and left of the stereoscopic eyepiece. These are employed for keeping the range finder on the target and have a cross wire reticle pattern.

(4) The range finder is turned in elevation by rotation of the elevating handwheel which is connected by gearing to a gear between the range finder tube and the left bearing ring.

(5) An optical lath is provided. When it is suspended on the supporting brackets, it provides an artificial infinity for test and adjustment of the range finder.

c. Director.

(1) The director includes a main casting, supported on a pedestal, and supporting a number of box enclosed mechanisms (figs. 92-95). The director determines and transmits the following data to the battery.

(a) Quadrant elevation.

(b) Future azimuth.

(c) Time of flight of projectile, expressed in fuze units.

(2) The values set into the director are:

(a) Present angular height.

(b) Present azimuth.

(c) Present slant range.

Figure 92 — Stereoscopic Director 36 (Kdo. Gr. 36) — View of Traversing and Elevating Handwheel

Figure 93 — Stereoscopic Director 36 (Kdo. Gr. 36) — View of Range Drum

d. Setting Up.

(1) Uncouple the carriage supporting the director from its towing vehicle and lower the platform from the front and rear bogies (fig. 90). Open the cases containing parts and accessories.

(2) Open the range finder clamp rings of the director. Remove the range finder from its case and clamp it to the director. Couple the range finder to the director. Place the two tracking telescopes and the four other telescopes on their respective mounting surfaces on the range finder. Check against a distant aiming point to make sure that the telescopes are alined with the range finder.

(3) Level the director by adjusting the three leveling jacks (fig. 89). Level the range finder using the range finder leveling screw and lock nut until the bubble of the level is centered.

(4) Turn the handwheel for angular height to the left until the zero reading of the angular height graduation of the horizontal range to datum point drum is exactly under the horizontal range to datum point index. Then turn the upper part of the coupling which transfers present angular height to the director until the zero-degree reading of present angular height is visible in the aperture of the present angular height instrument attached to the range finder.

(5) Remove the range finder eyepiece protector and hang it under the range finder. Set the head rest in the correct position. Hang the arm strap on the knob to the right of the eyepiece. Set the interpupillary distance and focus the eyepieces. If necessary, use the filters.

(6) Bring the panoramic telescope, which is on the top of the recuperator of the gun, to bear on the director. Set this value on the telescope of the director and bodily slew the director to lay on the red stem of the panoramic telescope on the gun.

(7) With the director alined on the gun telescope, set the graduated lateral deflection ring at zero. Set the graduated deflection ring of the course plate at zero.

(8) Screw the counterweights into the range finder and remove the cover from the correcting apparatus. If necessary, install the telescope extension tubes (rain protection) on the range finder.

(9) Adjust the range finder stereoscopically and check alinement of tracking telescopes and observing telescopes and binoculars with the range finder. Detailed information on this is not available at this time.

(10) Wind up the clockwork of the horizontal speed indicator.

(11) Connect the cables between the director, the switchboard, the distribution box, and the guns. Plug in the head and chest set telephones. Detailed information on this is not available at this time.

(12) Set in average values for future azimuth, Q.E., and fuze. Turn on the switch in the receptacle box at the director. Turn on the power with the transmission switch at the switchboard. Check the lamps in the indicators and fuze setter, noting broken or weak lamps. Check the future azimuth, Q.E., and fuze values obtained at the guns with that set in at the director. The director is now ready for operation.

e. Stereoscopic Director Operation.

(1) FUNCTIONS OF OPERATORS. It is believed that 11 operators are required.

(a) Elevation Tracker. Keeps reticle of elevation tracking telescope (mounted on right range finder tube) laid on the target by turning the elevating handwheel.

(b) Azimuth Tracker. Keeps reticle of azimuth tracking telescope (mounted on left range finder tube) laid on the target by turning the azimuth handwheel. An auxiliary elevation handwheel close to the azimuth handwheel enables the azimuth tracker to track in both azimuth and elevation when necessary.

(c) Stereoscopic Observer. Tracks the target stereoscopically, indicating slant range on range drum.

(d) Range or Height Reader. Reads off elevation figures on the range drum of the range finder to both the horizontal range operator and the target course and speed operator. When range only is being taken, the reader gives these to the horizontal range reader only.

(e) Horizontal Range Operator. By operation of the horizontal range handwheel keeps the center circle of the cursor (attached to horizontal range bracket) on the curve indicated on the range drum by the stereoscopic observer.

(f) Target Course and Speed Operator. Watches the trace made by the course pointer over the course plate (fig. 94) and rotates the course bearing disk to keep the parallel lines in agreement with the target course. Keeps the pointer of the horizontal speed scale in agreement with the speed registered on the horizontal speed indicator, or watches the dial of the horizontal speed mechanism, and keeps the colored disk rotating at the same speed as the pointer and the parallel lines of the speed plot in agreement with the track of the plot by turning the handwheel below the course plate.

Figure 94 — Stereoscopic Director 36 (Kdo. Gr. 36) — View of Course Plate

(g) Present Angular Height Operator. Takes readings from present angular height scale on range drum and sets these in on the present angular height scale of the rate multiplying mechanism. This is done either by direct rotation of the handwheel or by clutching in the variable speed drive and turning the handwheel to control the rate of change. Watches the elevation speed indicator, keeping the inner index matched to the pointer by one handwheel and the outer index matched to the main index by the second handwheel.

(h) Operator for DA and Rf Arm. Matches pointer of DA and Rf arm against pointer moving along course arm by turning the two handwheels mounted on the DA and Rf arm. One handwheel traverses the arm and adds deflection in azimuth to the present azimuth set into the future azimuth transmitter.

(i) Fuze Drum Operator. Reads the future angular height scale (to the right of the drum) and sets the curve indicated on this scale under the center of the cursor by turning the fuze handwheel. This also sets the fuze transmitter.

(j) Quadrant Elevation Operator. Reads future angular height scale (to the left of the drum) and sets the curve indicated on the scale under the center of the cursor by turning the tangent elevation handwheel. This also sets the quadrant elevation transmitter.

(k) Correction Operator. Reads off from the respective registers the drift adjustment, elevation corrections, and fuze setting corrections as shown under the cross threads and sets these in on the respective dials (fig. 95).

Figure 95 — Stereoscopic Director 36 (Kdo. Gr. 36) — View of Wind Correction Knobs

f. Operation by Telephone. When transmission of data from the stereoscopic director is desired by telephone, three additional operators are required to telephone the values (Q.E., future azimuth, fuze) to the gun crew.

g. Standby Settings. When firing has ceased, the following settings should be made:

(1) Traverse the director to zero.

(2) Bring the present angular height reading to zero.

(3) Set target height in range finder to 2,500 meters.

(4) Set horizontal range to 5,000 meters.

(5) Set horizontal velocity to 50 meters per second and bring the pointer under its arm.

(6) Set correction for drift to zero.

(7) Set future horizontal range to 5,000 meters.

(8) Set gun elevation to 60 degrees.

(9) Shut off power.

78. AUXILIARY DIRECTOR 35 (KDO. HI. GR. 35).

a. Description.

(1) The auxiliary director 35 (Kommandohilfsgerät 35) (figs. 96 to 99) is a portable director, smaller and less complicated than the Kdo. Gr. 36. Data computed in the director is telephoned to members of the gun crew, who then set in elevation, azimuth, and fuze time. The slant height or range scales are calibrated for use with the 8.8 cm Flak 18 and 10.5 cm Flak 38. Provision is made for two tracking telescopes although information is not available at this time on these.

(2) The slant range prediction is approximated by adding range rate times future time of flight to the present slant range which is obtained from a 4-meter stereoscopic range finder set up nearby. The super elevation and fuze are taken from three-dimensional cams, positioned by future angular height and future slant range. Lateral, vertical, and range rates are measured by tachometers and are manually matched. Deflections are computed by multiplying present angular velocity by present time of flight.

(3) The instrument and stand are carried in a two-wheeled trailer. The stand is collapsible for traveling. Three leveling screws on the head of the stand support the director. The director has four porter bars which form an integral part of the instrument and telescope within each other when the instrument is emplaced. The director weighs about 450 pounds.

(4) The only electric current required is for the telephone system. The 10-pole receptacle in the center of the bottom provides constant contact throughout complete traversing of the director because of the slip rings in the bottom of the director. The receptacle has colored dots: black, white, yellow, brown, brown, respectively for adjacent pairs of terminals. A key prevents incorrect positioning of the mating plug. The receptacles on the gun mount use colors in accordance with this color system. The two receptacles also at the bottom, but on either side of the center, move with the director and permit connection to the telephone sets for the director operators.

b. Operation.

(1) Limits of operation are:

Range of target		12,000 meters (39,360 ft)
Height of target		10,000 meters (32,800 ft)
Fuze time		37 seconds
Lateral deflection		± 600 mils (33.75 deg)
Vertical deflection		± 300/16-degrees (18.75 deg)
Rate of change of range		± 150 meters per second (492 ft per sec)

Figure 96 — Auxiliary Director 35 (Kdo. Hi. Gr. 35) — Rear Panel

Figure 97 — Auxiliary Director 35 (Kdo. Hi. Gr. 35) — Left Side Panel

Figure 98 — Auxiliary Director 35 (Kdo. Hi. Gr. 35) — Right Side Panel

Figure 99 — Auxiliary Director 35 (Kdo. Hi. Gr. 35) — Front Panel

(2) It is believed that nine operators are required:

(a) Azimuth tracker.

(b) Elevation tracker.

(c) Range operator.

(d) Azimuth rate setter.

(e) Elevation rate setter.

(f) Range rate setter.

(g) Future azimuth reader.

(h) Future elevation reader.

(i) Fuze reader.

(3) The azimuth and elevation trackers keep their telescopes on the target by operating their respective handwheels. The range operator sets in range values obtained from the 4-meter stereoscopic range finder nearby.

(4) The azimuth rate setter keeps the azimuth rate indicator alined with its index (at 6 o'clock relative to the rate dial for zero correction) by turning the azimuth deflection knob. He also applies correction by turning the azimuth rate knob.

(5) The elevation rate setter alines the elevation rate pointer with its index (positioned under the white line for zero corrections) and applies corrections by turning the elevation rate correction knob.

(6) The range rate setter keeps the range rate pointer alined with the index (at 6 o'clock for zero correction) and applies corrections by turning the range rate correction knob.

(7) The future azimuth reader observes the future azimuth scale and telephones the values indicated to the guns. The future elevation reader observes the future elevation scale on the right side panel and telephones the values indicated to the guns. The fuze reader observes the fuze dial on the left side panel and telephones the values to the guns.

(8) Each input handwheel has a flywheel mounted within the case which tends to give a steady rate of change. Brakes operated by push buttons permit quick stopping.

(9) Clutches are provided for driving in azimuth or elevation.

79. AZIMUTH AND ELEVATION INDICATORS.

a. Description.

(1) The azimuth and elevation indicators on the gun carriage are identical (fig. 100). Each indicator consists of a cylindrical case containing three concentric rings of 10-volt electric lamp sockets. Each socket has an individual positive electrical connection. All sockets in each indicator have a common negative connection.

Figure 100 — Azimuth and Elevation Indicators — Elevation Cover Removed

(2) Three pointers are pivoted at the center of each indicator, one for each circle of lights. At the end of each pointer is a translucent index. The two inner indexes are each wide enough to cover one light. The outer pointer can span two lights. The pointers are geared together at a ratio of 1:10:100; the shortest pointer moving 1 turn to 100 of the target pointer. The pointers are mechanically coupled to the azimuth and elevation drives of the gun carriage. A knob at the center of each indicator is used for synchronizing the indicator arms with the gun prior to operation.

(3) The case is bolted to the top carriage and has a cover which consists of a 10-armed spider which supports a translucent plastic sheet cupped within the spider. A dowel on the case fits a hole in the rim of the spider, permitting assembly in only one position. This assures maximum visibility of the lights. Two spring clips clamp the cover in place. At the center of the spider is a chained cap which protects the adjusting knob of the indicator.

b. Operation.

(1) Sight the range finder of the stereoscopic director on a distant aiming point (a distant terrestrial object or a celestial body) and bore sight the guns of the battery on this target. If the lighted lamps of the azimuth and elevation indicators of each gun cover the lighted lamps the gun is oriented with the director. If adjustment is necessary, remove the metal cap and engage the knob with the cross piece in the shaft, turn until the dial is blacked out, and release the knob.

(2) The gun is thereafter operated as the lights flash on around the circle by turning the elevating and traversing handwheels to keep the lamps blacked out.

80. FUZE SETTER.

a. Description.

(1) The fuze setter is mounted on the left side of the top carriage (fig. 101). It is manually operated and is capable of cutting two fuzes at a time. It may be used with either the stereoscopic director or the auxiliary director.

Figure 101 — Fuze Setter on Carriage

(2) For use with data electrically transmitted from the stereoscopic director, the fuze setter has a system of lights similar to that employed in the azimuth and elevation indicators. In the top of the fuze setter is a plate containing three concentric rings of 10-volt electric lamp sockets. Each socket has an individual positive electrical connection. All the sockets have a common negative connection. Three pointers are pivoted at the center of the circles, one for each circle of lights. At the end of each pointer is a translucent index. The two inner indexes are each wide enough to cover one light. The outer pointer can span two lights. The pointers are geared together at a ratio of 1:10:100, the shortest pointer moving 1 turn to 100 turns of the longest pointer. The pointers are geared to the fuze dial and to the setting ring of the fuze setter.

(3) For use with data telephoned from the auxiliary director, the fuze setter has a scale graduated from 15 to 350 degrees (fig. 102). The safe position is marked with a cross. (American fuze setter dials are marked in fuze seconds. A conversion scale is necessary for converting from American fuze seconds, with corrector values set in to the degree markings on this fuze setter.)

Figure 102 — Fuze Setter — Close-up, Showing Cover Removed and One Fuze Cap Disassembled

(4) The setting crank at the front of the fuze setter turns the pointers and the fuze dial. The crank at the side of the fuze setter turns the inertia flywheel which stores up mechanical energy for cutting the fuzes. The release lever releases the round after the fuze is cut. The cable receptacle from the fuze setter extends to the terminal box at the front of the top carriage.

b. Operation.

(1) Turn the setting handwheel to black out the lights (in operation with the stereoscopic director) or to aline the fuze scale in accordance with the values announced by telephone (in operation with the auxiliary director). Turn the power crank, thus storing up energy in the flywheel, and keep the crank turning at a uniform rate.

(2) Thrust the round sharply into one of the cups of the fuze setter, thereby engaging a toothed clutch which rotates the adjusting pin. This makes two complete turns before being automatically disengaged. The round is held in position by a key which rides in a circular groove at the bottom of the fuze. This key is tripped by a lever at the top of the setter and the round is released. Two fuzes may be cut at one time.

81. ON-CARRIAGE WIRING.

a. A receptacle containing 104 pins is at the end of the rear trail and is intended for connection to either of the directors (fig. 103). Each pin is numbered and groups of pins are identified by colored dot inserts. Conductors are brought from the end of the trail to a receptacle box at the front of the top carriage. The arrangement of wiring permits traversing the gun a maximum of two turns in either direction. Stops limit further travel and a dial (marked "MUNDUNG," meaning muzzle direction) just over the traversing handwheel is graduated to indicate the number of turns made.

Figure 103 — Data Transmission Receptacle on Rear Trail

b. Cables and plugs from the azimuth and elevation indicators, the fuze setter and the receptacle, adjacent to each, plug into the receptacle box.

c. The bell just above the fuze setter may be sounded to indicate that the director is on target or may serve as a time interval bell.

d. Conductors are carried in loose flexible coverings throughout the gun carriage and are not armored.

82. AIMING CIRCLE.

a. General. The aiming circle (figs. 104 to 107) is used for measuring angle of site, for declinating and determining azimuth angles, and for spotting. The instrument, removed from the tripod, may be used on a plane table for topographic survey. The aiming circle consists of a periscope, a telescope having 4- or 5-power magnification, an angle of site mount, an azimuth mount, and a tripod. The tripod is the same as that of the battery commander's telescope. Carrying cases for the instrument and the tripod are provided. A trench mount is furnished which can be embedded in the ground or in wood for use in place of the tripod. A lamp bracket and portable battery supplies light for the telescope reticle. Graduations are in mils.

Figure 104 — Aiming Circle

Figure 105 — Aiming Circle — Close-up

b. Description of Components.

(1) The periscope raises the line of sight, but has no magnifying power. It is attached, to the aiming circle by a dovetailed slide, but is not locked in place. The aiming circle may be used without the periscope.

(2) The telescope has an adjustable focusing eyepiece. Horizontal and vertical cross lines and a deflection scale are on the reticle of the telescope. On top of the telescope body is a level used with the angle of site mechanism. On the left of the telescope is a circular level. A sun shade is provided for use when the periscope is not attached.

Figure 106 — Aiming Circle Components

(3) The angle of site mount supports the telescope and includes a graduated elevation scale and micrometer, a magnetic needle, a circular level, and clamping devices.

(a) The elevation scale, graduated from 0 to 1,400 mils, and the micrometer 0 to 100 mils. The normal setting is 300 mils.

(b) The magnetic needle has a visible range of 10 degrees on either side of the magnetic north line. A knob below the window marked "N" locks the needle when it is not in use. A window at the "S" end permits observation from the rear of the instrument.

(c) The circular level is used with the compound head of the tripod for leveling the instrument.

(d) Clamping levers lock the angle of site mount on the azimuth mount.

(e) The folded 10-centimeter ruler (fig. 107), is for use when the telescope and angle of site mount, disengaged from the traversing mechanism, is in use on a plane table in topographic survey.

Figure 107 — Aiming Circle — Angle of Site Mount

(4) The azimuth mount has a tapered stud which supports the angle of site mount, an azimuth scale, graduated from 0 to 6,400 mils in 100-mil intervals, and a micrometer, graduated from 0 to 100 mils in 1-mil intervals. A throw-out lever permits rapid traversing of the instrument. The azimuth mount is clamped to the spindle of the tripod.

(5) The tripod is used for both the aiming circle and battery commander's telescope. The tripod includes a spindle, a worm and worm wheel mechanism, a ball and socket joint, and individually clamped legs. The spindle supports the instrument and is attached to the worm and worm wheel mechanism which is used for orientation. The ball and socket joint includes the ball at the end of the spindle, two clamping nuts, one of which permits cross leveling and the other, circular oscillation. The tripod legs have clamping levers at the head for locking each leg to the head. At the foot of each leg is a steel point and foot rest which facilitate embedding in the ground.

(6) The carrying case is provided for the instrument. The table of contents pasted in the cover includes one lamp bracket and four lamps, a dry cell battery holder, a dust brush, a cleaning cloth, and an impregnated cloth to be used in decontaminating parts of the instrument which may have been subjected to gas attack.

c. Operation.

(1) To set up the instrument, clamp the tripod legs at the desired length and embed them firmly in the ground. Level the instrument using the circular level and the ball and socket joint. Tighten the clamping nuts. Focus the telescope as required, using the sleeve on the eyepiece to set in the correction necessary for the observer's eye.

(2) To orient the instrument, a datum point of known azimuth or a magnetic bearing may be used.

(a) To orient on a datum point of known azimuth, set the main azimuth scale (100-mil intervals) and micrometer (1-mil intervals) to the azimuth of the datum point and turn the orienting knob until the datum point appears on the vertical cross line of the reticle. The instrument may also be relocated on the tripod spindle using the orienting clamping screw for large angular changes. The telescope may be elevated or depressed as required to center the point in the field of view.

(b) To orient on magnetic north, set the main azimuth scale and micrometer to indicate zero. Press the plunger releasing the magnetic needle and turn one of the orienting knobs until the north-seeking end of the magnetic needle appears approximately opposite the "N" index at the front of the instrument; then refine the setting so that the south-seeking end of the needle is centered in the reticle. The instrument may also be relocated on the tripod spindle using the orienting clamping screw for large angular changes. The aiming circle will then indicate magnetic azimuths.

(c) To orient on grid north, proceed as for magnetic north but set the azimuth to the magnetic declination of the locality (subtracting west declinations from 6,400 mils) instead of to zero. The instrument will then indicate grid azimuths.

(d) When orientation by magnetic bearings has been completed, turn the knob to clamp the magnetic needle.

(3) To read azimuth, bring the object on the vertical cross line of the reticle using the azimuth knob; the throw-out lever may be depressed for making large azimuth changes rapidly. Azimuths from 0 to 6,400 mils are read directly on the azimuth scale; the scale is graduated at 100-mil intervals and the micrometer is graduated at 1-mil intervals.

(4) To read angle of site, first make sure that with the telescope level bubble and the circle level bubble centered the angle of site scale and micrometer read normal. Then center the object in azimuth. Raise or depress the angle of site micrometer to center the object on the reticle cross lines and read the angle of site on the scale and micrometer.

(5) To prepare the instrument for traveling, place it in the carrying case provided.

d. Tests and Adjustments.

(1) The azimuth micrometers should read "0" when the azimuth scale indicates zero. The screw in the end of the azimuth micrometer may be temporarily loosened for this adjustment.

(2) The line of sight as determined by the center of the reticle should be horizontal when the bubble in the telescope level is centered. This may be verified by sighting on a distant point at the same level as the telescope, the error, if any, being read on the reticle. No corrective adjustment by the using arms is permitted.

(3) To check the accuracy of the declinator, it is necessary to set up the instrument in a position not subject to local magnetic attraction and sight on one or (preferably) more points of known azimuth. The average error should be noted and the necessary correction recorded. No adjustment by the using arms is permitted.

e. Care and Preservation. Refer to paragraph 87 for general instructions pertaining to the care and preservation of instruments.

83. RANGE FINDER MODEL 34.

a. This instrument (figs. 108 to 111) is used primarily for measuring distances by triangulation. Range values are read in the field of view.

Figure 108 — Range Finder 34 with Harness

b. Description. The instrument includes an internal 70-centimeter base line, all power optical system with two objectives, a common eyepiece of the coincidence type, and a scale on which the distance is indicated. It is furnished complete with a carrying strap, an eyepiece cap and strap, a shoulder harness with carrying pouch, and an adjusting lath with carrying case.

c. Operation.

(1) To set up the instrument, adjust the harness on the observer. See figure 108. The carrying pouch should hang on the back; the spring mounted holders for the range finder should extend in front of the observer. Carefully place the range finder in the holders and in line with the eye of the observer.

Figure 109 — Range Finder 34 — Assembled Views

(2) Focus the eyepiece by rotating the diopter scale to produce a sharp image; if the operator knows the value for his own eye, the setting may be made directly on the scale.

(3) To measure the range of a target, aline the instrument on the target, using the open sight. Select a clearly defined part, perpendicular if possible to the halving line. Center the target in the field of view. Turn the range knob until the images of the target appear in coincidence. Read the range value centered in the field of view.

Figure 110 — Range Finder 34 with Adjusting Lath

(4) To prepare the instrument for traveling, remove the instrument from the harness, close the end box covers, and cover the eye piece. Disassemble the harness and put it in the carrying pouch.

d. Tests and Adjustments. Information on this is not available at this time but will be published when available.

Figure 111 — Range Finder 34 — Harness

e. Care and Preservation.

(1) Refer to paragraph 87 on general instructions pertaining to the care and preservation of instruments.

(2) Keep the end box sleeves closed and eyepiece covered when the instrument is not in use.

84. SURVEYING ROD.

a. A 3-meter surveying rod (fig. 112), graduated in 1-centimeter divisions, is provided for orientation of the battery. The rod is hinged to reduce its length to about three-quarters of a meter for storage and travel. The folded rod is carried in a canvas case fitted with a sling strap.

Figure 112 — Surveying Rod and Carrying Case

85. PLOTTING RULES.

a. Three rules are furnished as plotting board accessories.

b. One steel rule (fig. 113) bears a linear scale, graduated from 0 to 14 kilometers in 5-meter intervals, and a quadrant, graduated from minus 800 mils to plus 800 mils in 50-mil intervals. At the zero end is a center for pivoting. This rule may be used for plotting azimuth and range values on a topographic map with a scale of 1:25000. Figure 113. Plotting Rules

Figure 113 — Plotting Rules

c. The steel protractor is graduated from minus 500 mils to plus 500 mils in 2-mil intervals. The radius of curvature is 480 millimeters. Two points permit pinning the protractor to a board.

d. The other steel rule bears a linear scale graduated from 0 to 14,600 meters in 50-meter intervals and a center at the zero end. At about 11,800 meters is a raised section. When this rule is set up with the protractor on a deflection chart, the raised section clears the protractor. The rule and protractor are used for plotting deflections on a chart with a scale of 1:25000.

86. BATTERY COMMANDER'S TELESCOPE.

a. Description.

(1) The battery commander's telescope is a 10-power binocular instrument used for observation and for measuring azimuths and angles of site. The instrument consists of a telescope and an azimuth mount, tripod, carrying case, and accessories. The tripod includes an orienting mount. A trench mount is furnished, which can be embedded in the ground or in wood, for use in place of the tripod.

(2) The telescope arms may be positioned vertically (fig. 114) or they may be swung horizontally (fig. 116) to increase the stereoscopic effect. The reticle, which remains erect in any position of the telescope arms, is illuminated by the removable lamp on the slide near the reticle.

Figure 114 — Battery Commander's Telescope with Cases

b. Operation.

(1) To set the instrument, clamp the tripod legs at the desired length, embed them firmly in the ground, and tighten the leg clamping levers. Using the spring plunger, clamp the telescope on the vertical spindle extending from the orienting mount. (The tripod has a mount which permits cross leveling and orienting.) Level the mount by centering the bubble in the circular level. When the bubble is centered, clamp the ball and socket joint on the lower mount.

(2) To prepare the telescope, release the telescope clamping knob (fig. 114) and turn the telescope arms to the vertical or horizontal position, as required. Set the proper interpupillary distance on the interpupillary scale (fig. 115), graduated from 55 to 75 millimeters, and tighten the interpupillary clamp knob. If the interpupillary distance for the observer is not known, it may be found by observing the sky and moving the eyepiece apart or together until the field of view changes from two circles or two overlapping circles to one sharply defined circle. The interpupillary wing knob is then clamped. Focus each eyepiece independently by covering one of them and looking through the telescope with both eyes open at an object several hundred yards away; turn the diopter scale until the object observed appears sharply defined. The diopter scale on each eyepiece permits immediate adjustment for each eye if the observer knows his own eye corrections. If required, place the light or dark filters over the eyepieces and the metal sunshades over the objective lenses. Tubular sections, about 8 inches long, can be attached to the sun shades for protection against rain.

Figure 115 — Battery Commander's Telescope — Close-up

(3) To orient the instrument, select a datum point of known azimuth and set this value on the azimuth scale (100-mil steps) and micrometer (1-mil steps). The throw-out lever may be used for making large changes in azimuth rapidly. Turn the telescope with the orienting knob until the datum point appears at the center of the reticle of the right-hand telescope. The orienting clamping knob may be temporarily released for making large angular changes rapidly. Thereafter, use only the azimuth knob, or, for large changes, the azimuth throw-out lever, and the correct azimuth of the point observed will be indicated. For azimuths in the 3,200- to 6,400-mil region additional numbers (0 to 3,200 mils) are provided, corresponding to the azimuth scale on the panoramic telescope.

(4) Direct the telescope on the object and rotate the elevating knob until the object appears at the center of the reticle. Center the angle of site level bubble by adjusting the angle of site knob. The angle of site is then read on the angle of site scale. It is not known whether the graduations on the angle of site scale are in mils or in 1/16 degrees. An indication of 300 corresponds to a horizontal line of sight.

Figure 116 — Battery Commander's Telescope — Interpupillary Scale and Angle of Site Mechanism

(5) The reticle (fig. 115), located in the right eyepiece, is a grid, the horizontal and vertical axis of which are graduated in 100-mil intervals.

(6) A throw-out mechanism is provided for rapidly traversing the telescope. A circular level is provided for leveling the head. The traversing head is graduated from 0 to 64 in 100-mil divisions with a micrometer adjustment from 0 to 100 in 1-mil divisions.

(7) To prepare the instrument for traveling, remove the sun shades and filters, if used. Loosen the telescope clamping knob and place the telescope arms in a vertical position. Disengage the telescope from the mount and place the instrument in the wooden carrying case.

Figure 117 — Battery Commander's Telescope — Azimuth Mount

c. Tests and Adjustments.

(1) The azimuth micrometer and azimuth scale should read zero simultaneously. The screw in the end of the micrometer may be temporarily loosened to permit adjustment.

(2) The angle of site mechanism may be checked by observing a datum point of known angle of site. Small errors may be corrected by temporarily loosening the screw in the end of the knob and slipping the micrometer and knob to the correct position. Should the angle of site scale and micrometer then fail to indicate "300" and "0" respectively, the instrument should be turned in for adjustment by authorized ordnance personnel.

Figure 118 — Battery Commander's Telescope and Aiming Circle — Tripod Head

d. Care and Preservation.

(1) Refer to paragraph 87 for general instructions pertaining to the care and preservation of instruments.

(2) Always release the telescope clamping knob before rotating the telescopes in a vertical plane. Failure to do this often results in damaging the instrument and causes double vision.

87. CARE AND PRESERVATION.

a. General.

(1) The instructions given hereunder supplement instructions pertaining to individual instruments included in preceding paragraphs.

(2) Fire control and sighting instruments are, in general, rugged and suited for the purpose for which they have been designed. They will not, however, stand rough handling or abuse. Inaccuracy or malfunctioning may result from such mistreatment.

(3) Unnecessary turning of screws or other parts not incident to the use of the instrument is expressly forbidden.

(4) Keep the instruments as dry as possible. Do not put an instrument in its carrying case when wet.

(5) When not in use, keep the instruments in the carrying cases provided, or in the condition indicated for traveling.

(6) The maintenance duties described are those for which tools and parts have been provided the using personnel. Other replacements and repairs are the responsibility of maintenance personnel, but may be performed by the using arm personnel, when circumstances permit, within the discretion of the commander concerned.

(7) No painting of fire control or sighting equipment by the using arms is permitted.

(8) Many worm drives have throw-out mechanisms to permit rapid motion through large angles. When using these mechanisms, it is essential that the throw-out lever be fully depressed to prevent injury to the worm and gear teeth.

(9) When using a tripod with adjustable legs, be certain that the legs are clamped tightly to prevent possibility of collapse.

(10) When setting up tripods on sloping terrain, place two legs on the downhill side to provide maximum stability.

(11) Dry cell batteries should not be kept in the battery boxes when the instrument is not in use. Dry cell batteries when weak deteriorate rapidly and will cause corrosion and other damage to containers.

(12) Data transmission cables should be protected against crushing by vehicles.

b. Optical Parts.

(1) To obtain satisfactory vision, it is necessary that the exposed surfaces of the lenses and other parts be kept clean and dry. Corrosion and etching of the surface of the glass can be prevented or greatly retarded by keeping the glass clean and dry.

(2) Under no condition will polishing liquids, pastes, or abrasives be used for polishing lenses and windows.

(3) For wiping optical parts, use only lens paper specially intended for cleaning optical glass. Use of cleaning cloths in the field is not permitted. To remove dust, brush the glass lightly with a clean camel's-hair brush and rap the brush against a hard body in order to knock out the small particles of dust that cling to the hairs. Repeat this operation until all dust is removed. With some instruments an additional brush with coarse bristles is provided for cleaning mechanical parts; it is essential that each brush be used only for the purpose intended.

(4) Exercise particular care to keep optical parts free from oil and grease. Do not wipe the lenses or windows with the fingers. To remove oil or grease from optical surfaces, apply ALCOHOL, ethyl, grade 1, with a clean camel's-hair brush and rub gently with clean lens paper. If alcohol is not available, breathe heavily on the glass and wipe off with clean lens paper; repeat this operation several times until clean.

(5) Moisture due to condensation may collect on the optical parts of the instrument when the temperature of the parts is lower than that of the surrounding air. This moisture, if not excessive, can be removed by placing the instrument in a warm place. Heat from strongly concentrated sources should not be applied directly, as it may cause unequal expansion of parts, thereby resulting in breakage of optical parts or inaccuracies in observation.

c. Lubricants.

(1) Where lubrication with oil is indicated, use OIL, lubricating, for aircraft instruments and machine guns.

(2) Where lubrication with grease is indicated, use GREASE, lubricating, special.

(3) Exposed moving points should be oiled occasionally. Interior parts are not to be lubricated by the using arms. Wipe off any excess lubricant that seeps from the mechanisms to prevent accumulation of dust and grit.

(4) The tripod pivots should be carefully oiled at frequent intervals.

(5) Do not oil optical parts.