Tag Archive for 'fire control'

Fire Control Equipment for 75 mm Model 88 (1928) A.A. Gun

Fire Control Equipment for 75 mm Model 88 (1928) A.A. Gun

These instruments are used with the Mobile Field Antiaircraft Gun described on page 110. The method used to predict the future position of a moving target in space differs from both the angular rate of travel and the linear speed methods, although based on the latter. Antiaircraft installations captured before the middle of 1944 showed very little use of computing directors and remote control systems. The system described herein is apparently all that was available.

The following instruments and computing mechanisms are employed in the system as off-carriage components:

a. Two-meter-base height and range finder.

b. Speed and course angle calculator.

c. Charge (propelling) temperature and wind corrector scale.

d. Spotting binoculars.

The data computed with the off-carriage components are transmitted orally to the gun where they are manually registered in the on-carriage fire control instruments. The on-carriage components consist of the following:

a. Elevation computing apparatus.

b. Azimuth computing apparatus.

c. Auxiliary elevation and lead corrector disc.

d. Fuze setter.

The accompanying illustrations show five of the significant components.

Japanese: p. 185 (April 1, 1945)

Sight Mounts for Self-Propelled Artillery: On-Carriage Fire Control

Sight Mounts for Self-Propelled Artillery: On-Carriage Fire Control

RANGE SCALES: In the above sight mounts there are four scales engraved about the periphery of a vertical range drum. The first scale, used for the Pzgr. 40, is graduated from -300 to 1400 meters; the second for the Spr. is graduated from 100 to 3300 meters, and the third for the Pzgr. 39, is graduated from 200 to 2400 meters. The fourth scale on the drum is a micrometer for the elevation scale located immediately to the right and above the telescope bracket. The elevation scale is graduated in units of 100 mils from 0 to 500.

MOUNTS: The telescope mount for the 7.5 cm Stu. K. 40 is attached to a bracket to the left of the weapon and is connected by a linkage bar so that elevation of the weapon is relayed to the telescope mount. The mount does not automatically compensate for trunnion cant. The telescope used with mounts of this type is of periscopic design and has a removable head. Quadrant elevation is obtained by placing the range drum index in agreement with the proper scale and depressing the telescope mount through the super-elevation angle necessary for the range and then elevating the gun until the apex of the triangle on the telescope reticle is superimposed on the target. There is no angle of site mechanism on the telescope mount, nor is there a longitudinal level vial or index arm to indicate when the gun has been moved through an angle equal to the original movement of the telescope mount. Deflection is introduced by operating the knurled knob at the top-right of the instrument. The deflection scale is graduated in increments of one mil from 0 to 20 on each side of zero.

 Sight Mounts for Self-Propelled Artillery: On-Carriage Fire Control

MOUNTS: The telescope mounts for these two guns are of the same general design, the only differences being in the ballistic cam and markings on the range drum. They are of the rocking bar type and have a range drum graduated for the various types of ammunition used in the weapons. A three power, straight tube telescope is used as the sighting component. For indirect fire, a panoramic telescope, the Aushilfsrichmittel 38 can be fitted.

Sight Mounts for Self-Propelled Artillery: On-Carriage Fire Control

Sight Mount for 10.5 cm (Stu. H. 42) on Pz. Kpfw. III chassis.

RANGE SCALES: There are three scales engraved above the range drum: the top scale is the elevation micrometer for the elevation scale which is graduated from 0 to 300 mils; the next, a range scale, used with the Spr. F. H. Gr., is graduated from 100 to 3300 meters; and the third scale, for the 10.5 cm Gr. 39 HL/A, HL 18, is graduated from 400 to 1500 meters.

MOUNT: The telescope mount for the 10.5 cm Stu. H. 42 is basically the same as the telescope mount for the 7.5 cm Stu. K. 40. The principles of operation are identical.

Sight Mount for 15 cm s. F. H. 13 on Lorraine chassis.

RANGE DRUM: The range drum is quite broad, but there are only two scales on it. The first is a range scale graduated from 100 to 8150 meters. The inner scale is engraved from 0 to 800 mils in 2 mil steps. An elevation scale graduated in units of 100 mils is engraved on a plate fastened to the left trunnion bearing. This scale in conjunction with a pointer actuated by the gun trunnion indicates the angle of elevation imparted to the gun.

MOUNT: The telescope mount for the 15 cm s. F. H. is not an azimuth compensating type. A panoramic telescope bracket is attached to a rack gear and is moved through vertical angles by operation of the knurled knob in the center of the range drum. Angle of site is introduced by turning a wing nut immediately below the telescope bracket. The angle of site scale is engraved about a spiral groove cut into a plate; the index is fitted with a lug that fits in the groove and raises up or down as the scale is turned. Operation of the angle of site mechanism when the range mechanism is locked causes the panoramic telescope to be tilted through an angle equal and opposite to the angle of site. The mount is cross-leveled by turning the wing nut below and forward of the range drum. There is no level vial to indicate a horizontal plane.

German: p. 179, 180, 181

Sight Mounts for Antitank Guns: On-Carriage Fire Control

7.5 cm Pak 41
Sight Mount for 7.5/5.5 cm A.T. Gun: 7.5 cm Pak 41
Sight Mount for 7.5/5.5 cm A.T. Gun

RANGE SCALES: There are five scales engraved about the periphery of the range drum. The first is an elevation scale graduated from 0 to 80 mils. The other four are range scales, numbered from 0 to III and graduated from 0 to 4200, 3800, 3400, and 3200 meters respectively. The range scale on the sector is graduated for ranges from 0 to 1500 meters.

TELESCOPE MOUNT: The telescope mount for the 7.5/5.5 is of simple construction. There is a range drum with its axis parallel to the axis of the telescope and a range scale inscribed on an arc that is located on the right side of the telescope mount. A deflection mechanism is located below the range setting handle.

8.8 cm Pak 43/41
Sight Mount for 8.8 cm A.T. Gun: 8.8 cm Pak 43/41
Sight Mount for 8.8 cm A.T. Gun

RANGE DRUM GRADUATION: The range drum has three scales engraved about its periphery. These scales, from left to right are: an elevation scale in steps of 2 mils from 0 to 800; a range scale marked for 8.8 cm Sp. Gr. L/4.7 with limits of 0 to 5500 meters; and a range scale marked 8.8 cm Sp. Gr. 39H1 with limits of 0 to 3000 meters.

TELESCOPE MOUNTS: There are two telescope mounts mounted side by side on the left side of the weapon. The first telescope mount is of the rocking bar type and is designed primarily for anti-tank use. There is no deflection mechanism apparent on the available model. The range drum is graduated from 0 to 4000 meters. The second telescope mount is of the same general design as that used with the 7.5 cm, 10.5 cm and 15 cm howitzers. Both its use and operation are also the same.

German: p. 178

Sight Mounts for Howitzers: On-Carriage Fire Control

MOUNTS: The telescope mounts of all three howitzers are of the same basic design. All are of the azimuth compensating type and automatically compensate for trunnion cant when cross-levelled. The angle of site mechanism has a scale graduated from 100 to 500 mils with 300 mils representing normal.

OPERATION: Range or super-elevation is introduced by turning the large handwheel below the bracket for the panoramic telescope. Operation of this knob causes the range drum to be rotated past the index and the index arm to be moved through an angle equal to super-elevation.

Angle of site is introduced by two operations. The first operation is to offset the angle of site level vial an amount equal and opposite to the angle of site. This is done by turning the small knob between the super-elevation handwheel and panoramic telescope bracket. The second operation is to rotate the telescope mount by means of the knurled knob beneath the super-elevation handwheel until the angle of site level is again on a horizontal plane. This second step moves the index arm an additional amount and positions it in an angle equal to quadrant elevation.

The second index arm which is actuated by the gun is brought into agreement with the first index arm by elevating the gun. The gun is then laid for quadrant elevation.

It is necessary to operate the angle of site mechanism on the panoramic telescope to bring the line of sight back on its original plane.

7.5 cm le. F. K. 18
Sight Mount for 7.5 cm Howitzer: 7.5 cm le. F. K. 18
Sight Mount for 7.5 cm Howitzer

RANGE DRUM GRADUATION: The range drum above has two scales: an elevation mil scale numbered from 0 to 800, divided into two mil units, and a range scale graduated in hectometers and numbered from 1 to 15.

10.5 cm le. F. H. 18
Sight Mount for 10.5 cm Howitzer: 10.5 cm le. F. H. 18
Sight Mount for 10.5 cm Howitzer

RANGE DRUM GRADUATION: The mil scale on the range drum for the above instrument is graduated in the same manner as for the 7.5 cm howitzer. The range scale is graduated for zone 5; the scale is divided into 50 meter units from 100 to 9150 meters.

15 cm s. I. G. 33
Sight Mount for 15 cm Howitzer: 15 cm s. I. G. 33
Sight Mount for 15 cm Howitzer

RANGE DRUM GRADUATION: In addition to the 0 to 800 mil scale on the above instrument there is a second mil scale, filled with red, placed to the right of the 0-800 scale. This second scale is graduated in 2 mil steps from 800 to 1330 mils. The range scale is preceded by the Roman Numeral I and is divided in increments of 25 meters from 25 to 1475 meters.

German: p. 177