a. General

The 8-cm model 34 mortar (see figs. 54 and 55) is the standard heavy infantry mortar of the German Army and like the U.S. 81-mm M1 mortar it is a smoothbore, muzzle-loading weapon for high-angle fire. For manhandling it is broken down into three parts: (1) the base plate, (2) the tube, and (3) the bipod with the traversing, elevation, and cross-leveling mechanisms. It is basically similar to the U.S. 81-mm mortar, except that the cross-leveling mechanism is not connected with the bipod leg, as in the U.S. 81-mm mortar, but is controlled by a handwheel located underneath the elevating mechanism between the bipod legs.

Figure 54.—8-cm mortar, model 34, in action.

This weapon is so similar to the U.S. heavy mortar that anyone who has used the latter can handle this German weapon effectively after a little practice. The German sights are graduated in mils, are basically the same as the U.S. mortar sight, and so will not cause any difficulty. This weapon is a serviceable mortar and should give a good account of itself in American hands.

Figure 55.—Right view of 8-cm mortar, model 34.

b. How to Identify

The 81-mm heavy mortar, model 34, may be identified by—

(1) Rectangular base plate with only one socket to take the ballshaped section (the spherical projection) on the breech (or base) end of the tube.

(2) Bipod with cross-leveling handwheel located between the bipod legs.

c. Characteristics

(1) General.—Very similar to the U.S. heavy mortar, this German weapon is a muzzle-loading, smooth bore mortar which is fired by dropping the mortar shell down the barrel—not by a trigger arrangement as with the German 5-cm light mortar. A panoramic sight is mounted on the left side (as you face the muzzle) of the traversing-mechanism yoke. It can be carried by three men or loaded on a horse-drawn cart.

(2) Table of characteristics.—

Principle of operation	_ _ _ _ _ _ _	Muzzle loader, fired by a firing pin situated at the inside breech end of the barrel.
Weight in action	_ _ _ _ _ _ _	125 pounds.
Caliber	_ _ _ _ _ _ _	81.4 mm (3.2 inches).
Maximum range	_ _ _ _ _ _ _	1,900 meters (2,078 yards).
Minimum range	_ _ _ _ _ _ _	60 meters (66 yards).
Effective range	_ _ _ _ _ _ _	400 to 1,200 meters (437 to 1,312 yards).
Weight of shell, model 34	_ _ _ _ _ _ _	3.5 kilograms, or 7 3/4 pounds.
Rate of fire	_ _ _ _ _ _ _	6 rounds in 8 to 9 seconds (but this rate cannot be maintained).
Sights	_ _ _ _ _ _ _	Line on tube for rough laying; panoramic sight for fine adjustments.

d. How to Operate (Figs. 55 and 56)

(1) Safety.—In the event of a misfire, wait one minute; put on "safe" by pressing in the spring-actuated bolt, which is located on the ball-shaped section of the breech (or base) cap, and then turning the bolt in a clockwise direction until the arrow on the bolt points to the letter "S" (sicher—"safe") (about 90 degrees); loosen the mortar barrel clamp, rotate the tube 90 degrees, and tighten the mortar barrel clamp again; and finally gently raise the breech end of the barrel until the shell slides out into an operator’s hands. Be sure that the bore of the barrel is kept clean, in order to prevent shells from sticking.

Figure 56.—Left view of 8-cm mortar, model 34.

(2) Preparation for action.—(a) Set the base plate and bed it into the ground; set the ball-shaped section of the breech cap of the tube into the base-plate socket, with the flat section to the side. Turn the tube in the socket until the spring-actuated bolt is on top; spread the bipod legs, put the bipod in position with the elevating handwheel toward the tube, and see that the line formed by the bipod legs is parallel to the line formed by the forward edge of the base plate; open the mortar barrel clamp and set the elevation so that one-third of the elevating screw shows above its tube, and then place the barrel inside the clamp between the position marks on the barrel itself; place the sight on the sight base, tighten the mortar tube clamp, and set the sight to 1200; lay the mortar roughly by moving the bipod legs and then set the legs by pressing the spikes into the ground.

(3) Elevation.—Check the firing table (see table 3, p. 110, below) for the elevation necessary for the range and charge that you are using, and adjust the sight accordingly. Set the elevation clinometer by moving the elevating crank.

(4) To zero mortar.—Sight the upper part of the sight on your aiming point or stake, and lay the mortar for direction by using the deflection adjustment on the sight. Note the angle shown on the deflection scale of the sight.

(5) Determination of direction of fire.—Set up an aiming stake or select an aiming point in line with the target (see fig. 57). With the deflection scale on the sight at zero degrees if the aiming point or stake is in front, or at 180 degrees if the aiming point or stake is in back of the mortar, lay accurately for line. Be sure the cross-level bubble is kept centered while you are determining the direction of fire.

Figure 57.—Laying 8-cm heavy mortar for direction during training.

(6) Corrections for direction.—Corrections are made by adding or subtracting the required deflection (positive or negative) on the deflection scale of the sight, and then relaying the mortar by using the traversing handwheel.

To correct for direction to the left, the extra deflection must be added to the angle on the deflection scale; to correct to the right, it must be subtracted from that angle. For example, if a round falls to the right of the target and the estimated correction for direction is 30 mils to the left, the setting on the deflection scale should be increased by 30 mils.

(7) To load and fire.—When the order to load is given, take the shell in the right hand and insert it, fins first, into the muzzle of the mortar, guiding it in with the left hand. On the order "Fire," allow the shell to slide down the barrel and remove the left hand from the muzzle. At this point all members of the crew should lie flat on the ground.

(8) Immediate action.—In case of misfires, follow the safety precautions listed under d (1), page 105, above. If the primer has been struck, insert another propelling cartridge into the base of the shell. If the primer has not been struck, a new firing pin may be needed, or the inside of the barrel may require cleaning.

e. Ammunition

The model 34 mortar shell is of conventional type with a percussion fuze. Charge 1, containing 154 grains of powder and giving a muzzle velocity of 246 feet per second, is fitted to the shell. Charge II, containing 293 grains of powder and giving a muzzle velocity of 344 feet per second, Charge III, having 432 grains of powder and giving a muzzle velocity of 427 feet per second, or Charge IV, containing 570 grains of powder and giving a muzzle velocity of 499 feet per second, are used as additional increments and fit between the tail fins.

Ammunition is carried in steel cases, each case holding 4 complete rounds. Twenty-four rounds are usually carried by a mortar crew in action. (See the firing table on p. 110, below, for elevation and charge information.)

f. Maintenance

The mortar requires the usual care and cleaning given to U.S. mortars. Cleaning materials will be found with the equipment or can be improvised from materials at hand.

 

FIRING TABLE 8-cm Heavy Mortar, Model 34 (GERMAN) 8-cm Shell No. 34 WEIGHT OF SHELL NO. 34—3.5 KILOGRAMS (7.75 POUNDS)

Range		Elevation	Charge	Elevation	Charge
Meters	Yards	Mils		Mils
60   80   100   120   140   160   180   200   220   240   260   280   300   320   340   360   380   400   420   440   460   480   500   520   540   560   580   600   620   640   660    680   700   720   740   760   780   800   820   840   860   880   900   920   940   960   980   1,000   1,020   1,040   1,060   1,080   1,100   1,120   1,140   1,160   1,180   1,200   1,220   1,240   1,260   1,280   1,300   1,320   1,340   1,360   1,380    1,400   1,420   1,440   1,460   1,480   1,500   1,520   1,540   1,560   1,580   1,600   1,620   1,640   1,660   1,680   1,700   1,720   1,740   1,760   1,780   1,800   1,820   1,840   1,860   1,880    1,900	65.4   87.2   109.0   130.8   152.6   174.4   196.2   218.0   239.8   261.6   283.4   305.2   327.0   348.8   370.6   392.4   414.2   436.0   457.8   479.6   501.4   523.2   545.0   566.8   588.6   610.4   632.2   654.0   675.8   697.6   719.4    741.2   763.0   784.8   806.6   828.4   850.2   872.0   893.8   915.6   937.4   959.2   981.0   1,002.8   1,024.6   1,046.4   1,068.2   1,090.0   1,111.8   1,133.6   1,155.4   1,177.2   1,199.0   1,220.8   1,242.6   1,264.4   1,286.2   1,308.0   1,329.8   1,351.6   1,273.4   1,395.2   1,417.0   1,438.8   1,460.6   1,482.4   1,504.2    1,526.0   1,547.8   1,569.6   1,591.4   1,613.2   1,635.0   1,656.8   1,678.6   1,700.4   1,722.2   1,744.0   1,765.8   1,787.6   1,809.4   1,831.2   1,853.0   1,874.8   1,896.6   1,918.4   1,940.2   1,962.0   1,983.8   2,005.6   2,027.4   2,049.2     2,071.0	1,545   1,526   1,507   1,488   1,469   1,450   1,430   1,410   1,390   1,370   1,349   1,327   1,305   1,283   1,259   1,235   1,210   1,185   1,157   1,127   1,094   1,058   1,016   1,325   1,313   1,301   1,289   1,276   1,263   1,250   1,237    1,224   1,210   1,196   1,182   1,167   1,152   1,135   1,118   1,101   1,082   1,062   1,040   1,017   991   962   926   874   1,212   1,203   1,193   1,183   1,173   1,163   1,152   1,141   1,130   1,118   1,106   1,094   1,081   1,067   1,052   1,038   1,021    1,005   987   968   945   917   881   1,152   1,143   1,135   1,126   1,116   1,107   1,097   1,087   1,077   1,067   1,056   1,045   1,033   1,021    1,008   994   980   963   946   925   901   869	1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   1   2   2   2   2   2   2   2   2    2   2   2   2   2   2   2   2   2   2   2   2   2   2   2   2   2   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3    3   3   3   3   4   4   4   4   4   4   4   4   4   4   4   4   4   4   4   4   4   4   4   4   4    4	- - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   1,447   1,437   1,426   1,415   1,404   1,393   1,382   1,371   1,360   1,348   1,337   - - -   - - -   - - -   - - -   1,383   1,380   1,372   1,365    1,357   1,349   1,341   1,333   1,325   1,317   1,309   1,301   1,292   1,284   1,275   1,267   1,258   1,249   1,240   1,231   1,222   1,212   1,203   1,193   1,183   1,289   1,282   1,276   1,269   1,262   1,256   1,249   1,242   1,235   1,228   1,221   1,214   1,206   1,199   1,191    1,184   1,176   1,168   1,160   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -    - - -	- - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   2   2   2   2   2   2   2   2   2   2   2   2   - - -   - - -   - - -   - - -   - - -   3   3   3   3    3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   - - -   - - -   - - -   - - -   4   4   4   4   4   4   4   4   4   4   4   4   4   4   4    4   4   4   4   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -   - - -    - - -

 

²¹ Actually this is an 8.1-cm mortar, but it is called an 8-cm by the Germans.
²² Schwerer Granatwerfer 34 (s.Gr.W.34). The German tactical symbol for a heavy mortar is or .