Rules for adjustment and firing

 

 

Conduct of fire. The duties of the battery commander were : the choice of the position, the control of the guns in battle, the supervision of the adjustment and the selection of the kind of fire. However he directed personally only the battery fire and, as a rule, the section commanders directed fire with range and traverse corrections.

Adjustment and fire for effect were usually carried out setting the sight by means of the graduations of the range crank, and not of the sight-bar in metres. A graduation was 1/1000 of the line of sight for the Krupp guns and a Russian line (2.54 mm) for the old Russian 9 pdr and 4 pdr field guns M. 1867. There was not a direct correspondence between the two systems and to shift from meters to graduations and vice versa, it was necessary the use of the firing table. In fact with 87mm field guns changing the elevation of 1 graduation, at close range the point of fall shifted of around 30 m, but at 3000 m of only 14 m. Nevertheless, a full turn of the range crank corresponded approximately to 300 m at long ranges, 400 m at medium ranges and 500 m at short ranges. This system was more complex and less accurate than the other, and was replaced by the measurements in meters in the Direction for firing in field and mountain artillery, published for the first time in 1897.

The battery was brought into action with the guns loaded with shells. The first round was shot at the elevation corresponding to the estimate distance; the extent of the bracket was determined according with the result of the observation of the fire. To change the elevation, the section commanders calculated the new graduation and the direction of the turn of the range crank. Then they ordered the changes to their guns. The aimers should count the correct number of graduations (4, 8, 16 and so on), paying attention to the direction and the precision of the turn, set the ordered height of the sight and aimed. The leading gun made the modifications only on the range crank and fired, while the remaining guns, before firing, should also set the height of the sight.

When the observation was difficult, a bracket with 4 graduations was ordered and two sections shifted to shrapnel fire, while the remaining two sections kept up the shell fire. If the observation was so difficult that was impossible even to see the cloud of smoke formed by the burst of the shells, the adjustment might be carried out by section or half-battery salvos, lowering down the bracket up to two graduations.

 

Rate of fire. In battle formation the guns of a battery were deployed side by side at intervals of 30 – 50 paces. As a rule the guns fired in succession at an order of the commander, beginning from leeward. In certain cases they could also fire a salvo simultaneously. Every section fired at the portion of the target which was in front of it; if the battery commander preferred a different distribution of fire, he should give a special order.

The “Red booklet” established three different kinds of fire for effect, slow, ordinary (4-6 rounds per minute) and rapid (8-9 rounds per minute), but did not specify whether it was produced by a six guns or an eight guns battery. The contemporary German regulations stated that a six-guns battery should fire 6 rounds per minute with ordinary fire and 10 rounds per minutes with rapid fire. During the adjustment a battery could not fire more than 3-4 rounds per minute, in order to enable the observation of the fire.

 

Scale fire (шкална стрелба). The “Red booklet” described also the so called “scale fire” elaborated by the Russian gen. Shklarevich and tested at that time at the Ofitserskaya Artilleriiskaya Shkola of Tsarskoe Selo. Regarded soon as too complex, it was abandoned both in the Russian Rules published in 1892 and in the Bulgarian Direction for firing adopted for the first time in 1897. The scale by gun was employed only at close range to set as soon as possible the bracket of 1 graduation, otherwise the scale by section should be adopted.

The conduct of this kind of fire was not easy, and it was a matter of the highest importance that everybody kept cool. The leading role was played by the section commanders, which should listen carefully the orders of the battery commander, transmit them timely and clearly, without shouting, and control the correct and rapid action of the gunners. The battery commander should only give the orders and observe the fire. He should avoid to give a great number of orders that could not be understand or could take much time to be executed, and in general he should avoid everything that might cause disorder and confusion in the battery.

At first the battery commander ordered the basis (the elevation that should be adopted by the third gun in the scale by gun or by the second section in the scale by section) and the step of the scale (the difference of elevation between two near guns or two near sections). The elevation should rise in progression from the guns or the sections placed in succession. The step should correspond to the extent of the bracket to obtain and the difference between the highest and the lowest elevation to the limits, inside them might fell the errors of ranging.

The battery was deployed with the guns loaded with shells, the sight set in scale by guns beginning from 8 graduations with 87mm and 10 graduations with 75mm guns, with steps at intervals of 2 graduations :

 

guns :

1st

2nd

3rd

4th

5th

6th

75mm

10 grad.

500 m

12 grad.

560 m

14 grad.

640 m

16 grad.

700 m

18 grad.

760 m

20 grad.

820 m

87mm

8 grad.

520 m

10 grad.

580 m

12 grad.

640 m

14 grad.

700 m

16 grad.

760 m

18 grad.

820 m

 

At first fired the gun whose sight was regarded as more appropriate for the distance esteemed by the battery commander, then the fire was carried on by the gun whose elevation was the most suitable to bracket the target according with the observation of the first shot, but without skipping a step of the scale. When the bracket was obtained, the limits were repeated by section, two sections being with the sight placed at the low limit and one at the long limit. When the low bracket was obtained, after the observation of 3-4 rounds, the guns shifted fire for effect. With shrapnel the fire was open at the low limit of the bracket, with the sight and the fuze set to obtain short rounds.

 

Fire when the observation was difficult. When the observation of the rounds bursts near the target was difficult, the adjustment was made with shells, shifted to shrapnel for the fire for effect. At first the target was picked into the high bracket by means of section or half-battery salvos, exceptionally also by single shots. The bracket was not reduced by halving, but always lengthening or shortening one of the limits by 2 graduation; it might be lengthened or shortened by 4 graduations only if the bracket was very high (16 graduations, for instance). As soon as the low bracket of 4 graduations was obtained, two sections shifted to shrapnel fire, with the sights set in scale by gun. To set the scale at the height of the short rounds, a section loaded with shells fired a salvo at the middle of the bracket : if at least an observation was obtained, the scale was set so that only a shrapnel round was over; if not even one observation was obtained, the base of scale was put at the short limit of the bracket. Then the bracket was narrowed up to 2 graduations, by means of the observations of the shells burst, and the sights were set in scale by sections using the two limits of the bracket as steps.  The fire for effect was carried on with two sections firing shrapnel according with the common rules, and the rest of the battery firing shells to verify whether the target had changed its position.

When only the rounds burst very far from the target could be observed, the low bracket was narrowed at first at 8 graduations and the scale per guns was set using them with steps at intervals of 2 graduations. Then the bracket was narrowed only to 4 graduations and the fire went on as above.

 

Fire against moving targets. The conduct of this kind of fire depended upon the direction and the rapidity of the movement of the target. As a general rule, the adjustment was carried by two guns firing slowly. Their fire began with the limit of the scale toward which the target was moving (the upper limit if it was approaching, the lower limit if it was mowing away). When a round was observed falling not far from the target, the guns ready to fire shot some rounds in close succession. As soon as the target went out of the area of dispersion of the shells, the rapid fire ceased and the adjustment was resumed.

The “Red booklet” envisaged two different methods of fire against moving targets, both employing the scale fire :

    the guns, loaded with shells, set their sights in scale. As soon as the bracket of 8 graduations was obtained, the limits, towards which the target was moving, were verified, and the scale for the waiting guns was set with steps at intervals of 2 graduations. Taking account of the movement of the target, two guns adjusted the fire, shooting some testing rounds, while the rest of the battery got ready to fire a salvo simultaneously or an accelerated fire in succession. The firing guns should try to locate when the target entered into the area of dispersion of the shells, in order to fire at the right time. If the battery shifted to shrapnel, in order to increase the number of the effective hits, a section continued the testing fire with shells.

    when the target was moving infantry, the sights were set in scale by guns through 8 graduations, in order to catch the target with individual shots within the area of a bracket of 8 graduations in breadth. Shifted over to shrapnel fire, the fuzes were set for normal burst with sights in scale. switch

 

Indirect fire. Usually the guns were deployed into the open and fired against a target that was directly seen by the aimer. However, in order to protect the pieces and the gunners from the enemy fire, a battery might even fire from a covered position, placing the guns 80-100 paces behind a slope. In this case the adjustment was carried out as above, but the observation and the conduct of fire required an observing position on the flank of the guns, from which a good view of the target and its surroundings might be obtained. It should be as close to the guns as the conditions permitted, in order to be constantly in communication with the battery.

The battery commander from the observing position determined the firing data and assisted the aimers in the adjustment, ordering the corrections. During the shrapnel fire he observed the height of burst and provided them the data for setting the fuze properly. If a section aimed, the others took a direction parallel to it. The angle of elevation was calculated for the shrapnel, extracting the angle of sight from the angle of projection (quadrant elevation), measured with the quadrant level or obtained from the adjustment with shell.

 

Fire against entrenched troops. Shelling the interior of redoubts, the number of the short rounds and of the hits on the parapet should not exceed ¼ of the rounds fired by the battery. Shrapnel fire against troops lying down behind low ground features or in ditches did not differ from fire against troops standing into the open, except that the mean interval of burst should be small. Against entrenchment or troops laying down, the height of burst was regarded as normal when even more than one burst of every salvo was low, and not more than one burst was on graze; against field works some low burst were before, some behind of the parapet and sometimes even some on the parapet itself.

 

The “Red booklet” contained only few mentions about the observation, the protection and the reconnaissance in field artillery.