Direction for firing in fortress-siege artillery






After having been in force for three years in a provisional version and another two years in the definitive version, the first Bulgarian Rules for firing in fortress-siege artillery were replaced in 1902 by a new Наставление за стрелба въ крепостно-обсадната артилерия (Direction for firing in fortress-siege artillery) that was mainly a work of maj. Ivan Vatev, the head of the technical section of the Artillery Inspection.

Beside some minor corrections and additions, the new text included three new chapters : “Adjustment and fire with shell measuring the deflection of the projectiles”, “Shell and time fire at range less than 1500 m”, “Fire with a group of batteries”. In addition, it introduced the firing plan that should be always compiled before opening fire and added a great number of model of plans arranged for the different kind of fire and for the different kind of artillery pieces.


The direction includes three sections and two appendices :

I.     General information : 1. Reconnaissance, 2. Distance and targets, 3. Observation, 4. Kinds of fire, 5. Laying, 6. Battery preparation of fire, 7. Determination of the firing data, 8. Rate of fire, 9. Battery fire direction.

II.   Firing rules : 1. Adjustment and fire with percussion shell at great range; 2. Adjustment with percussion shell and fire with time shrapnel, 3. Adjustment and fire with time shrapnel, 4. Adjustment in direction, 5. Distribution of fire; 6. Transport of fire, 7. Adjustment and fire with shell measuring the deflection of the projectiles, 8. Adjustment and fire with time shrapnel measuring the burst of the shrapnel, 9. Adjustment and fire in particular instances, 10. Fire with quick-firing guns, 11. Fire with a group of batteries.

III.  Firing practice : 1. Aim and purpose of the instruction by means of the firing practice, 2. preliminary fire, 3. training fire, 4. fighting fire, 5. fire with a group of batteries.

App. I : Firing plans.

App. II : Instruction to record the result of fires and other practical information.


Generalities. The task of the fortress-siege artillery is to develop an effective fire from positions adequately and beforehand occupied prevailing over the enemy with its firepower. The direction stresses that the success of the shooting and the outcome of the fight result mainly from the skilful direction of the fire by the battery commanders and from the cooperation of his assistants, the section commanders and the gun NCOs.

Since the directive cannot foresee all the problems that fortress-siege artillery may encounter in practice, the shooter must adapt the rules of the directive according with the combat conditions and the time available, in order to fully achieve its objective as quickly as possible.


Reconnaissance. A detailed reconnaissance of the target is regarded as a necessary condition for an easy and fast adjustment, so it must be done whenever there was enough time. Reconnaissance must search and locate the target, to precisely determine its characteristics, its dimensions and its distance from the battery. It must concern also the ground around the target in relation to its influence on the observation of the hits and on the effectiveness of the fire, the presence of artificial or natural defences and their position with respect to the target and, if necessary, for the choice of auxiliary aiming points. The distance can be measured previously, calculated immediately before firing with the help of the rangefinder, determined on the map, or even appreciated by eye.

Reconnaissance must be carried out or led by the officers in charge of fire direction, possibly from high places or, if the target is covered, from the side, using binoculars. In the latter case, to adjust the fire it is necessary to find auxiliary points that must be close to the target and clearly visible. On defence, until the arrival of the enemy, all the area that he could occupy must be explored and studied, making special marks on the ground to calculate the distance and facilitate observation of the fire.

During the reconnaissance, the battery commander evaluates which place allowed the best observation and direction of the battery’s fire, and establishes whether it is possible to send auxiliary observers. In any case, until the opening of fire, he must determine 1) which elevation and deflection to give to the gun, 2) whether to direct the fire with the bar sight or the quadrant, 3) on which point of the target to make the adjustment.


Distance and target. The directive emphasizes that knowing the distance to the target made easier the adjustment and the passage to the fire for effect, specifying that it could be determined 1) by eye, 2) by measurements, 3) by maps, 4) by sound, 5) with the help of the rangefinder.

The battery commander must know the characteristics of the targets in order to be able to destroy them as quickly as possible, and identify the most important point of the target in order to direct the fire at it.

In relation to the position of the target, the directive requires the employ :

a)    against vertical open targets : horizontal fire with full charge, to provide the greatest energy to the shells;

b)    against vertical targets under cover : jumping fire with a charge selected in such a way that the trajectory passed over the obstacle and the target, and the projectile had a sufficient final horizontal velocity;

c)    against horizontal targets : plunging fire with a charge proportional to the solidity of the target.

In relation to the nature of the target, the directive requires to select the projectile as follows :

a)    against permanent concrete or armored fortifications : high explosive shell (melinite, ecrasite, liddite…);

b)    against old stone buildings : common shell with a black powder explosive charge;

c)    against earthworks: torpedo shell in order to produce deep holes, but also common shell;

d)    against artillery crews and infantrymen behind parapets : shrapnel;

e)    against troops in open field : at the limits of the range high explosive or common shell, at great and medium ranges shrapnel, at close range, case shot or shrapnel with the fuze set at zero range.


Observation. The purpose of the observation is to determine the point where the projectiles land in length and sideways with respect to the target and to the line on which the adjustment is made.

As a rule, the battery commander himself observe the firing during the adjustment, standing in a place from which he can be heard by the battery. In addition, each battery has some observers who support or replace him during the observation. If necessary, they observe the terrain in front of and around the target, informing the battery about unexpectedly appearing targets or about any changes of the target itself. To speed up the adjustment, it is enough for the battery commander to quickly get an idea of ​​the fire based on the general observation of a few shots or salvos and resolutely make the corrections required.

The means of observation can be binoculars, telescope, alidades, various tools to measure angles, the direction drawn along the area with stakes, with sabres or with natural or artificial points.

The connection with the battery is made by voice, telephone, optical signals or even by cyclists and orderly. The observation of the fall and the burst of the shell is communicated with the following terms: short, long, on target, high, normal, low, impact (hit), right, left, off target, exact (for the direction), not visible, doubtful, missed. For the lateral falls, it is also necessary to report the approximate distance in meters of the deflection.

The objects of the observation are :

1)    the deviation in the distance (whether the point of fall is behind or in front of the target line),

2)    the lateral deviation (whether the point of fall is on the firing line, right or left),

3)    the burst of the shrapnel (whether it is behind or in front of the target),

4)    the effect that shell cause on the target.

The smoke from the burst of the shell equipped with a percussion fuze is regarded as the safest means of observation. The direction and the force of the wind has a great influence on observation : if the direction is perpendicular to that of the shot, the observation was easier, but if it blows obliquely it is difficult to judge, after the smoke has appeared, whether the burst occurrs behind or in front of the target. If the wind blows against the direction of fire, the smoke is blown in front, so it is easy to consider long falls for long and vice versa.

By night, the observation is almost impossible, unless the enemy is illuminated, as in a camp.


Kinds of fire. The directive distinguishes  three basic kinds of fire, as in the Rules published in 1897 : horizontal fire (прицелна стрелба), jumping fire (прехвърлена стрелба) and plunging fire (надвесна стрелба).

In addition, the directive list the following kinds of fire :

a)    in relation with the target : dismantling fire (демонтирна стрелба) aimed at annihilating the enemy artillery, and destruction fire (демолирна стрелба) aimed at destroying a building;

b)    in relation with the direction : frontal fire (фронтална стрелба) when the direction of the fire is perpendicular to the front of the target, enfilade fire (анфиладна стрелба) when the target is shelled by the flank, and oblique fire (коса стрелба), when the direction of the fire is oblique to the target;

c)    in relation with the visibility of target : straight fire (права стрелба) when the target is visible from the aimer, and covered fire (закрита стрелба) when the target is not visible.


Laying. The direct laying is made with the bar sight, but is accurate only against moving targets or target that can move at ranges from 4000 m upwards; against non-moving targets such as batteries, infantry behind fortifications and trenches, the bar sight can be used only if a precise adjustment is not necessary. When it is required, as usually happens with the targets of the fortress-siege artillery, the first elevation and the first direction are given with the bar sight, the subsequent elevations with the quadrant, and the subsequent directions with auxiliary points (graduated ruler, aiming marker...). As soon as possible, all the guns must be aimed at the same target, taking into account the difference between the guns. The battery commander must choose the target and calculate the correction.

The indirect laying is made when the target is not visible through the notch of the sight and the tip of the front sight, but from a point standing higher in front of the target or behind it. In this case, the first direction is given by hanging lines (crossing the plane of the direction), and the elevation with the quadrant. Depending on how the target is viewed, the lines are drawn differently, with the help of the plumb line, the aiming markets, and the rangefinder. The de departure angle is given with quadrant or at first with the quadrant and then with the bar sight, the angle of elevation is taken directly from the firing table, while the angle of sight must be calculated in different ways depending on whether or not the target can be seen from the gun.


Battery preparation of fire. The directive stresses that it is essential to open fire immediately, to make the adjustments with the greatest speed and that the materials are well conserved, the breakdowns immediately repaired and the men who left the ranks replaced.

The correct direction of fire requires that :

a)    the battery commander 1) knows the sector he has to fire at, 2) choose the kind of projectile, the weight of the charge and the type of fuze, 3) controls the preparation of the charges, the distribution of the shells, the condition of guns, platforms, shelters, the supply of ammunition, the wounded, and the spare parts;

b)    the platoon commanders, the gun commanders and the battery aimers are informed about 1) the target they has to fire at and the aim they has to pursue; the deployment of the target, the topographical features of the land it faces, 3) the order given by their heads at any level;

c)    the battery has indications to quickly concentrate or distribute the fire according with the circumstances and receives a specific table of the targets at which it may fire.


Determination of the firing data. Knowing the distance at which the round is fired, the property of the target and the type of fire, the firing data – sight height, quadrant angle, deflection, combustion of the fuze – can be easily determined with the help of the firing tables. As for the powder charge, with horizontal fire the battery must take the full charge indicated by the tables, with jumping fire it determines the charge that will give the slowest trajectory, overcoming the cover, with plunging fire the charge depends by the angle of descend. In any case, all the firing data necessary are indicated in the firing plan, prepared before the beginning of the combat.


Rate of fire. The directive emphasizes that great part of the success of the artillery fire depends on its speed, specifying that in combat whoever carries out the adjustment first usually prevails.

The directive considers the following methods of firing:

a)    fire by gun (огън по оръдейно) with consecutive and continuous loading is considered normal in most war situations as it simplifies the direction of the fire and the service to the gun;

b)    rapid fire (беглия огън) allows greater speed and cand be used when the battery commander does not have the opportunity to direct the fire himself, such as during an assault, and is necessary to increase the rate of fire, but it is possible only if the war situation and the moral and physical strength of the crew allow them to load the guns fire calmly and diligently;

c)    accelerated fire (бързия огън) is used when a great rapidity was still required, but the fire should remain under the direction of the platoon commander;

d)    fire by salvos (залповия огън) by platoons or by battery allows a great rapidity of fire and is employed a) to facilitate the adjustment in case of unfavourable observations; b) to distinguish our shots from those of other batteries; c) to increase the psychological effect on the enemy; d) to surprise the enemy with unexpected fire. It gives to the battery commander the possibility of maintaining a disciplined fire, its limit are the pauses that occurred between the salvos, from which the enemy can take advantage.


Direction of the battery fire. The directive states that preventive dispositions are more appropriate than the commands themselves to direct the action of the battery in fortress-siege warfare; therefore, it is advisable to compile detailed firing plans, according to the attached models.

The battery commander must occupy a position where he can easily observe the fire and direct the action of the guns. Before the beginning of the fire, he gives to the platoon commanders, the guns commander and the battery aimers all the indications about the target, the methods of fire, the projectiles, the charges, the fuzes and so on. Then he orders to open fire, indicating which gun or flank has to shoot first. When he considers it appropriate to entrust the fire to the platoon commanders, he gives the corresponding orders, fixing the interval between the shots and the maximum daily consumption of ammunition.

The platoon commanders repeates the battery commander’s orders or directs the fire personally, reducing the rate of fire when the smoke interferes with the observation. In addition, they control that the servants correctly carry out the service at the gun and that the established corrections are made with precision.



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