Direction for firing in fortress-siege artillery
Firing at an artillery deployed behind parapets. The fire can be made as follows :
1) Horizontal fire
a) with shell (table 1). Firing at long range, from 4000 m upwards, aiming directly at the target is permitted, in other cases the gun must be always masked. The adjustment is carried out on one of the enemy’s guns or on a point on the edge of the parapet. A hit on the parapet is considered short. The adjustment is satisfactory, if the ratio between long and short rounds and between deviations to the right or to the left is between 1/3 and 2/3 of the rounds fired. The fire for effect is concentrated.
b) with shrapnel (table 5). The adjustment is made according with the general rules, taking care that the mean trajectory passes two probable deviations above the edge of the parapet and with an average interval of 40 m using a central chamber shrapnel and at the edge of the parapet and with an interval average of about 60 m with diaphragm shrapnel.
2) Plunging fire :
a) with shell (table 4). The departure angle must be about 30° and the charge is determined according to it (the charge decreases with increasing angle). The adjustment begins at the intermediate charge and the initial angle was always 30° : if the first round is long, the elevation changed to 26°, if it is short to 34°. The short bracket is always 1°. The adjustment is satisfactory, if the long rounds are 1/3 – 2/3, and the ratio between the deviation to the right and to the left is between 1/3 and 2/3.
b) with shrapnel (table 5). Adjustment and fire for effect are made according with the general rules : the average bursting interval must be about 40 m and the fuze burning correction not be less than 0.2”.
3) Jumping fire (enfilade);
a) with shell (table 2). The charge must be such as to allow the shell to pass over the edge of the cover, having enough force to hit the enemy gun. The width of the short bracket is 4 probable deviations of the tables. The initial elevation is taken from the tables according with the distance. The adjustment is carried out on the closest cover according to the general rules. After the limits of the short bracket have been confirmed, the target is shells per battery series by changing the elevation of the battery to half or full bracket, until through the enfilade about half of the rounds fly over the cover.
b) with shrapnel (table 5). Determination of the charge, adjustment and fire for effect are carried out as with shell with the interval of the burst fixed at about 40 m.
Shelling an area. This method is employed to shell an area where the target is supposed to be, hoping to hit it with one of the battery series. Being very inaccurate and very expensive, it must take place only against very important targets. As a rule it is made with shrapnel, shells are used only when the shrapnel does not reach the target, the characteristics of the target excludes its use or the area is not large.
To shell a deep area, after having fired a battery series with elevation and fuze at the near limit, in the following series they are increased according to the depth of the area, by half or a whole short bracket, and the fire continues until the long limit is reached. With shells or plunging fire, the increase indicated above is halved. At the same time, it is necessary to change the direction of the gun to move the fire also to the side.
Firing on the smoke of a masked artillery. To adjust on a masked battery two Moller instruments – one close to the firing battery and the other to the side of the battery – are aimed on the smoke of one of the enemy firing guns and by taking the value of an instrument graduation, the elevation is found according with the general rules, by means of the quantities measured for the deviation of the projectiles from the target. Depending on the situation, the target may be shelled with horizontal, plunging or jumping fire with shell or shrapnel.
Firing with shell at buildings. The fire can be made as follows :
1) With horizontal fire : stone buildings are destroyed either by methodical shelling or by breaking up their foundations or protective beams. In the first case, great final velocity, small angle of incidence and large angles of impact (not less than 45°) are required.
2) With plunging fire : the fire is made according with table 4, except that the angles of departure of 26°, 30°, 34° are replaced by angles of 64°, 60° and 56°. The short bracket is 1°. The fire is not distributed and everything is conducted as in plunging fire with angle of departure of 30°.
3) With jumping fire : the fire is made according with table 3. The angle of incidence, on the basis of which the charge is chosen, is determined as in the enfilade fire, calculating that the trajectory passed at 1/3 of the height of the building, starting from the base (at long range and with powerful charges even at 1/2), and the average trajectory at 1/3 of the upper edge of the building. The directive recommends first destroying the glacis with mine shells and then firing at the walls, if possible with a sloping trajectory.
To destroy specific targets, the directive prescribes the use of the following kind of fire :
a) against wire nets, palisades, barricades and other artificial obstacles : with mine shell horizontal or jumping fire, according with the position of the obstacle;
b) against camps, bivouacs, parks and other inhabited places : with shell to set fire to them or with shrapnel destroy animate targets inside them;
c) against roads and other means of communication that could not be observed by the battery : with shrapnel firing at those points where troops, transports, materials etc. can be expected to be located, such as railway stations, bridges, passages, descents, road crossings, ports;
d) against kite balloon and searchlight : accelerated fire at full charge with shrapnel or H.E. shell with time fuze and great angle of departure.
Firing on moving targets. Against moving targets, especially at more than 1500 m, the directive prescribes the use of shrapnel. Shell is used only against very fast moving targets, to react vigorously to a threat or at close range, when there is no time to set the fuze. There are two different cases :
1) Adjustment and fire with shell or percussion shrapnel.
a) If the target moves towards the battery, a bracket of 200-600 m is taken, depending on the speed of the target’s movement (at pace 200 m or 16 probable deviations, at trot 400 m or 32 probable deviations, galloping 600 m or 48 probable deviations). At the small limit of the bracket, the guns open a slow fire that is accelerated as the target approaches the place where the shells fall. As soon as shells are perceived to fall close in front of, or behind the target, the guns open a rapid fire. Then, if the target continues its movement, the guns reduces the elevation by 200-400 m and repeats the same procedure.
b) If the target moves away from the battery, the procedure is reversed.
c) If the target moves perpendicular to the direction of fire, the fire is made as with non-moving targets.
d) If the target moves obliquely with respect to direction of fire, the fire is made as with moving targets.
2) Adjustment with shell and fire with time shrapnel : Adjustment is carried out as above. Slow fire is made only by one of the flanking platoons, while the others loaded time shrapnel with bar sight and fuze 100-300 m less (more) than the small (large) limit of the bracket on the advancing (receding) target. After a long (short) percussion round, the guns loaded with shrapnel open a rapid fire. Then, if the target continues its movement, the percussion platoon retreats (advances) by 200-400 m, the other platoons by 100-300 m and both repeates the same procedure. If the target stops, the fire continues with shrapnel, like on troops standing in the open. With infantry moving jerkily, during the stops, the guns aim at the centre of the 100-200 m bracket and open a moderate shrapnel fire. When infantry resumes running, the fire increases in intensity. At close range (800 m with cavalry, 500 mm with infantry), the guns switches to case shots fire. With heavy guns, time fire is carried out according with table 6.
Night fire. With electric lighting, the target is taken in the short bracket of 8 probable deviation firing with shell or percussion shrapnel, then the area is shelled by shrapnel with fuze set for normal bursts. If the target is dimly lit, the area is shelled up to a certain depth starting from the limit at which the short shot closest to the target is obtained or the fire is made according with the elevation and lateral deviation calculated by day.
Fire with quick firing guns. Fire with 57mm QF guns must be simplified and accelerated as much as possible in order to fully develop their characteristics. As a rule they must employ rapid or accelerated fire, fire by salvos is allowed only at great range to facilitate observations.
With quick firing guns the direction lists the following kind of fire :
a) Against target placed at less than 1500 m, fire is directed by the gun commander or by the aimer, unless the distance to the forward points has been previously measured. After the table 8 has been compiled, every guns fires directly with time shrapnel. The gun commander observes the effect of the shot and, if necessary, orders the required corrections. The interval of the bursts is considered good at 40-150 m with a burst height of 2-8 m. To accelerate the fire, the crew prepares previously 10 shrapnel set at the distance corresponding to the point where the target is expected to pass and give the elevation with the bar sight of the elevating gear. As the target approaches 500 m, the gun switches to the most accelerated fire with case shot.
b) Against target placed at more than 1500 m or when the distance to the forward points has not been previously measured, fire is directed by the battery commander. The fire for adjustment is carried out with shell. The target is taken in the 200 m bracket, which is reduced up to 100 m without repeating the limits, and the time fire for effect is switched to the centre of the short bracket.
c) Firing with shell against moving targets, when the enemy has entered the effective area, the battery commander orders “Alt!” and opens fire reducing the last elevation by 100-300 m according with the speed at which the target is moving. If the target moves obliquely to the direction of the fire, the elevation is reduced by 50-100-200 m and the lateral adjustments mechanism is increased in the side of the movement of the target, according with its speed. If the target moves perpendicular to the direction of the fire, adjustment and fire for effect are carried out as on a non-moving target.
d) Firing with time shrapnel against moving targets, to speed up the firing, the table 8 reports only the lateral deviation and the combustion of the fuze. The fire for adjustment is carried out with shell. The target is taken in the 200-400-600 m bracket, then at the small limit of the bracket the combustion of the fuze is set for normal bursts. At first, the guns carries out a slow shrapnel fire, which is gradually accelerated as the target enters the effective area. Then the battery commander orders “Alt!” and the last elevation is reduced by 200-400 m as above. If the target periodically appears and disappears, the commander can order to open rapid fire with a set number of rounds.
e) Fire with case shot is carried out by setting the sight at 400-500 m and aiming at the top of the target. It is carried out at maximum speed and continues, if the target advances, up to the last stop, and, if it retreats, until it has left the effective area.
Fire with a group of batteries. The group consists of 2-4 batteries, possibly with guns of the same type and calibre. Every battery commander chooses the projectile and directed the adjustment and the fire for effect of his battery, the head of the group intervenes only when difficulties are encountered, an error is identified, the target must be changed or fire must be accelerated, stopped or switched.
Once the adjustment is complete, the battery commander informs the head of the group of the elevation found and in during firing, when he finds a difference with the data of the firing table, communicates the fuze for normal bursts. The head of the group writes down all his own observations and those of the lateral observers and if he finds any errors, he promptly communicates them to the relative battery.
If possibly, the head of the group must see all the terrain over which the group’s batteries can fire, otherwise, some observation posts must be placed between the batteries and the head of the group.
When some batteries are assigned a common target, the head of the group decides whether the fire must be conducted per battery or simultaneously by the whole group :
a) in the first case each battery fires independently;
b) in the second case the concentrated fire gives good results in a short time, if the observations of the various batteries are distinguished, using guns of different types (for horizontal/jumping fire) or calibres, different projectiles (shell/shrapnel) or fuzes (percussion/time), different rate of fire (by gun/by salvos).
If the group includes two batteries of the same calibre firing at the same target, it is advisable to assign one to carry out the adjustment with shell and the other to establish the corresponding fuze. However even if the observation is difficult, accelerated and simultaneous fire must never be renounced in order not to give the enemy the possibility of hitting the individual batteries, which has opened fire one after other.
The head of the group can indicate the distance and the direction from the start of the fire. If the group includes four batteries, with good conditions the target can be taken in the bracket of 2 salvos, then the batteries can start firing independently. The battery commander can open fire on his own initiative against suddenly appearing targets for which a fast and strong action is required, informing the head of the group as soon as possible.