The article which follows deals with the possibilities for concentrating
fire and is confined to an explanation of the simplest methods. The directive
embodying these details is in the nature of a supplement to the German Army
Manual 104. (H. Dv. 104) 1940. No new aiming and firing procedures are involved
nor is additional laying and firing equipment required.
Attention is particularly directed to the possibility of bedding-in the base
plate and to the terms "voice control action" and "position correction."
The German thought here shows the tendency towards concentration of
supporting fire, and though it purports to be a supplement to the Manual of 1940, it
does, in fact, it appears, represent a considerable change in policy.
An American unit in the field compares the supplement and the earlier
Manual as follows: "The earlier Manual considers that medium mortars should
normally be sub-allotted in pairs to forward companies, and even foresees occasions
when single mortars may be placed under command of infantry platoons; the
control of medium mortars by the mortar platoon commander and their
concentration at battalion level is regarded as exceptional whereas in the later supplement
all the emphasis is laid upon concentration as the normal policy. Recent fighting
has demonstrated the effectiveness of the new policy."
Since mortars are likely to be among our most formidable enemy weapons
in the future, this whole account should prove of interest.
Where an English equivalent exists but differs from a literal translation
of the German, the English equivalent has been preferred. The terms "section"
and "section commander" have been used to translate the German "Gruppe"
and "Gruppenführer" and mean respectively a section consisting of two mortars, and
the NCO in charge of such section.
* * *
(1) Concentration of the fire of several mortars increases fire effect.
The fire of one section, two sections or of a complete platoon may be concentrated,
depending upon the tactical situation, the number of the targets, their nature, and
the ground. When two sections or a complete platoon are engaged, the fire unit
will be the section. The effectiveness of the concentration will be especially high
if the target can be taken by surprise by a sudden hail of fire at maximum intensity.
(2) Platoon and section commanders must, therefore, continually strive
to concentrate their fire on the most important targets not only at the beginning
of an attack but throughout its duration. Should a number of targets appear at the
same time it may then be more effective to silence them one after another by the
concentrated fire of the section, than to engage them simultaneously each with a
single mortar. The platoon or section commander must decide (guided by the
nature of the target, its breadth and importance, and the demands of the situation,
or of his own troops) how, and in what order targets are to be engaged.
(3) Concentration of fire may also prove very effective in defense when
directed on enemy OPs, machine-gun nests, assembly areas in dead ground, woods,
outskirts of villages and so on; it may be the deciding factor in the repulse of
enemy attacks. Platoon or section commanders must take all measures within
the framework of the fire plan to ensure that the fire of their mortars can be
concentrated on the maximum number of points.
(4) Sound intercommunication is essential for rapid concentration of fire--in
the case of a section, between the section commander and his mortars,
and in the case of two sections or the whole platoon, between the platoon commander
and the individual sections.
In the first case, transmission of orders by relayed voice or remote control
procedure will normally suffice. The provision of a line link from the section
commander's OP to the mortar position, or to the OP of the second mortar is only
necessary where considerable distances are involved owing to the nature of the
ground or enemy activity, and will be the exception.
On the other hand, when two sections or the complete platoon are engaged,
a line link will frequently be necessary from the platoon commander's OP to the
section OPs. The platoon commander will detail the sections providing signals
apparatus, and decide whether the link is to be laid and maintained by platoon HQ
orderlies or by section personnel.
(5) Rapid and unhesitating target indication makes for quick fire concentration, and
increases the flexibility of the fire. A given target may be indicated by:
(a) Pointing out on the Ground
This method is the rule where a section is to engage. The section
commander points the targets out personally to both detachment commanders in
cases where he hands over fire control to them. Should he control a mortar
himself, then in order to save time he will normally entrust the detachment
commander of this mortar with the task of indicating targets to the other mortar.
When a complete platoon is in action, this method of target indication is
only possible if the sections are close together. In general, the method is
excessively lengthy, and as a result, the platoon commander will normally choose
one of the following procedures according to the situation, and time available.
(b) Fire by the "voice control" section
In order to be able to control and, if necessary, concentrate the fire of
several sections, or to bring the fire of one section quickly down onto a target,
the platoon commander will site his OP within shouting distance of a section OP
(i.e. the OP of the "voice control" section). Then, to indicate a target to the
other sections, he orders the "voice control" section to fire on the target using
one mortar. In this connection it should be noted that the element of surprise will
be forfeited by the preliminary round. This method is therefore only to be recommended
when engaging targets which cannot quickly move out of the fire (see paragraph 7 below).
(c) Named features
The platoon commander names a number of conspicuous topographical
features distributed in breadth and depth over the battlefield in the presence of
the section commanders:
e.g. "right hand edge of wood", "haystack", "lone tree", "brown knoll". Any
target appearing will then be described in relation to one of these reference
points, or its distance in line from one of them given in terms of mils** measured
by the binoculars:
e.g. "machine-gun right hand edge haystack", or, "OP 50 mils left of the lone
tree". This method is quick, and will be found convenient where speed is necessary, as
for instance in the case of an encounter attack or while an attack is still in
(d) Target key
The target key takes the form of a simple field sketch or panorama, in
which conspicuous points are indicated by a capital J and a number.*** The key is
then distributed to sections. Indication of targets follows in accordance with
paragraph 5 above. Fire orders will be determined and referred to in relation
to individual J-points. The key must agree with the key in use by the unit to which
the mortars are subordinated (company, battalion, etc.) This method takes time, and
its use is, therefore, frequently confined to the deliberate attack and to defense.
(6) When fire is concentrated individual mortars will nonetheless be
laid on the target or the allotted portion of the target area in accordance with
the laying procedure given in Army Manual 104. Bunching and careless behavior
during laying must be avoided.
(7) In order to retain the element of surprise when fire is concentrated,
ranging will normally be carried out by a single mortar firing on a registration
point (i.e. another target, or a feature in the vicinity of which the enemy is believed
to be). This registration point must lie at approximately the same range as the
target which is to be engaged, and should not differ from it in line by more than
300 mils.**** A range finder is considerable assistance when firing on the registration
point. As long as all mortar platoons are not equipped with this instrument, the
platoon commander must obtain one on loan from one of the MMG platoons. Measurement
of large variations in line using the binoculars requires much practice and
should be frequently exercised on training.
(8) The other mortar in the section accepts the established range to the
target and corrects it for position correction. Position correction is the distance
in meters measured along the line of fire by which the second mortar of a section
is either forward or to the rear of the first one.
In the above sketch the line R-A is the position correction of the left mortar in
relation to the right one. Should large switches be made, then the position
correction alters, as shown by the line R-B. In this case it must be worked out afresh.
The mortar position NCO estimates, or if sufficient time is available,
paces the position correction. In order to do this he moves prolongation of the
line Z-R counting his steps, until he reaches a point at which the left mortar
appears to be at right angles. He adds this distance (in meters) to the ordered
range for the right mortar. For example, if the ordered range for the right
mortar is 1,200 meters, and position correction for the left mortar 55 meters,
then the order for the left mortar will be "left 1,260." Should the second mortar
be sited forward of the first one, then position correction must be subtracted
from the range.
(9) Fire for effect, will normally be proceeded with only after the mortar
has registered. When engaging fleeting targets, parties of troops in dead ground,
wooded areas, or targets of considerable size, then shooting-in may be dispensed
with if the situation demands it. When concentrating fire on large targets surprise
effect or the necessity for conserving ammunition may make it expedient to
register or shoot-in only one of the mortars.
(10) Bedding-in the base plate will minimize the disadvantages which
arise when shooting with mortars which have not registered.
The following directions will be complied with when bedding-in the base plate:
After the detachment commander has aligned the base plate in accordance
with H.Dv. 104, he will mark its dimensions on the ground and have the bed dug
out. Its forward edge should be dug to a spade's depth***** and the rear edge to half
a spade's depth; this will produce a slope of 15 degrees (see sketch).
An additional depression will be made to correspond with the breech piece
socket, and the rear edge of the base plate should be level with the surface before
firing. The base plate will then be stamped in. Large stones, roots, etc., should
be removed from the bed.
On loose, sandy soils with a grass or heather surface, the turf that has been
removed should be used to make the bed.
If the ground is frozen or hard the bed should first be broken up in order
to prevent bounce, which makes shooting-in more difficult, and puts a severe strain
upon the mortar.
On stony ground the bed should be dug deeper than usual and made up with earth or clay.
The construction of the bed takes from 3 to 5 minutes.
(11) When firing mortars which have not shot-in one must be prepared
for a considerable dispersion of the first rounds, which may possibly also involve
some short ones. This method should accordingly only be used when one's own
troops are not situated too close to the target which is being engaged.
b. Concentration of Fire within the Section
(12) When preparing to concentrate his fire, or when actually firing,
the section commander may either entrust detachment commanders with fire
control, or himself control it.
(13) He will adopt the first course if the mortar positions are far apart. In
this case the section commander merely indicates the target to the detachment
commanders (or the relevant portion of the target, if the target is large), lays
down the registration point for each mortar, should this be necessary, and instructs
detachment commanders to report to him when ranging is completed. The
detachment commanders carry out ranging individually and the section commander
helps them out with observation. As soon as ranging has finished, the detachment
commanders switch onto the target line and report, e.g., "Right mortar ranging
complete. Mortar aligned on target."
According to the situation, the section commander may order both mortars
to carry on with fire for effect either immediately after ranging has finished, or
on his order. The amount of ammunition expended during fire for effect will depend
upon the nature of the target and the state of ammunition supplies.
Should ranging have been carried out on registration points which differed
considerably in line from the target, then if the situation permits, line and range
to the target may be confirmed by a few rounds before fire for effect begins.
(14) Should the section commander himself act as fire controller, then
he may either range both mortars one after the other, or only one of them. In the
latter case the detachment commander who has been detailed to assist the section
commander will range the other mortar while registration is proceeding. The base
plate of this latter mortar may be bedded-in if the ground permits (see
paragraph 10 above).
The mortar position NCO determines the position correction for the mortar:
As soon as ranging has finished, the mortar position NCO applies the
necessary position correction to the range, and passes the result to the second
mortar. The section commander then proceeds with fire for effect in accordance
with paragraph 13.
c. Concentration of fire of Two Sections or of a Complete Platoon
(15) The section is the fire unit even when the fire of several sections is
being concentrated. The section establishes the necessary data and carries out
the engagement of the target in accordance with the platoon commander's orders.
(16) If the fire of several sections is to be concentrated, the platoon
commander will site his OP at a point from which he can obtain the maximum
uninterrupted observation over the battlefield. He details the section which he
proposes to have close at hand as voice control section, and arranges communication
to the other sections. He makes suitable preparations for target indication, bearing
in mind the time factor and the tactical situation (see paragraph 5 above).
(17) Concentration of the fire of the sections will be regulated both in
space and time; regulation in space will be co-ordinated with the method of target
indication and must be as simple as possible e.g., "right section right half of
target, left section left half of target. Section commanders will distribute the fire of
the individual mortars.
(18) Limitation in time may be necessary on tactical grounds or for
technical reasons--for instance, when ranging. Normally ranging will be in
accordance with paragraph 7, which makes it possible for the platoon commander
to lay down the registration points for individual sections.
The tactical situation may demand that sections range gradually, and at
varying intervals, in order to preserve the element of surprise. In this case the
platoon commander will order the time at which each section is to range.
(19) As soon as ranging is reported complete, the platoon commander will
order fire for effect. This will be carried out in accordance with
paragraphs 12-14. Simultaneous opening of fire by all sections in the case of surprise fire may
be produced on the commander's order. The order will be passed, as the situation
demands, by line, or by the fire of the voice control section. It can also be
arranged on a time basis. If fire has to be brought down on the target at a
certain time, the time of flight must be borne in mind.
(20) The platoon commander will observe the general pattern of each
section's fire and report it to the relevant section, e.g., "No. 1 section short",
or "Left mortar No. 3 section shooting left 30 mils". The section commanders
thereupon adjust their MPIs (main points of impact). The fact that the platoon
commander is also observing does not, however, absolve section commanders of
their duty of constantly watching their fire and making independent efforts to improve it.
(21) Concentration of the fire of several sections is facilitated if the
mortar positions are sited as close together as the situation, task and ground
permit. Under these circumstances, also, the section continues to be the fire
unit. Ranging may occasionally be carried out by only a single mortar. In this
case position correction must be applied to all the other mortars when firing for
effect. However, should the mortars not have been shot-in, shooting-in may be
omitted (see paragraphs 9-11).
*Translated from the German Manual "Richtlinien für die Feuerzusammenfassung
mit s. Gr. Werfern" 8 February 1943.
**A Mil is 1/6400th part of a circle and at any range subtends a distance of
approximately 1/1000th of that range. There are approximately 18 mils to one degree.
***The "J" indicates an infantry (German-Infanterie) target. German practice is
to number targets from the right, using numbers from the block 100-199 for
battalion support weapon targets, e.g. MMGs and mortars; and from the block
200-299 for regimental support weapons, e.g. infantry guns. German artillery
proper adopts a similar system except that numbers are used without the letter
prefix. Note: It is to be observed that originally the Roman J was a
Gothic I (see H. Dv. 139/9, paragraphs 91, 92) derived from Infanterie, and
may still be found in some documents.
****i.e. about 17 degrees.
*****German entrenching tool is 8 1/2 inches long.