to be continuedOrganization and conduct of defense using a trench system (from experience of defense of the 49 Army during the winter 1943-44).
I. General conditions and progress of defense works.
During the winter 1944-44 the 49 Army defended a broad frontage. The length of the Army’s sector until January 1944 was 56 kilometers, beginning from January – 86 kilometers. This sector was defended by the following units: until January 1944 5 rifle divisions and one fortified region (total 48 battalions), from January to February – eight rifle divisions and one fortified region (total 75 battalions), from March 1944 – four rifle divisions and one fortified region (total 39 battalions). Average length of the divisional sector was 12-15 kilometers, regimental sector – 6-7.5 kilometers.
Terrain in the area of the Army was mostly completely opened plain with no forests, intersected by ravines, valleys and streams and small rivers, the entire area was accessible for operations of large forces of all arms. The frontline except single sectors passed along banks of rivers and gullies.
Transition to positional defense was made by the Army in the course of autumn offensive operations of the last year. The forward edge of defense was determined by the line reached during the general offensive of the Army in August-September and local operations conducted in October-November 1943.
In this connection there were some sectors where terrain was unsuitable for defense. Such sectors were, for example: GORMANY, ZASTENOK YURIEV, KOZIYANSKIYE or KOZLY, LENINO, POLYASCHITSA. In this areas as a result of the autumn operations troops of the Army captured the forward edge of hostile positions and advanced to eastern slopes of high ground occupied by the enemy. These sectors presented no advantages from the point of view of defense because hostile areas there dominated our forward lines.
The experience of defense has demonstrated that in some sectors it is expedient to leave combat outposts on the line reached during the offensive, and transfer the main battle line backward to a more profitable defense position.
Lack of forests and the onset of cold season, lack of motor and draft transport in supply units for transportation of wood, insufficient supply of engineer equipment (wire, mines), small personnel strength of units (600-700 men in a regiment) and a large width of defense front – all that influenced tempo of defense works.
Works on development and improvement of defense lasted the entire winter season and are still in progress at the present moment.
Development of defense positions proceeded in the following order:
a) foxholes of rifle companies were connected into a continuous trench of full profile
b) After that shelters and dugouts for personnel were built.
c) Finally, communication trenches were constructed by orders of battalion commanders (one or two communication trenches per a battalion).
Trench shelters and niches for ammunition were built simultaneously with construction of firing positions of light and medium machine guns.
Overall volume of engineer defense works made by the army during the winter period is presented in the table in appendix 1.
Simultaneously with building the main defense position reserve positions of divisions and intermediate positions of corps and the Army were reconnoitered.
The main position was built by units of the first echelons, reserve positions – by second echelons of divisions. The rear defense lines were built by the second echelons of the corps and partly by the army replacement regiment.
The table reproduced in the appendix 1 shows that although the volume of the work was very extensive, still the plan wasn’t fully carried out. The reasons for failure to carry out the plan were:
- large shortfall of personnel in rifle units, as a result instead of 800 riflemen stipulated by the plan, only 500-600 were actually employed on construction daily;
- large number of men were distracted to clearing trenches of snow (in average this work demanded 200 men in each division daily);
- a number of local operations connected with regrouping of our forces;
- terrain devoid of forests and a need to transport wood from distant regions sometimes led to pauses in work.
II. Brief characteristic of engineer defense works
The main defense belt in most sectors consisted of two trench lines (in some sectors – of three lines) connected by communication trenches (1-2 per a battalion).
The first trench line was continuous, interrupted only by recessions (swampy hollows) which were covered by snow walls and vertical masks made of available materials (timber, soil).
The most common profile of the trench in the Army’s area was 130 centimeters deep, 90 centimeters wide at the top and 60 centimeters wide at the bottom. In some sectors by building of snow parapets the trenches were made 1.9-2.1 meters deep. Revetment of trenches was in most cases absent.
The second trench line was situated 200-400 meters from the first line.
The third trench line was not built except single sectors. The third trench line of 3 kilometers length constructed east of POLYASCHITSA (700-800 meters from the first line) was covered with snow during the winter and stays unoccupied.
Second trench line was cleared of snow only for deployment of small garrisons – battalion reserves.
The first and second trench lines were outfitted with open emplacements for all types of infantry weapons – main and alternative positions (usually 2-3 per each piece of weapons) and adapted for internal defense (machine gun emplacements for fire along trenches, adaptations for fire to the rear etc).
In most tactically important sectors platoon and company strong points and battalion centers of resistance were created. In these sectors additional works for development of combat and communication trench network were made. Such strong points can be illustrated by the BOBROVA, KOVSHICHI-BAYEVO, and MEDVEDOVKA strong points (see the appendix 2).
Defense of strongpoint was organized as all-around, anti-tank, anti-artillery and anti-air defense.
In the sector of the 154 Fortified Region strong points are reinforced with anti-tank areas.
Layout of firing positions
Trenches of the first and second lines were outfitted with open emplacements for all types of infantry weapons – main and alternative emplacement (2-3 per each firing position). In many cases emplacements are of universal type which can be adapted for all types of weapons (medium and light machine guns, anti-tank rifles, light mortars). Overhead cover made of one layer of logs is made above some emplacements where terrain permits and good camouflage can be made. Up to 30% of emplacements are equipped with revetment.
All main and alternative firing emplacements are adapted for flanking and oblique fire and only single emplacements have a frontal field of fire, mostly for fire along ravines and hollows. In those cases where machine gun emplacement embedded in a trench doesn’t provide flanking fire it is advanced forward and connected with the combat trench by a communication trench 5-8 meters long.
Experience of defense suggests effectiveness of firing positions of so-called “redan” type, when the weapon emplacement is protected from the front by high parapet and has open sectors on sides for flanking fire along the front. Employment of this type of firing positions requires especially elaborated system of fire. It is necessary to have a position for frontal fire at 8-10 meters from such a position.
For internal defense of trenches 2-3 “hedgehogs” made of wire or cheval-de-frise braided with wire are prepared at the rear parapet near every weapons emplacement which can be dropped rapidly into a trench.
In the first and partly in the second trench lines there are up to 40-60 rifle pits, 4-5 main and 5-10 alternative machine gun positions per every kilometer of front. For sheltering of the gun and storage of ammunition each weapon emplacement has a niche, and there are also trench shelters for crews with overhead cover of 1-2 layers of logs and personnel shelters for 8-12 men.
Firing positions of batteries consists of a combination of the following elements: gun emplacement, circular parapet, shelter for the crew and for 45-50-mm guns, ammunition bunkers – at the firing position itself and at a distance of 50-75 meters from it, living shelters for personnel, and shelters for draught.
In view of employment of battalion and regimental guns for direct fire their firing positions were built in close proximity to combat trenches (depending on natural defilades at a distance from 200 to 500 meters) and connected with them via communication trenches. Firing positions of guns were connected with shelters for crews via trenches.
A large part of anti-tank guns was positioned between the first and the second trench lines, having 2-3 alternative positions for point-blank fire in the most important sectors.
Firing positions of 82-mm mortars are situated behind the second trench line (sometimes by batteries of 4 mortars), on reverse slopes and in hollows and consist of trenches, ammunition pits and shelters for personnel. Each mortar has 2-3 positions. Living shelters for personnel are built in close proximity to firing positions.
In the defense system of the Army a network of communication trenches was developed in all directions. Full-profile communication trenches connect combat trenches of the first, second and third lines, and also main, alternative and additional emplacements for weapons, living shelters, ammunition pits, observation and firing positions of artillery and mortars.
The most common profile of communication trench has a depth of 110 centimeters, width at the top – 90 centimeters, width at the bottom – 60 centimeters.
A branched network of communication trenches enables hidden maneuver of weapons and personnel, conduct of combat, protection of personnel from small arms fire and shell splinters, hidden delivery of food and ammunition to the first line etc. In some sectors dimensions of communication trenches differ from normal to the smaller values. In these sectors maneuver of weapons is limited. In some sectors communication trenches connected with terrain defilades (ravines) provide hidden communications from command posts of battalion and regimental commanders, thus staff officers can be present at the decisive point in combat. Some sections of communication trenches are adapted for fire in a requisite direction (fire on approaches to combat trenches, defense of flanks and junctures, fire to the rear etc).
Observation and command posts.
Observation posts of platoon and company commanders are situated in the first trench, some 5-10 meters from their living shelters. In most cases they are opened pits for a paired picket. Only the small part of them has overhead cover or shields. In some sectors (154 Fortified Region) OP of company commanders are situated 200-300 meters behind the first trench line and are equipped with dug-outs having an overhead protection of 3-4 log layers.
OP of battalion commanders are usually situated 300-400 meters from the first trench line. OP of rifle and artillery battalion commanders are more strongly constructed and equipped with shelters, and in some places with work and rest spaces.
Communication between platoon OP and platoon commanders is carried out in most cases by sound signaling, mostly using a rope or wire connected with an empty case installed in the commander’s shelter, or by tolling a case installed on the observation post.
Communications between company or battalion observation post and company or battalion command post – mainly by telephone and runners.
Most company and battalion OPs are supplied with scout periscopes and partly with binoculars. Artillery OPs have stereoscopic periscopes.
A liaison sergeant or officer from a supporting battery is placed at the company observation post with schemes and tables of prepared fires in the company sector.
In most cases OPs of rifle battalion and artillery battalion commanders are collocated.
Artillery OPs (battery, battalion) are connected with OPs of infantry commanders (company, battalion) by telephone lines.
Altogether not counting platoon and company OPs there are in average four observation posts per 1 kilometer of the front.
Command posts of battalions and regiments are equipped with dugouts having anti-splinter overhead cover and are situated: battalion CPs – 1-1.5 kilometers, regiment CPs – up to 2 kilometers, division CPs – 5-6 kilometers from the forward line.
Sanitary and utility facilities in trenches.
Dugout shelters are built to provide rest to personnel manning the forward line. There situated in close proximity to firing positions (5-10 meters) and can accommodate one section (in the fortified region - 1-2 weapons squads). Shelters have overhead cover of 3-4 log layers, revetment of walls, most have floors and all of them – furnaces.
In trenches there are water supply wells, sinkholes and latrines. In the area of command posts – field bathes, and gas cameras.
In general the trench system built in the Army’s area is the only possible means in open terrain to provide protection for troops, camouflage of fire system, and owing to extensive system of communication trenches it enables hidden maneuver of personnel and weapons, command and control of troops and their supply and sanitary servicing.
Experience of building the trench system and its maintenance in winter conditions provides the following conclusions:
1) The trench system should be built on the basis of the commander’s decision. In practice this elementary proviso of manuals frequently wasn’t followed. Often trenches were built on lines reached as a result of combat by connecting open foxhole, and the depth of the defense was developed from combat formations built in the process of offensive.
Therefore, construction of defense works should be preceded by a tactical decision of commanders of regiments, battalions, companies, and platoon. In accordance with this decision weapons and personnel should be distributed both along the front and in depth. Only after that construction of trenches should be proceeded with.
2) If defense positions were occupied in autumn, all the principal defense works should be completed before snowfall. A combination of continuing construction of fortifications with snow clearance is beyond capabilities of units, which have a large shortfall of personnel, and troops hardly have enough time to clear the first line of trenches of snow.
To equip the defense positions with shelters and dugouts under conditions of deficit of woods in the Army’s area, it is efficient to procure elements (doors, frames, furnaces) in a centralized fashion on the level of the army (corps, division) and supply units with standard sets.
3). Experience has demonstrated that intensive hostile fire on the forward line of our defense demands engineer reinforcement of artillery observation posts and firing positions, first of all – those situated on the forward line and in close proximity. For example, in the sector of the fortified region such reinforcement of artillery OP and FP was made by deepening them by 60-90 centimeters, constructing stronger parapet (30-40 centimeters high and 3,5-4 meters wide), constructing ammunition pits and Г-shaped shelters, increasing thickness of overhead cover in pits and shelters to 4-5 layers of logs, and laying mines on approaches to the observation posts.
4) In case of deep snow cover it is expedient to employ snow walls using them as combat and communication trenches, which strongly reduce volume of defense works.
5) Local civilians should be employed for clearing trenches of snow.