By the time of the proposal to develop a new ACS base armored personnel carrier has already mastered a number of new specialties. Cable stacker, communications vehicle, artillery reconnaissance, self-propelled mortar and several versions of ammunition transporters were created. Thus, the companies Bussing-NAG and Demag, who created the basic project and were engaged in its further development, have already had some experience in refining the existing structure for various needs. Due to this, the process of creating a new technology should not be delayed or complicated.
According to some reports, one of the prerequisites for creating a new project could be a change in existing armored vehicles projects. Newer Medium Modifications tanks Pz.Kpfw.VI were equipped with 75 mm long-barreled guns, which is why the existing guns were out of work. A significant number of guns of 7,5 cm KwK 37 L / 24 were produced and accumulated in warehouses. These systems could still be used in the construction of armored vehicles, but they no longer met the existing requirements for the arming of tanks. The result could be a proposal for the development of various carriers of obsolete guns, allowing them to be used with at least some acceptable results.
Reconstruction of the appearance of ACS Sd.Kfz.250 / 8 based on chassis type Alte. Figure Tanks-encyclopedia.com
The project of the new ACS on the chassis of the armored personnel carrier received the designation leichter Schützenpanzerwagen 7,5 cm - light armored carrier 75-mm gun. In addition, by analogy with the previous technique on a similar chassis, the designation Sd.Kfz.250 / 8 was proposed. It not only allowed to distinguish the new car from the previous ones, but also to clarify the sequence number of the project for the modernization of the armored personnel carrier. Interestingly, in the future, the name of the project has not changed. During the construction of serial equipment, the industry eventually had to switch to the use of a modified chassis, but this did not affect the designations of the machines.
The main requirement for the Sd.Kfz.250 / 8 project was the use of new artillery weapons. In addition, the minimum change in the basic design and other nuances aimed at speeding up and simplifying the upgraded equipment could be specified. The result of such requirements was the emergence of a project involving the use of a set of new units, which should have been installed directly on an existing machine without significant modifications. This had certain positive consequences in fulfilling customer requirements, and also to some extent improved and simplified the future work of the self-propelled gun crews.
According to reports, initially the project leichter Schützenpanzerwagen 7,5 cm, which started no later than the start of 1943, was developed based on the first version of the Sd.Kfz.250 armored personnel carrier, also known as Alte (“Old”). The armored personnel carrier of this model had a number of characteristic features that markedly complicated the construction and its production. By the fall of 1943, a new version of the machine was developed, characterized by greater simplicity of design. This version received the symbol Sd.Kfz.250 Neu (“New”). In the future, the "New" BTR also found application in the Sd.Kfz.250 / 8 project, but the first version of the ACS was based on the chassis of the previous version.
The semi-tracked armored personnel carrier Sd.Kfz.250 of the first modification had a characteristic armored body formed by the combination of a set of sheets of different thickness and shape. The corps received a bonnet layout with division into two main compartments: the engine and some transmission units were located in the front, and the rear was given to a single habitable volume that combined the control compartment and the troop compartment. Due to some peculiarities of the project requirements, the two compartments differed insignificantly in their dimensions.
The front part of the hull of the BTR, which had surrendered to the engine, received a characteristic faceted shape. There was a sloping frontal sheet, which was joined by a sloping roof and upper side plates at an angle to the vertical. The roof of the engine compartment at the rear was connected to the frontal sheet of the habitable compartment, and the sides, without changing the slope, went over to the defense of the upper part of the hull. In the rear of the hull there were small sloping side sheets converging to the stern. Also in the central and aft parts of the hull there were inclined lower sheets, in combination with the upper ones forming the characteristic shape of the hull. Behind the crew defended sloping stern sheet. The roof of the habitable compartment was missing.
The front hull sheet was 10 mm thick and mounted at an angle 30 ° to the vertical. The 14,5-mm frontal sheet of the habitable compartment with viewing devices was located at an angle 12 ° to the vertical. All the details of the sides and the stern had a thickness of 8 mm. From the bottom, the body carried a 6-mm bottom. This hull design provided protection against small arms. weapons and light fragments.
In front of the hull, under the armored hood, the Sd.Kfz.250 Alte armored personnel carrier had a Maybach HL 42TRKM carburetor engine with an 99 hp power. The engine was connected to a Maybach VG 102128 H mechanical transmission, providing seven forward gears and three reverse gears. With the help of transmission units, the engine torque was transmitted to the drive wheels of the tracks.
A characteristic feature of the armored vehicle was a semi-tracked chassis, which simplified the design of the transmission due to the absence of the need for some units of steering control. Rotate Sd.Kfz.250 was due to the management of the front wheel axle. The wheels received suspension on leaf springs. At the same time, a tracked propulsion unit was used. There were four large diameter skating rinks on each side. The rollers were installed in a staggered manner (the front wheels were in the inner row) and equipped with an individual torsion bar suspension. In front of the caterpillars placed drive wheels associated with the transmission, in the stern - guides. Due to the wide use of existing developments on tracked vehicles, an armored personnel carrier received tracks of a used design with finger lubrication.
BTR Sd.Kfz.250 Neu. Photo of Chamberlain P., Doyle H. "Complete reference book of German tanks and self-propelled guns of the Second World War"
The crew of the armored personnel carrier consisted of two people and was located on the ground in front of the inhabited compartment. Behind them along the sides there were places for four paratroopers with weapons. To get to their seats, the crew and the landing should have been through the only door on the left side of the stern leaf. In addition, with a certain skill, you could take advantage of the lack of a roof. To observe the road and the situation, the crew had two inspection hatches in the upper front plate and two similar units in the sides.
The armament, depending on the modification of the armored personnel carrier, consisted of one or two MG 34 machine guns of 7,92 mm caliber. One of them was mounted on the installation of the front sheet of the crew compartment and had a shield. The second was placed on the stern pivot installation. It was also possible to fire from personal weapons over the side.
The combat weight of Sd.Kfz.250 in the basic configuration was 5,8 m. The length of the vehicle was 4,56 m, width - 1,95 m, height - 1,66 m. On the highway, the armored personnel carrier developed speed to 60 km / h. Power reserve was 320 km. There was an opportunity to overcome various obstacles, including shallow (up to 0,7 m) reservoirs.
As part of the leichter Schützenpanzerwagen 7,5 cm project, it was necessary to create a set of units with which the armored personnel carrier could be the carrier of the required type of weapon. An analysis of the possibilities has shown that a superstructure with a system for mounting an instrument, which should be installed on top of the hull, will become the main tool of this kind. In this case, it was possible to equip the 75-mm cannon with an armored personnel carrier, as well as to increase the size of the combat compartment to a certain extent, while maintaining acceptable ergonomics.
Right over the frontal sheet and sides of the habitable compartment, it was necessary to mount a U-shaped in plan plan of armor plates. The thickness of this armor had to match the details of the hull. In the front sheet of the superstructure there was an embrasure of the required dimensions, in which the KwK 37 L / 24 gun was to be located. Such modifications of the hull, as well as the installation of the necessary internal units led to an increase in the overall height of the armored vehicle to 2,07 m and to an increase in the combat weight to 6,3 t.
Self-propelled gun based on the "New" BTR. Photo by Achtungpanzer.com
The main weapon of the self-propelled gun was to be the 75-mm cannon KwK 37, previously used as a weapon of various armored vehicles of the existing types. The gun was equipped with a barrel length 24 caliber, which did not allow him to disperse ammunition to high speeds. The maximum initial velocity of the projectile at the exit from the barrel reached 450 m / s. Depending on the type of ammunition, it was possible to penetrate armor from 35 mm (armor-piercing tracer) to 100 mm (cumulative) at a distance of 1 km. By the beginning of 1943, similar characteristics no longer met the requirements for tanks, but the use of KwK 37 on other equipment still seemed to be justified.
The gun was mounted on a mobile unit, which allowed firing within a small horizontal sector with limited vertical pickup angles. This allowed direct fire and the use of self-propelled gun leichter Schützenpanzerwagen 7,5 cm as a means of direct fire support of troops.
As an auxiliary weapon of self-propelled guns, it was proposed to save one of the rifle-caliber machine guns. It was placed on the top of the superstructure with a cannon and was intended for firing at targets in the front hemisphere. According to some information, the machine gun could be fixed and used as a coaxial gun. In this case, he could perform the functions of sighting means.
Inside a relatively small fighting compartment formed by a manned compartment of the corps, it was possible to place racks for ammunition only on 20 shells. For longer firing, the ACS needed to deliver projectiles.
The car should have been driven by a crew of three or four people. In front of the habitable volume was a driver. Also next to him could be the commander. The gun was placed at the disposal of the gunner and loader. If necessary, the commander could be excluded from the crew, and his duties were transferred to the gunner, driver or loader.
The first self-propelled artillery mounts of the Sd.Kfz.250 / 8 type were assembled already in the spring of 1943. For the construction of this technology, the necessary tools and some other components were sent to one of the factories engaged in the production of serial armored personnel carriers. Soon, factory workers retooled the existing armored personnel carriers using new superstructures and 75-mm guns. As a base for self-propelled guns of the first release, armored personnel carriers of the Alte version with a characteristic complex hull structure were used. It was released only a few of these machines, which were planned to be used in field and military tests, the results of which could be decided on the further assembly of equipment. Until the end of 1943, only eight cars were assembled.
As they were released, new self-propelled guns were sent to the troops to test capabilities in real conditions. According to various sources, the operation of this technology did not last too long. The specific combination of firepower and level of protection led to significant risks. As a result, not always the new Sd.Kfz.250 / 8 self-propelled guns could successfully complete the assigned combat mission and not suffer from enemy fire.
Apparently, it was precisely the not-too-successful experience of combat use that forced the customer, in the person of the army, to temporarily abandon the further assembly of leichter Schützenpanzerwagen 7,5 cm self-propelled guns and the use of such equipment in the military. Opinion about the absence of noticeable prospects for such machines persisted for quite a long time. It was only in the autumn of 1944, when Germany had to face the most serious problems associated with the loss of military industry enterprises, they remembered about an interesting project again.
The personnel of one of the units is studying a new materiel. Photo Acemodel.com.ua
At the beginning of autumn 1944, the command ordered to resume the release of SAU on the basis of Sd.Kfz.250 armored personnel carriers. The existing project was refined using new components, after which the assembly of serial equipment began a second time. The first modernized self-propelled guns went to the troops until the end of October.
As already mentioned, in the fall of 1943, the industry discontinued the production of Sd.Kfz.250 Alte armored personnel carriers, which was associated with the start of production of a simplified version of the car with the designation Neu. The main differences between the two cars were in the form of the hull. The updated project abandoned units of complex shape. Thus, the width of the roof of the engine compartment was increased, which made it possible to abandon sloping sides, and the side parts of the habitable compartment now had developed futuristic niches of rectangular cross section and inclined upper sheets. At the base machine, the body consisted of 19 sheets, and in the upgraded project only 9 was used. While maintaining the basic weight parameters and dimensions of the updated armored personnel carrier was a little easier and much easier to manufacture.
In addition, by this time, the development of the K51 (Sf) tool, which was a further development of the old KwK 37, was completed. The new gun had a caliber 75 mm and was equipped with a barrel length 24 caliber. The general characteristics of the two guns were about the same level. The new development was distinguished by greater ease of production and other technological advantages.
On the roof of the Sd.Kfz.250 Neu chassis was mounted a superstructure of the existing structure, slightly modified for the existing case. It housed a gun and a machine gun on a separate installation. The characteristics of such a self-propelled artillery installation almost did not differ from the parameters of machines that were previously produced on the basis of a different chassis.
SAU Sd.Kfz.250 / 8 on the march, 21 June 1944, the place is unknown. Photo of Wikimedia Commons
It is known that the serial Sd.Kfw.250 / 8 of the new version was supplied to the army and included in the 4 platoon of light tank reconnaissance companies. At the same time, only a few companies underwent similar re-equipment, since the production of serial SAUs did not exceed several dozen. Until the end of 1944, only the 10 self-propelled guns were assembled, and in the winter and spring of the 45, another 51 machine.
Although the engineers were able to use an outdated tank gun on a new vehicle, the leichter Schützenpanzerwagen 7,5 cm self-propelled guns had a number of characteristic drawbacks. First of all, it was a weak bulletproof booking body and a large height of the machine. Thus, the enemy was easy to see self-propelled, after which its destruction, or at least damage was not too difficult task. As a result, units armed with such equipment constantly suffered serious losses.
According to reports, due to difficulties with the supply of finished equipment and constant losses on the front to 1 in March 1945, there were only five SAU Sd.Kfz.250 / 8 ACUs in the ranks. Other cars either failed or did not have time to enter the unit. Naturally, such an extremely small group of self-propelled guns could not have a noticeable effect on the course of the fighting in Europe. Moreover, even the 69 armored vehicles produced over the entire production period were not able to influence the results of the war.
The leichter Schützenpanzerwagen 7,5 cm or Sd.Kfz.250 / 8 project was the first attempt to install an 75-mm gun on a light armored personnel carrier. The base armored vehicle was already used as a basis for various equipment and therefore was of some interest in the context of new projects. However, the desire to equip the existing half-track chassis with a relatively powerful gun did not lead to the expected results. The production volumes of such equipment left much to be desired, and specific characteristics did not allow to count on high combat effectiveness. The subsequent development of artillery systems based on Sd.Kfz.250 followed different paths.
Chamberlain P., Doyle H. Complete reference book of German tanks and self-propelled guns of the Second World War. - M .: AST: Astrel, 2008.