Military Review

T105 Engineering Tank (USA)

In 1943, the United States military industry proposed an engineering project. tank T76 The armored vehicle, built on the basis of the M4 Sherman serial medium tank, was equipped with a launcher for solid-fuel unguided missiles mounted on the site of the gun. Such weapons allowed an engineering tank to shell various obstacles and fortifications of the enemy from some distance, however, the proposed project had noticeable shortcomings. Soon, an attempt was made to improve the machine, but the new prototype under the designation T76E1 also did not differ in outstanding characteristics. They refused to further develop the T76 project, but decided to implement the existing ideas as part of a new project, the main element of which was to be the T105 launcher.

Recall that the purpose of several projects of engineering tanks was to create a self-propelled armored vehicle capable of destroying various obstacles and barriers with the help of unguided missiles with a high-explosive warhead. Earlier, launchers were tested, which are a package of guides for small-caliber missiles, but they did not justify themselves. Because of this, the T76 project was launched, which involved the use of 7,2 inch caliber missiles (183 mm). They had to be launched with the help of a barrel-rail placed on the site of a regular tank gun. Such a method of using missile weapons made it possible to solve the tasks posed with acceptable efficiency.

According to the test results of experimental tanks T76 and T76E1, some conclusions were made. Also, a number of proposals relating to the further development of such technology. The positive features of the launcher on the site of the tank gun were installed, and some ideas were proposed to get rid of existing shortcomings. To implement all the proposals planned in the framework of the project with the designation T105. It should be noted that this name was worn prospective launcher. However, it is often used in relation to the engineering tank as a whole.

T105 Engineering Tank (USA)
The only prototype engineering tank with a launcher T105. Photo

In the new project T105, we should use the already tested approach to the formation of the image. As a basis for a promising engineering machine, it was proposed to take a serial tank of a common model, which was to lose its regular weapons and get a new type launcher. As before, the medium tank M4A1 "Sherman" was to become the basic element of a promising project. This technique was produced in large quantities and most actively used by the army. For this reason, the future mass production and operation of engineering tanks could be significantly simplified.

Medium tank M4A1 was an armored vehicle with machine-gun armament and relatively powerful armor. The modification A1 tanks "Sherman" equipped with a cast body, consisting of several large units. The case had frontal parts with a thickness of 51 mm, including the characteristic removable semicircular cover of the transmission compartment. Used 38-mm bead and roof thickness up to 25 mm. The hull of the tank had a recognizable appearance formed by several inclined surfaces. In particular, the roof was tilted back. When used in a new project, the base tank was supposed to keep the existing cast turret close to a cylindrical shape, which has a sloping forehead and stern niche. The thickness of the turret armor reached 76 mm in the frontal part, the sides were thinner - 51 mm. Also used gun mask thickness 89 mm.

The M4 Sherman family of tanks had a layout traditional for American armored vehicles. In the lower front part of the hull were placed the main transmission devices, behind which was a control compartment. The central part of the case contained the fighting compartment, under which the drive shaft passed. The feed was given to the installation of the engine and auxiliary devices of the power plant.

A star-shaped tank was mounted vertically in the stern of the M4A1 aviation Continental R975 C1 air-cooled engine with up to 350 hp The engine was connected to the driveshaft passing under the floor of the fighting compartment. The shaft transmitted torque to a mechanical transmission, the main element of which was a gearbox with five forward gears and one reverse gear. The transmission was covered by its own armored cover, which served as the lower frontal part. The transmission connected to the front-wheel drive wheels.

The undercarriage of an M4A1 armored vehicle and an engineering tank at its base had three trucks with two small-diameter support rollers on each side. According to reports, an experienced tank T105 had a suspension with a vertical spring and a supporting roller in the upper part of the truck. The drive wheels of increased diameter were placed in the front of the hull, the guides - in the stern.

The M4A1 Sherman medium tanks were equipped with several types of rifled guns, but it was proposed to dismantle this weapon in the new project. Together with the cannon, the appropriate equipment of the fighting compartment should be removed from the tank, such as stacking and shelving for ammunition. At the same time, the means of mounting the gun and the guidance actuators were to remain in place. They were planned to be used together with the new rocket armament.

In previous projects, the T76 / T76E1 used a launcher equipped with a guide in the form of a pipe of the appropriate diameter. The product T105 should have received new funds for the initial acceleration and direction of the rocket. Instead of a barrel-pipe, a different design was proposed for a similar purpose. To keep the rocket in the desired position, four longitudinal beams were used, connected by several bridges into a rectangular square section. In its composition there were a large number of horizontal connecting elements and a smaller number of vertical racks. The dimensions of such a launcher allowed to place in it a rocket caliber 183 mm. The “muzzle” part of the guides was placed openly, while the “official” section of the beams received a metal casing. Apparently, with his help, protection of the missile and the crew of the armored personnel preparing for launch was to be provided.

The guides of the new launcher were mounted on a vertical plate with a hatch for access inside the "trunk". The hatch cover during firing served as a shutter. The plate, in turn, served as the mask of the gun, and also connected to the longitudinal force elements mounted on the attachments of the standard gun. Such means of installation allowed to direct the launcher using existing drives. Horizontal guidance, as before, had to be carried out by turning the entire tower. To change the angle of elevation, in turn, it was proposed to use the available electromechanical or manual actuators. To aim the launcher at the target, it was necessary to use a telescopic sight at the gunner’s workplace.

The T105 launcher was supposed to destroy enemy targets with the help of special unguided 7,2 caliber inches. According to some reports, these were products known as T37 or 7,2-Inch Demolition Rocket. The T37 missile was an ASW Mk20 / 22 anti-submarine missile bomb bomb that was modified for use by land vehicles. The product had a large body caliber 183 mm without a head fairing. A tubular shank with an annular stabilizer joined the tapering body. The length of the rocket was 890 mm, weight - 28 kg. Inside the case was a charge in the villa 15 kg of substance C2. Own solid-fuel engine accelerated the rocket to a speed of about 50 m / s and allowed to fire at targets at distances less than 300 m.

Transporting an experimental car on a tank trailer. Photo

For the production of a shot from the T105 installation, the crew of an engineering tank should have opened the base plate hatch, manually loaded the unguided rocket onto the guides and locked the “barrel”. After that, with the help of a sight and standard drives, guidance was performed followed by a shot. The ignition of the solid-fuel rocket engine was carried out using an electrical system. Unlike the T73 launcher from the previous project, the new T105 did not have a gap between the casing and the back plate. Because of this, the powder gases of the engine were not removed to the sides and remained inside the launcher, increasing the pressure acting on the rocket.

The T105 project was designed for future practical applications, which led to the original execution of the launcher. The guide plate-mask as well as the internal systems of the installation were made in the form of an additional module that is fully compatible with serial tanks and does not require any modifications to its design. With the tank to be re-equipped, it was necessary to remove the standard gun mount and the mask, instead of which the T105 system unit was installed. Due to this, there was no need to deploy the production of special towers for engineering tanks. In addition, there was a theoretical possibility of converting existing armored vehicles into missile weapons carriers.

It is known that no later than 1944 of the year, at least one sample of a promising launcher for 183-mm missiles was manufactured. This product was used in the assembly of an experienced engineering tank T105. The serial Sherman model M4A1 lost its regular 75-mm gun, instead of which they installed the T105 system. In this form, the prototype engineering tank was launched for testing.

Unfortunately, there is no exact information about the testing of an engineering tank and the results of these checks. The results of testing at the test site can only be judged by the fact that the T105 launcher and the tank equipped with it did not go into mass production. Probably, an experienced armored vehicle confirmed the fundamental possibility of firing barriers using unguided rockets carrying a high-explosive charge. The firing of single rockets of a relatively large mass should have had a corresponding impact on the target.

At the same time, apparently, some problems were identified that drastically reduced the real potential of the equipment from the point of view of use in combat conditions. The main reason for claims to the project could be an insufficient firing range. T37 missiles could fly at a distance of no more than 300 m, which in some situations would lead to unnecessary risks. To effectively defeat the barrier or to strengthen the enemy, an engineering tank would have to enter the artillery shelling zone. Another problem of the T105 project could be the absence of serious weapons for self-defense. There could also be claims regarding the ergonomics of the crew compartment: it would hardly be convenient for the crew to work with large and heavy rockets in conditions of limited manned space.

According to the test results, the T105 engineering tank with the same-name launcher for unguided missiles, built on the basis of the M4A1 Sherman armored vehicle, was not recommended for use in mass production. As proposed, the unusual engineering machine had a number of serious flaws that did not allow the operator to fully realize its full potential on the battlefield. As a result, the project was closed for lack of prospects. The further fate of the only prototype is unknown. Perhaps it was used to create new experimental equipment based on the Sherman medium tank.

Despite the unsuccessful completion of the next project, the US military and the designers did not lose interest in the engineering tanks with rocket weapons. The works were continued, and further led to the emergence of new projects. At the end of 1944, the development of the T31 engineering tank project started. Unlike its predecessors of a similar purpose, this machine had to carry two launchers and other weapons at the same time, necessary both for destroying obstacles and fortifications of the enemy, and for self-defense.

Based on:
Hunnicutt RT Sherman. A History of the American Medium Tank, Navato, CA. Presidio Press, 1971
1 comment

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  1. CT-55_11-9009
    CT-55_11-9009 31 December 2016 04: 08
    Thank you, an interesting topic. And the development of the topic to post-war machines with the possibility of launching missiles from the barrel of a gun (Sheridan, for example), will be?