The development of tactical aviation and aviation armament has always placed new demands on military air defense. The armies needed new and new anti-aircraft self-propelled guns, but not always promising models managed to enter service. An example of such a development, which showed itself well in tests, but did not get into the troops, can be considered the American self-propelled gun with cannon armament Vulcan Wheeled Carrier from the Standard Manufacturing Company.
At the turn of the seventies and eighties, one of the main elements of the military air defense of the American army was the M163 self-propelled anti-aircraft gun, built on the basis of the M113 armored personnel carrier and armed with a six-barreled 20-mm M61 Vulcan cannon. Such a combat vehicle, created in the mid-sixties, no longer fully met modern requirements. In particular, the military wanted to get a ZSU with higher mobility and maneuverability on all landscapes.
ZSU Vulcan Wheeled Carrier on trial. Photo Ftr.wot-news.com
A new version of a combat vehicle for military air defense was proposed in the early eighties by the Standard Manufacturing Company (SMC) from Dallas, pcs. Texas. Not long before this, the designers of SMC formed the appearance of a promising multi-purpose chassis with increased cross-country ability, which could be used in the construction of a wide variety of military and civilian equipment. In the shortest possible time, the company worked out several preliminary projects. It was planned to offer a potential customer the chassis itself, transport vehicles based on it and several samples with one or another weapon.
In accordance with the fundamental decision of the developers, first of all, it was necessary to implement the project of an anti-aircraft self-propelled installation on a promising chassis. Such a machine, having shown itself well at the test site, could not only get into the troops, but also pave the way for other unified samples. Design work on the new ZSU started no later than 1980-82.
SMC experts decided that a promising self-propelled gun should carry the same armament as the existing M163 vehicles. The presence of the M61 Vulcan gun was reflected in the designation of the project. The ZSU was named Vulcan Wheeled Carrier (VWC). Subsequently, the only prototype of this machine was given its own name Excalibur.
Together with the existing tool in the project, it was planned to use the most daring and new ideas aimed at obtaining the maximum possible characteristics. It should be noted that this approach ultimately led to very remarkable results. The finished car differed from other equipment not only by the special design of individual units, but also by its recognizable appearance. For all its specific problems, the SMC VWC self-propelled gun had a futuristic exterior and looked like a piece of technology from a fantastic work.
The self-propelled gun moves over sandy terrain. Photo Ftr.wot-news.com
The designers of the Standard Manufacturing Company, using a number of original ideas, created a four-axle wheeled combat vehicle with a characteristic cockpit and a large cargo platform suitable for mounting special equipment. In the Vulcan Wheeled Carrier project, the platform was intended to install a full-revolving combat module with an automatic cannon. From the point of view of general architecture, the new model of military equipment differed little from some other developments of that time.
The main unit of the promising chassis was the body of a fairly simple design. The VWC prototype was reportedly unarmored and made only of structural steel and other materials. In the front of the hull there was a large, non-standard cabin, and behind it were the engine compartment and volumes for installing the transmission. A small fighting compartment was located behind the engine, which contained some elements of the tower and the gunner's workplace.
Probably due to the experimental nature of the project, the ZSU of the new type received only a partially enclosed cockpit located in the front of the hull. The volume for the crew was formed by a pair of inclined bottom plates connected to low sides and a horizontal bottom. The upper frontal parts were missing; instead there were a pair of racks to which a light lattice roof was attached. Glazing was completely absent, which, however, simplified embarkation and disembarkation.
The main part of the body had a rectangular cross-section with bevels in the bottom area. Directly behind the cockpit, a lightweight casing of the power plant with mesh inserts was placed, behind which was a cylindrical unit with a turret shoulder strap. The stern housed a large rectangular hull with a hinged rear wall. Large shelves were installed along the sides, which served as wings.
The promising chassis was equipped with an eight-cylinder V-shaped diesel engine of the Detroid Diesel brand, which developed power up to 135 hp. To save space, a hydromechanical transmission was used inside the body, distributing torque to all eight driving wheels. It was this kind of transmission that allowed the designers to reduce the height of the car while obtaining all the desired features. In other words, the internal chassis assemblies associated with the chassis did not interfere with the installed combat module.
View to starboard and stern. You can consider the units of the tower. Photo Ftr.wot-news.com
In the new chassis family, Standard Manufacturing Company engineers used the original undercarriage architecture, tentatively known as Trailing Arm Drive. On each side of the Vulcan Wheeled Carrier hull, it was proposed to install four TAD-type suspension wheels. The main element of this design was a backward-turned balancer, reminiscent of a torsion bar suspension device. One end of the balancer was proposed to be movably attached to the body, and the wheel was mounted on the other. Above, with some inclination forward, a spring was installed, connected to the arm of the balancer. Under load, it worked in tension.
The balancer of the TAD system differed from similar devices in increased dimensions and, in fact, was a hollow beam. Inside the balancer, at its ends, there were two gears connected by a chain drive. The balancer suspension unit to the body included a shaft from the final transmission of the transmission, with the help of which power was supplied to one gear, then to the chain, the second gear and from it to the wheel. For all its complexity, such a chassis design combined four-wheel drive and high cross-country ability, provided by a large stroke of the balancers.
The chassis received a suspension control system. Depending on the terrain, the driver could change the ground clearance. Oscillating balancers with springs varied this parameter in the range from 10 to 22 inches (254-559 mm). Despite the change in ground clearance, the suspension in all conditions “worked out” any unevenness of the terrain.
At the design stage, it became clear that the recoil of the M61 gun did not match the characteristics of the new chassis. In this regard, it was necessary to abandon firing on the move and equip the combat vehicle with jacks. In the front part of the cabin and on the sides of the aft hull sheet, there were three hydraulic outriggers with round supports. During combat work, the supports lay on the ground and took on the weight of the machine. In the retracted position, the front round support went into the niche of the lower frontal sheet, and the aft ones were located under the rear bumper.
The driver and commander of the ZSU were to be in a two-seater front cockpit of a semi-open type. Their workplaces did not have any protection and were not even equipped with glazing. Only a lattice roof overhead protected them from some external influences. The left cab workplace was intended for the driver, the right one for the commander. It was proposed to get into the cockpit through large openings between the fenders of the front wheels and the roof. The hydraulic cylinder of the front jack was located between the two workplaces.
Trailing Arm Drive type undercarriage diagram connected to on-board power distribution. Drawing from patent
On the rear cargo platform of the vehicle, using a special ring with a shoulder strap, it was proposed to install a combat module with anti-aircraft weapons. The SMC VWC project envisaged the use of an original rotating turret, partially based on the units of the existing M163 SPAAG. Such unification, to a certain extent, simplified the assembly of the prototype, and was also supposed to help in the further operation of the equipment.
An asymmetric horizontal platform with attachments for various devices was placed directly on the pursuit. In front of the platform, on the longitudinal axis, a swinging installation with a 20-mm six-barreled M61 cannon was placed. The relatively heavy weapon was mounted on a sturdy frame with spring balancing devices. Used electric drives of vertical guidance, duplicated by manual mechanisms.
The left side of the platform was given for the installation of a large box for ammunition. Due to the high rate of fire of the Vulcan cannon, the combat vehicle needed large ammunition and a box for it, differing in appropriate dimensions. It is curious that the outer wall of the large box was an additional protection for the gunner and completely covered him from attacks from the left.
Guidance equipment was placed on the starboard side. Based on the operating experience of the M163 self-propelled guns, the new VWC was equipped with an AN / VPS-2 guidance radar. The antenna of this station was placed on its own rack with vertical guidance drives. The movement of the antenna was carried out synchronously with the vertical guidance of the gun. Various elements of the radar and other devices were placed in boxes in the stern of the platform. The data from the locator was transmitted to a computing device that automatically controlled the gunner's sight.
In the center of the turret there was a gunner's workplace. He could freely observe the surrounding air situation "overboard", if necessary, direct the gun and open fire. In combat work, he was assisted by the available means of automation and mechanization.
ZSU on rough terrain. Photo Yuripasholok.livejournal.com
Despite the lack of armor and maximum lightweight design, the promising SMC Vulcan Wheeled Carrier anti-aircraft self-propelled gun was not the most compact and lightweight. The total length of the vehicle reached 5, 5-6 m, width - about 2-2, 5 m. Due to the special design of the chassis, it was possible to reduce the size of the frontal projection. The total height of the vehicle, taking into account the anti-aircraft armament (in the stowed position), did not exceed 2, 2-2, 5 m. The combat weight reached 16 thousand pounds (7, 26 tons).
In 1982-83, Standard Manufacturing built the first and, as it turned out, the only prototype of a new type of ZSU. Moreover, as far as is known, it was the only real car built within the entire family of projects. Other prototypes on a unified or similar chassis were not built or tested.
An experienced anti-aircraft self-propelled gun with its own name, Excalibur, entered the training ground and in the shortest possible time showed all its capabilities. For obvious reasons, the testers were primarily interested in the parameters and potential of the original chassis. The vehicle was equipped with a fairly old weapon, and its parameters had long been established. However, during one of the test stages, it was necessary to check the interaction of a sufficiently powerful gun with an unusual chassis design.
During sea trials, it was found that the fully loaded ZSU is capable of reaching speeds of up to 45 miles per hour (more than 70 km / h) on the highway. The power reserve is up to several hundred kilometers. The parameters of mobility in different landscapes were also determined. The suspension with long travel balancers and low pressure wheels allowed the self-propelled gun to move on soft soils and snow, as well as climb steep slopes. According to known data, from the point of view of mobility, the chassis with units of the Trailing Arm Drive type, at least, was not inferior to other wheeled vehicles.
Before firing, the Excalibur car had to be hung on jacks, which to some extent reduced its real combat potential. At the same time, regardless of the guidance angles, the self-propelled gun maintained an acceptable position and behaved quite stable. From the point of view of combat use, the SMC VWC ZSU differed little from the serial M163.
Various options for vehicles based on a promising chassis. Drawings from the patent
In general, the two cars turned out to be worthy rivals for each other. In some respects, the new wheeled self-propelled gun was ahead of its tracked predecessor, but in other respects it lagged behind it. The clear advantages of the promising model were the improved characteristics of mobility, regardless of the terrain. Also, the wheeled chassis was easier to operate and cheaper to manufacture. But at the same time, the new car was distinguished by the absence of any protection and limited combat capabilities.
In the mid-eighties, a prototype Vulcan Wheeled Carrier with its own name Excalibur was shown to representatives of the US military, and they determined the future of the original project. The new anti-aircraft self-propelled gun was considered unsuitable for adoption. Several of the positive features and benefits provided by the design innovations could not outweigh the whole set of disadvantages.
The most notable problem with the SMC VWC project was the lack of any crew protection. People did not have protection not only from bullets and shrapnel, but even from wind and rain. For this reason, the vehicle was not of particular interest to the troops. The new undercarriage design, with all its advantages, turned out to be very complex in production and operation, and in this respect it was inferior to other wheeled vehicles. Placing a separate gear inside the balance bar made maintenance difficult, and exposed springs posed some risks.
The weapons used were another serious problem. The M163 self-propelled gun, equipped with a 20-mm automatic cannon with radar guidance, by that time ceased to suit the military. A new machine with similar equipment, which has no advantages over the existing model, was not needed by the army.
Other versions of combat and special vehicles. Drawings from the patent
After this decision of the military, work on the Vulcan Wheeled Carrier project stopped. The only prototype built went to the sump. In the future, the combat module with weapons and equipment was removed from it. Over time, the remaining chassis was partially dismantled. Outdoor storage is bad for any vehicle, and the SMC VWC is no exception. The unique machine is still rusting and waiting to be sent for restoration or melting down.
It should be recalled that the anti-aircraft self-propelled unit was created by engineers of the Standard Manufacturing Company with the aim of promoting a new chassis design and a whole family of equipment built on its basis. As the work on the VWC topic was carried out, the designers were developing the proposed chassis and working on the issues of creating new samples for various purposes. The possibility of using the chassis in different roles was studied, and in addition, improvements to its design were proposed.
All major developments on the topic of promising chassis became the subject of patents. In total, SMC received a dozen of these documents, confirming its rights to the original ideas. In the patents, alternatives to the TAD suspension have been cited. In particular, the possibility of using it together with the transmission of the on-board circuit with the distribution of power through chain transmissions was considered. The possibility of installing a spring with different angles and placing an additional shock absorber inside it was also being worked out.
On the basis of the chassis of various versions, it would be possible to build a variety of transport vehicles for people and cargo, both armored and unprotected. The chassis could become a carrier of anti-aircraft weapons in the form of guns or missiles, anti-tank guided complexes, etc. In general, multi-axle vehicles with a gross weight of up to 8-10 tons could find application in a wide variety of areas and have a noticeable impact on the development of the US Army's fleet of equipment.
Forgotten and abandoned "Volcano Wheeled Carrier" Photo: Yuripasholok.livejournal.com
According to the plans of the early eighties, new developments should have been promoted using an anti-aircraft self-propelled gun of an unusual appearance. This machine, having coped with the main tests, failed to get a positive assessment from a potential customer. As a result, it was abandoned, and soon SMC had to curtail work on the entire topic of new chassis, since they now had no prospects.
To get into the troops, a new model of military equipment must not only show high performance, but also meet a number of different requirements. The promising Vulcan Wheeled Carrier project from Standard Manufacturing Company did not meet the basic requirements of the potential customer, which led to its closure. An interesting project of a self-propelled anti-aircraft gun of a specific appearance remained a bright, but meaningless episode in the history of American military equipment.
