Military Review

The project of electrothermochemical gun 60 mm Rapid Fire ET Gun (USA)

The idea of ​​electrothermal fire weapons appeared a long time ago and immediately interested both scientists and the military. Nevertheless, several decades of work in this direction did not lead to noticeable results. Until now, no army in the world has weapons of this type. Perhaps in the future electrothermal guns will be installed on armored vehicles or ships, but so far they did not go beyond the limits of the landfills and were used only during the tests. For several decades, such weapons were built only as experimental samples.

In the early nineties, American specialists built and tested an electrothermochemical gun, which could later be used on warships. The project was developed by order of the US Navy and in the future could lead to the rearmament of their ships. It was assumed that in the future such weapons will be used to perform various tasks. This required to ensure the possibility of using guns against surface and shore targets. In addition, it was proposed to increase the rate of guns, which would allow the use of these weapons and for the implementation of air defense.

The project of electrothermochemical gun 60 mm Rapid Fire ET Gun (USA)
General view of the 60 mm Rapid Fire ET Gun on the ship installation

Electrothermochemical technology (ETH or ETC from Electrothermal-chemical) was created a few decades ago and is intended to improve the performance of barreled weapons, primarily artillery. Weapons built on this technology are generally similar to traditional barreled weapons, but have some differences. The main thing is the principle of the formation of gases for throwing projectile. In the ETH arms it is proposed to use not traditional gunpowder, but new special compositions. In addition, instead of the usual primer-igniter, the projectile must be equipped with a special igniting device, with the help of which the maximum energy output is achieved. Some projects of such systems even offered devices that produce plasma. Due to the latter, it was proposed to increase the energy return during the combustion of the propellant charge.

All existing experimental ETC guns had a similar principle of operation. In general design, they almost did not differ from the "traditional" guns. At the same time they were equipped with an electric propellant ignition system and had to use original projectiles with a cap of a new design. New ammunition and special equipment led to the complication of the design of the gun, however, allowed to increase the flexibility of its use.

One of the main advantages of electrothermochemical guns is the ability to change the muzzle energy by adjusting the parameters of the electric pulse, which is responsible for igniting the propellant charge. Thus, the electric part of the gun provides control of the main parameters affecting the characteristics of the fire. As a result, the operator of the complex gets the opportunity to use the most suitable for the current situation, the mode of operation of the instrument. In practical use, this allows you to change the firing range while maintaining the required kinetic energy and more effectively hit these targets.

Draft ETH gun, developed by order of the US Navy, has not received a full designation. He stayed in stories called 60 mm Rapid Fire ET (or ETC) Gun - "60-mm rapid-fire ETX-gun". Apparently, the absence of a different name or index was due to the experimental nature of the project. The usual alphanumeric index could appear in the case of receiving an order for the development of full-fledged weapons for ships and the successful completion of such a project.

The breech of the gun. Drum for shells clearly visible

Despite this, it is known about the development of an artillery installation on which a promising weapon could be mounted. This system consisted of a deck of boxes, in which a part of special equipment was located, and a movable gun carriage with the possibility of pointing the gun in two planes. The mobile part of the installation had a design traditional for such systems. Directly above the deck there was a cylindrical swivel base on which two vertical posts were mounted with mounts for the rocking artillery unit. This design provided guidance in any direction along the azimuth and within a certain sector of the vertical plane.

Of greatest interest in the 60 mm Rapid Fire ET Gun project is the gun itself, in the design of which several interesting ideas were used. First of all, interesting layout of the gun. It had a 60 mm caliber barrel about 14 feet long (about 4,25 meters), equipped with a characteristic round muzzle brake. In the breech breech there was no traditional chamber, because the gun was built on a revolving scheme. Behind the barrel was a drum with cylindrical chambers for ammunition. A similar scheme was used in view of the need to increase the rate of fire of the weapon. Other layout options, apparently, could not provide the required rate of fire.

The barrel was fixed in a rectangular restraint, in the back of which a horizontal beam was provided with fastenings for an equipment unit responsible for the ignition of the propellant charge. In addition, these two devices were connected to the axis of the drum for the shells. The design of the gun had a separate mechanism for turning the drum. The authors of the project decided to abandon the use of the energy of powder gases or recoil, because of what it took to use a special mechanism, the task of which was to turn the drum before each shot. The rotation of the drum and some other operations were carried out by hydraulic drives, which to some extent could complicate the operation of the implement.

The prototype gun had a drum on 10 shots. The drum consisted of two bearing discs with holes in which the tubular chambers were fixed. The rear disc drum is in contact with the rotation mechanism. According to the available data, an obturation system was provided to exclude pressure losses in the barrel. Before the shot, the chamber took root to the breech breech, thereby providing an acceptable seal. Before turning the drum, the mechanism “released” the chamber and allowed the next one to be brought to the barrel.

The first series of tests at the site. Used conventional shells

The remaining footage chronicles show that the experienced gun had no mechanisms designed to extract spent cartridges from the drum and reload. Perhaps such equipment could appear at a later stage of the project or in the development of a full-fledged combat system for ships. However, the prototype did not have the ability to self-recharge after using all the available ammunition.

The experimental ETK-gun received a combined propellant ignition apparatus, since during the tests it was proposed to use "ordinary" and electrothermochemical ammunition. A mechanical drummer was used to fire a conventional powder projectile; an electric igniter was used for ETX shots. According to others, the gun in all cases used an electric igniter.

As part of the 60 mm Rapid Fire ET Gun project, the issue of ammunition was actively explored. The gun could use traditional powder powder projectiles, in addition, some new versions of ammunition were developed. Research has been conducted on the subject of promising missile compositions, electrochemical ignition primers, etc. Also studied various options for the composition of the shells and the prospects of various materials of the liner. Offered cylindrical sleeve and bottle shape, made of metal or plastic with a metal tray.

The development of the perspective ETC-gun project was completed in 1991 year. At the beginning of the next year, the first tests started, during which the gun was mounted on a test bench and checked the operation of the main mechanisms. During this phase, the operation of the mechanisms was checked without the use of ammunition. The first stage of inspections made it possible to identify and eliminate some shortcomings, and also showed the efficiency of the proposed mechanisms. All this made it possible to proceed to field testing of the gun with real shooting.

Breech of the gun when using ETH ammunition

Not later than March 1992, the 60 mm Rapid Fide ET Gun was delivered to the test site and installed on a stand of a simplified design. The stand allowed the pump to swing in a vertical plane and was equipped with recoil devices. Horizontal guidance was not provided, since there was no need for it. A similar device was used throughout the second test phase and soon gave way to a more advanced installation. The second phase of the test was carried out using "traditional" artillery shells. Information about the use of new ETH-shells are not available. The gun showed its capabilities, firing single and bursts. The length of the queues was limited by the capacity of the drum.

At the beginning of the summer of 1992, the first electrothermochemical projectiles, designed specifically for the promising weapon, appeared. Exact information about their design is not available, but it is known that they were equipped with the original ignition system and non-standard composition of the propellant charge. Later on, both “standard” and electrothermochemical projectiles were used in tests. Apparently, there were some problems with the finishing of shells, because of which their use had to be limited.

Around the end of the autumn of 1992, the assembly of an artillery installation was completed, which could be used on various warships. This device made it possible to direct a weapon in two planes and to bombard various targets on the shore, on the surface of the water and in the air. As well as the stand for field testing, the ship installation was equipped with recoil devices. In addition, apparently, it was the underdeck part of the artillery installation that had to be equipped with certain mechanisms for reloading the gun, but the details of this are unknown.

According to reports, the promising 60-mm ETX gun was tested before the 1992-93 winter. The gun fired in different modes using different ammunition. All this allowed us to collect the necessary information about the operation of the gun as a whole and its individual units. In addition, practical research was carried out on original projectiles using a non-standard method of igniting a propellant charge.

The gun on the ship's artillery installation, the last stage of testing

In the future, a new gun could become the weaponry of warships and solve the tasks of destroying surface targets or air defense. However, the 60 mm Rapid Fire ET Gun project did not leave the test stage. For various reasons, such weapons were not of interest to the military. Upon completion of the tests, the project was closed due to the lack of prospects. The gun and ammunition for it turned out to be too complicated and expensive for the full implementation and operation of navy. In addition, the fate of the project to a certain extent was affected by the change in the situation in the world associated with the collapse of the Soviet Union. Funding for promising projects has been reduced. A new electrothermochemical gun and many other developments fell under this reduction.

According to some sources, the reason for the closure of the project 60-mm ETH-gun was the rejection of another program. In the eighties, the mass of American organizations engaged in a large number of projects under the Strategic Defense Initiative. The 60 mm Rapid Fire ET Gun project also had some relevance to the PIO, although it was not directly related to missile defense or other strategic areas. The refusal of the PIO led to the closure of the mass of projects one way or another connected with this program. One of the “victims” of such a refusal was the project of a promising ship gun.

After completing the tests, the only experienced gun was probably sent to the warehouse of one of the organizations that participated in the project. Her fate is unknown. Nevertheless, it is known that this was not the last American project of naval artillery weapons, based on unusual ideas and solutions. In the future, US scientists engaged in the development of laser weapons and the so-called. rail guns. The latter in the foreseeable future may become a new weapon of warships. Electrothermochemical systems, in turn, have not gone beyond the design or testing stage.

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  1. inkass_98
    inkass_98 20 November 2015 07: 37
    Too expensive, as Cyril wrote, rearmament would have cost, and changing and expanding the range of ammunition does not lead to savings. Again, if the project had been submitted for testing in its entirety, with a reloading system, then there could have been more sense. Most likely, this gun and ammunition for it did not have any significant superiority over the traditional types of such weapons, and therefore there was no point in developing it further and taking it into service. We worked out the scheme, carried out experimental shooting - and frogs.
    1. corporal
      corporal 20 November 2015 09: 13
      And I still did not understand from the article what kind of beast such and such an electrochemical ammunition is.
      Liquid throwing component? Which is dosed and ignited by an electric discharge. Not?
      1. opus
        opus 20 November 2015 20: 55
        Quote: Corporal
        Liquid throwing component?

        Not really. It can be both "solid" and gaseous, polyethylene (PE) capillaries, polyoxymethylene (POM) capillaries, acrylic, etc.

        Ignition of an opaque substance JA2 in ETCP.

        The main purpose of introducing electric energy into the ETC cannon is to control the released chemical energy. And the burning rate can be controlled electrically to achieve maximum ballistic qualities. The expansion coefficient and peak pressure in the chamber vary with different ignition forces. By adjusting the ignition strength, temperature adjustment is possible.
        In the study of electrothermal ignition, the properties of a capillary plasma injector, the burning of a propellant in a closed barrel (tunnel), and a charge chamber simulator were studied. The capillary plasma injector has been designed to transmit electrical power of up to approximately 100 kJ. The purpose of the closed-barrel (tunnel) experiments was to investigate the effect of capillary plasma combustion on various explosives. A charging chamber simulator with a translucent acrylic tube was used to see in detail the early phase of ignition before real fire tests using a 120 mm gun.
        1. corporal
          corporal 21 November 2015 05: 21
          Thanks for clarifying. what But somehow it's all complicated ....... Scientists are wise.
          1. opus
            opus 21 November 2015 12: 20
            Quote: Corporal
            Thanks for clarifying. But somehow it's all complicated ....... Scientists are wise.

            actually quite simple:
            a polyethylene tube (one end is sealed), a strong short current pulse of high power is supplied to it (radially), the tube turns into a mini plasma meter (type like an x-ray laser), a plasma is generated.
            1.Small caliber of this plasma (its impact) is thrown by a missile charger
            2. medium large caliber, this plasma provides fast initiation of MV (JA2), pressure (and its slew rate) is several times higher than ordinary MV.
            The effect is obvious
            1. corporal
              corporal 21 November 2015 15: 41
              More or less understood. Thank you hi
        2. voyaka uh
          voyaka uh 22 November 2015 17: 43
          Very clear explanation - thanks.
  2. Forest
    Forest 20 November 2015 10: 34
    I wonder how the designers were going to reload the guns. Here, either immediately with a drum, but then the mechanism will take up a lot of space, and not the BC will be scanty, but you need to spend a lot of shells to fight ships / aircraft, or with pens, but then the meaning of rate of fire disappears.
  3. Alex_T
    Alex_T 20 November 2015 11: 44
    The article general phrases, no specifics, the topic of electrochemical ammunition is not disclosed.
    1. AUL
      AUL 20 November 2015 13: 36
      An article on the topic: "Somewhere someone did something."
      Could and more specifically disclose the idea of ​​ETX ammunition. And without this article is a dummy.
    2. opus
      opus 20 November 2015 21: 33
      Quote: Alex_T
      no specifics the topic of electrochemical ammunition is not disclosed.

      1. Capillaries (tiny tube with a very narrow channel) are taken from polyethylene (PE), capillaries from polyoxymethylene (POM), acrylic; or propellants JA2, LOVA (with them it’s somewhat different than with capillaries, here the symbiosis of explosives and plasma is for large calibers) and so on.
      2. Loaded into the breech
      3. In the breech 2 electrodes (radially)
      4.The current is supplied to them:
      The pulse generation circuit consists of two 300-kJ capacitor bank modules connected in parallel to create a pulse longer than 1 ms with a start delay system. The capacity of each module is 1236 pF, the inductance is from 20 to 160 GN, and the circuit resistance is less than 10 ohms. A vacuum electrical switch for pulsed and constant currents and trailing diodes were installed in each module. The charge current receives the desired pulse shape if we adjust the charge voltage and the start time of the individual modules. Thus, a current pulse of up to 100 kA is formed with a duration of 1 or 2 ms.
      As a result of the action of powerful EMR, complex processes of the formation of plasma ejection arise at the ends of the capillaries (4 mm x 15 mm) (the capillary is a tube that is muffled on one side), high-temperature plasma beams are formed with high energy (speed and temperature), etc.
      This affects the propellant charge (after the plasma accelerates in the laval nozzle, which the breech is equipped with), it flies out of the barrel at high speed.

      In short, this is the essence and principle. Here are the energy characteristics of the "exhaust"
      Problems (difficulties)
      electrode corrosion
      - destruction of capillaries to the formation of a plasma beam (sometimes capillaries made of polyoxymethylene (POM) break into thin fragments
      - high pressure plasma leaks from the closed side of the capillary or at the junction of plastic and metal near the exit of the jet nozzle.
      - requires a lot of petalism wink
  4. evil partisan
    evil partisan 20 November 2015 13: 16
    If my memory serves me, then for the first time I read about this principle in the year 82-83 in the journal "Foreign Military Review" at our military department. The principle of operation and the device of art. guns on liquid explosive. More than 30 years have passed, but there are still no serial samples. Although the ideas, in my amateur opinion, of course, are worthwhile and implementation is not to say that some are not real. Come on ...
  5. Susul
    Susul 20 November 2015 13: 35
    But what is there to disclose?
    They wanted to use the old idea of ​​a missile launcher in an EM field.
    There are several ways.
    1. The classic version, a standard metal shell takes off from the barrel and receives additional acceleration in the device located at the end of the barrel. This is an option to upgrade existing weapons systems.
    2. The projectile has a metal (or special feromagnetic) core and a dielectric sheath (so as not to short-circuit the rail and not to evaporate), after the start pulse, it is accelerated by the EM field along the channel between the rails. The idea is very expensive energetically but more than feasible.
    3. option 2 but the projectile on top of the dielectric sheath still has an aluminum rim, which, when in contact with high-voltage rails, evaporates and turns into plasma, which gives the projectile significant acceleration. This showed significantly greater energy efficiency than the second option. But there is a problem - it is hot plasma. The wear of such a barrel does not hold water.
    In general, EM weapons are far more realistic than laser weapons. it does not have such unsolvable problems as scattering at a distance, scattering in dust or fog, it does not have problems with the formation of a plasma cloud at the point of contact, which is not permeable to the laser, and many other problems of light weapons. But here it eats energy as much, if not more. I won’t talk about the price

    It would be better if gunsmiths would consider the idea of ​​liquid explosives, which could be fed into the barrel as the projectile passes and maintain high pressure in it. The idea is not new either, it has been considered since 1913, and even it seems like they made a poster sample that showed high results, but then it was not realistic to make a working product

    But hell, I completely forgot ... After all, the greater the initial speed, the greater the air resistance. And a shell fired at twice the speed will fly off not twice as far. A very fast shell will burn nafig, like a space car.
    1. pimen
      pimen 20 November 2015 14: 37
      Quote: SUSUL

      It would be better if gunsmiths would consider the idea of ​​liquid explosives, which could be fed into the barrel as the projectile passes and maintain high pressure in it. The idea is not new either, it has been considered since 1913, and even it seems like they made a poster sample that showed high results, but then it was not realistic to make a working product

      But isn’t it easier in such an idea to simply add a charge and play with the burning time?
    2. The comment was deleted.
    3. AUL
      AUL 20 November 2015 16: 33
      SUSUL, I am familiar with the operating principle of the EM gun. But, if you read the article, and not just the comments, it was about ETX ammunition. And this is from a completely different opera.
      By the way, if you look at the photos of these samples - that’s where the EM gun doesn’t smell.
      But for your mini-collection - thanks anyway! hi
    4. opus
      opus 20 November 2015 21: 46
      Quote: SUSUL
      They wanted to use the old idea of ​​a missile launcher in an EM field.

      there is no "overclocking" of the MS in the EMF.
      The propellant charge in the experiments was just made NOT OF METAL.

      The electrodes (2 or 4) are there radially in the chamber.
      They are for the initiation of plasma in the capillaries (PE tubes, ROM 4 mm x 30 mm (or 15 mm), plugged on one side)
      They achieve:
      -Reducing the delay time of the ignition of MV.

      -increasing the burning rate of MV

      -increase in pressure in the breech and the rate of increase in pressure in the breech

      -regulation of the pressure in the breech (number of initiated mixtures) and the rate of gas outflow by changing the current supply to the electrodes and the pulse duration.
      -increase up to 4 times the propellant properties of the mixture.

      The simulator has the same cam design as the existing 120 mm gun with the exception of acrylic chamber wall withstands pressure up to 30 MPa.

      A capillary plasma injector is placed along the central axis of a transparent acrylic chamber. A chamber with a volume of 10 l can be filled with explosives JA2 weighing up to 8.4 kg. An electrical pulse is supplied from two modules of capacitor banks through a coaxial cable.
      1. pimen
        pimen 21 November 2015 08: 54
        tell me, here’s such an idea: a charge forms a shock core that accelerates a blank (well, do you need to experiment with the funnel angle and the thickness (metal?) of the facing?
        1. opus
          opus 21 November 2015 12: 22
          Quote: pimen
          tell me, here’s the idea: a charge forms a shock nucleus,

          what's the point?
          to melt a propellant charge pan?
          or the chamber wall?
          1. pimen
            pimen 21 November 2015 12: 31
            like everything is pessimistic ... Impact core - to disperse a blank by means of a cumulative jet with a sharp focus (into a hole at the end of the barrel), what’s wrong?
            1. opus
              opus 22 November 2015 17: 14
              Quote: pimen
              Impact core - to disperse a blank with a cumulative jet, o

              1. What is a "shock core"?
              Impact core - compact metal form resembling pest resulting from metal cladding compression cumulative charge by its detonation products

              and it "needs" a projectile?
              Why such a "crap": BB (MV), a metal pestle striking at the bottom of the shell?
              some nonsense
              2. What is "cumulative jet"?
              Take a block of ice, direct a stream of COOLED water from a hose onto it - you see a process equivalent to a cumulative stream.

              Why such a "crap": the COP striking at the bottom of the projectile (and melting it?
              some nonsense

              Quote: pimen
              with a sharp focus (in the hole at the end of the trunk), what's wrong?

              all wrong
              Gas pressure in a vessel of constant volume V varies in direct proportion to its absolute temperature

              the basic equation of the molecular kinetic theory of gases:

              What is the initiation of CS in the chamber, what is the initiation of CF in the chamber: one result6
              at the bottom of the projectile, P gases and gas velocity (which is proportional to P and T of gas)
  6. Mountain shooter
    Mountain shooter 21 November 2015 15: 08
    The limits there are not only (and not so much) the properties of the propellant charge, but mainly high-temperature erosion of the barrels. There wear is an order of magnitude (tenfold increase)! Barrel resource - 500 shots! So the task is multifactorial. Everything is there - accuracy, power, and rate of fire. Recently there was a report about plastic leading belts of small-caliber artillery shells - and this is also "from this time."
    1. pimen
      pimen 21 November 2015 15: 24
      Yes, the trunk will have a hard time, but it’ll come down for direct combat. As I imagine it: three straight pyramidal guides (two below) for the disc, the shock core will provide the obturation
  7. Sobi
    Sobi 21 November 2015 19: 50
    As part of the research work "Levsha" and "Levsha-M", the first experiments on ETX-throwing were carried out. They gave positive results. It has already been decided to develop this direction using the existing 2A82 type cannon.
  8. bmv04636
    bmv04636 23 November 2015 23: 17
    and we had experiments on an explosive generator. The energy of the explosion translates into an electromagnetic pulse. Maybe in this case the ship’s guns will go