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ATENÇÃO:
A publicação de qualquer imagem ou informação referentes ao nazismo, fascismo ou quaisquer outros regimes totalitários deve ser entendida como reprodução do rigor histórico e não como apologia a estes regimes, líderes ou símbolos.

T31 Demolition Tank (M4A3E8 HVSS) - case report

Ladies and Gentlemen...
    Another unique girl, either because of her characteristics or because of her construction: only one manufactured, at the end of WWII. Meet the imposing T31 Demolition Tank!! 

T31 Demolition Tank - a specialized engineer M4A3 (HVSS)
History:
    According to Plato: "The necessity is the mother of invention".
Plato - Athenian philosopher and thinker
    And the requirements of the battlefields in WWII generated the development of many ideas and concepts, at least, unusual. And this vehicle that we will see above fits perfectly with that definition of Plato.
   The actions on the fronts, increasingly fluid and fast, required mechanization and high mobility, even more when powerful defenses were found. The important thing was to act quickly, pour a high concentration of fire and resist enemy counterattacks. The tank can be considered as essential of this new doctrine, being able to inflict and receive heavy punishment, maintaining mobility ...
    The United States, with its vast industrial power, since the beginning of the world conflict sought to try to recover the lost time that pacifism of the 1920s and 1930s imposed on its armored war industry. The lessons learned hard in the initial battles of the War were gradually being assimilated, both in the field of ideas and technological development. Since the declaration of war in late 1941, the US military industry has been poring over the drawing boards for conventional tank designs and the so-called specialized engineer vehicles.
    These armored vehicles should be able to attack the enemy's fortifications and strengths points quickly and, at the same time, open the path for other more conventional vectors, which would follow them ... Many types of guns, howitzers, mortars and even missiles were considered to achieve this goal, with the need pushingthe creativity to its limits. From 1942 to 1944 there were countless projects and drawings, but few even reached the phase of mock-up.

    In this report, we will focus on a specialized armored vehicle, with a big and peculiar turret. She was designed to move around in a hostile environment, pushing its way through obstacles and warding off infantry attacks with its powerful defensive weaponry. This project was known under the designation of T31 Demolition Tank.

Development:
    On 11 November 1944, the senior member of the Joint Army-Navy Experimental and Testing Board (JANET) wrote to the Army Service Forces requesting the development of the engineer armored vehicle T2. The requisition also outlined its desired characteristics: The M4A3 tank with the horizontal volute spring suspension (HVSS) was specified as the basic vehicle, but with belly armor increased for better protection against the explosions of land mines.
The logical choice chassis for the T31 Demolition Tank:
M4A3(76) W HVSS - "Easy Eight"
    Other features included an improved dozer blade and mine excavator as well as a periscope type flame thrower in the assistant driver or commander's hatch. A new special big turret was required armed with a pair of automatic rocket launcher of 7.2 inch on each side of turret (like ears) and two .30 caliber machine guns in front. Three pilot vehicles were requested ASAP. The Ordnance Subcommittee on Automotive Equipment spelled out the characteristics in greater detail and recommended the procurement of four pilots. This action, reported in OCM 26173, also designated the vehicle as the Demolition Tank T31.
A crude reproduction of a profile of the initial specifications for the
specialized vehicle T31 Demolition Tank 
    Design layouts were started in January 1945 and the following month, a contract was negotiated with the Heinz Manufacturing Company to build four pilots. Heinz immediately started construction of a mock-up to study the equipment arrangement and stowage.

    The T3l's main armament was specified as two T94 7.2 inch rocket launchers with one mounted on each side of a narrow turret, like ears.
T31 Demolition Tank armament, from top to bottom:
1- .50 MG Browning in the commander cupola
2- two T94 7.2 inch rocket launchers in the "ears" of turret
3- the central "weapon" is a 105mm dummy gun
4-  two .30 MG Brownings in ball mounts in the front of turret
5- .30 MG Browning in the front bow
    Each revolver type launcher carried five T94 7.2inch (183mm) rockets (the same rockets used by the Sherman Whiz-Bang ...see here...) and was enclosed in an armored blister. The launcher cylinder could be re-loaded from inside the turret and a minimum of 30 rockets were carried.

7.2inches demolition rocket

Two Shermans rocket-launchers: T-34 Calliope and T-40 Whiz-Bang
    The front and sides of the special turret were 63,5mm thick. The double rear access doors were 38mm thick, with a vision block and a ball type pistol port installed on the left leaf of the double door. The tank commander's all-round vision cupola was raised with an armored collar about 76mm to improve the downward vision over the flat turret roof.
T31 Demolition tank rear vision. Notice the
commander's cupola over the armored collar,
the double rear door, with vision block and
ball-type pistol port in the left door leaf.
    Two eriscopes with 360° rotation also were provided in the middle-front turret roof, for the "gunners" and a fixed periscope for aiming the rocket-lauchers, in front and between the gunner's ones.
Top view of the T31 Demolition Tank.
Notice the periscopes and the  strange "ears" with the main weapon systems.
    The hull/chassis used was the standard M4A3 with horizontal volute spring suspension (HVSS), except that the floor was increased to maximum thickness of 38mm of armour, for better mines blast protection. Fittings were provided for attaching an M1A1 bulldozer blade in the HVSS bogies.


M1A1 dozer blade components.
    As we have already seen, the concept of the T31 was that the vehicle would make its way through heavily defended terrain, with the increased protection shield in its ventral portion against anti-personnel mines and with the dozer blade being able to remove anti-tank obstacles in front of it, until it reached on the strengths to be destroyed with their heavy rockets. In order to increase the protection factor against infantry and increase the attack power, it was planned to install flamethrowers of the model E6R3, which could be fired from the hatch of the commander or the co-driver. This weapon was known as M3-4-E6R3 mechanized flame thrower.

    This weapon system consists of three main groups: 1-the sponson fuel group (M3) with 95 liters of fuel; 2- the transmission fuel group (M4) with 95 liters fuel and the flam gun (E6R3).
The installation of the flamethrower and its equipment did not interfere
with any of the tank systems or weapons. 


    The sponson fuel group is mounted on the sponson shell directly to the right of the assistant driver. The transmission fuel group is mounted on the transmission case of the vehicle. The E6R3 gun is mounted in a specially designed periscope holder which may be installed in either the assistant driver's hatch door or in the Commander periscope mount. 
The E6R3 flame gun mounted in the side of periscope of co-driver hatch.
The hatch is open. Is possible see the fuel hoses of flame-thrower
going to the interior hatch. Notice the black smoke stain
in the front of co-driver station. The tank is a M4A3(76)W HVSS.

Those were the only pictures I found of the E6R3 gun installed in the commander's hatch. 
The tank in example is a T33 flamethrower.
T33 flamethrower tank. A derivation of M4A3E2 (HVSS) with new turret.
    The range of the fire jet ranged from 20 to 60 meters, depending on the viscosity of the ignition fluid and the pressure of the propellant cylinders. When installed in the co-driver hatch, the range of the fire field was 45 ° to the left and 90 ° to the right.

    The fire gun was installed on the right of a special periscope and was maneuvered by the operator who could rotate the periscope + gun with his hands, while fire the gun with his right hand. The weapon was not very popular, due to the operator's concern to have his face "leaning" against the flamethrower and the  ... But it was a very efficient weapon, although with little autonomy.
The "early" E6R2 gun flame. Notice the position of the projector
behind of the periscope (left corner above)
Notice the operator's position (left corner below)
In the drawing, the E6R2 flame gun firing over the periscope.
This gun flame was quickly replaced by the E6R3

The  E6R3 gun flame. Notice the position of the projector
on the right side of the periscope (left corner above)
The operator's position is very similar to the early version...
In the drawing, the E6R3 flame gun firing beside of the periscope
     The standard .30 caliber bow machine gun was retained. Although the OCM called for four pilots, initial work began on a single soft plate turret. This was considered necessary to work out the installation of the experimental T94 rocket launchers. Work on this first pilot started in April 1945 and was completed in August, when the first T31 tank was sent to the Aberdeen Proving Ground, where a demonstration of promising technology was held to representatives of the military department.
    The unusual tank was shown to the command of armored and engineering troops. After that, the tank came to the test, during which he had to show the characteristics of mobility and demonstrate the fighting qualities. The presence of three machine guns, a flamethrower and two rocket launchers in a single vehicle is something to watch with great interest and curiosity.
T31 demolition tank - side view
Notice the oil leak in the first whell of the third bogie
    According to the reports, there were no problems with barreled guns. For self-defense, a specialized engineering tank can use the relatively old and well-dominated machine guns, which have long been fault-free. The same happened with the flamethrower, already a veteran of the battles in the Pacific islands. The problems were the T94 launchers, the main weapon of the armored vehicle. As planned in the project, the tank crew was to load the rockets in two drums, after which it could make ten shots (single shots or in two rounds). This would be followed by refilling. The amount of the internal ammunition allowed the two drums to be emptied three times.
The T31 in trials, in Aberdeen Proving Ground.
August, 1945. 
     The launchers failed to operate satisfactorily during the tests. The left one froze completely and the right one could be rotated only by hand when loaded. By this time, the war was over and only limited funds were available. 
    I did not find records on the degrees of elevation and depression of the rocket launchers, but based on the photos and drawings, the "ears" with the main weapons could vary between -15 ° and + 34 ° of elevation, with the turret allowing a 360 ° drift. Of course, these are speculations based on the engineering of the project.
M4A3 (HVSS) Demolition Tank showing the possible
degrees of depression and elevation (-15° and +34°)
    It was considered that further development of an engineer vehicle should be based on a more modern tank since the M4 series was no longer in production. Cancellation of the project was approved by OCM 30058 on 17 January 1946 and no further pilots were constructed.
     After completion of the tests, the only prototype T31 went to storage, and then was disassembled as useless. A sad end for such an imposing machine.

Specs:
    I didn't find the specifications for T31 Demolition tank, but since she was built in the M4A3(76) W HVSS chassis, the dimensions of width and length are the same as the chassis of the medium tank. The weight was speculation... The height is also an estimate, in which I made a proportionality rule using the profiles of the two vehicles, side by side.

Demolition Tank, M4A3 (HVSS) T31
Typeengineering specialized tank
Place of origin                               United States
Service history
In service          1945 - single prototype
Used byUnited States
Wars
Production history
DesignerU.S. Army Ordnance Depar.
DesignedJanuary 1945
ManufacturerHeinz Manufacturing Comp.
ProducedAugust 1945 (prototype)
No. built01
Specifications
Mass42.0 short tons (?)
Length6.27 m
Width2.99 m
Height3,39 m (?)
Crew5 (commander, 2x gunner/loader, driver,
co-driver/bow gunner)

Armor
108mm front (max.) 
Main armament
two T94 7.2 inch rocket launchers (30 rounds)
Secondary
armament
.50 caliber Browning M2HB mg
(600 rounds),
.30 caliber Browning M1919A4 mg (6750 rounds)
M3-4-E6R3 flamethrower
EngineFord GAA V8 gasoline engine;
450 hp @ 2,600 rpm
Power/weight13.5 hp/ton 
TransmissionSpicer manual synchromesh
transmission, 5 forward and 1 reverse gears
SuspensionHorizontal volute spring
suspension (HVSS)
Fuel capacity662 litres
Operational range
161 km on road 
Maximum speed42 km/h) on road

The kit project:
    For many years, I wanted to build this specific armored vehicle. Many, many years ago, a conversion kit from the defunct Cromwell Models existed, but the owner did not send the kit to these distant and poor lands. 
      I thought seriously about building this turret from scratch, but other projects were added up ... 
    And so, recently Sebastian Debold, owner of  BoldDivision (the same guy who released the wonderful M4A2 Mine exploder T10, which you can enjoy building by clicking here, in Panzerserra Bunker...), asked me about the feasibility of launching this conversion kit on the market. 
     Of course, I was very happy and encouraged him to the task ... and behold, the turret today is a reality. Thank you Sebastian, for listening the desires of crazy old people like me ... and I guarantee that there are many around the world !!!
    This is the BoldDivision box kit: Sherman T31 demolition tank  HUZZAH!! The bald one is ecstatic !!!
BoldDivision box kit (#35036)
    The donor kit will be an Academy U.S. Medium Tank M4A3 Sherman 105mm howitzer & M1(A1) dozer blade (#13207). You've seen this kit being built here ...
Academy box kit  (#13207)
      Starting the chassis...
Cleaning the wheels...Dremel and scalp...

Wheels, ok! - Bogies, ok! - Chassis, Ok!!
Transmission cover, Ok! - Real chassis panel, Ok!!

"Closing" the chassis with upper hull... The Academy kit is easy....

But not perfect: closing the holes in the bottom of sponsons...

The girl with HVSS suspension ready: left view...

Right view... Cool!!
     One thing is hammering in my head: the T31 was designed to use the E6R3 flamethrower and the M1A1 dozer blade. So, why not build this kit as if the problems with the rocket launchers had been solved and the vehicle sent to production, even with the end of WWII ??
    The idea for my kit would be a representation of a TOTALLY operational version of the T31 Demolition Tank, with a dozer blade and the E6R3 periscope flamethrower ... In summary, the representation of a COMPLETE T31.
     The tank will be fully operational, without the side skirt fenders, which normally were removed, even more with the dozer installed. And as she would be the "late" version, she would be using the tracks model T-80 and not the "early" T-66. Something like this:
M4A3 (HVSS) Demolition tank T31
Fully operational with M1A1 dozer blade and M4-3-E6R3 flame thrower
in the co-driver periscope and tracks model T-80

      But continuing with the building, let's take a little care of the "small" turret from BoldDivision !!!
The BoldDivision T31 demolition tank kit...
The green one is from Academy, don't forget!!!

The kit comes complete with metal weapons, a small sheet of PE
and very well-cast parts ... A beauty !!!

The main blocks, after being cleaned ...
      Of course, I will make the main weapons with some movement ... I chose to use a metallic axis to "transfix" the turret, to allow the synchronous movement of the two rocket launchers ... My idea is to glue the two "ears" on the metal shaft with cyanoacrylate. With that, I will have resistance and movement ...
Notice the metal shaft, with the "scratched" ends with carborundum discs (Dremel)
 to increase the bonding retention

The metal shaft is nothing more than oxyacetylene welding rods, which
you buy at hardware stores at a bargain price !!!
Surgery done...waitng the adaptation of the "ears"...

Ears in position: rocket-launchers in 0°

Weapoms in drepression....

...and in elevation!!!  Like a glove!!

By the book!!!
     Another thing I did was to rectify the circumference of the base of the turret and the fit of the turret in the hull. I did this with a dry-ended industrial compass, cutting off excess and irregularities in the contour. My objective is to keep the turret moving, but with locks, to avoid accidents when handling the kit.
The base of the turret: in red, the circumference of the base of the tower and the socket
perfectly rectified with the use of a compass ...
And in blue, a rectangular Plastruct rod to work as a lock.

Swinging the whole thing, to test the rotation system lock ...
Perfect!!

Is she cute or not ?? !!!
    As you know, I will do what would be the operational version of the T31 demolition tank ... Studying the turret, I verified that there are no ventilation and/or exhaust systems for the tower's crew. Now, imagine the amount of fume and smoke inside the turret when the rocket launchers were firing ... Although there are posterior openings in the "ears" for the exhaust of the firing gases, I imagine that this environment should be very impregnated with smoke . Looking for a solution on the same production line as the Shermans, I opted to install two fans/exhausters from the Sherman 105mm turret (which produced a lot of smoke when shooting ...) on the roof of this tower. Here's how it got:
The T31 turret with details added: Commander hatch (with periscope) Academy
Two open periscopes for the gunners (Dragon)
The long fake nose with 105mm (BoldDivision)
aerials made with acupuncture needles
and the two fans from the standard 105mm Sherman turret

Less toxic gases for my brave crew ...

Turret's rear view. I replaced the excellent BoldDivision hatch because
I wanted the Commander's periscope to be open ...

The future place of my flame gun...
Notice the details in light-gray from Dragon 

The girl almost ready...rear view
      Now let's build the Academy's M1A1 blade ... Piece of cake !!!
Mains struts for the dozer blade

Construction is easy, fast and perfect
You just have to be careful that the dozer blade is not bent in relation to the support arms:
check for possible twists on a perfectly flat surface. 
Here, I use my glass plate with sandpaper as a template.

Adding details from the kit...

The blade almost done...

The dozer blade hydraulic systems, which will be installed
in the tank's transmission cover ...

The blade being installed in the chassis. I used a 1mm piece of plasticard as a height template.
This distance plus the thickness of the tracks will keep the blade at a discreet height and mainly,
in a perfect horizontal position.

Right side...

The girl, almost ready...
      I'm going to use .50 Browning machine gun from the Academy's Sherman kit. This machine gun comes with a wider hinged base, which does not fit on the BoldDivision support. So I cut the resin piece and installed the Academy piece (wider) in place. I took advantage and installed the .50 barrel lock in the correct position.
The new parts from Academy kit: .50 Browning support and barrel lock.

Next step: flamethrower!!!
      As we can see in the images below, the flame gun E6R3 transfixes the periscope (co-driver or Commander), being exactly on the right side of the periscope, in no way affecting or altering this device.
Flame gun E6R3 specs


      I chose to use a 2mmx1mm rectangular Plastruct rod to make the flame gun. I cut two segments and glued them together at 90 °.
Plastruct rod with 2x1mm. Two segments
with 9 and 5mm, glued in perpendicular.
Notice the pencil marks for surgery...

After the rounding surgery and tuning the plastruct to 1.5mm wide in its vertical portion,
I cut 1mm at the same time, to fit the piece to the hatch...

Time to make the flame shield clamps. I made them with very thin pieces of plasticard ...
I know the design was not identical, but at this size, it was the one that most simulated this union...

I think (... and the GI also ...) that the final result convinces ...

Installing the flamethrower in the co-driver's periscope

Like a glove!!!

Ready to toast the bastards !!!

Notice the two small holes in the front of the gun ...
Fully armed girl (ops ... Fifty is missing at the top of the tower ...)
and dangerous, ready for painting and markings ....
Kojak is TOTALLY satisfied

T31 demolition tank...right side...
The bald one is very, very happy!!!
Choosing stuff for the rear deck...
As usual, the details are Value Gear!!

Primer time: Tamiya rules!!!

Olive drab from Ak...

The chassis in details...

The girl with shades of green!!!

Indeed, the girl is very huge...and cute!!

Right side

Left side

Hey, BoldDivision...I'm here!!!
    Whenever possible I like to make a drawing in 3 views for the markings and painting... Meet JUDY MAE, a M4A3 (HVSS) Demolition Tank T31.

    The "shiny and wet" look is due to the thin layer of Future / Pledge that I applied to the model before decals, to avoid the obnoxious silverig ...
JUDY MAE has just been baptized ...

Notice the spare wheels in the front hull and transmission cover,
but away from the flaming jets of the flamethrower ...



Judy Mae is sooo cute!!

And starting to paint the accessories...
T31 almost ready ...

Value Gear stuff in place...

Value Gear stuff in place...right side...

Rear view

Next step: weathering...


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