Churchill Mk IV AVRE with Canadian Indestructible Roller Device (CIRD) - case report

Noblemen and Commoners!!!

      A British special vehicle this time, by Jove!!! I finished this girl in 2010. This project was a pre-release building of the new (in 2010) TankWorkShop's conversion kit.
     Jay Galbierz, from TWS, sent me this pre-launch conversion kit, for a test-drive assembly. The Churchill Mk. IV AVRE with CIRD.

     

Churchill Mk.IV AVRE with Canadian Indestructible Roller Device
(CIRD) (late version)

Churchill Mk IV AVRE with CIRD (early version)

Churchill Mk IV AVRE with CIRD (early version)

History:

      Methods of exploding mines by pressure depended on roller attachments. Two of these were used with Churchills and Shermans. The Anti-Mine Reconnaissance Castor Roller (AMRCR) was a perambulator device developed directly from the Fowler Rollers used by earlier tank types like the Matilda and Covenanter. The AMRCR device was cumbersome and heavy , however, and it was not used operationally.

Churchill Mk IV with Anti-Mine Reconnaissance Castor Roller (AMRCR)
side view

Churchill Mk IV with Anti-Mine Reconnaissance Castor Roller (AMRCR)
3/4 front view

Churchill Mk.IV with Anti-Mine Reconnaissance Castor Roller (AMRCR)
in field tests

Sherman V with Anti-Mine Reconnaissance Castor Roller (AMRCR)

Sherman of 79th Armoured Division fitted with AMRCR
(anti-mine reconnaissance castor roller) in field tests - 16 October 1943

    A much more successful development was the Canadian Indestructible Roller Device (CIRD or C.I.R.D.) which, as its name implies, was of Canadian Army origin. Designed in September 1943, it consisted essentially of two heavy armoured rollers attached to projecting side arms in front of the vehicle, and the CIRD proved most effective on trials.

      The rollers were arranged so that when either one passed over a mine, exploding it by pressure, the blast caused the roller to jump up in an arc over the side arm so that the motion caused the spade end of the roller arm to dig into the ground. By a mechanical arrangement, plus the motion of the tank, the roller subsequently returned to its travelling position. 

       Two sizes of roller were put into production from several tested , these being of 15t and 18 inches diameter respectively. The latter was intended for the Churchill. The CIRD could be used with either the Sherman or the Churchill tank, and was put into production for both.

Sherman V with CIRD

     Sherman CIRDs were intended to support Sherman Crabs in flail regiments, though they were not in fact used operationally: the CIRD was among the equipment which could be attached to the special fittings on the side of the Churchill AVRE. Though issued , however, the ClRD does not appear to have been used in action by 79th Armoured Division. There were several experimental equipments developed which involved the use of the CIRD and one or two of these have connection with explosive mine clearing devices (Bangalore torpedoes).

Sherman CIRD with Bangalore torpedoes

      The Cruiser tank Cromwell was also tested with CIRD.

Cromwell IV with CIRD

      The device was available for D-Day and was shipped across the channel. Sherman CIRDs were issued as pilot tanks, on the scale of one per troop, to the three regiments of the 79th Armoured Division operating flail tanks in North West Europe. RAC Reports note that one of these, 30 Armoured Brigade, was equipped with "36 pilot Sherman Vs with 12 Roller equipments". However, there are no records of the CIRD being used in action and all units were withdrawn before the end of 1944. 

      But it was tested again around February 1945. Before the crossing of the Rhine the 79th Armoured Division formed a number of experimental wings to deal with the problems expected when crossing the Rhine. F Wing was based at Geel, Belgium, and (among other things) tested a series of anti-mine devices, one of which was the "spectacular" CIRD. In December 1945,  the Specialised Armour Development Establishment (SADE) continued to test the CIRD.

      Maybe no more than a dozen CIRDs were built. Photographs made during testing show various Sherman Vs (incl. T-148350) in use as pusher tanks.

Sherman M4A2 with CIRD

      No devices themselves are known to survive, but a number of Shermans with the distinctive fittings on the hull sides are preserved. Noteworthy is that two of them survive in Canada which is odd since the CIRD was developed and tested by the Canadian Army in Great Britain.

font: Sherman Register website

Specs:

Churchill Infantry Tank  Mk IV - (A22)
Type	Infantry tank
Place of origin	United Kingdom
Service history
In service	1941–52 (British Empire)
Used by	United Kingdom, Soviet Union Canada, Ireland, Poland
Production history
Designer	Vauxhall Motors (A22)
Manufacturer	Vauxhall Motors
Produced	1941 to 1945
Number built	5,640 approx.
Variants	See family
Specifications
Weight	38.5 long tons
Length	7.44 m
Width	3.25 m
Height	2.49 m
Crew	5 or 6 (commander, gunner, loader/radio operator, driver, co-driver/hull gunner + AVRE engineer)
Armour	102 mm hull front, 89 mm hull side, 51 mm hull rear, 89 mm turret front, 76 mm turret side and rear
Main armament	AVRE: Petard, a 290mm Spigot mortar throwing the 18 kg "Flying dustbin"
Secondary armament	Two 7.92mm Besa machine guns
Engine	Bedford 12-cylinder, 4 stroke, water-cooled, horizontally opposed, L-head petrol engine 350 hp (261 kW) at 2,200 rpm
Power/weight	9.1 hp (6.7 kW) / tonne
Transmission	Merritt-Brown 4-speed constant-mesh epicyclic gearbox
Suspension	Coiled spring
Operational range	90 km
Speed	24 km/h
Steering system	Triple differential steering in gearbox

The kits:

      For this project, the kit was: Churchill Mk III AVRE, from AFV (the model IV not yet existed)

Churchill Mk III AVRE AFV 

      ...and the fantastic resin conversion kit from TWS:

TWS resin conversion kit 1020

      In actual pictures, the Churchill CIRD was always the model Mk IV. As at the time the Model IV from AFV had not yet been released, I used the turret from old conversion kit from Legend to convert the model III to the correct model IV:

Old Legend LF 1063 conversion kit

      Let's rock...Building the Churchill: the suspension and the springs...

AFV parts. Notice the resin part (TWS) in gray

      Building the Churchill's suspension

Suspensions done...

      The AFV Churchill can be build in two versions: A, with an additional armour in the region of the equipment pivots and B, without this armour. As in the picture of Churchill AVRE CIRD this armour is not present, I'll opt for the Type B assembly (without shielding ...)

      To prevent warping of the tank's hull, I did the alignment the sets of suspension by its top. The springs of the suspension could hide a flaw in this step ...Using a wooden block perfectly symmetrical for this ...

      Using the photo-etched from AFV, for detailing the rear of AVRE:

      And an essential after-market complement: a machine gun Besa, from RB Models.

Besa from RB Models...

      Building the driver´s armour and the front glacis; I've used, with abundance, welder for corrugating the upper surface of the front part of sponsons (notice the whitish plastic) ... Later on, this site will accumulate mud ....

Testing the Legend's turret. The turret diameter is much smaller because was made for the Tamiya kit .... I'll have to make a graft for the thing work ...

Almost a tank....

      To prevent the turret not keep "dancing" in the hull, it's time of surgery: Cutting the Legend's turret housing.  I used many plastic pieces from AFV in the turret Legend.

Starting the turret's surgery

Done...

Sanding the turret's base in my Panzerserra's sanding tool!!!...

Smooth !!

        Looking the Churchill AVRE- CIRD turret, I noted a difference between the turret in the pic and the Legend turret. In the actual photo, the roof's ventilator is positioned to the front left near to the lifting attachment point (at the edge). This is a feature from Early version.

Notice the ventilator position in the turret's roof. - Ealy version

      But the legend turret presents the ventilator in the late position, further shifted to the center of the tower

Notice the ventilator position in the Legend's turret

      The differences;

Ventilator positions.

      To fix this, surgery in the resin... Removing the late ventilator...

   
        And scratching in plastic a new ventilator;

      Done!!

Churchill Mk IV early turret !!!

      To complete the turret, making a new housing, with thick plasticard (2mm)

Corrected diameter

      Dry-run in the hull: No more dancing...

     
       After that, let's complete the turret. legend and AFV playing together...Notice the hull with fenders and vinyl tracks...

Metal barrel guns from RB Models...

Some scratch in metal...

Almost ready...

    Finally, the resin parts from TWS coming to play:

Cleaning all the TWS resin parts...

Making the arms for the rollers devices:

      The brackets for the long arms of the apparatus are drilled to align with the part of the chassis. Instead of using the parts of the AFV, I used clothes pins to align the pieces properly

Rivets made with pins.

In position. Notice the adjustment between resin and plastic part: awesome!!!

Almost done...

      

      The TWS kit features the two pivots of CIRD´s articulation arms in resin, very well molded and richly detailed, such as the threads of the screws:

Pivots very well detailed...

      But the CIRD device is too heavy for these pins, in resin .... I decided to remove these screws and drilling the resin pivots and hull, so as to pass through the hull a metal wire to stabilize and align the CIRD. Drilling with a drill of 1.5 mm diameter:

Cutting the resin screw and open the 1,5mm hole

The metal wire used for reinforcement.
Notice the the connecting rod bearings also perforated

The metal wire passing through the hull...

...and the tips of the shafts reinforced by metal.

      After this surgical step, while the heart beat returns to the normal, we will build the "forks" in the front of the arms of CIRD. The internal springs of the forks I remade with copper wire, because the ones of kit were a bit too thick:

The internal fork's springs

 Cutting the solid plastic rod (organic in the kit) in the right size...

Reinforcing the fork's junction...

....and aligning the arms with the forks

       Bringing together all the sub-parts ...

      While the various stages of glue dries, I'll fix a flaw ( in my opinion...) in this AFV kit: Turrets without locks ... And the AFV turret and hull has no locks ... 

      I have a trauma about turrets without locks: One day, a colleague visiting me grabbed one kit and turned the tank upside down to see the details of the model below ...

CRASH....The turret flew !!!

      There was a turret at the floor and I promised, this day (and subsequent ones, while fixing the poor flying turret ...) that NEVER leave a turret without locks IN MY KITS!

      Never..Ever...Ever !!!

      Here's what I invented to prevent future accidents: I glued a piece of thick "tree" at the base of the tower, with

Future Panzerserra rotation device...

       I open a hole in the bottom of the hull, perfectly aligned with the turret's center pin with the exact height between the bottom of the turret and the hull's bottom.

      So I held my turret in the hull through the screw that pierces the bottom of the hull. Simple like that. A light grip allowing the turret to rotate and ...

Panzerserra's lock sistem...

Voiláá´...The turret never will fly !!!

       Turret in position: ready for painting...

      Primer:

After primer, the casting markings, from Archer..

      After that, green paint:

Turret in green. Notice the casting marks...

In this picture, I realized I had forgotten to add the reinforcement armor in the front hull's machine gun.

The additional armour 'bolted'  in position...

... and painted in green. Fool !!!

CIRD in close...

Tonal variations in green...

A layer of Future, for decals...

       While the Future dries, I did the exhaust painting job...

oxides...

Exhaust in position...

       Best part: Markings !!!

decals...

The Black Bear was born !!!

front view

Turret in detail...

Weathering...

Tools and accessories...

Chipping ...

Starting the paint job in the figure...My Achilles heel

Uff...

       Heavy weathering...These special vehicles attract mud like magnets ...

      And the Girl was ready:

Churchill Mk IV AVRE with Canadian Indestructible Roller Device (CIRD) 

Churchill Mk IV AVRE with CIRD - right side

Churchill Mk IV AVRE with CIRD - left side

Churchill Mk IV AVRE with CIRD

    

  Another kit, another pleasure, another history !!!

Thanks for your presence in our Bunker!!!

See you, another time !!!