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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.

Crusader Mk.III AA Mk.II/ Mk.III - twin 20mm gun - case report

Gunners!!
      The girl about whom we are going to speak was born of the need to promote self-propelled air protection over an armored or infantry group. This should be achieved in a simple, economical and using a reliable and disponible armored chassis.
      This is the story of the versatile Crusader III AA Mk.II/ Mk.III - 20mm gun.
Crusader III AA Mk.II - 20mm gun
History:
      In September 1941 it was decided to develop a self-propelled anti-aircraft gun (SPAAG) based on a tank chassis for Royal Artillery. The main gun chosen was the Bofors 40mm AA automatic gun. Light anti-aircraft tanks, mounting multiple machine guns, already existed but they were cramped and unpopular on account of their limited range.
Vickers Light Tank AA Mk 1, a stop-gap anti-aircraft tank armed with
four 7.92mm Besa machine guns, 15 September 1942.

      After the end of the North African Campaign, the availability of better tanks such as the Sherman, Churchill and Cromwell relegated the reliable Crusader to secondary duties such as training tanks, anti-aircraft mounts or gun tractors. In these roles they served for the remainder of the WWII.

      The Anti-Aircraft versions (AA) of the Crusader were developed in response to the perceived need to counter German “tank-busting” ground attack aircraft. They consisted of a Crusader Mk.III armed with Bofors 40mm AA gunCrusader Mk.III AA Mk.I
...or Oerlikon 20mm AA twin gun: Crusader Mk.III AA Mk.II/Mk.III
     The Crusader III A.A. Mk II prototype appeared from Morris Motors in the summer of 1943, the pilot model being issued for testing in June.  The armor thickness in the turret was 30mm at the front and 14mm on the sides and 17mm on the rear.
A brand new Crusader Mk.III AA Mk.II - upper view
Crusader Mk.III AA Mk.II - 3/4 front view
       The Oerlikon 20mm AA twin gun were housed in a low, multi-sided turret, built from single layer armour, which certainly looked more suited to the hull than the Crusader Mk.III AA Mk I Bofors had done.
Oerlikon 20mm AA twin gun in a naval mount.
The gun of Crusader is almost the same...
      The tank had a crew of four: the driver/ radio operator (Mk.III), two loaders and a Commander tank/gunner who also acted as radio operator (in the Mk.II). The tank carried 600 rounds of ammunition, some of it in 60-round magazines, but these were so bulky they had to be reloaded by hand inside the turret.
Magazines of 60 rounds for Oerlikon 20mm AA twin gun
      The Oerlikon 20mm AA twin gun used anti tank fragmentation or fragmentation-frangible ammunition. The rate of fire was up to 450 rounds per minute, the horizontal range was 7200 m and height range 3000 m. The guns had a muzzle velocity of 830m/sec. They fired high explosive, incendiary and practice rounds, with or without tracer.
      The turret was designed for three men and had two versions: the early Mk.II and late Mk.III.  Power Mountings Ltd devised the high speed transverse and elevating gear but it appears that, even in experienced hands, the turret was liable to over run the target due to inertia so the maximum transversing speed as limited to 10 deg/sec, although it could turn faster. 
      The turret ergonomics were poor and claustrophobic and all crew members, except the driver, were cramped and uncomfortable. A change was implemented in the Mk.III version, with the displacement of the radio from the turret to the front hull.
Crew stations in a Crusader Mk.III AA Mk.III
      Urgently undertaken, the resultant redesign was the Crusader III AA Mk.III which had an improved turret with better protection for the gunner, in the form of a raised "lips" in the turret aperture, with a narrower aiming frame than the Mk.II version.
A lucky comander of Crusader III AA Mk.III  pointing a battle damage in the rear
of turret. Notice the armoured "lips" in the rear, front and sides of turret's aperture.
Somewhere in France - 1944.
      His task was made less onerous by repositioning the radio to the left of the driver, who now became the operator. For some reason, so far unexplained, the armament was supplemented in the Mk.III turret with a Vickers K, .303 MG in an armoured jacket, between the 20mm guns. Unlike the Bofors version, hydraulic power for the turret was taken from the tank's own engine.

      It seems that only the Mk.III models were sent to France during the Normandy invasion and the reconquest of Europe. I have not found any phot of Mk.II model operational (so far ...).
Points of differentiation visible between the Mk.II and Mk. III
models of Crusader III AA
     Due to Allied air superiority in the France Invasion and subsequent battles, almost none of the AA versions (40 and 20mm) saw much action against aircrafts but they were present and prominently in the "ground" fighting (with great success against soft targets and / or infantry) from the Normandy Landing to the final victory against Germany.
Crusader AA Mk III Allahkeef  - 22nd Armored Brigade HQ, 7th (GB) Armored Division, landing
from an LST on Gold Beach  - June 7, 1944. - Notice the waterproof canvas in the turret's front
Although the Allies possessed aerial superiority, the crews of the AA Crusaders did their job...
 Look at this Crusader Mk.III AA Mk.III from 27th Armoured Brigade somewhere in France:
while the driver seems to be talking to someone, the loader is aware of threats that might come from the sky.
Normandy, june 1944.

Crusader Mk.III AA Mk.III after leaving a LST in Arromanches
France -  August, 1944.
Children being children somewhere in Holland - 1945.
Crusader Mk.III AA Mk.III
      In parallel with the development of the Crusader Mk.III AA, the turret armed with the Oerlikon 20mm twin gun was also installed on a Centaur (turret Mk.III upgarded) and an AEC Mk II armored car (early turret Mk.II), but as Allied air superiority was undisputed, these versions were not implemented. 
Centaur AA Mk.I tank prototype. Notice the modified Mk.III AA Oerlikon twin 20mm gun
in the Crusader AA like turret
Centaur AA Mk. I with small Crusader AA 3 men turret

Centaur AA Mk. II mounted an enlarged turret that included an extra man, a gunner,
sitting alongside the tank commander who now tracked the target for him.

AEC Mk.II prototype with modified Mk.II (early) AA Oerlikon twin 20mm gun

      The same aerial superiority also relegated the Canadian Skink AA tank project to the ground support task. the Canadian tank had an armament of 4 Polsten 20mm guns.
Tank AA, 20 mm Quad, Skink
      A total of 238 of Crusader Mk.III AA Mk.II/Mk.III was built.

Specs:
Crusader III AA Mk.II/Mk.III 
TypeAnti-aircraft tank
Place of origin                                               United Kingdom
Service history
In service1944–1945
WarsSecond World War
Production history
DesignerMorris Motors - Power Mountings Ltd
Designed1941-42
ManufacturerMorris Motors
Produced1943
No. built238
Specifications
Weight19.600 Kg
Length5.97 m
Width2.77 m
Height2.24 m
Crew4 (Commander, loader, loader, driver) 

ArmourFront hull: 20mm
front turret: 30mm
Main
armament
2x Oerlikon 20mm gun - 600 rounds  (-5°/+87°)
Secondary
armament
1 Vickers K .303 machine gun - 1500 rounds
EngineNuffield Liberty Mark IV
27-litre V-12 petrol engine
340 bhp (254 kW) at 1,500 rpm
Power/weight17 hp (12.7 kW) / tonne
TransmissionNuffield constant mesh
4-speed-and-reverse
SuspensionChristie helical spring
Ground clearance0.41 m
Fuel capacity500 liters in 3 fuel tanks (+163 L auxiliary)
Operational
range
322 km on roads
235 km cross country
Speed46 km/h (road)
24 km/h (off-road)
Steering
system
Wilson epicyclic steering


The kit:
      Today we have the Italeri Crusader III Mk.III (#6444), but when I built this girl, the only option available in the market to have a Crusader AA was to buy a resin conversion kit.

      There were conversion kits from Verlinden, Accurate Armour and ARMO. My choice was the ARMO one... A very cheap find on eBay (formerly, this happened ...).
   
      But most of the time, the cheap is expensive !! And in my case, when I purchased and built this kit, the research was still not very accessible for me. We would build and paint the kit as it was in the instructions and we would trust that things would be right! Well ... not always ..
      In this case, we will see the competitors of the time: Verlinden and Accurate Armour: in those times, very expensive for my poor wallet ... and besides, very difficult to find and order (I'm talking BEFORE the high speed internet and me living in the Brazil ...). but let's discuss the other two models:
Nice turret from Verlinden, but  is the Mk.II version
Notice the big aiming frame and the absence of MG coaxial between the guns.

Accurate kit is PERFECT, but hard to find (and expensive...) to me, in those times
Perfect conversion kit, for the model Mk.III
Notice the welded grid that some tanks presented to hang things (green arrow).
 Let's discuss this later ...
      She was like this: cute, but totally wrong, especially the markings ... 
My old Crusader Mk.III AA "KOLA"
Notice the wrong front fenders, with step: Italeri never fixed this ...




This is KOLA, my old Crusader MkIII AA ... Cute, but ...
       And so she was in my showcase for many, many years. The Italeri released the specific model, I started to research more seriously and depth and finally the time has come for me to try to "recycle" this style. I admit that buying an Italeri would be easier, but it's a lot more fun to rescue a "Fallen Angel" from the depths of Hell.
HALLELUJAH!!!
     Starting by the turret: let's try to improve this thing!! (I hate to discard kits .. I think it's a childhood trauma: I wanted so much to have kits and I had no access to them ....). So, after this confession, let's go!!
      The main flaws of the ARMO kit are the "flat" aspect of the turret and the edge of the tower's ceiling ... like a lip, an overhang ...
But the true turrets are higher and without this overhang ...
      And I kept thinking: how did they make this mistake ?? my explanation is that they may have been based on old and low resolution photos. Some crusaders featured this welded grid to hang things....
The "roof lip": See above the turret of Crusader in the Saumur Museum (colors)
And turrets with grids welded in the roof edge (green arrows)
The same grids in low resolution (red arrows)...Maybe the lips explained??
      Whatever the reason of the flaw, we will try to improve the ARMO turret, giving it a less flat appearance and removing the projections from the edge of the turret roof. Fix the projection is easy: just cut. To increase the height of the sides of the turret, I added 1mm to its total height by gluing a square rod of Plastruct to the base and around its perimeter (included the front shield).

See the "recipe to transform the ARMO turret in something more like true...
Chuck approves!!
       My old Crusader girl without accessories in the rear with plastic surgery performed in the tower!!
I close the driver hatch and fix the front fenders too!!!

Notice the new periscopes from spare parts of Churchill AFV Club...

The white portions in the turret base is the 1mm square rod Plastruct.
Notice the front fenders in flat position (correcting the old mistake from Italeri Crusaders kits...)

Almost ready for painting...
      Well, the girl has a more beautiful head, now ...
The 50 shades of green...



      Now, I did my homework right: After researching my books and old papyri, let's represent our girl as a brave Polish warrior, rendering her services on the 1st Polish Armoured Division, promoting air protection with the 10th Mounted Rifle Regiment, an armoured recce regiment. Our girl belongs to Headquarters Squadron, fought in France, 1944.
     Before the decals, let's turn the surface of the painting into something smooth and shiny, to prevent the damn silvering. I decided to use a Gloss Varnish from Vallejo, instead of the Future (or Pledge) that I usually use. Let's test this Spanish alchemy ...
Using the Gloss Varnish from Vallejo with airbrush.
Small dilution in water (30%) and we will apply in the areas
that will receive the decals ...

The aspect is very good...and dry very quickly!!

Decals in position... A detail: the varnish is very"adherent" to the decal.
Be careful when placing the decal on the surface of the kit: it should be well wet ...
If not, it is very difficult to relocalize the decal ... It almost sticks immediately ...


1st Polish Armoured Division - 10th Mounted Rifle Regiment (Armoured Recce Regiment)
 Headquarters Squadron - France, 1944.




     Now, its weathering time!!!   But, before..testing Value Gear stuff... These Crusaders were heavily used in the Normandy Landing and all battles asfter. Although they hardly fired against planes, they were precious as infantry support ... And operational tanks mean things on the rear decks ...
Value Gear details....


Final touches...


      The Polish Crusader was ready. Meet Crusader Mk.III AA Mk.III belonging to the 1st Polish Armoured Division, promoting air protection with the 10th Mounted Rifle Regiment, an armoured recce regiment. Headquarters Squadron - France, July1944.
Crusader Mk.III AA Mk.III - 1st Polish Armoured Division
10th Mounted Rifle Regiment (Armoured Recce Regiment) - Headquarters Squadron
France, July1944.










Crusader Mk.III AA Mk.III with Kojak and Rover, the dog.

Two weapons with the same origin of concept, but who fought in support of infantry, most of the time:
Skink AA tank and Crusader Mk.III AA
Love the "futuristic looks" of the turrets!!!

Skink AA tank and Crusader Mk.III AA

Same origin of concept, but different sides:
3 cm Flakpanzer IV Kugelblitz and Crusader Mk.III AA Mk.III

From the series "Impossible Encounters". Same strain ... but ...
Canadian Skink AA, German 3 cm Flakpanzer IV Kugelblitz
and British (with Polish colors) Crusader Mk.III AA Mk.III

Crusader Mk.III AA Mk.III - 1st Polish Armoured Division
10th Mounted Rifle Regiment (Armoured Recce Regiment) - Headquarters Squadron
France, July1944.

This overhauling project is over...
Thanks for watching!!