Churchill Mk IV ( AVRE and gun) with carpet layer bobbin ( types A and D) - case report

Tommies:

      Now it's time for another double british project: Churchills tanks with carpet layer bobbins. Let's see the early and late version of these specialized tanks.

Churchill Mk IV gun tank with early type bobbin

Churchill Mk III AVRE tank with late type bobbin

History:

      The tank Mk IV (A22) Churchill was a heavy British infantry tank used in the Second World War, best known for its heavy armour, large longitudinal chassis with all-around tracks with multiple bogies, and its use as the basis of many specialist vehicles. It was one of the heaviest Allied tanks of the war. The origins of the design lay in the expectation that war in Europe might be fought under similar conditions to that of the First World War and emphasised ability to cross difficult ground. The Churchill was rushed into production in order to build up British defences against an possible German invasion and the first vehicles built had flaws that had to be overcome before the Churchill was accepted for wide use. After several Marks had been built a better armoured version - the Mark VII - entered service.

      The Churchill was used by British and Commonwealth in North Africa, Italy and North-West Europe. In addition many were supplied to the USSR and used on the Eastern Front.

Carpet-Laying Devices:

      Known generically as "bobbins," the tanks carpet-layers were devices for laying mats over soft and/or boggy ground. The Bobbins were designed for laying rapidly and, if necessary, under fire, a carpet in a lane over poor or bogged ground and over barbed wire obstacles for the rapid advancement of troops, trucks and AFVs. The primitive and early designs of these apparatus was first tried out in March 1939 on a Cruiser Tank Mk. I, further trials being carried out on a Matilda II tank and a Universal Carrier.

      Development for fitment to the Churchill began in April 1942, the pilot model being tested in July. In the tested prototype, the bracket of the bobbins (2) was simple and fragile, protruding from the central portion of the tank's front glacis.

Churchill Mk III gun tank with primitive carpet layer

      A similar device was also used during the Dieppe raid (Operation Jubilee) and consisted of a two small carpet bobbins fitted between the front horns of a Churchill III.

Canadian Churchill Mk III carpet layer used in Dieppe.
photograph taken by the Germans after the failure of Raid

      The apparatus has proved fragile and unreliable in battle conditions, being redesigned for future applications. The development designation was by type (A through D), and production models were referred to by mark (I through III).

• The Type A was a single and slim bobbin design in a double-fork-like structure, more robust than the first tests used in the raid on Dieppe, but still with a fragile and delicate appearance. The Mark I also known as the T.L.C. for tank landing craft. The Mark I laid a wire-reinforced 2.768 mm wide canvas mat in front of the tank from a horizontal roller mounted on fixed arms. The canvas mat was later replaced by a 3.352 mm wide, 31 m long canvas carpet reinforced by wire and "chespaling" (chestnut palings). Its primary object was to enable wheeled vehicles and infantry to cross barbed wire obstacles. On meeting such an obstacle the weighted free end of the carpet was dropped on to the ground whilst the tank ran on to the free end, and then the carpet automatically unwound itself, so that the vehicle ran over it across the obstacle. On completion of the crossing the spindle device could be jettisoned. Production of this model was completed by the end of 1944.

Churchill Mk II with Type A Mk I carpet layer- first version
Notice the difference in the structural reinforcement of the arms
in the photos below and above.

Churchill Mk IV with Type A Mk I carpet layer- final version

• The Type B was a twin bobbin design using the same twin forks from Type A that deployed two narrow carpets directly under each track, but it was not produced in quantity or used in Normandy. The canvas mats was reinforced by wooden slats. When in motion the spindle unwound a separate carpet under each track. 

Churchill Mk IV with Type B carpet layer.

• The Type C was a single and big design. The Mark II was developed specifically for the circumstances of the invasion, when reconnaissance of the beaches discovered strips of soft blue clay in which vehicles could bog easily. Similar blue clay was found on the beaches of Brancaster in  Norfolk, and tests were done there with a special trials wing of 79th Armoured Division established for that. The solution being a heavier 2.768 mm wide mat of canvas and tubular steel, usually referred to as "shuttering" or "steel shuttering," which required mounting the roller on a girder frame above the turret. In the Mark II, the carpet was 69 meters long.  

  

  Churchill Mk IV with Type C Mk II Bobbin commencing to lay the mat

  
  

  

  Churchill Mk IV with Type C Mk II Bobbin
  the arms of this apparatus were moveables

•  The Type D was a single and big design. In the Mark III, it was nearly 107 meters long, but the larger roller and its weight made the vehicle clumsier, instable and harder to deploy in the beaches.    

  

  Churchill Mk III AVRE with Type D  Mk III Bobbin
  the arms of this apparatus were fixed

  

  the same vehicle of the photo above
  immediately after the carpet being applied

  

  Churchill Mk III AVRE with Type D Mk III Bobbin
  working in the beach

                     In all of the designs, the carpet was to unroll in front of the A.V.R.E. so that it could drive on the carpet as it unspooled. Operating speed was 3,5 to 8 km/h. and the bobbin could be jettisoned by a small charge.  

  

  The empty core of a discarded Type C Mk II Bobbin rests in the sands
  at the Gold beach (Le Hamel)

      At least twenty-four carpet-layers of all types sailed in the assault landing craft, tank (LCT), on D-Day.

      Another specialized tank with similar breed was the log carpet device was also intended for soft ground. It consisted of 3.5 meter-long logs that averaged 15 to 20 centimeters in diameter and were joined by a 5 cms wire cable, and the whole assembly was mounted on a removable steel frame fitted to sockets mounted on the sides of the A.V.R.E.

      To deploy the log carpet, small charges were blown, cutting cables that secured the logs to the frame, which in theory allowed their weight to pull the entire carpet forward off the frame, with the A.V.R.E. following over it as it unrolled. Eleven were employed on D-Day., with relative success.

      These AVREs would carry a crew of 5 and were armed with a Petard 290 mm spigot mortar as well as one 7.92 mm Besa machine gun. Once beyond the problem soil, the AVRE could remove the carpet-laying frame with bobbin, and carry on with its roll of giving transport protection and breaching enemy defenses.

      The AVRE bobbin proved successful, with the main difficulty being durability of the mat they laid, which could only be used a temporary roadway. Reinforced or steel versions of matting were eventually used.

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	Harland and Wolff (A20) Vauxhall Motors (A22)
Manufacturer	Vauxhall Motors
Produced	1941 to 1945
Number built	5,640 approx.
Variants	See family
Specifications
Weight	38.5 long tons (Mark I) 40.1 long tons (Mark VII)
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	For Churchill I-VI: 102 mm hull front, 89 mm hull side, 51 mm hull rear, 89 mm turret front, 76 mm turret side and rear Mark VII-VIII - 152 mm hull and turret front, 95 mm hull sides and turret sides and rear, 51 mm hull rear
Main armament	AVRE: Petard, a 290mm Spigot mortar throwing the 18 kg "Flying dustbin" QF 2 pounder (Mark I and II) QF 6 pounder (Mark III and IV) QF 75mm (Mark VI and VII) QF 95mm (Mark V and VIII)
Secondary armament	Two 7.92mm Besa machine guns 3 inch howitzer (Mark I)
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, two amazing kits from AFV Club: Churchill Mk IV with Type A carpet layer (#35285) and Churchill Mk III with Type D carpet layer (#35274). Will be a construction nearly 100% OOTB with a small gap: I will change the angled turret type Mk III AVRE by a rounded Mk IV AVRE, from my scrap box. Just to do something different ...

The two boxes in my bench...Hurrah!!!

      Starting for the suspensions: war time line production....

Sponsons and suspensions...

First step; installing the bogies.
 The trick is to glue only the inferior portion of the sponson to facilitate
engagement of the bogies in the top of the sponsons

After that, gluing the superior gap in the sponson,
between the boogies. beware to not glue the bogies!!!

Another sponson: the inferior portion is glued and
the superior shows the gap...

In the gap, engagement of the bogies, one by one...

Glued!!  I use dichloromethane as welder...Amazing!!!

The production line...

Done the bogies!!!

Cleaning the parts of suspensions...

Again, production line: transversal parts first

Done in the four sub-assembles...

Time to add more pieces ...

After weld the parts...next step; fit the rocker arms...

Doing....

Almost there...

Wheels...lots of wheels...

On your feet, soldier !!!

No differences, until now...

But now it is possible to know who is the AVRE and who is the gun

Some metal scartch...

Done...

      The tensioning cable for the wadding trunks were very rough and thick. I decided to redo it using acupuncture needles. They are fantastic for this ...

The needles and the plastic parts from the kit (Stretchers)...

Cyanoacrylate. Welding does not adhere to the needles ...

Done in the side wadding trucks...

The rear stretcher...

In place....

Much better...

I filled the large bobbin Mk III Type D to save carpet !!!
Thin plastic...

The AVRE is almost done !!!

The turret AVRE

Testing...testing...

The turret's trunk does not touch the risers ...

Metal welding...

The early girl...

...and the two sisters ready for painting...

The early one...

...and the Normandy girl !!!

      I wanted to play a little with the green tones of these girls: I used primers of different shades (Olive drab and Bronze green) and will work with reversed colors: the girl painted with Olive Drab will characterize with bronze green and painted with bronze-green will characterize with Olive Drab.

The girls with basic colors: Olive drab and bronze green...

       In parallel of painting work, I do the historical research for the models; My girl AVRE will be the LANCER, serving in the 79th Armoured Division (Funnies), 6th Assault Regiment, 82nd Assault Squadron, which landed the LCT 2027 in Gold Beach on June 6, 1944.

      My decals made with Corel Draw and printed by my old (but still functional) Laserjet Color:

above; colors in transparent decal
below: white decal for constrast

      My early girl will be the same of the kit ( based in real pictures...) . Boring, but accurate ....

      The girls with shades of different greens and with Future, to prevent silvering in the decals...

Churchill Mk IV with carpet layer type A

Churchill Mk IV AVRE  with carpet layer type D

Building the long carpet: nice and easy.
I painted the carpet with Vallejo Khaki

The early carpet: paper toilette (adult)
with pva glue + Khaki...

Markings

The girls almost done...

Churchill Mk IV AVRE with carpet layer bobbin ( type D)

Churchill Mk IV with carpet layer bobbin ( type A)

       And finally, the Churchills Bobbins are ready for action.

• Churchill Mk. IV AVRE LANCER - carpet layer type D,  serving in the 79th Armoured Division (Funnies), 6th Assault Regiment, 82nd Assault Squadron, which landed the LCT 2027 in Gold Beach on June 6, 1944.

Churchill Mk IV AVRE  "LANCER" with carpet layer bobbin ( type D)

Churchill Mk IV AVRE "LANCER" with carpet layer bobbin ( type D)
with Kojak and Rover, the dog

• Churchill Mk IV T68090R with carpet layer Mk I Type A in test duties, England, 1943.

Churchill Mk IV with carpet layer bobbin ( type A)

Churchill Mk IV with carpet layer bobbin ( type A)
with Kojak and Rover, the dog.

Bobbins, side by side...

I had forgotten the LCD markings (in chalk) in the  Churchill AVRE.
This was a common practice on D-Day

Thanks, Tommies !!!

See you soon !!!