Panzerserra Bunker- Military Scale Models in 1/35 scale: janeiro 2016

Cruiser Tank Mk.III - A13 Mk.I - case report

Tommies!!!

We will see the building of a vehicle that represents a whole philosophy of armored warfare. The Cruiser tank Mk III - A13 Mk I.

Sorry about the pics, but when I built this little beauty (2009), my digital camera was very primitive. Without further ado, let's to the battle !!!

A13 Mk.I/Cruiser Tank Mk.III in rough terrain...

History:

The cruiser tank (also called cavalry tank or fast tank) was a British tank concept of the inter-war period. This concept was the driving force behind several tank designs which saw action during the WWII. In British use, the cruiser formed part of a doctrine paired with the "infantry tank", a much slower but better armoured design intended to work in concert with the infantry in punching holes through enemy lines for the cruisers to exploit.

MatildaII roaring thru the desert: A typical infantry tank...December, 1940.

Background

Like the ships of the same name, cruiser tanks were intended to be fast and mobile, and operate independently. In this case, the independence was not from other ships in a fleet, but independence from the slow-moving infantry, their heavier infantry tanks, and artillery.

Once gaps had been punched in the enemy front by the infantry tanks, the cruisers were intended to penetrate to the rear, attacking lines of supply and communication in accordance with the theories of J.F.C. Fuller, P.C.S. Hobart, and B.H. Liddell-Hart. The cruiser tank was designed to be used in a way similar to cavalry in its heyday and thus speed was a critical factor, and to achieve this the early cruiser designs were lightly armoured and armed.

This emphasis on speed unbalanced the British designs; on limited engine power, the speed was only possible by sacrificing armour protection (by comparison infantry tanks operating at soldiers' pace could carry far more armour). At the time, the concept of "speed is armor" was considered the overriding concept in the British tank corps (unsurprising considering its birth in the Landships Committee of the Royal Navy, which also applied the concept to the ill-fated HMS Hood).

HMS Hood - Speed is armor concept...

It was not understood at the time that this principle of mobility over all else meshed poorly with the corresponding German policy of trading speed for superior armor and armament, ensuring that even a single round from a German medium tank could easily destroy a cruiser.

An even bigger problem for most cruiser tanks was the small calibre of their main gun. The first cruisers were armed with the QF two-pounder (40mm) gun. This gun had adequate armour penetration against early war tanks, but was never issued high explosive ammunition. This made the cruisers less able to deal with towed anti-tank guns.

The breech of the 2pdr. gun in a Valentine turret.
A small gun...

However, as fighting enemy tanks was part of the projected role of the cruiser tanks, they were the first to be upgraded to the heavier 6 pounder (57mm) gun when it became available, and a great deal of effort was put into developing cruiser tanks armed with the powerful 17 pounder QF (76,2 mm) gun when it became available. The Cromwell itself had too small a turret ring for a high powered gun - and carried a general purpose QF 75mm gun - but benefitted from a high power engine giving it a maximum speed around 64 Km/h on roads.

Cromwell cruiser tank at full throttle ... Weeeeee!!!
Notice the 75mm gun

It was the following tank design in the British cruiser line, the Comet tank with a shortened 17 pdr, that entered service late in the war. As the UK had large numbers of US M4 Sherman tanks, the conversion of the Sherman to take a 17pdr (as the Sherman Firefly) proved effective in providing more 17pdr gun tanks.

Sherman Firefly sporting (proudly) your big 17pdr. gun

Ironically, despite the emphasis on high mobility, most cruisers were plagued by mechanical unreliability, most noticeably the Crusader tank in the hot and gritty desert of the North Africa Campaign. This problem was usually caused by insufficient development as most of the early cruiser tank designs were ordered "off the drawing board" in order to bring them into service as quickly as possible and was not fully solved until the debut of the Cromwell tank in 1944, with its powerful, reliable Rolls-Royce Meteor engine (derived from Rolls-Royce Merlin).

History - Interwar:

In 1936 the British War Office designated two different kinds of tanks for future development: heavily armoured infantry tanks to be used in close co-operation with infantry during attacks, and fast mobile cruiser tanks (replacing the older "medium" class) designed to move quickly through enemy territory.

In 1934 Sir John Carden of Vickers-Armstrong produced a new medium tank, the A9, using elements of the Medium Mk III design (which had been abandoned due to financial reasons) but lighter and using a commercial engine so it could be produced at lower cost. It was subsequently accepted as an interim design for limited production as the A9 Cruiser Tank Mark I. It was expected to be replaced by a Christie suspension design. In 1937–1938, 125 examples of the A9 were produced.

A9 cruiser Mk I prototype - 1935

A damaged A9 Cruiser Mk I CS abandoned in Calais, 1940.

The A9 was lightly armoured but capable of 40Km/h and carried a QF 2pdr (40 mm) gun that was effective against current tanks.

At the same time as the A9, the A10, was also designed by Carden for use as an infantry tank. Built on basically the same design but with added armour plate to give 30 mm of protection. It was realised that it was insufficiently armoured for the role. Under "heavy cruiser" designation, it was put into production in July 1938 as another interim design. It had the same armament as the A9 and was the first to be equipped with the Besa machine gun. A total of 175 Mk IIs were produced by September 1940.

A10 cruiser Mk II "heavy tank" prototype - 1936.

A10 cruiser Mk II "heavy tank" operational in desert - 1941

Combat experience of the A9 during the Battle of France in 1940 was to reveal several shortcomings, including inadequate armour and a lack of space for the crew, but it nevertheless saw useful service in the Western desert in 1941. The A10 saw action in France, North Africa and Greece.

Orders for the Mk I and Mk II Cruisers were restricted, since the British Army had decided to produce a more advanced and faster cruiser tank which would incorporate the Christie suspension designed by American inventor J. Walter Christie and have better armour.

In 1936, General Martel, a pioneer in tank design who had published works on armoured warfare and pioneered the lightly armoured "tankette" to enhance infantry mobility, became Assistant Director of Mechanization at the War Office. Later that year Martel had witnessed Soviet tanks at the Red Army's autumn manoeuvres including the BT tank, which had they had developed from Christie's work.

BT-2 russian Christie light tank

He urged the adoption of a tank that would use the suspension system and also follow Christie's practice of using a lightweight aircraft engine such as the Liberty Engine or a Napier Lion. The government authorized purchase and licencing of a Christie design via the Nuffield Organization.

The Christie A13E1 tank prototype

The tank - given the identity A13E1 (see above) - was very rudimentary and too small for British use, but the suspension was very effective and this became the basis of the Cruiser Mk III (A13). Following testing of two Nuffield-built prototypes (A13E2 and A13E3), the A13 was ordered into production and a total of 65 were manufactured by mid-1939.

A13E2 prototype

A13E3 prototype

The Mk III weighed 14.2 t, had a crew of 4, a 340 hp engine which gave a top speed of 48 km/h and was armed with a 40 mm 2 pounder gun and a machine gun. However, when it was introduced into service in 1937, the Army still lacked a formal tank division. The trackless element of the Christie suspension was discarded as adding little value for the extra complexity.

A13 Mk I cruiser tank MkIII

The Cruiser Mk IV (A13 Mk II) was a more heavily armoured version of the Mk III. Production started in 1938.

A13 Mk II cruiser tank MkIV

History - World War II:

During early World War II, the Crusader was probably the best-known cruiser, it was first used in mid 1941 and thereafter used in large numbers in the Western Desert Campaign. The contemporary Covenanter was unreliable and was retained in the UK for training use.

Crusaders in desert - the crews are having a nap time...

Covenanter in training in England

The Cavalier, Centaur and Cromwell came out of the planned successor to the Covenanter and Crusader.

Cavalier cruiser tank with 6pdr. gun

Intended to be in production by 1942, the project was delayed and the Crusader was upgunned as an interim measure with 6 pounder gun.

Crusader Mk III with 6pdr Mk III gun

Crusader Mk III with 6pdr Mk V gun

Cavalier was a development of Crusader. Centaur and Cavalier used a Nuffield Liberty petrol 410 horsepower (310 kW) engine and Cromwell the new Rolls-Royce Meteor V12 petrol 600 horsepower (450 kW).

The Centaur and Cromwell saw action from the Invasion of Normandy onwards. The Comet was a development of the Cromwell using a modified 17 pounder gun and was fielded in the beginning of 1945. By this point in the war, the firepower and armour protection of the cruisers made them indistinguishable from medium tanks.

Comet cruiser tank

In the course of the war, technological improvements enabled heavier tanks to approximate the speed of the cruisers and the concept became obsolete. The last of their line was the Centurion. The Centurion was designed to satisfy the "Heavy Cruiser" criterion by combining the mobility of a cruiser tank and armour of an Infantry tank in one chassis.

Centurion heavy cruiser tank

This idea - and the Centurion along with it - then evolved into the "Universal tank" concept, a design that could "do it all". Ultimately, the Centurion tank transcended its cruiser tank origins and become Britain's first modern main battle tank.

History of the A13 Mk I - Tank, Cruiser, Mk III:
It was the first British cruiser tank to use the Christie suspension system, which gave higher speeds and better cross-country performance; previous models of cruiser tanks had used triple wheeled bogie suspension.

Design and development:

British cruiser tank design began with the Mk I and somewhat heavier Mk II in the mid-1930s. Just as prototypes were arriving in 1936, General Giffard LeQuesne Martel, a pioneer in tank design who had published works on armoured warfare and pioneered the lightly armoured "tankette" to enhance infantry mobility, became Assistant Director of Mechanization at the War Office.

General Giffard LeQuesne Martel
10-oct.-1889
03-sept-1958

Later that year, Martel witnessed demonstrations of Soviet tank designs, including the BT tank, which had been influenced by American J. Walter Christie's work. Martel urged the adoption of the Christie suspension and Christie's practice of using a lightweight aircraft engine, such as the Liberty Engine. The government authorized the purchase and licensing of a Christie design via the Nuffield Organization, rather than contact the Soviet authorities.

The vehicle obtained from Christie became the basis of the Cruiser Mk III (A13). It had to be extensively redesigned by Morris Commercial Cars as it was too small and had several faults that Christie had not addressed. A new company Nuffield Mechanization & Aero Limited was formed for the development and production of the design.

At a meeting of the General Staff, an official specification was determined, which included 30 mm (1.2 in) armour, a 2-pounder gun and a road speed of 48 km/h. A subsequent review of the specification by Martel and Percy Hobart approved 30 mm armour all round provided cross-country speed could be kept at 25 miles per hour (40 km/h). Pending the delivery of the A13, an interim design was approved from the A7, A9 and A10, the A9 being selected. Orders for the resulting Mk. I's were limited pending the arrival of the A13.

Sir Percy Cleghorn Stanley Hobart
14-Jun.-1885
09-Feb.-1957

The first prototype (A13-E1) was delivered in 1937. Following the testing of two prototypes, the A13 was ordered into production. The original order was for 50 tanks and 65 had been built by mid 1939. The Mk III weighed 14 long tons (14 t), had a crew of four, a 340 horsepower (250 kW) engine and a top speed of 48 km/h and was armed with a 2 pounder gun and a machine-gun. When it was introduced into service in 1937, the army still lacked a formal tank division.

Combat history:

Like most British cruisers, the A13 was fast but under-armoured and mechanically unreliable. As part of the British Expeditionary Force sent to France, the Cruiser Mark III equipped units in the 1st Armoured Division but most were lost.

An A13 Mk.I/Cruiser Tank Mk.III from 1st. Armoured Division
captured by Germans - June, 1940

A few were used in Greece and in the Western Desert 1940–1941 (Libya), where they equipped units of the 7th Armoured Division. The design was used as the basis for the Cruiser Mk IV.

Specs:

Tank, Cruiser, Mk III (A13 Mk I)

Type	Cruiser tank
Place of origin	United Kingdom
Service history
In service	1938–1941
Used by	British Army
Wars	Second World War
Production history
Designer	Morris Commercial Cars
Designed	1936/1937
Manufacturer	Nuffield Mechanisations & Aero, Limited
Produced	1938–1939
Number built	65
Specifications
Weight	14 Long tons (14.2 tonnes)
Length	6.0 m
Width	2.54 m
Height	2.59 m
Crew	4 (comm., gunner, loader, driver)

Armour	6–14 mm
Main armament	QF 2-pounder gun 87 rounds
Secondary armament	.303 Vickers mg 3.750 rounds
Engine	Nuffield Liberty V12 petrol - 340 hp (250 kW)
Suspension	Christie
Operational range	140 km
Speed	48 km/h

The kit:

I used the Bronco Models kit (CB-35025) in 1:35 scale. The box is large and made of a cardboard a little thin for my taste. Presents a fine illustration of a Mk III in combat. Pity that the figure of the Commander is not included...

Box art

The content: parts packed in individual term-sealed bags...

The kit in the box...

When the kit was release and read first reviews, I was made aware of the problem with tracks that was too tight in the tank ... Lets confirm this...Uops... As Scarlett O'Hara said: "Tomorrow. I think about this ..."

Oh, crap...Short!!!

The vinyl tracks...

PE inherent to the kit. Involved in a double plastic film and very, very thin...

Booklet cover...

...and schemes...But the booklet is awful !
Confusing instructions out of order ...

Great decal sheet... 3 versions.

1st Option: A13 Mk.III - B Squadron, 3rd. Royal Tank Regiment, 1st Armoured Division, BEF, France 1940.

2nd Option: A13 Mk.III - 2nd Royal Tank Regiment, 3rd Armoured Brigade 1st Armoured Division, France 1940.

3rd Option: A13 Mk.III - 4th Hussars 1st Armoured Brigade UK 1940 (Acting as enemy on excercise).

Starting by the lower hull, by the book:

The plastic is soft and good to work...

Alignment of the suspension's armor.
The arrows point to drive sprocket axes

The upper-hull in place... See the white marks in the plastic,
due to warping of the upper-hull

Chassis done..

Rear plate...

Reinforcing the joints...

Using the PE's...

Testing the drive sprockets in place, in dry-run...

Driver's station...

Exhaust tubes..Very well!

Here, a little trick: Indent the holes of the idler-wheel mounting in 2 mm, to minimize the vinyl track's lenght problem...

On your feet, Soldier !!!

Testing,,. testing...

Too tense...deforming the drive-sprocket and the track.
I will dip the track in boiling water and stretch it there while it's hot
I'll get a few more millimeters with this technique ...