Author: Vollketten (US forums)
Today, we have another guest article by Vollketten. Enjoy!
I’ve been running a thread with a suggested Italian tech tree on the NA forum for some time and have occasionally put out an article of the TOG and Matilda tanks so I thought I would share with the FTR record the details of what was Italy’s best tank to see service in WW2.
In December 1938 a heavy tank (a vehicle weighing over 20 tonnes) for the Royal Italian Army (Regio Esercito) was called for in Troop Regulations. It was envisaged to be armed with a 47mm gun of 32 calibers and two 8mm machine guns to work with the standard ‘M’ series tanks but to be of the 20 to 25 tonne range with a top speed of 32 kmh. Very quickly though it was apparent that the 47/32 gun wasn’t going to cut it as the main gun on this tank so by July 1940 new characteristics was chosen. It was to be increased in weight up to about 32 tonnes, maintain the same top speed but be armed with a 75mm gun with a coaxial 20mm cannon and either machine gun fixed in the hull and/or a secondary turret mounting machine guns.
In October 7th 1940 Marshal Graziani chief of staff publishes a note of Mussolini’s (From July 1940 demanding production of a 75mm gun armed tank with approval of this tank to weigh 28 tonnes on 7th August 1940) calling for the construction of 500 tanks armed with a gun of 75/18mm (or a 75/34 Ansaldo gun) and a coaxial 20mm Breda cannon. It was to have a 330hp Ansaldo diesel engine and a top speed of 40kmh. This prototype became known as the P.75.
The initial design (below) under the (then) Italian nomenclature of P.75 (P=’Pesante’ meaning Heavy and 75 being the gun calibre, later the number was to mean the design year) The designers appear to have been strongly influenced by the German Neubaufahrzeuge in the initial phase but later revised the design significantly.
Above a slightly revised P.75 with the large hull gun replaced and the rear turret removed has shortened the hull allowing for a single rear road wheel instead of a double wheel unit. Doing this allows for much better gun depression at the back of the vehicle.
However with the increases in armour and weight necessitating a larger engine this was reversed by the time of the later prototypes. The turret design however maintained a good degree of elevation and depression.
A wooden mock up was prepared by Ansaldo some time at the end of 1941:
But was already evolving in the P.40 we know in the form of the second prototype:
Before it could go into production though the prototype had to go through many modifications in particular to the rear of the hull and to the turret which was still at this time retaining the coaxial 20mm cannon. The initial plan to use a 330hp diesel engine was replaced with a petrol engine delivering 420hp. The Royal Italian Army Supreme Command however still favoured production under licence of the Panzer IV but eventually yielded to pressure and the first 500 P.40’s were ordered on the 22nd April 1942. This was increased to 579 in October.
Prototype mounting 75/18 (coaxial 20mm cannon has been abandoned)
Upgunned mounting 75/32
Testing of the armour took place in August 1942 and serial production was due to begin in November 1942 as it was officially adopted on 22nd November 1942. However delays from the SPA factories caused by allied bombing meant that production did not begin until May 1943 with an order for 1200 vehicles but by the time of the fall of Italy on the 8th September 1943 only 21 vehicles had been completed.
Production version P.40
The production version maintained the prototypes suspension system of four double wheeled suspensions units using semi-elliptical leaf springs. This system was common to many Italian tanks of the era and was found to be robust and reliable giving good cross country performance. Why reinvent the wheel right?
The transmission system gave 5 forward and a single reverse gear with two universal joints and the ratio 1:8.53. The braking system was actuated by compressed air and the turret was electrically rotated. (The Italians fielded one of if not the first tank to use an electrical turret traverse)
Fitted with episcopes for vision an internal intercom system and the Marelli RF1CA radio the vehicle was a sound design incorporating many of the lessons of the war up to that date. At some point consideration was given to the use of a Maybach HL-120 440 hp engine for the P.40 which would have given it a power to weight ratio of 16.9hp/tonne.
The armour of the P.40 was well sloped having clearly been inspired by the Italian lessons fighting against the Soviet T-34s in Russia with their own very outclassed 5 tonne light tanks. A captured T-34 had been shipped to Rome for study.
Speed: 40 kmh
Ground pressure: 0.940kg.cm2
Pignato describes the armour as having been made from ‘special’ armour plates bolted to internal rigid steel plates with added angled bars strengthening the armor plated-floor. Which suggests a mix of high hardness armour plate fastened to softer metal underneath.
Front: 50mm at 70 degrees (rounded gun mantlet is an additional 50mm thick) So 100mm total.
Top: 20mm at 8 degrees
Sides: 45mm at 85 degrees
Rear: 45mm at 70 degrees
Upper Glacis: 58mm at 45 degrees
Lower Glacis: 30mm at 10 degrees
Nose: 45mm at 45 degrees
Lower front hull: 45 mm at 52 degrees
Upper Side: 45mm at 55 degrees
Lower Side: 40mm at 80 degrees
Rear hull: 40mm at 80 degrees
Rear Upper: 40mm at 80 degrees
Rear Lower: 40mm at 50 degrees
There was even a 16 wheel 4 axle heavy trailer 14 metres long which reached prototype stage for the haulage of this tank made by the firm of Viterbi:
At the same time that the P.40 was being developed though and partially as a result in delays in the production of a newer more powerful vehicle under the designation P.43 was already under development. This vehicle was to feature a 480hp engine and with frontal armour between 80 and 100mm thick, armed with a 90mm gun and weighing about 35 tonnes with a power to weigh ratio of 14hp/tonne.
The P.43 was due to be ready in October 1943 and an order for 150 copies had already been placed. A further improvement still was also under development known as the P.43 bis which was to feature a 105mm gun but due to Italy’s capitulation neither the P.43 nor the bis version ever came to be. But that is another story.
After the fall of Italy on 8th September 1943 the Germans continued the production of the P.40 at the Ansaldo works in Genoa producing another 101 vehicles although about of 40 of which were never fitted with engines and were relegated to either being buried as bunkers or having their turrets removed and used as part of defensive positions in Italy. A number of being fitted the German 7.5cm KwK 40 gun.
Above: P.26/40 (P.40) turret fitted with 7.5cm German KwK 40 and another fitted onto a concrete bunker. The second turret is noteable because it is all welded and fitted with a covers over the side vision port
Those which were operational were designated Panzerkampfwagen P40 737 (I). One was certainly sent to Kummersdorf for testing an inspection where it is believed to have formed a company with a Pz VI, A tiger II, two M4 Shermans, a Jagdpanzer VI Jagdtiger to engage advancing soviet forces in early April 1945.
Above: P26/40 on display at Kummersdorf proving grounds possibly October 1943.
Today surviving examples are on display at the Museo Storico della Motorizzazione Militare in Rome albeit with no engine and the School of Italian Cavalry in Lecce which is in running order. (Ironically this one has a 190hp diesel engine fitted to it reportedly giving it performance cross country comparable to that of a Leopard 1)
My old thread at: http://forum.worldoftanks.com/index.php?/topic/200193-italian-tanks/#top
Circular 7/873 / 10.3.1.4 dated 22nd November 1942
Hitler’s Italian Allies:Royal Armed Forces, Fascist Regime, and the War of 1940–43 by MacGregor Knox
Italian Medium Tanks in Action by Nicola Pignato
Italian Armoured Vehicles of WW2 by Nicola Pignato
Italian Medium Tanks 1939-45 by Battistelli