4,7 cm PaK (t) (Sfl.) auf Fahrgestell Panzerkampfwagen 35R 731(f) – this photograph clearly shows the junction between the new angular superstructure and the original rounded hull. Source: panzerserra.blogspot.com, edited.

The Renault R-35 Tank

When Germany invaded France in May 1940, it took on one of the world's greatest tank powers, a nation fielding over six thousand tanks of various types. A substantial portion of that arsenal consisted of Renault R-35 light tanks, of which around 1,600 were in service. Roughly half of these fell into German hands after France's capitulation. At first glance this might seem like an impressive haul, but in truth the Renaults made very little impression on their new owners.

The Renault R-35 had been designed as an infantry support tank, and its characteristics reflected that role – most notably its top speed of just 20 to 23 km/h. That was perfectly adequate for keeping pace with foot soldiers, but the Germans practised a very different style of armoured warfare, one that demanded speed (for comparison, contemporary versions of the German Panzer III and Panzer IV could reach around 40 km/h). The French tank's armament was also considered very weak by German standards – judge for yourself: the French 37 mm S 18/21 gun could penetrate 15 mm of sloped armour at 400 metres, while the German KwK 36 of the same calibre punched through 29 mm of sloped armour at 500 metres.

Perhaps the biggest drawback of the captured vehicle in German eyes was its two-man crew. The only genuinely attractive feature of the Renault R-35 was its 40 mm frontal armour – but that was nowhere near enough of an advantage to offset all the other shortcomings. In short, the Germans had acquired 800 "new" tanks but were frankly unsure what to do with them. Only 131 were kept in their original configuration: these were fitted with German radios and some received new commander's cupolas. Designated Panzerkampfwagen 35R 731 (f), they were never used as front-line tanks but assigned to various police and security units, primarily in occupied France and possibly also in the Balkans. A number likely ended up in Russia with anti-partisan formations as well.

Tank destroyer on the Renault R-35 chassis – note the canvas tarpaulin pulled over the otherwise open roof of the fighting compartment. Source: worldwarphotos.info, with the permission of the site operator, edited.

In preparation for the planned invasion of Britain (Operation Sea Lion), the ex-French tanks were used in experiments involving waterborne transport and the landing of heavy armoured vehicles. They were also widely used for training new crews – among those who trained on these machines were the tankmen of the 21st and 23rd Panzerdivisionen. A further 250 R-35s were converted in late 1940 and early 1941 into turretless artillery tractors, designated Mörserzugmittel 35R (f), which subsequently saw extensive use on the Eastern Front.

A New Tank Destroyer

What concerns us in this article, however, is a very different conversion of the original Renault R-35 – one with the somewhat unwieldy designation 4,7 cm PaK (t) (Sfl.) auf Fahrgestell Panzerkampfwagen 35R 731(f). The more knowledgeable reader will already have gathered from that name that this was a self-propelled anti-tank gun, or tank destroyer. The idea behind it was actually quite logical. In their original form, the Renault R-35 tanks had no future. The only way to give them meaningful combat value was to rearm them with a far more powerful weapon. As for the tank's low speed, the designers arranged things so that it would not be a disadvantage. The new tank destroyer was intended to equip non-motorised infantry divisions – formations in which the original French tank was essentially right at home, and the same applied to the tank destroyer built on its chassis. In that context, the vehicle's modest speed was no problem at all.

The army submitted its requirement for a new fighting vehicle to the Waffenamt on 23 December 1940. The Waffenamt in turn approached the firm of Alkett (Altmärkische Kettenwerk GmbH) and commissioned a detailed design and a prototype. Alkett was not chosen at random – by that time the company was already series-producing the structurally very similar Panzerjäger I tank destroyer.

Prototype and Production

The first prototype of the new vehicle was completed on 8 February 1941. For cost reasons, it was built using mild, non-armoured steel plate throughout.

Tank destroyer on the Renault R-35 chassis – note the tarpaulin supports erected above the fighting compartment. Source: panzerserra.blogspot.com, edited.

After brief army trials, the prototype was demonstrated to Hitler himself on 31 March 1941, by which point an order for 200 vehicles had already been placed. The first 30 were to be delivered during April, with the remainder to follow by the end of August. The Führer evidently had no objections. Series production was naturally entrusted to Alkett, which had been preparing for it since February. Even so, the first production batch was not completed on schedule – not a single vehicle was delivered in April 1941, but in May 93 rolled out of the factory at once. Production then continued until October of that year, when the final 19 machines were completed. Of the 200 vehicles ordered, 174 were finished as standard tank destroyers and 26 as special command vehicles without artillery armament.

Design Description

Converting the original French tank into a German tank destroyer was not actually all that complicated. The chassis and hull, together with all internal components, were taken over virtually unchanged. Each side of the running gear therefore retained five road wheels, a front drive sprocket, a rear idler and three return rollers supporting the upper run of the track. The front road wheel was independently sprung, while the remaining four were paired into bogies. Suspension was provided by horizontally mounted rubber springs. The road wheels themselves were also fitted with rubber tyres to dampen vibration and noise. The tracks were 26 cm wide, each consisting of 126 relatively small links.

The hull was bolted together from several cast sections. Armour thickness was 40 mm on the front and sides and 32 mm at the rear (some sources give the frontal figure as 43 mm). The hull roof was 25 mm thick and the floor of the hull tub 10 mm. The internal layout of the hull broadly followed German practice, with the engine at the rear, the fighting compartment in the middle and the transmission at the front. Both the engine and the gearbox were located on the right-hand side of the hull, and the driveshaft connecting them ran along the right side of the fighting compartment. This general arrangement closely resembled that of the German Panzer II light tank.

Renault R-35-based tank destroyers on coastal patrol duty in France. This photograph provides a particularly clear view of the support struts beneath the raised rear section of the superstructure. Source: Flickr.com, with the permission of the publishing user, edited.

Power came from a Renault 447 four-cylinder petrol engine of 5.9 litres displacement, producing a maximum output of between 82 and 85 horsepower. As already noted, the engine was mounted at the rear on the right-hand side. To its left sat the radiator and fuel tank, which held 166 litres of petrol (though figures of 150 and 168 litres are also sometimes quoted). The gearbox, offering four forward speeds and one reverse, was located in the right-hand front section of the hull. To its left was the driver's position; he steered the vehicle using a pair of brake levers and a conventional three-pedal arrangement (brake, clutch, throttle). Directly in front of him was an instrument panel with the main gauges, observation visors and the entry hatch – more on that shortly.

The first step in converting the tank into a self-propelled gun carrier was, of course, removing the turret. The circular opening left in the hull roof was then enlarged, and a new floor was most likely installed beneath it. The armoured superstructure that the Germans fitted in place of the original turret naturally had a matching cutout in its own floor. This allowed the gun crew to stand with their feet relatively deep inside the hull, meaning the new superstructure did not need to be particularly tall. The superstructure overhung the hull roof on all sides, which provided a reasonably generous interior for both the gun and its crew. There was also a raised rear section that extended over the engine compartment and reached almost to the back wall of the hull.

This raised rear section of the superstructure served as the ammunition stowage space for the gun. Since it carried a considerable weight, the designers sensibly supported its far end with three bracing struts. The raised rear section with its ammunition was the only enclosed part of the superstructure – the rest of the roof was open to the sky. In bad weather, the crew could erect supports from strip steel above the fighting compartment, stretch a waterproof tarpaulin over them and secure it with straps to the fixing points on the walls of the superstructure.

A close-up view of the driver's hatch cover and the 4.7 cm Pak 38(t) gun. Source: Flickr.com, with the permission of the publishing user, edited.

As already mentioned, the hull of the original French tank was not welded from flat steel plates but cast, giving it rounded contours – and this caused the engineers at Krupp no small amount of headaches. The German superstructure, by contrast, was welded from flat armour plate, making it far from straightforward to mount securely on a curved hull. The superstructure therefore required additional welded protrusions on its underside to conform to the rounded shape of the hull beneath it, which inevitably added to production costs (this is nicely visible in the photograph HERE). The front wall of the superstructure was 25 mm thick and the sides 20 mm. Both side walls featured fairly large entry doors that opened toward the front of the vehicle. Immediately below each door was a step to assist the crew in climbing aboard.

In the forward section of the superstructure, the anti-tank gun was mounted on a pedestal bolted to the roof of the original hull. The mounting provided a traverse of 35 degrees (17.5 degrees either side of centre) and elevation from -8 to +10 degrees. The opening in the front wall of the superstructure for the gun barrel naturally had to be large enough to permit the full range of movement. The gap around the barrel was safely covered by a second layer of armour attached directly to the weapon – in other words, a gun shield. To the upper left of the barrel opening was a second, closable aperture for the gun sight.

The 4.7 cm Pak 38(t) Gun

The main armament of the new tank destroyer was the 4,7 cm Pak 38(t). As the letter in brackets suggests (t = tschechisch, meaning Czech), the gun was originally a Czech – or more precisely, Czechoslovak – weapon. In the autumn of 1938, the Czechoslovak Army had ordered 132 examples of this new gun from the Škoda works, at the time designated the 47 mm KPÚV vz. 38 (KPÚV standing for kanon proti útočné vozbě, or anti-tank gun). Before the first batch was completed, however, the Czechoslovak Army had ceased to exist, and the contract was taken over by an entirely different customer – the German Wehrmacht. The captured weapon significantly outperformed the German 3.7 cm Pak 36, so it comes as no surprise that the Germans incorporated it into their arsenal without hesitation and continued production.

A pair of 4,7 cm PaK (t) (Sfl.) auf Fahrgestell Panzerkampfwagen 35R 731(f) tank destroyers; the vehicle on the right has its gun sight cover slightly open. Source: worldwarphotos.info, with the permission of the site operator, edited.

The gun barrel measured 2,040 mm in length, approximately 43.4 calibres (hence the German designation L/43.4). Aiming was accomplished via a monocular sight with 2× magnification and a 30-degree field of view. The standard anti-tank round was an armour-piercing shell weighing 1.65 kg, which left the muzzle at 775 m/s. The Germans designated this ammunition Pz.Gr. 36(t) (Pz.Gr. = Panzergranate). At 1,500 metres it could penetrate 35 mm of sloped homogeneous armour, at 1,000 metres it dealt with 41 mm, and at 500 metres it defeated 48 mm (though significantly different figures are sometimes quoted). Also available was a high-explosive fragmentation round for use against soft targets, and from 1940 onwards a sub-calibre round, the Pz.Gr. 40, with a tungsten core capable of penetrating 59 mm of armour at 500 metres.

The new German tank destroyer – the 4,7 cm PaK (t) (Sfl.) auf Fahrgestell Panzerkampfwagen 35R 731(f) – weighed approximately 11 tonnes, only about 600 kg more than the original Renault R-35. From this it can be inferred that the tank destroyer's driving characteristics were very similar to those of the original tank: a top speed of around 20 km/h, a road range of approximately 140 km and a cross-country range of only 80 km.

The Crew

The vehicle was crewed by three men: a driver, a loader and a gunner who also served as commander. The driver sat alone in the left-hand forward section of the hull, with the two-part entry hatch directly in front of him. The upper section of this hatch incorporated his main observation visor. When there was no immediate danger – for example during road marches away from the combat zone – the driver could open the entire upper section of the hatch cover and enjoy an essentially unobstructed view. In more hazardous conditions he could close the hatch and open the visor cut into it. And if things were really getting lively and shells were flying all around, he could close even that visor and peer out through a narrow slit. Should the slit not give him a view of where he needed to go, there were two additional slits on either side of the entry hatch. The commander/gunner and loader had their positions in the armoured superstructure beside the gun; they observed from the vehicle either simply by looking over the top of the superstructure walls, or somewhat more safely through retractable periscopes (photo HERE). On the left side of the superstructure was a FuSprGer "a" radio set with a voice range of approximately 2 to 3 km. The rod antenna was mounted externally on the left side armour panel.

The command version featured a Kugelblende 30 ball mount in the front wall instead of the gun, borrowed from the Panzer III tank – though the MG 34 machine gun itself is absent in this photograph. Source: panzerserra.blogspot.com, edited.

Command Versions

Alongside the standard combat vehicles, a number of special command versions were also built, known as the Führungs-Fahrzeug. These were intended for company commanders and for battalion headquarters. The command vehicles were not fitted with the anti-tank gun; instead, the opening in the front armour was modified to accept a Kugelblende 30 ball mount for an MG 34 machine gun, borrowed from the Panzer III. The gun had to be removed to make room for an additional radio set and other equipment. No source, however, specifies what radio configuration the command vehicle actually carried. It is also somewhat puzzling that no photograph shows more than a single antenna – always just the one.

Organisational Structure

As already noted, the first 93 vehicles of the new tank destroyer type were delivered by the end of May 1941, a mix of combat and command machines. By June 1941 the Germans had enough of both to equip the first three units. The fortunate recipients were tank destroyer battalions (Panzerjäger-Abteilung) numbers 559, 561 and 611. Each battalion received 27 combat vehicles and 4 command vehicles. A tank destroyer battalion consisted of a headquarters, a signals platoon and three combat companies (Kompanie), each company fielding 9 tank destroyers – accounting for the 27 combat vehicles per battalion. On 19 June 1941, a training company was also formed, the Panzerjäger Ersatz Kompanie (Sfl.) 35R(f). This company was subordinated to the 43rd training battalion (Panzerjäger Ersatz Abteilung 43) and was responsible for training crews on the new type of tank destroyer.

Combat Deployment

All three tank destroyer battalions mentioned above took part in Operation Barbarossa in June 1941. The 559th was assigned to the LVI. Armeekorps (56th Army Corps), which was part of Panzergruppe 4 under Army Group North. The 561st was attached in reserve to the 9th Army, under Panzergruppe 3 of Army Group Centre. The 611th was allocated to the XLVII. Armeekorps (47th Army Corps) of Panzergruppe 2, also under Army Group Centre.

Command version, here shown with the machine gun fitted (though it is barely visible). Source: Flickr.com, with the permission of the publishing user, edited.

How did the new vehicles fare on the Russian front? According to the first combat reports, it was nothing short of a disaster. As early as 5 July 1941, the commander of Panzerjäger-Abteilung 611 reported that all the "French" tank destroyers were write-offs due to severe mechanical failures. The other battalions fared no better and soon had to revert to towed anti-tank guns. Similar experiences were reported from the Eastern Front by other units that received these vehicles later and endured the first Russian winter with them. Complaints centred on weak engines, tracks wholly unsuited to icy terrain, and the rapid freezing of road wheels, engines and batteries. One might wonder why such fundamental faults were not discovered during testing of the first prototype – most likely because those trials took place in France, not the Soviet Union.

Based on these hard-won lessons, German high command decided not to deploy the vehicles on the Eastern Front any further and to keep them as a reserve in Western Europe. In practice, they continued to serve mainly for training and guard duties in occupied France. Their losses consequently fell sharply, and a December 1943 report still counted 92 tank destroyers of this type, 88 of them in serviceable condition. After the opening of the Western Front, some of these tank destroyers apparently entered combat (or at least left their barracks). The literature offers no details, but photographs survive – taken by Allied soldiers in both France and the Netherlands – showing abandoned or knocked-out examples.

One particularly well-documented wreck is that of the tank destroyer bearing the turret number 211, which Canadian soldiers came across near the Dutch town of Vught. The vehicle had apparently become bogged down in sandy ground, and during attempts to free it under its own power, the right track snapped. The crew were unable to resolve the situation and decided to abandon their vehicle – but in keeping with the principle of leaving nothing useful to the enemy, they first ensured the gun was rendered unserviceable. They drained the fluid from the recoil mechanism and then fired one last round, which destroyed the weapon.

A 4,7 cm PaK (t) (Sfl.) auf Fahrgestell Panzerkampfwagen 35R 731(f) on patrol somewhere in France. Source: panzerserra.blogspot.com, edited.

On paper, converting ex-French tanks into self-propelled guns seemed a reasonable proposition; in practice, it proved the truth of the old adage that you get what you pay for. The 4,7 cm PaK (t) (Sfl.) auf Fahrgestell Panzerkampfwagen 35R 731(f) was not a successful fighting vehicle. What failed was not the new armoured superstructure, nor the gun, but the Renault R-35 chassis itself. It is therefore rather ironic that on 30 July 1941 – by which point the Eastern Front had already exposed the vehicle's fundamental problems – the Waffenamt asked Alkett to build a prototype of the same tank destroyer armed with the more powerful 50 mm Pak 38 gun. The original order already anticipated a weight increase of approximately 500 kg for such a vehicle, which would only have placed additional strain on the already overstressed engine and worsened an already poor cross-country performance. Whether this prototype with the heavier gun was ever actually built unfortunately remains unknown.

Technical Data

ARTICLE
CONTENTS:

THE RENAULT R-35 TANK

A NEW TANK DESTROYER

PROTOTYPE AND PRODUCTION

DESIGN DESCRIPTION

KANON 4,7cm Pak 38(t)

THE CREW

COMMAND VERSIONS

ORGANISATIONAL STRUCTURE

COMBAT DEPLOYMENT

TECHNICAL DATA