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German/Czech Panzerjager 38(t) fur 7.62cm 

PaK36(r), Sd.Kfz.139, "Marder III", Part 1 

 
 

Picture 1: 
During the 1930's, 
Czechoslovakian 
industry continued to 
develop its healthy and 
robust tank design and 
construction program. 
By 1938, the Czechs 
began production of a 
new more advanced 
light tank, the TNHP-S 
LT vz.38, designed and 
manufactured by the 
Ceskomoravská-Kolben-
Danek company (CKD), 
located in Prague. But, 
before the first vehicles 
could be delivered to 
Czech troops, the 
country was annexed 
into the German 
Republic in March '39, 

and the German Wehrmacht confiscated the first ten tanks that had been built. It didn't take German officials long to realize 
the importance of this excellent little Czech tank and the special abilities of the industry that produced it. As a result, 
construction of Czech light tanks continued with German supervision in the same CKD/Praga factory that was then 
renamed BMM (Böhmisch Mährische Maschinenfabrik AG). Not only was the new light tank-- now officially known by 
the Germans as Panzerkampfwagen 38(t), shortened to Pz.Kpfw.38(t)-- kept in production at BMM through 1942, but the 
chassis was also utilized as the basis for a couple of vehicle conversions, including a few tank hunters/destroyers.  
 
One of these Pz.Kpfw.38(t) tank conversions is the subject of these two web pages, a conversion known as the Marder III 
with 7.62cm gun, seen in this photograph. This vehicle used the 38(t) tank chassis without its turret, and instead mounted a 
1936 Russian 7.62cm field gun on top of the hull as main armament. These Russian 7.62cm field guns had been collected 
by the hundreds during the early Blitzkrieg successes into Russia, and they were not only mounted on the Pz.Kpfw.38(t) 
chassis to create the early Marder III, but the Russian PaK36 guns were also mounted on other available tank chassises, like 
the Pz.II Ausf.D/E, the resulting tank hunter known as the Marder II (Sd.Kfz.132).  
 
The German's need to quickly convert anything they could to tank hunters was necessary because they were not able to 
fulfill their own tank production requirements, particularly after the invasion of Russia. Initially, the Marder III tank hunter 
conversions were provided as stop-gap measures until better-designed tank killing vehicles (Jagdpanzers) became available. 
But most of the converted tank hunters were used during the war as long as they could move and shoot, a few of them 
fighting until the end of the war.  
 
In the case of the Marder III with 7.62cm gun, only the last versions of the Pz.Kpfw.38(t) chassis, the Ausf.G and H, were 
used for the tank hunter conversion. The main difference between the two Ausfs. was a modification to the engine that 
increased horsepower in the Ausf.H. This web page is Part 1 of a two-part series on the Marder III with the 7.62cm gun. In 
this section we will explore the general layout of the vehicle and take a close look at the forward hull positions. In Part 2 we 
will climb into the fighting compartment at the back and see how the German crew manned the Russian PaK36 gun.  
 
 

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Picture 2: 
Before we 
continue, a brief 
note is required 
concerning the 
German name 
"Marder". The 
Wehrmacht 
created a number 
of tank hunter 
conversions that 
were all named 
"Marder" (German 
for "marten") and 
trying to keep 
them organized 
can be difficult. 
To show you how 
crazy this can be, 
the Marder II, for 
instance, utilized 
the chassis of the 
German produced 
Pz.II tank, but it 

could be armed with either the Russian 7.62cm PaK36 gun, or the German 7.5cm Pak40. The same is true of the Marder 
III; the name was used for a couple of different conversions of the Pz.Kpfw.38(t) chassis, using either the same Russian or 
German guns. Not only that, but when using the German Pak40 as the main weapon, the gun could be placed differently on 
the chassis, with concurrent changes in the location of the engine and other components. So, to be as clear as possible in 
these web pages, I will typically refer to our vehicle as the Marder III with 7.62cm gun, meaning that this is the conversion 
from the Czech Pz.Kpfw.38(t) tank chassis by the addition of a Russian 7.62cm gun, a gun shield, and a new 
superstructure, the gun crew standing at the rear of the vehicle. The AFV in this picture is one of these Marder IIIs with 
7.62cm gun that currently resides at the Aberdeen Proving Grounds in Maryland. The photo is one of my own and we will 
be seeing more of this particular vehicle later.  

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Picture 3: 
The conversion of the Pz.Kpfw.38(t) tank to the Marder III tank hunter involved the removal of the tank's roof plate with its 
turret ring, and the substitution of a cruciform gun support. The gun and mount, with protective armor plates for the gun 
crew, were added next. The new superstructure bolted directly to the tank chassis and was composed of seven armored 
plates. The new gun shield consisted of six armored plates that were initially bolted together and attached directly to the 
gun mount so it had a limited traverse of 21 degrees to the left and right. The gap between the former roof of the upper hull 
and the gun shield was filled with additional armor plates, mounted at different angles, with a couple of hatches included 
for the driver and hull machine gunner. The superstructure and gun shields offered only limited protection for the crew 
servicing the Pak36 gun, but the rear of the superstructure, as well as the top, were completely open.  
 
However, a canvas tarp was provided that could cover the top of the superstructure and gun in order to protect the fighting 
compartment during transport. This had to be removed though before entering into combat. Approximately 30 rounds of 
7.62 ammo could be conveniently stored on/in the Marder III machines. Three rounds of these rounds were stored in small 
bins on each side of the gun and used as ready rounds while the remainder were located in storage tubes in floor openings 
leading down into the hull on either side of the gun mount. In addition, the Marder III conversions kept the original 
7.62mm Czech ZB vz.37 machine gun mounted on the front hull plate, located between the driver's and machine gunner's 
front visors. This particular BMM factory photo illustrates the long Russian 7.62cm gun well. Also notice the removable 
crew seats located back in the fighting compartment for the commander and gunner, the external gun crutch on the front 
hull plate (in the released position), and the side visor for the driver, still located on the original tank side armor plate. 
There is a similar visor on the other side of the vehicle also.  
 
 

Picture 4: 
From the front, the Pz.Kpfw.38(t) chassis is particularly 
evident under all that new Marder III superstructure and 
gun shield armor, and the photo shows clearly the two 
vision covers for the driver and hull machine gunner in 
the bow. The driver's cover is the one that is open. 
Between the vision covers is the hull MG, located in a 
ball mount that was bolted directly to the armor plate. 
Notice the German Notek convoy light that has replaced 
the original tank headlight, located on the front armor 
plate, near the left mudguard. On the other side of the 
bow plate (our left) is an extendable tube with an aiming 

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circle that is welded to the top. This allowed the driver 
to operate the bow machine gun on his own (when 
necessary), locking the MG in its ball mount and aiming 
it with this circular sight. You might also notice that the 
two recoil cylinders for the big gun are located in the 
recoil trough under the gun tube, and the sight opening 
in the gun shield is located on the left side of the 
weapon, where the gunner stood.  
 
There is also a distinctly German radio antenna base 
mounted on the left side of the armor (our right). Inside, 
the radio was probably the typical Fu.2 or Fu.5 located 
by the hull machine gunner, who was also the vehicle 
radio operator. The early Marder III had superstructure 

armor secured with rivets and bolts, but later vehicles used welded plates in many of these areas. There were around 344 
Marder III with 7.62cm guns produced from April to October in 1942, and perhaps an additional 19 vehicles converted 
from Pz.Kpfw.38(t) tanks in 1943.  
 
 

Picture 5: 
This image from the BMM 
archives illustrates well the 
front of the gun and cradle as 
well as the forward crew 
areas in this version of the 
Marder III. Notice the ceiling 
openings over the driver's and 
machine gunner's positions. 
Normally there were hatch 
plates covering these areas, 
but they are missing here, 
although the holes for 
attaching the hatch hinges are 
still present on the armor 
sidewalls, next to the 
openings. This is a photo of 
one of the very early vehicles, 
evident by the early external 
gun support. This simple tube 
support crutch will later be 
strengthened with additional 
steel angles. The differential 
steering brakes and clutches 
inside are accessed through 
the hatch you see on the front 

bow plate.  
 
Notice the recoil cylinders for the 7.62cm gun inside the recoil trough, and the equilibrator cylinders that are visible 
through the opening located directly below the recoil cylinders. These two equilibrator cylinders were necessary because 
the gun was very barrel heavy. The two seats you see in the rear fighting compartment were removable. The seat backs 
could be lifted off the seat bottoms and placed into tubes that were welded on the wire rack (that was used to stow the 
canvas cover) at the back of the vehicle. Then, the seat bottoms, which were hinged to the side armor plates, could be lifted 
over the plates to lay outside. The support tube under the seats was hinged to the bottom of the seat, and went over the side 
with the seat. With the seats removed, the floor space behind the gun was unobstructed for the commander and gunner 
during combat.  
 

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Picture 6: 
This is a internal 
schematic I have 
created by piecing 
together the best 
aspects from a 
couple of different 
published 
drawings. The 
original tank 
chassis remained 
relatively 
unchanged, 
particularly in the 
bow where the 
driver and hull 
machine gunner 
sat, separated by 
the transmission. 
The drive shaft 
arrives at the 
gearbox from the 

rear-mounted engine by traveling through the hull, but the slip ring that was used to power the turret of the tank is no longer 
needed and disconnected on the drive shaft. The water-cooled engine, with its radiator and fan located behind, are in the 
same position as in the tank, and the fighting compartment above is then elevated relatively high over the engine and drive 
shaft as a consequence. In later versions of the Marder that used the German 7.5cm PaK40, the engine will be moved to 
positions further forward, allowing the fighting compartment to be lowered into the hull, providing a lower profile as well 
as improved protection for the gun laying crew.  
 
The 7.62cm gun mount is supported by a cruciform steel box structure that attaches to the side armor with six large bolts 
and is bolted and welded to the front armor and engine compartment partition as well. Notice the equilibrators mounted on 
the lower front of the gun mount as well as both the elevation and traverse hand wheels that are mounted on this left side of 
the weapon. When the protective canvas cover was used over-head, supporting tubular hoops were attached across the side 
gun shields and also across the rear uprights. Although the exhaust pipe exited the tank armor directly to the right of the 
engine, it progressed to the rear of the vehicle under protective plates. At the rear, the exhaust pipe was attached to a 
muffler that crossed the top of the stern armor plate, the muffler seen in this drawing in cross section as the circle at the far 
right.  
 
 

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Picture 7: 
This is the front area of an early Pz.Kpfw.38(t) showing most of the same equipment found in the Marder III with 7.62cm 
gun. I have reproduced the manual image fairly large so you can clearly see some of the details of the controls. The driver's 
steering levers and handgrips are a bit hard to see on the right side. Notice that there is a push button on the end of each 
grip; we will investigate these in more depth later. The steering levers are attached to control shafts that are attached to a 
central pivot box, bolted to the top of the gearbox. From this pivot, additional control arms radiate forward to the controlled 
differential steering controls, the steering box being attached to the front end of the gearbox, but mostly out of view here. 
Notice that the gearbox case is surrounded by a metal cover on the sides and top, perhaps to protect the operators from its 
intense heat when in operation. Also notice the foot pedals located forward of the driver's seat, his visor with protective 
glass block and padding on the front armor, and some of the details of the ZB viz.37 MG.  
 
Here is a list of some of the equipment we can clearly see in the photo: to the left is the small hull gunner's vision block, 
while is a small instrument gage, perhaps a transmission oil temperature gage. The driver's vision flap shows the opening 
mechanism on the left side and to the right of the flap is the small panel with lights and switches that are part of a visual 
communications system between driver and vehicle commander-there will be more about this system later. Notice the large 
protective pad mounted on the hull wall to the right of the driver and the comfortable looking seats provided for both the 
driver and hull machine gunner. Both these seats are adjustable forward and back, and the backrests can be reclined, as you 
can see. I don't know the purpose of the long lever on the hull wall in front of the pad, but it looks like the type of lever that 
controls louvers, perhaps for the engine compartment.  
 
Originally, the Pz.Kpfw.38(t) tank was to be equipped with a Czech radio, the vz.37 radio set, but in German vehicles this 
is said to have been replaced with one of their own units, probably a Fu.2 or Fu.5. I don't see the radio in any of the 38(t) 
photos or drawings I have, but it was most likely mounted someplace over on the hull gunner's side of the vehicle. 
Remember that the upper hull of the 38(t) did not overhang the tracks, so there was no internal track sponson to place 
equipment upon. I have not been able to nail down the location of a radio rack in the Marder III with 7.62cm gun, but it 
probably was mounted over the drive shaft, or on the hull wall just to the left of the machine gunner.  
 
 

Picture 8: 
This is an Imperial War 
Museum photo of the interior 

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of the front of the Marder III, 
and many of the same controls 
are again visible. The photo 
shows the driver's side; the hull 
MG mount on the front armor 
plate is just barely visible at the 
far left, on the other side of the 
three bins with all the holes that 
I suspect held MG ammo boxes 
for the ZB vz.37 MG (access to 
the bins from the other side). 
Above these bins, which were 
mounted on the cruciform 
support for the gun that is over 
our heads, there was enough 
room to mount a gas mask 
container for the driver. The 
hull machine gunner had one in 
a similar position over on his 

side of the vehicle. Below the bins you can see the corner of another rack or bin and I suspect this is the back corner of the 
radio rack, located above the drive shaft arriving from the engine at the back of the AFV.  
 
On this side of the transmission you can again see the two steering levers with handles forward of the driver. As I 
mentioned previously, each lever actuates, via connecting rods, the steering clutches and brakes (epicyclic gears) for that 
particular track. There were actually two belt brakes and a clutch for each side of the steering differential. When the driver 
pulled back on one steering lever, it engaged the clutch on that side and began applying pressure to one of the brake bands 
to slow the sprocket, therefore turning the vehicle in that direction. If the button on the end of the steering lever handgrip 
was pushed at the same time the lever was pulled back, the second brake band would also be activated, and the vehicle 
would then turn much quicker, or could even be turned in place.  
 
To the far right is a periscopic vision block the driver used to view out the right side of the Marder III, and just below it is a 
vent opening to provide some fresh air circulation into this side of the bow. These hull vents were a hold over from the 38
(t) design; in reality, the over-head hatches on the Marder III with 7.62cm gun were such a poor fit that fresh air circulation 
for the driver and machine gunner was probably not a problem. The hull machine gunner also had a vent opening on this 
side of the hull, but there were no vision device included on his side wall, just on the front armor plate forward of his seat. 
Notice that the large protective pad that was mounted on the right hull wall next to the driver in the 38(t) is missing in this 
Marder, but the mystery lever just in front of it is still intact.  
 
 

Picture 9: 
An enlargement of 
part of the 
previous picture 
provides some 
additional detail of 
the gearbox area. 
The gearbox was 
an improved 
version of the 
English Wilson 
type, license built 
by the Czechs at 
Praga and then 
called the Praga-
Wilson gearbox. It 
provided five 

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forward and one 
reverse gears and 
was very smooth 
in operation. Here, 

most of the gearbox is visible directly to the left, with the gearshift lever on the top of the case. Notice that in this 
enlargement you can now see the shifting gate alongside the gearshift. The gearshift action is a straight line and the gate has 
notches along its length to positively locate the shift lever for each gear position, including neutral and reverse. The 
gearbox is a preselector type, which means that in order to shift gears you first selected the gear by shifting, and then you 
pressed the clutch pedal to engage it. Interestingly, the gearbox was lubricated and cooled by oil from the engine-- the oil 
was circulated by three pumps through the gearbox, a cooler/radiator, a filter, and then returned back to the engine behind 
the firewall. Down on the floor, in front of the driver's seat, are foot pedals for clutch, brake and accelerator.  
 
 

Picture 10: 
In this particular Marder III, most 
of the driver's forward vision 
block and visor are now missing, 
but the frame is intact, minus the 
glass block and its holder that 
would normally be bolted to this 
side of the opening. To the right 
of the visor is the commander's-
driver's signaling system seen in 
the previous picture. For some 
reason it has been partially 
blanked off by a small piece of 
sheet metal. This system consisted 
of a series of three lights (red, 
green, and blue), and 
corresponding activating 
switches, that allowed the 
commander in the fighting 

compartment (who had his own control panel) to signal the driver when to turn, stop, etc, based on a prearranged code. By 
the way, the cruciform support for the 7.62cm gun above us is just out of view to the upper left. The over-head hatch is 
open, allowing light down into the position.  
 
 

Picture 11: 
The engine in the rear of the Marder III with 
7.62cm gun is a Swiss-designed, six-cylinder, 
water-cooled, Praga produced, "TNHPS" (also 
known as the Praga EPA) of around 126hp. For 
the last production run, the Ausf.H, the engine was 
reaspirated to produce 150hp at 2500rpm, this 
accomplished by adding another carburetor and 
making other required adjustments, and the new 
engine was then known as the Praga AC. The 
Praga manufacturing company, part of CKD, was 
an automobile manufacturer first and foremost, 
and this engine was one they had been perfecting, 
as a license holder from the Swiss, for a number of 
years. In this modified drawing from a British STT 
report you can see both the intake and exhaust 
manifolds located on the right side of the engine, 
but the intake from the air cleaner enter lower on 

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the cylinder head than the exhaust. The air cleaner sits on the right fuel tank; there is another rectangular fuel tank on the 
left side. Both these fuel tanks sat very low in the compartment and were isolated from the engine by steel bulkheads. The 
floor panels under the fuel tanks were secured using smaller diameter bolts, and if a fuel tank was ruptured and exploded, 
most of the force would be released downward through the blown out floor plates, sparing the engine and the other fuel 
tank. The large rectangular box sitting on the left tank (at the bottom of the picture) is the battery box for the 12v batteries.  
 
The water radiator for the engine was located near the rear of the vehicle in a thin bulkhead-- you see it here between the 
engine and cooling fan. The scirroco fan, attached directly to the engine, pulled cooling air in through slits in the side of the 
engine compartment and then through the radiator. The cooling air was then exhausted via a grating on top of the cowling 
that was opened and closed via a sliding cover. The drive shaft can also be seen leaving the engine compartment through a 
firewall and traveling along the floor of the hull to attach to the gearbox in the bow, off to our left.  
 
 

Picture 12: 
This is a US Army image of the ZB 
vz.37 machine gun and its ball pintle 
mount that was bolted to the front 
armor plate between the driver and 
hull machine gunner. The weapon is 
shown here with a belt of ammo in 
place. The official Czech designation 
for the ZB vz.37 MG was 7.92mm 
kulomet vz.37, but the Germans called 
them the MG 37(t). Designed by 
Vaclav Holek of the Zbrojovka Brno 
(ZB) firm, they were designated either 
medium or heavy machine guns, 
depending on which reference you 
use. When mounted on an armored 
vehicle in the ball mount like you see 
here, most of the protruding barrel was 

protected in a massive armored trough, and a 2.6x spotting scope was used for aiming. You can see the scope mounted 
above the MG in the picture. The cloth sack you see hanging below was used to catch the spent shell casings for recycling.  
 
When mounted on the Pz.Kpfw.38(t), the bow machine gun could be fired by either the gunner or driver. When fired by the 
driver, the gun was locked in the forward position in its ball mount, and the driver fired the weapon via a remote Bowden 
cable running from the gun to a push button at his position (I think this was located on his left steering lever). I do not know 
if this same system was maintained in the Marder III vehicles, but the cable you see running out the back of the MG in this 
picture is the Bowden cable. You can also see it clearly in the interior picture of the tank, Picture 7 above.  
 
 

 

Picture 13: 
This is the ZB vz.37 MG again, this time in the infantry guise, the main difference being the carrying handle you see on the 
front of the receiver. The tank version of the weapon also had a lighter barrel, but other than that the two versions are about 

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identical. This is an air cooled, gas operated weapon, and the gasses are bleed from the middle of the barrel which then act 
on a piston that is connected to the bolt. Because it was designed from the start as an anti-aircraft weapon, the ZB vz.37 had 
two rates of fire, roughly 550 rounds per minute for use against infantry, and 750 for anti-aircraft work; in the Pz.Kpfw.38
(t) and Marder III only the slower rate of fire was used, and this was said to have been reduced to only 450 or so rounds/
minute.  
 
One interesting aspect of this MG is that it lacks a cocking lever that you normally see one side of the receiver. Instead, the 
user pushed the two handles forward until they engaged the bolt, and pulled them back again to cock the gun. In this way 
the gunner did not have to take his hands away from the handles and their firing buttons, a distinct advantage in some 
situations. Typically, the ZB vz.37 was fed by metal link belts, the belts holding 100 or 200 rounds.  
 
After the German annexation of the Czech and Moravia territories in March of 1939, the ZB gun factory was kept 
operational under German supervision and new weapons were then supplied to German rear echelon troops, particularly the 
Waffen SS. The machine gun was also exported in great numbers before and during the war, and in 1936 a manufacturing 
license was sold to England. They changed the name of their license-built guns to BESA, short for "Brno Enfield Small 
Arms", as the guns were made at the Royal Small Arms Factory at Enfield Lock, in north-east London. The weapon was 
very popular and the British mounted it in many of their armored vehicles. The infantry version that was also license-
manufactured in England from an earlier ZB machine gun design, the ZB 26, was also well received by the British Army, 
their name for it using the BRno and ENfield, shortened to BREN. You will find British AFVs armed with the BESA well 
into the 1950's and even the 1960's, and of course the BREN Gun was very popular with the British infantry forces for at 
least that long. The ZB vz.37 proved to be compact, reliable and highly accurate, qualities that make it popular in a number 
of other countries as well.  
 
Let's crawl out through the over-head hatches now and explore the fighting compartment of the Marder III with 7.62cm gun 
in Part 2.  
 
 

TO MARDER III 7.62CM PART 2

 

BACK TO AFV INTERIORS HOME PAGE

 

(c) 2002, 2003 AFV INTERIORS Web Magazine 

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German/Czech Panzerjager 38(t) fur 

7.62cm PaK36(r), Sd.Kfz.139, "Marder 

III", Part 2 

 
 

Picture 1: 
This is the second part of a 
two-part web page series 
exploring the interior of the 
Marder III tank hunter with 
7.62cm gun. Part 1 covered 
the bow of the interior and 
the engine compartment, and 
in this second part we will 
examine the fighting 
compartment behind the gun 
shield.  
 
This is the view of the rear of 
the Marder III at Aberdeen 
that we saw earlier. 
Beginning at the rear plate, 
you'll notice the same rear 
hull plate that was used on 
the late 38(t) tank and that it 
includes a large circular plate 
for internal fan and radiator 
access. In the center of this 
plate is a hole and bracket 
support used for crank-
starting the engine. The 
starter crank was inserted 
into the opening so it 

connected with the fan shaft, which was connected directly to the crankshaft of the engine, located 
further forward in the chassis. The exhaust pipe and muffler are easily seen crossing the top of the 
rear plate; a cast armor cover protects the location where the exhaust pipe exits the vehicle. The exit 
for the engine cooling air is located under the basket at the back of the engine compartment, protected 
by a grating. The size of this opening can be controlled by a sliding plate, so that during winter, for 
instance, the plate can be slid across the opening to keep the engine-warmed air inside the engine 
compartment. This is the same design for exhausting engine cooling air that you see on the Pz.
Kpfw.38(t) tank, as well as those vehicles converted from the tank like the Hetzer tank hunter.  
 
Further forward from the air grating is the modified engine cover; the crew serviced the gun standing 

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on either side of this cover on a built-up floor, and occasionally they had to stand on the engine cover 
itself. The floor over the engine could become so hot that the crew's shoes would begin to melt. 
Evidence of the two seats that were available in this area has mostly disappeared over the years. 
However, the left seat bottom support is still attached to the left side plate, and one of the seat backs 
is still visible, stowed in the two tubes welded to the rear of the tarp stowage basket. Notice that the 
rear of the gun cradle trough is supported by a crutch rising from the floor, and some of the ammo 
storage tubes are also visible in the floor openings to either side of the gun mount. The vertical 
sliding breech of the Russian weapon is also now clearly visible, with a recoil shield mounted on 
either side to protect the operators. Tubular supports for the gun shields are also visible radiating out 
from the gun mount to the gun shield armor. The cross hoop that would support the front of the 
canvas cover is installed on this vehicle, but the rear supports for the second hoop are missing.  
 
 

Picture 
2:
 

wartime photograph of a British-captured vehicle located in a vehicle park in North Africa helps to 
further illustrate how the vehicle was designed and constructed. The Marder III was apparently 
crewed by four men-- a driver and hull machine gunner/radio operator down in the front hull, and two 
soldiers up in the fighting compartment servicing the gun-- a commander/loader to the right, and a 
gunner to the left. The Russian 1936 7.62cm field gun was altered very little from its original field 
setup when used in the Marder III. The primary change, of course, was the removal of its wheeled 
carriage. The first captured guns were used exactly as they were found by the Germans along with 
captured 7.62mm Russian ammunition, typically APHE (M.1936) and HVAP (M.1942). But the 
Germans soon had Rheinmetall-Borsig begin reboring the chambers in order to accept their own 
produced ammunition similar to the PaK40 rounds, AP (Pz.Gr.) and APCR (Pz.Gr.40). This reboring 
was necessary because the traditional German cartridge cases were larger in diameter than Russian. 

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Most of the Marder III tank hunters apparently used the altered gun with the new German 
manufactured ammunition, although it was still made in the 7.62cm size. Because this new ammo 
looked so similar to the 7.5cm Pak40 ammunition, an identifying white band was painted around the 
new 7.62cm projectiles.  
 
Other areas modified on the Russian field guns included moving the elevation hand wheel from the 
right side to the left so the gunner could control both elevation and traverse from his left side. Notice 
the vertical sliding breech block design and the elevation hand wheel on this left side of the weapon. 
The elevated engine cover is also clear in this picture, as are the locations for the two seats. The rear 
of the gun cradle runout trough is supported by the gun crutch, and the two different styles of recoil 
guards on either side of the breech are also apparent.  
 
As I mentioned earlier, three ready-rounds were stored on either side of the superstructure in 
horizontal ammo bins. Here you see the right bin with its cover still secured in place, located in front 
of the right seat. But the left bin's cover is missing, and the top storage tube is now visible, seen at the 
far left of the left seat. The remaining 24 rounds that were carried on the vehicle were stored 
vertically in tubes that were located on either side of the gun mount. We will see these in a few 
moments.  
 
 

Picture 
3:
 
We are 
now 
looking 
at a 
closer 
view of 
the 

Aberdeen vehicle, revealing some additional detail. The ready round ammo storage on the right side 
of the superstructure armor is also visible in this photo, but this time the cover is missing as well as 
the lowest of the three storage tubes. Rounds were stored tip in and brass shell showing, so if the 
rounds were stowed in the bins and the cover was off like this, you would see the butt end of the 

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brass shells, each protruding an inch or so from the bin when the cover was removed. The gun crutch 
support (and its attachment to the rear of the cradle runout trough) is also clear in this photo, as well 
as the remains of the left seat support. Remember there was a tractor-type seat bottom that was 
welded to this base support, and the whole thing could be pivoted up and over the side of the 
superstructure plate when the vehicle was prepared for combat.  
 
To either side of the gun you can see the floor openings leading down into the hull where additional 
7.62cm ammo storage bins and tubes are attached. Although it is difficult to see the gunner's 
elevation hand wheel in this picture, the traverse wheel is visible behind the seat support. The sights 
for the weapon would be mounted on this left side of the gun-- the opening in the gun shield shows 
where the ZF3x8 direct viewing telescopic sight would be mounted. Although it is hard to see here, 
there is a storage tube for the sight mounted on the gun shield directly to the right of the sight 
opening. The ZF3x8 provided a magnification of 3x and had graduation rings in the graticle for AP, 
AP40, and HE ammunition. This was a rocking bar reciprocating sight with range indicator graduated 
for both AP and AP40, and the ZF3x8 was commonly used also on the PaK40 weapons. The 
elevation indicator was graduated in meters for all three types of ammo, and in mils up to 800. There 
are additional photographs of the tubular telescopic sights in other pages in AFV INTERIORS, 
including the 

Marder II 

pages. To the left of the sight opening in the shield is another stowage box. 

This larger rectangular storage bin held an indirect panoramic sight that could also be used with the 
gun.  
 
Notice the tubular supports again that lead from the gun trough mount out to the gun shields. At the 
top of the shields are simple mounts for a couple of general purpose viewing periscopes, two on each 
side. These periscopes enabled the operators to observe the battlefield without exposing their heads 
above the superstructure armor. The only periscope mount that is completely intact here is located at 
the upper left, but at least the basic support brackets are still visible at the other three periscope 
locations on the shield.  
 
 

Picture 4: 
In this picture, again 
notice the stowage box 
for the gunner's optics at 
the far left and the 
periscope mount at the 
top of the gun shield. As 
I mentioned earlier, there 
was one primary sight 
available to the gunner, 
the common ZF3x8 
telescopic sight, but on 
occasion an indirect sight 
was also apparently used. 
Of course, the gunner has 
had access to an elevation 
quadrant for indirect 

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shooting, the quadrant 
mounted on the flat 
bracket you see slightly 
to the right. Although it is 
barely visible in this 
enlargement, there is a 
gas mask canister bracket 
to the left of the optics 
stowage box, and now 
that storage tube for the 

telescopic sight is visible on the front gun shield. By the way, each crewmember had a gas mask 
container and a breathing tube located somewhere near their combat positions.  
 
Some of the gearing for gun tube elevation is visible under the gun. As we have seen before in most 
other WWII AFVs, the elevation handwheel turned a pinion gear under the gun mount that engaged 
this geared rack attached to the cradle, which then elevated and depressed the weapon. In the recess 
in the floor to the left of the gun support you can see the ammo storage bins and tubes for 11 rounds. 
Keep in mind that these were bins with lids; the storage tubes you see are inside light armor boxes 
that originally had lids just like the ready round bins on either side of the hull. The fist bin on the left 
has five tubes inside, the bin next to it has three (partially hidden here), and the bin on this side of the 
opening has three more. The hinges for the bin covers are still intact, but the covers are missing. They 
may have been removed by the crew or too fragile to survive combat-- the only two Marder III with 
7.62cm gun vehicles that I have examined are also missing their ammo bin covers. The ammo bin 
layout on the other side of the gun is slightly different, and we will see that momentarily.  
 
You can also see the six bolts that attach this end of the cruciform gun support to the hull. A similar 
arrangement was used to attach the other end to the hull, as well as the two side extensions. The 
equilibrator spring cylinders that were used to balance the gun in its cradle are mostly visible 
protruding out the front of the lower gun shield in other photographs. But the springs inside the 
cylinders were attached to chains, similar in appearance to bicycle chains, and these chains were then 
attached to the sides of the runout trough. In this picture, you can see the left equilibrator chain 
attachment on the trough just to the upper-right of the traverse handwheel. The other equilibrator 
chain is attached to approximately the same position, but on the other side of the trough.  
 
 

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Picture 5: 
The commander's side of the gun, here shown in the Aberdeen vehicle again, also has ammo stowage 
bins and tubes in the floor opening that leads down into the interior of the hull. There are 13 tubes in 
the bins on this side, consisting of two bins with five tubes (right and center) and one bin with three 
tubes, to the left. By the way, all these ammo bins extend down to the floor below, so from the inside 
you see the walls of the bins rising up to the openings up above. Does this ammo storage location 
seem a bit odd to you? I can easily visualize the commander and the gunner struggling over these 
bins and stored rounds as they attempt to service the gun behind the shield. Image trying to use the 
periscopes at the top of the shield. Also, the gunner's handwheels are situated right above the bins, 
and for the gunner to use the sighting optics and handwheels to lay the weapon, while leaning over or 
perched on top of these ammo tubes, must have been a lot of fun.  
 
The storage box on the right side of the front gun shield held barrel cleaning heads-- the poles were 
stored elsewhere. You can identify these boxes by their rounded sides. Also seen over here is a 
bracket for the commander's gas mask container, visible at the far right of the photo. It appears that 
the Germans did not use the original Russian gun optics, but one of their own as I mentioned 
previously, the ZF3x8. It is interesting to note that even though the Germans manufactured their own 
ammunition for the captured 7.62cm Pak36 weapons, and used the same size cartridge cases as was 
used for the Pak40, that the performance of the 7.62cm PaK36 and the 7.5cm Pak40 were very 
different. That means that an unaltered ZF3x8 sight used on the altered 7.62cm PaK36 would not be 
accurate either. I suspect the sight was modified with new graticles, or perhaps there was a guide 
provided to allow gunners a correction factor.  
 
If you look closely, you will see a stowage bracket under this end of the runout trough for an MP38 
or 40. These brackets are characteristic in design, fashioned from a length of metal channel that has 
been bent into an L shape. The butt of the machine pistol fit into the shorter end of the L, and the 
barrel was held into the longer portion by a spring clip you can just see at that end. Typically, there 
was also a leather strap attached about halfway down the longer side of the bracket so the SMG could 
be stored in its canvas bag and still strapped into the bracket. This is the only Marder III vehicle that I 
have seen with a bracket located in this particular position, but some kind of close defensive weapon 
like a machine pistol is supposed to have been carried in the fighting compartment, and this seems 
like a reasonable location to store it.  
 

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Picture 6: 
A closer view of this same 
area provides us with 
additional details, including 
the characteristic gas mask 
container bracket at the far 
right (which is missing its 
leather straps for securing 
the canister, as most old 
vehicles are) and the 
MP38/40 stowage bracket 
under the recoil trough. Also 
clear here are the recoil 
shield to protect the 
commander from the weapon 
when firing and the support 
crutch under this end of the 
recoil trough. The elevation 
pinion gear is attached to the 
gun mount fairly far forward, 
the gear mounted to a shaft 
that crosses under the gun 
cradle from one side to the 
other. On this end the shaft 
exits the mount and passes 
back to where a hand wheel 
use to be located when the 
Russian gun was in its 

original form. You can see this transfer gearing and drive shaft mechanism located directly under the 
diagonal shield support, and under the gun tube cleaning head storage box mounted on the front 
shield. In the field version of the original Russian gun, the elevation hand wheel was attached on this 
side, and there were two gun layers, the elevation layer on this side of the weapon and traverse layer 
on the left.  
 
One of the changes the Germans made to the captured Russian 7.62cm 1936 weapon was the addition 
of a muzzle break, which reduced the recoil to about two-thirds of its original length. By the way, it is 
interesting to note that the Russian weapon was originally developed with help from the German 
Rheinmetall-Borsing Company in the early 1930s, although this original design was reworked by the 
well-known Russian gun designer Grabin to eventually become the 1936 7.62cm weapon. In fact, this 
Russian gun was similar in many regards to the German Pak40, particularly in penetration 
performance. The official German designation for the Russian gun is "7.62cm Panzerabwehrkanone 
36(r)", or simply, 7.62cm Pak 36(r). But as I search through German reference material, it looks like 
the (r) was dropped after the chambers were bored out to receive German manufactured 7.62cm 
ammo for the gun.  

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As you can see here, the breech mechanism is a vertical semi-automatic sliding block, and is 
percussion fired. In some of these pictures you can see the semi-automatic breech spring on the left 
side of the breech ring and the breech-operating lever on the right. Mounted on the top right corner of 
the breech ring is a lever with a hole at the end that was the lanyard attachment when the weapon was 
used as a field piece. Unfortunately, both these levers are barely visible in this picture. By the way, 
7.62cm equals 3.00in, that's why such an odd metric number was used. That means that the bore of 
this tube was exactly the same diameter as the US 3in gun used on the US M10 Tank Destroyer, for 
instance. The performance of the two weapons was not the same, but the bore was.  
 
 

Picture 7: 
There were three special 
German produced 
rounds that were 
commonly used with the 
bored-out 7.62cm 
weapon mounted on the 
Marder III. The most 
common of these was 
the 7.62cm Pzgr Patr 39 
rot, a black conventional 
armor piercing shell 
with ballistic and 
penetrating caps, and an 
explosive filling 
detonated by a base 

fuze. Another round, although less common, was the black 7.62cm Pzgr Patr 40 (the top projectile 
seen here). This was a full-caliber, tungsten-cored projectile, but it was less commonly used in 
combat due to the German shortage of tungsten. It was, however, fitted with a tracer element in the 
projectile base-- the cap you see in the illustration.  
 
The last of the three shells made for use with the modified 76.2cm Pak36 gun was based on the 
common Sprgr Patr 39 (the bottom projectile in the illustration), a conventional German-made, HE 
projectile filled with explosive amatol and fuzed with the common K1 AZ23 fuze. These projectiles 
were generally painted olive green, although olive drab or field gray might also have been used. The 
markings you see on this projectile tell you a number of things about it. The Roman Numeral IV 
indicates that it is a relatively heavy projectile. Markings ran from I to V, III being what was 
considered "normal" weight. The markings on the parallel portion of the body are FES, then lg.21-11-
43 l. The FES refers to the fact that a sintered-iron driving band is used (FES is short for Fuhrung 
Sintereisen) and the series of numbers indicate the shell was manufactured on the 21st of November, 
1943. All the labeling on these projectiles was white paint, although with other rounds it could vary.  
 
 

Picture 8: 

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From a US Army ordnance 
manual comes this schematic 
of the inside workings of the 
common German percussion 
fuze AZ23, used on the HE 
shell fired by the altered 
7.62cm Pak36 gun. We haven't 
talked much about fuzes in 
AFV INTERIORS, and this 
seems like a good opportunity 
to discuss and examine the 
general workings inside one of 
the most common German 
fuzes.  
 
There were two basic types of 
nose fuzes used by the 
Germans in WWII, regardless 
of the caliber of projectile. The 
first type were those that were 
actuated by directly striking 
the target and having the 
striker or needle driven into 
the detonator, called direct-
action fuzes, or in German, 

"Aufschlangzunder", or "AZ". The second type of fuze was a bit more rare. These were actuated by 
the deceleration of the shell on landing at the target. In this case, an inertia pellet in the fuze ran down 
the central channel tube and drove a needle into a detonator. These nose fuzes were known as graze-
action fuzes, since just grazing a surface would start the pellet down the tube and detonate the shell. 
Often, German nose fuzes used a combination of both types as a sort of insurance that the shell would 
explode on target. The use of graze-action fuzes in their HE rounds meant that firing through forest 
branches at a target out in a field could result in the round exploding while still in the forest as it 
grazed a branch or tree trunk along the way.  
 
The AZ23 was one of those German fuzes that had both types of fuze action installed inside. It had a 
tip that was closed by a light foil disc, which covered the wooden striker rod that you see here. But a 
detonator pellet was also inside the central channel, near the fuze magazine. A safety mechanism was 
built into the fuze and was composed of five interlocking centrifugal blocks that were surrounded by 
a leaf spring, the blocks normally situated close together so that they blocked the striker from being 
able to hit the detonator. But the centrifugal blocks would move out of the way when the projectile 
spun during flight, causing centrifugal forces that were greater than the leaf spring that held them 
closed, and thereby opening the channel for the wooden striker to hit the detonator when the 
projectile finally struck the target. The smaller illustrations to the right show the centrifugal block 
safety mechanism both before firing and after firing. Early models of the AZ23 fuze metal casing 
were made from bare aluminum and were unpainted, but later versions appear to have been made 
from steel and were painted a deep olive green. These were the AZ23 types probably seen most often 

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on HE shells carried in the Marder III with 7.62cm gun, and since the projectile was often also 
painted olive green, this probably gave a uniform color appearance to the entire projectile.  
 
The set screw you see illustrated at the bottom of the sketch allowed a time delay before detonation, 
that is, after the fuze struck the target. The delay could be set to direct-action (non-delay), where a 
protective shutter was slid away by centrifugal force, leaving a direct path for the flash from the 
detonator pellet to pass into the fuze magazine. But if delay was chosen by turning the set screw, the 
shutter was locked in place and the flash was then diverted into a side channel that was filled with a 
delay powder. This powder took a short time to burn through before igniting the fuze magazine. The 
letter "M" you see near the set screw refers to "Mit", meaning with delay, and the letter "O" means 
"Ohne", or without. The time delay was only around 0.15sec for the AZ23, but that was enough for 
the HE shell to penetrate a building wall, for instance, before detonating.  
 
 

Picture 9: 
As you probably know if you read AFV 
INTERIORS regularly, the common German 
Pzgr Patr 39 AP projectile (seen here) also had 
a time-delayed fuze that detonated an 
explosive charge inside the armor piercing 
projectile after it penetrated. This was 
probably one of the most frightening aspects 
of German AP projectiles to Allied tankers 
during WWII, and the resulting explosion 
after piercing the armor caused most of the 
internal fires you read about so often.  
 
Case primers in the base of all brass, or brass-
coated, cartridge shells used with the Marder 
III with 7.62cm Pak36 were percussion types 
(this gun was percussion fired, not electrically 
fired as were most German tank guns), 
typically the C/12nA. The brass 6340 
cartridge cases, like those you see being 
cleaned here, were all the typical 715mm 
(28.15in) length types. By the way, that's a 
Marder II with PaK40 in the background, so 
these rounds are 7.5cm types and could not be 
used in the 7.62cm PaK36. However, the 
projectiles do look almost exactly the same. 

Let's take a closer look at these AP projectiles.  
 
Notice that these black-painted Pzgr Patr 39 AP projectiles do not have a smooth body, but have at 
least two lips running around their circumference, one next to the soldier's left hand near the tip, and 
the other further down, just before the long parallel area of the projectile. The ring near the tip shows 
the limit of the ballistic cap that was placed over the end of the piercing cap, and the second ring 

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shows the end of the piercing cap itself. The thin metal ballistic cap provided an aerodynamic shape 
for flight, and the solid steel piercing cap directed the impact shock away from the tip, toward the 
shell shoulders, so the projectile could cut through the cap and begin penetration through the armor 
plate. These two rings delineating the edge of the two caps will be clearer in the next illustration.  
 
 

Picture 
10:
 
This 
drawing 
shows a 
German 
Pzgr Patr 
39 AP 
projectile 
and you 

can now clearly see the limits of both the ballistic cap at the tip of the projectile, and the piercing cap 
located further down, although the drawing is a bit exaggerated to better show the locations. The fuze 
used on these black AP projectiles was the Bd Z 5103, and it was a base fuze located away from 
potential impact damage as the projectile punched its way through the armor. The "Bd Z" in the fuze 
name stands for "Bodenzunder", or base fuze. This base fuze used a simple graze system like most 
base fuzes-- the pellet was held in the safe position by a thin shear wire. With deceleration force, the 
shear wire broke, and the delay was created by the fact that it took a fraction of a second for the 
released detonator pellet to move the distance to the fuze magazine and then ignite it. A tracer pellet 
was also carried in the base of this projectile, so the gun crew could follow its flight.  
 
So, after all this talk about ammunition and fuzes, what was the difference between the projectiles the 
Germans made for the 7.5cm Pak40 and those for the converted Russian 76.2cm Pak36 guns? The 
only major difference was the diameter of the projectile and the size of the driving bands around the 
outside of the projectile-- the 7.62cm PaK36 projectiles simply had a thicker diameter and driving 
band to more perfectly fit their slightly larger gun tube bore. Although the brass shells cases for both 
types of rounds were exactly the same size, the projectiles were NOT exactly the same size, and you 
could NOT shoot one type of projectile through the barrel of the other gun. 7.62cm PaK36 projectiles 
were too wide to fit inside the bore of the 7.5cm PaK40 weapon, and 7.5cm ammo was too small to 
correctly seat in the rifling of the 7.62cm tube. The two types of projectiles were only 0.11cm, or 
1.1mm different in size, so to be sure the gun crews and others could quickly differentiate between 
their ammo types, all German 7.62mm ammo manufactured for the 7.62cm guns had a wide white 
band painted around the projectile. There have been rumors over the years that the Germans may 
have placed a thin sleeve inside the Russian Pak36, thereby reducing the bore to 7.5cm, so that they 
could use their own Pak40 ammo in the altered Pak36. I have not found enough information about 
this to either substantiate or refute this rumor-- I wonder if any of you can? But that's enough about 
ammunition for now-- let's get back to the Marder III's interior.  
 
 

Picture 

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11: 
This is 

Bundesarchiv photo of an interesting modification made to at least one Marder III with 7.62cm gun. 
You may have noticed that there was no provision for crew heat in the fighting compartment, and it 
must have been brutal in the Russian winter to fight in these machines. But at least this one Marder 
III (a prototype?) had an accommodation for the gun crew, a CREW HEATER! A sheet metal box 
and ducting has been constructed to bring warm air from the engine compartment up to the fighting 
compartment, circling around to the right side and then exiting up by the commander's position. And 
although we can't be sure, there seems to be a canvas tube extension that brings the warm air down 
into the hull, or perhaps over to the gunner as well. You can see the engine cooling air exhaust duct at 
the lower right, and at the other end of the ducting, just before the opening to the crew compartment, 
there appears to be a control handle on top to adjust the flow of warm air.  
 
Other details that you can see here which definitely WERE inside other Marder IIIs with 7.62cm gun 
include the pivot hinge for the seat that you see at the top of the photo. Also notice the cover to the 
ready round ammo bin on the right side of the hull, seen at the upper left corner of the picture. Once 
again the gun crutch support is visible to our left and includes the chain keeper that kept you from 
loosing the securing pin holding the bracket to the trough.  
 
 

Picture 
12:
 
There 
were a 
number 
of 

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conversions of the Pz.Kpfw.38(t) to tank hunters that were used from mid-war on, and the Marder III 
with its 7.62cm weapon was certainly not the best of the group. For one thing, the gun crew was very 
exposed when in combat, not only from the sides where armor protection was minimal, but from the 
rear where it was nonexistent. This often photographed Marder was captured by the British in North 
Africa and was photographed after being hauled into one of their foreign vehicle dumps.  
 
Let's see what interesting, if minor, details we can identify on this Marder III. Notice that the support 
rods for the canvas cover are intact, and one of the periscopes on the far-left side of the gun shield is 
also in place. There has been some damage to the right rear corner of the tank hunter, but both 
seatbacks have been saved and are in their stowed positions back on the canvas stowage basket. The 
hinged two-piece driver's hatch has been opened and is hanging down on this side of the side 
superstructure armor. Anything else you see interesting here? Interior paint for the fighting 
compartment was the same as the base exterior color. The driver's and hull machine gunner's area 
was painted either white (Czech tradition) or light ivory (Elfenbein-- German tradition), I haven't 
been able to confirm which with any certainty.  
 
 

Picture 
13:
 
Most 

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historical references indicate that Marder III tank hunters were generally issued to Panzerjäger 
Abteilungen and served mainly on the Eastern Front, but a few of them (66?) were also delivered to 
North Africa from July to November in 1942. There, the Marder IIIs served with the 39th Panzerjäger 
Abteilung and with the 15th Panzer Division in the 33rd Panzerjäger Abteilung. During the desert 
fighting, the vehicle proved to be very effective against British Matilda II tanks, possessing one of the 
few German weapons besides the 8.8cm gun that could knock out a Matilda. It is interesting to note 
that in some British after-action reports, Marder III results were sometimes attributed to the feared 88 
guns, which actually had not even been in action during these particular battles.  
 
One of the maintenance problems that appears most often in German field reports is the breaking of 
Marder suspension springs. Apparently, the weight of the converted vehicle overtaxed the design 
limitations of the suspension, and Marder III/38(t) tank suspension leaf springs became one of the 
most sought after items in maintenance depots. This particular Marder III with 7.62cm gun is one of 
the early vehicles, and the photo is one of a series of BMM factory photographs, a couple of which 
we saw earlier. Notice the smoke discharger box mounted on the rear armor plate, under the muffler. 
A typical German AFV fire extinguisher is mounted on the right-rear corner of the superstructure 
armor (right side of basket), but you will also see it mounted on the left side in some period photos.  
 
Most of the photos used in these pages have been directly credited, the majority being Imperial War 
Museum images, or those from the BMM archives, or from WWII British STT intelligence reports 
(School of Tank Technology). If you have additional information about the Marder III with 7.62cm 
gun, I would be very interested in hearing from you and perhaps adding the material to these pages.  
 
 

TO MARDER III, 7.62CM PART 1

 

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