Anti-tank
weapons
used by the Finns in the Winter War
Part II
In Part I
Anti-tank
rifles
THE
20 mm L-39 ANTI-TANK RIFLE
(Note the length of the weapon,
the removed muzzle cap and the bipod))
The design and production
of a domestic anti-tank rifle for the Finnish Army was
delayed in the late 1930s by doubts and differences of
opinion over which caliber to adopt. Initially a 13 mm
caliber was the favorite alternative but in 1939 a decision
was also reached to also construct two 20 mm weapons for
tests in mid 1939.
The design work was given to Aimo
Lahti who had two 20 mm prototypes produced during
the summer. They were then tested. Theoretically, the
difference of muzzle velocity and penetration between
the 13 mm and 20 mm wasn't big, but the 20 mm round had
superior fragmentation effect when it penetrated the armor.
(Note the free traverse
once the locking mechanism is opened)
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On August 11th 1939, the
L-39 performed well, fulfilling all requirements, and
on the basis of these superior results the 20 mm weapon
was selected and further development of the 13 mm rifle
was dropped. On September 6th, 1939, General Heinrichs
finally proposed that the production of this good weapon
should start immediately.
Before the production
of the weapon was started, the Winter War broke out, as the
Soviet Red Army attacked on November 30th, 1939. The two L-39
prototypes were first used on the Isthmus front*, near the
Lake Ladoga. The weapons were issued to the AT-platoon of
JR 28, and the platoon was subordinate to Os.Metsäpirtti (detachment
Metsäpirtti), which was part of the delaying / covering
troops of the Rautu (R-) group. The two prototype weapons
were used with great success against the light Soviet tanks,
and the weapon was reported to be effective at ranges of up
to 400 metres.
*
= Source "Marskin Panssarintuhoajat" by E.Käkelä. Some
other sources say that they were used in Ladoga Karelia
2 men were required to carry
this weapon off road. During winter, a sledge was used,
and on road marches a vehicle was used if available.
After the
Winter War
Later on, the L-39 received
improvements e.g. night sights, AA-sights and a
targeting scope.
In the attack phase in 1941
the 20 mm round proved to be too weak against most
types of tanks. As the L-39 proved to be a very
accurate weapon it was often used to destroy enemy
gun positions, mg-nests etc. at long range.
Beginning on 1944, the L-39 was also used against
the armored ground attack planes. A new pillar mount
was designed and the rifle was fitted with extra
recoil spring and a fixed striker for full automatic
operation. This full automatic AA-weapon was designated
as L-39/44.
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CHARACTERISTICS
OF L-39 ANTI TANK RIFLE
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Caliber:
System of operation:
Overall length:
Barrel length:
Weight:
Feed device:
Sights, Front:
Sights, Rear:
Max ROF:
Practical ROF:
Muzzle velocity:
Max (theoretical) range:
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20 mm
Gas-action, semi-automatic
2 240 mm ( 88.2 in )
1 300 mm ( 51.2 in )
49.5 kg ( 109 lbs. )
10-round box magazine
Blade
Tangent
30 r.p.m.
15 r.p.m.
800 m/s ( 2624 f.p.s. )
6.5 km |
The weight of the AP ball-cartridge
was 337 g, of which the AP-bullet weighted 152 g
Penetration
When the armor plate was at a 60° angle
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|
300 m |
500 m |
1 000 m |
Weapon manual |
20 mm |
16 mm |
12 mm |
Test firing in 1943 |
20 mm |
15 mm |
9 mm |
(Table source: "Marskin panssarintuhoojat",
p.110)
Note that
as no data is available from the armor plate hardness, the
performance isn't automatically comparable to the penetration
values of other weapons, especially if the used source is
different.
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Back to Top !
THE 14 mm MODEL 1937 ANTI TANK RIFLE
(The 0.55 inch "Boys" AT-rifle)
(Picture source:"Sotilaskäsiaseet Suomessa
1918 - 1988 osa 3", p.267)
This weapon was developed
in Britain, in the mid 30s. The weapon was named "Boys"
after one of its chief designers, Capt. Boys
(deceased just before the production started). It was
manufactured by Royal Small Arms Factory Enfield, and
it's original designation was "0.55 inch Boys Anti Tank
Rifle Mark 1".
100 of these weapons were donated
by the British government after the Winter War had begun.
They arrived in January, and were immediately distributed
to the troops. A second batch of 100 weapons arrived only
after the war had already ended.
From the 100 rifles that saw service,
30 were issued to the Swedish voluntary troops (SFK,
Svenska Frivilligkåren), as was wished by the
British government. The actual combat losses during the
Winter War was 6 rifles. Many others were discarded as
damaged or other reasons (in June 1940, 178 rifles
were left).
Back to Top !
CHARACTERISTICS
OF "Boys" ANTI TANK RIFLE
|
Caliber:
Overall length:
Barrel length:
Weight:
Feed device:
Muzzle velocity:
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13.97
mm
1 614 mm
915 mm
16.6 kg
5 round box
990 m/s |
While the caliber of the
weapon was quite small, the gun was said to be adequately
effective against the T-26 tanks, and lighter vehicles.
Of course, the requirement was that you should hit the
"soft" points of the tank.
The AP-projectile
(bullet) weighed 48 g
Penetration
When the armor at a 60° angle
(according to Mr.Honner's site, the muzzle velocity
was 908 m/s)
(Table
source: "Guns vs. Armour"-website, by D.M.Honner)
During the Finnish firing
tests, that were made during the war, the following penetration
was recorded by the
"14.00 psl"("AP-bullet), with the muzzle velocity of 750 m/s.
The armor plate was at a 70° angle.
100 m |
200 m |
300 m |
400 m |
500 m |
600 m |
800 m |
1 000 m |
1 500 m |
18 mm |
16 mm |
14 mm |
13 mm |
12 mm |
11 mm |
8 mm |
6 mm |
4 mm |
Data was kindly provided
by Esa Muikku
Note that
as no data is available from the armor plate hardness, the
performance isn't automatically comparable to the penetration
values of other weapons, especially if the used source is
different.
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Back to Top !
Special
THE
13 mm (13.2 mm) AT-MACHINE GUN L-35/36
(Picture source: "Marskin Panssarintuhoojat", p.107)
At the same time, when the
37 mm Bofors AT-gun was chosen as the primary AT-weapon,
a decision was made to choose the 13 mm heavy machine
gun (mg) as the secondary weapon for the
frontline troops. While many central European countries
like Germany and France decided to have only one AT-weapon,
the Finnish terrain (relatively few roads and short
firing ranges) also required also a lighter (and
cheaper) weapon for the infantry. The State Rifle
Factory ("Valtion Kivääritehdas") received
the order to design and manufacture a 13 mm mg.
The new weapon was to have
several requirements;
1) a high rate of fire, enabling the gunner to score at
least a few shots on an attacking tank
2) the weapon was to be accurate
3) and switching targets was to be fast.
One of the reasons why the
production of the "secondary" AT-weapon was delayed was
the so-called "Calibre squabble"("Kaliipeririita"
in Finnish), a public debate between two Army
officers, (then) Major Y.A.Järvinen
who opted for a 20 mm weapon, and Captain M.Terä,
who supported the production of the already chosen 13
mm AT-mg.
No serious resource allocations
were made to produce a prototype, so it took until 1938
to produce the first prototypes. The designer for the
gun was the well known Aimo Lahti.
A total of 6 AT-mg prototypes
were produced, of which one was a semi-automatic version.
In addition one mg was manufactured for the lone Landsverk
armored car, alongside with two different AA-version prototypes
(one single barreled and one 2-barreled).
A wheeled carriage was designed,
on which the weapon could be pulled or pushed. The AT-mg
could be disassembled into 4 parts, enabling the infantry
to carry them. It was possible to remove the gun from
the carriage, and converting the weapon into a semiautomatic
AT-rifle by attaching a bipod and a butt. The weight of
this AT-rifle was 35 kg, making it heavy compared to the
AP-performance.
(Picture source: "Marskin
Panssarintuhoojat", p.105)
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The weapon was finally tested
against its rival, the 20 mm L-39, which was ironically
also A.Lahti's design, and the L-39 was a clear winner.
The 13 mm weapon never went into production, and only
3 weapons saw service in the Winter War. One as the main
weapon of the Landsverk armored car, one as a single barreled
AA-mg, and one in its designed role as an AT-mg in the
Taipale sector in the Karelian Isthmus.
The weapon
was a failure in its AT-role. The previous weapon
tests had been made in the summer, so the weapon's tendency
to freeze was unnoticed. The battle experience showed
that the weapon wasn't suited for AT-role. It was said
that "even from a 30 m range, the weapon couldn't penetrate
the armor of a T-26 tank no matter where it was hit, plus
the weapon was always out of order".
Back to Top !
CHARACTERISTICS
OF THE L-35/36
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Caliber:
System of operation:
Overall length:
Barrel length:
Weight:
Feed device:
Cyclic rate:
Muzzle velocity:
Max range: |
13.2 mm
Gas-recoil
? (arm. car version, some 1.8 m)
?
70 - 75 kg
15-round metal belt (arm. car version, 20 round clip)
500 r.p.m.
1 000 m/s (arm. car version some 950 m/s)
5.4 km |
The weight of the AP-cartridge
was 160 g, of which the projectile weighed 50 g.
Penetration
When the armor was at an 60° angle.
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|
300 m |
500 m |
1 000 m |
Weapon manual |
22 mm |
18 mm |
12 mm |
Test firings in 1939 |
15 mm |
13 mm |
7 mm |
(Table source: "Marskin panssarintuhoojat",
p.105)
Note that
as no data is available from the armor plate hardness, the
performance isn't automatically comparable to the penetration
values of other weapons, especially if the used source is
different.
But the armor hardness
was probably quite low, when comparing the above figures to
the feedback
from the actual users.
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Back to Top !
THE
MOLOTOV COCKTAIL
Picture source:
"Talvisodan Historia 2", p.60
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While the Molotov Cocktail
was first used as a weapon in the Spanish civil war,
the "poor man's AT-weapon" was baptized as the "Molotov
Cocktail" in the Winter War. Even today it's a common
weapon of terrorists and rioters, because it's easy
to manufacture and to use.
The Molotov Cocktail, that
was used by the Finns in the Winter War was developed
by a design team, led by Captain Eero Kuittinen,
commander of the Er.PionK (the peace time separate
Pioneer company).
In 1939, a "Pioneer Technical
Manual, no.1" was printed in Viipuri, and according
to it, a 1/2 liter liquor bottle with a screw cap
was ideal for making this type of a weapon. As the
flammable liquid, petrol, spirit, a mixture of petrol
and kerosene or a mixture of waste spirit and kerosene,
could be used. The manual advised 1-2 cubic centimeters
of tar to be added, to create smoke.
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Picture
on the left was taken in the Armour Museum in Parola,
Finland
On the left are three diffent kinds
of "Molotov Cocktails". The bottle on the left is an empty
liquor bottle (the text "VIINAA" means booze), and it
has a piece of cloth tied around the bottle's neck. The
bottle in the center is a bit "improved", but still very
crude, and finally on the right is a factory-produced
version.
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For making the weapon, the
manual instructed: "After the bottle has been filled
with the liquid, the screw cap is properly closed
and sealed with an insulating tape. On the opposite
sides of the bottle, straps of cloth or insulating
tape is to be attached, to prevent the heat of the
"Bengal match" (a sort of a big match, that
didn't go out easily, also known as "myrskytikku"
in Finnish) from breaking the glass. Both
matches, with their insulating tapes, were fastened
on two points by more insulating tape (see
the example on the left) and wire used to
strengthen the result.
Picture source:
"Talvisodan
Pikkujättiläinen"
p. 314
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In Finland, as the lack
of AT-weapons was appalling, the industrial production
of Molotov Cocktails was quick to start. The production
began in the State Liquor factory in Rajamäki, and
while the early models had mostly petrol, the mixture
was soon changed into the following:
60 % of Potassium Chlorate
32 % of Coal tar
8% of Noulee
A total of 542
194 Molotov Cocktails were produced between December and
March, produced by a work force of 87 women and 5 men.
The late production
Molotov Cocktails had, as it's incendiary device a
small sulfuric acid capsule in the bottom of the bottle.
This removed the need for the AT-man to pre-ignite
the bottle, as the ignition medium was lit upon the
bottles breaking.
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Before the war, the
Molotov Cocktail was seen more as a weapon that would
blind or suppress the target tank, making it easier
to destroy it by other Molotov Cocktails or by satchel
charges. The idea of breaking the bottle on the rear
end of the tank (where the engine compartment
was located), near the ventilation, wasn't
yet realized, but that changed quickly after the war
started. The hot engine (the Soviet engines
at that time were gasoline engines) of the
tank caught fire quite easily, making this weapon
quite effective against the tanks of early WW 2.
Late in the war, the Soviet
tankers attached bushes or wire mesh to protect the
rear end of the tank (hoping that the bottle
wouldn't break, as it wouldn't hit the armor),
but the Finnish solution was to tie 2 - 3 stones at
the end of strings and tying the strings on the bottle
so that the stones would shatter the glass. Also barbwire
was wrapped around the bottle, so that if the bottle
hit the mesh protecting the ventilation, the chance
of setting the engine on fire increased.
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SATCHEL
CHARGE
("Kasapanos" in Finnish)
In 1936, Captain Kaarlo
Tuurna, serving in the Pioneer battalion, developed
the Finnish kasapanos. In tests it was noticed that 0.5
kg of TNT could break 12 mm of armor if pressed tightly
against the armor plate. Thus it was concluded that a
kasapanos with 0.8 kg of TNT was sufficient. This was
of course an insufficient explosive charge for WW 2 tanks,
but at least the basic design and requirements of the
weapon were set.
Although the industrial production
of satchel charges had been started before the war, the
design was developed further during the war. The factory
produced satchel charges (see examples left and
right), were made in 2 kg, 3 kg and 4 kg versions.
The explosives were in a box covered by sheet metal, while
the wooden handle and fuse were those of the stick hand
grenade (German m/32 hand grenade, the "potato
smasher").
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Picture was taken in the
Armour Museum in
Parola, Finland
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Picture source:
"Talvisodan
Pikkujättiläinen"
p. 314
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The early models of the
factory produced satchel charges had both of the larger
sides coated by special glue in order to decrease the
chance that the satchel charge would fall off from top
of the rear deck of the tank. The glued sides were protected
by plywood, which was removed only moments before the
throw. The glued satchel charge wasn't a success, as the
glue clung easily to the clothes (gloves etc.)
of the user. If the glue was touched by snow or
dirt, the effectiveness of the glue was reduced considerably.
The late production satchel
charges had small hooks on each side of the explosives
container box, on the "upper" edge (if holding
the satchel charge in hand, see example on the left).
The hooks were intended to clung the charge on the tank
(if lucky), e.g. to the wiring net covering
the engine ventilation. A more often used method to increase
the chance of getting the satchel charge to stay on top
of a tank was to attach barbed wire around the explosives,
which clung on more easily.
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Picture source:
"Talvisodan Historia 2", p.60
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Of course, the factory produced
satchel charges weren't the only ones used. The troops
made ones themselves, and in fact, Finns called nearly
all sorts of explosive bundles as "kasapanos". One simple
(and one of the most widely used) method
was to tie the explosives on a piece of wood (see
the picture on the right), and ignited by a priming
wire.
Effectiveness
of the "kasapanos"
It was quickly noted that a 1
- 2 kg charge was sufficient for severing the track of
a tank, if blown under or next to the track.
A satchel charge with 6 kg of explosives, built
around a stick hand grenade, was powerful enough to knock
out any tank met in the war, if it exploded on top the
tank (usually on the rear deck of a tank).
In a notice, issued on February
1940, to the ground troops by the Chief of Engineering
section of the Finnish General HQ, the effectiveness of
various explosive charges was reported to be as follows:
- 2 kg was sufficient to
destroy vehicles with the weight of around 6 tons
(FAI, BA-3, BA-6, BA-10, T-37, T-38)
- 3 kg was sufficient to
destroy vehicles with the weight of around 12
tons
(T-26, BT-2, BT-7)
- 4 kg was sufficient to
destroy vehicles with the weight of around 30
tons
(T-28)
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Back to Top !
AT-MINES
In 1932, the Finnish General
Staff set the requirements for an AT-mine, which was the
starting shot for the use of AT-mines in the Finnish military.
The start was difficult, and therefore a committee
led by Lt.Col K.Pylkkänen was formed, and in
1936, an AT-mine designed by the committee was approved
by the Army. The design (the m/36) was
mainly the handwriting of a committee member Lt.Col
T.Raatikainen.
The Ordnance section of the Defense
Ministry developed the design of the m/36 further, and
the more powerful design (the m/39) was
accepted in 1939. While it was was very easy and quick
to build a mine barrier with m/36 mines, the m/36 and
m/39 were kept under tight secrecy (even from career
soldiers) well until 1938, which caused the mine
model with its relatively complicated fuse to be quite
unknown among the reservist pioneers.
As the casing material of both
of the previous mine types was iron, and both types were
difficult to produce, a mine with a simple construction
and a wooden casing was introduced (the m/S-39).
As the mobilization ("extra
rehearsal", "YH" in Finnish) started, the total
number of AT-mines was only 5 000 (4 825 mines
were given to the troops in the Karelian Isthmus, while
the troops defending the rest of the border received only
175 mines), all of which were m/36. The production
of m/39 hadn't even begun yet. Between Nov 10th and 26th,
the Army received only 2 157 new AT-mines. The shortage
of factory produced AT-mines, and the complete absence
of factory produced anti-personnel mines, forced the troops
to build most of the mines and booby-traps themselves.
One self made AT-mine was a piece of log that was split
in two, carved hollow and filled with explosives.
Of course, guidelines and instructions
for this were available for the troops. The troops had
app. 10 000 percussion fuses, 10 000 friction fuses, 300
000 blasting caps with priming wire, 150 000 electric
caps, 35 000 m of exploding priming wire (blasting
cable?), 150 000 m of priming wire and some 226
tons of explosives.
During the war, thousands of AT-mines
were bought from abroad, e.g. some 60 000 from Britain
alone.
Back to Top !
AT-mine
m/36
Total
weight: |
5.5 kg |
Explosives
weight: |
2.8 kg |
Height: |
13 cm |
Base
width: |
31 cm |
Cover
width: |
26 cm |
The mine had a cast
iron casing, and the fuse required a weight of 350
kg, to detonate the mine. The first fuse design
wasn't satisfactory, as it was judged to be too
complicated (a new fuse type wasn't developed
until after the Winter War). Also the explosive
charge was considered too small.
The toothing of the
base plate made it difficult to use the mine daisy
chained, where a rope is fastened to a mine (or
several mines), and pulled on the last minute
under the track to ensure a "hit".
1. cap of the detonator
("kansitulppa" in Finnish)
2. spring ("jousi")
3. cover plate ("painokansi)
4. pitch gasket ("pikitiiviste")
5. explosive container ("räjähdysainesäiliö")
6. handle ("sanka")
7. explosive ("räjähdysaine")
8. fuse ("sytytin")
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Picture was taken in the Armour
Museum in Parola, Finland
(Source: "Marskin panssarintuhoojat",
p.52)
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Back to Top !
AT-mine
m/39
Total
weight: |
7 kg |
Explosives
weight: |
3.2 - 3.5
kg |
Height: |
12 cm |
Width: |
23 cm |
The mine had an iron
casing, the strength of the explosion could be increased
by adding an extra 2.5 kg of TNT below the mine.
1. cap of the detonator
("kansitulppa" in Finnish)
2. cover plate ("painokansi")
3. spring ("jousi")
4. pitch gasket ("pikitiiviste")
5. hoop ("vanne")
6. explosive container ("räjähdysainesäiliö")
7. plywood box ("vanerirasia")
8. detonator tube ("räjäyttimen putki")
9. detonator ("räjäytin")
10. fuse ("sytytin")
11. explosive ("räjähdyspanos")
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Picture was taken in the Armour
Museum in Parola, Finland
(Source: "Marskin panssarintuhoojat",
p.95)
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Back to Top !
AT-mine
m/S-39
Total
weight: |
6.5 - 7.5
kg |
Explosives
weight: |
3 - 3.8
kg |
As iron become more
expensive and as the iron casing was relatively
hard to produce, a mine with a wood casing was designed.
The wooden casing
reduced production costs, and made it easy to manufacture.
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(Picture source: "Talvisodan
Historia 1", p.175)
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The 37 mm
Infantry Guns
37 K/14 and 37 K/15
The acute shortage of antitank weapons forced
the Finnish Army to use quite desperate tools in an effort to
increase antitank capability. One of these efforts was the use
of old WW1 vintage infantry guns in an antitank role.
Finland had 14 old infantry guns, the 37 mm
Infantry Gun Model 1914 (made by Obuhoff) and 37 mm Infantry
Gun Model 1915 (made by Rosenberg). Both were (as far as I know)
Russian built during the WW1 and captured by the Finns during
the War of Independence.
In order to make statistics more pretty, these
type of guns were listed as 37 mm AT-guns with the 37
PstK/36 (Bofors). Some were even sent before the war to
front-line units, such as the 15th Infantry Regiment (JR 15)
of the 5th Division, defending in the Summa sector. The JR 15
had in early November received a two gun platoon of 37 mm Bofors
guns. Around mid-November it received two platoons of 37 mm
Infantry Guns (five 37 K/15 guns each), and combined them into
an antitank company.
As both guns were able to defeat only 10 mm
of armor (if the plate was vertical, i.e. 90 degree angle) from
a range of 200 meters, using a solid steel shot, all guns of
this type were quietly withdrawn from the front-line after the
first engagements, as totally useless weapons.
Back
to "Weapons used in Winter War" -page
Back
to "Finnish AT-weapons"-page
Go to Part I
Proof-read by: Dale
Milton, Solomons Maryland USA
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