Cutaway model of six cartridges (pict 01) for the Belgian FRC 47mm C 47 Anti-Tank Gun. The offical Belgian name of the gun was the “Canon antichar de 47mm SA FRC M.31 (L/34)”. The gun was designed and produced in the 1930’s by the Fonderie Royale de Canons (FRC) in Herstal. It was used in three different versions: towed anti tank gun in the field army, fixed anti tank gun in bunkers and forts, and motorised gun aboard the Belgian T-13 light tank destroyer. It was an effective gun by all accounts. The relatively low weight of the gun allows it to be manhandled. At least 750 guns were in use in 1940. The Germans took over the C.47 guns as spoils of war and called it the 4.7cm PaK 185(b). Most ended service as coastal guns in the defensive works of the Atlantikwal, positioned from Guernsey upward along the coast up to the Frysian islands in the north of the Netherlands.
Within the C47 gun two types were available and in use; the model 1932 (pict 12) and the model 1936 (pict 13). The difference between the two guns was that model 1936 was the shorter gun version, making it more suitable for use in bunkers.
Weight of the towed gun : 525kg.
Elevation : -5 to +20.
Traverse : 20deg.
Rate of fire : 18rpm.
Effective range of the gun : 2000 mtrs.
Shellcases are brass made and 280mm long. A percussion primer with a black powder magazine is placed in the base of the shellcase. The most common base stamp is C.47 (12 o’clock), 1937 (year of manufacturing at 3 o’clock), FN (Fabrique National at 6 o’clock), and the lot number which is placed at 9 o’clock.
Nine types of cartridges were available;
Left on picture 01/02 :
The “cartouche a OEA” (cartouche a Obus Explosive En Arcier / High explosive cartridge with a steel projectile body) cartridge of which the projectile is fuzed with the “Fusee detonateur percutante de 24/31 R.Y.G Mle 1918- instantane”. The HE projectile weighs 1.665kg and has a Vo: 450m/s to a 5400m max. range. The complete cartridge weighs 2,435 kg.
The powdercharge in the shellcase exists of two packages of powderstrips, each package tied together with strings; All strips are 14,3 mm wide and appr. 0,5mm thick. In the lower package the strips are 134,3mm long, in the upper package the strips are 65,7 mm long. The total weight of the propelling charge is 0.155 kg.
The projectile body is hot pressed and machined and is made of mild steel. When pressing the projectile body over a rod while manufacuring, the chance exists that microscopic small cracks appear in the base. To prevent hot gasses from the propelling charge to reach the 0,175 Kg TNT charge in the projectile body upon firing, a 0,5mm thick steel disc is brassed to the base of the projectile. This acts as a gasket and so prevents the projectile from premature explosion. The projectile body is threaded on the inside in top to receive the sheet metal transport bushing, which is placed in the cast explosive TNT charge. All types of 47mm C47 projectiles have a red copper driving belt. The colour of the HE projectile is ocre/yellow with black ink stenceling.
Picture 05/06/07 :
Functioning of the fuze “fusee detonateur percutante de 24/31 R.Y.G Mle 1918- instantane”:
This fuze is a instantanious impact fuze with an –according to the instructionbooklet- 0,001sec delay between impact and activation. It exists of a long brass body (A) with a protruding mushroom shaped aluminium dome (B) on top. The booster (C) is screwed in the base. The firing cap (D,red) is placed in the firing cap housing (E) . This is a long tube with grooves machined in the upper part which also houses the firing pin (F,white). Two bushings are placed over the top part of the tube. Both bushings are kept in upward position by a spring. The inner bushing (G,blue) has six longitudal lips with grabbing hooks on the inside, the lockingbush (H,green) has a rim on the inside that forces the lips into their inner position when in locked position. In this safe position –before firing-, the firing pin (white) cannot reach the firing cap, even if the aluminium dome on top is fully pressed downward (5mm). Upon firing, inertia moves down the lockingbush, -riding the spring (J)-, followed by the inner bushing (blue), the hooks slipping over the lower grooves. At a certain moment both bushings are in their lowest position, and as soon as the lockingbush starts moving upward again, the hooks of the inner ring (blue) are locked in the lower groove, preventing it from moving upward again. As accerleration of the projectile has now stopped, the weaker lower spring (K) will force the tube with the interlocked bushings –in lower position- forward, moving the firing cap(red) forward to just a few tenth of a mm below the point of the firing pin (white). Upon impact, the aluminium dome is hammered inward, pushing the firing pin into the firing cap. As can be expected this fuze is very sensitive.
Second from left on picture 01 / right on picture 02 :
The same “cartouche a OUA” (cartouche a Obus Explosive Arcier / High explosive cartridge with a steel projectile body) cartridge of which the projectile is fuzed with the “Fusee detonateur percutante de 24/32 Modele 1899”.
Picture 03/04:
Functioning of the fuze “Fusee detonateur percutante de 24/32 Modele 1899”:
Upon firing, inertia moves back the upper arming ring (3) inside the nose cap (2), riding the spring (4). The three inward bent lips of the locking ring inside the upper arming ring grip over the rim of the firing pin masking fork (5)below it. The upper arming ring is locked in lower position and cannot move upward again.
Also upon firing the lower arming ring (6, light green) moves back, riding the spring below it. Around this lower arming ring another ring with inward bet spring lips is placed (7, light blue) which prevents the firing cap housing (8) from moving forward. When the lower arming ring (6) is moved back by inertia upon firing, it bends the lips of the outer ring (7, light blue) outward, releasing the firing cap housing (8). The lower arming ring is locked behind the rim of the firing cap housing and cannot move up again. The only thing that now hold back the firing cap housing (8) is a light pull type spring (10) that is screwed in a thread in the firing cap housing , as well as a thread in the flange below. Upon impact, the firin cap housing is thrown forward –stretching the spring (10)- , as well as the firing pin masking bolt (5) which is thrown forward, releasing the firing pin (red). The firing cap (blue) is driven into the firing pin. The flame of the firing cap is led through black powder booster pellets (9,11) which boosts the flame into the detonator (12). This will explode the booster in the projectile as well as the main charge.
In this cutaway one side of the firing pin masking fork (5) has been cut off (dark green surface) to make the firing pin (red) visable.
Picture 08 :
There is also a practice version of the High Explosive projectile, the OEFA (Obus Explosive Fonte Arcier / High explosive cartridge with cast iron projectile body). The projectile was –according to my calculations- 159,5mm long (against 190mm for the HE) and filled with firmly pressed black powder. The projectile colour was red. It was used with the “fusee detonateur percutante de 24/31 R.Y.G Mle 1918- instantane”.
Third from the left on picture 01 :
The “cartouche a ORPT” (cartouche a Obus Rupture Pastille Tracante / cartridge with armour piercing projectile and tracer element). The projectile exists of a steel projectile with a hardened nose. A machined aluminium windshield is screwed on top of the projectile. A pressed steel cup –containing the tracer mixture- is kept in place with four indentations in the base of the projectile. The projectile weighs 1.56kg and has a Vo: 675m/s. The complete cartridge weighs 2,61kg.
The powdercharge in the shellcase exists of two packages of powderstrips, each package tied together with strings; All strips are 14,3 mm wide and appr. 0,5mm thick. In the lower package the strips are 134,3mm long, in the upper package the strips are 65,7 mm long. The total weight of the propelling charge is 0,315 kg.
Penetration: 57.7mm face hardened steel plate at 0 deg @ 300mtrs; 47.5mm facehardened steel plate at 30deg @300 mtrs.
The colour of the projectile is grey with black ink stenceling.
Third from the right on picture 01 :
The “cartouche a ORFA d’instruction” (cartouche a Obus Rupture en Fonte Arcier d’instruction / practice cartridge with Armour piercing projectile from cast iron). This is a practice armour piercing shot that was made of cast iron. It was not hardened. The tracer mixture is placed in a drilled hole in the base of the projectile.
The powdercharge in the shellcase exists of two packages of powderstrips, each package tied together with strings; All strips are 14,3 mm wide and appr. 0,5mm thick. In the lower package the strips are 134,3mm long, in the upper package the strips are 65,7 mm long. The total weight of the propelling charge is 0,315 kg.
Second from the right on picture 01 :
The flatnosed projectile. The projectile is made of cast iron and has a flat nose. It may be a short range practice projectile, either a high pressure test cartridge. A pressed steel cup –containing the tracer mixture- is kept in place with four indentations in the base of the projectile.
The powdercharge in the shellcase exists of two packages of powderstrips, each package tied together with strings; All strips are 14,3 mm wide and appr. 0,5mm thick. In the lower package the strips are 134,3mm long, in the upper package the strips are 65,7 mm long. The total weight of the propelling charge is 0,315 kg.
Right on picture 01 :
The “SM” (Salvo en Manoeuvre / Blank). It has no projectile. It has a powdercharge of 100 grams B.C.N.1 powderstrips, tied together in a package, placed in the base of the shellcase. On top, two three mm thick cartboard discs are placed. Two other 3 mm cartboard discs are placed appr. 12 mm below the top of the shellcase mouth. The space between these discs is filled with pressed saw dust.
Picture 09 :
The “Douille d’instruction amorcee”, subcalcalibre training round. The cartridge exists of a shellcase with a round brass cap fixed to the top. In the base a steel ring is placed, which houses a short barrel that protrudes through the top of the round brass cap. The cartridge used in this subcalibre training device are the 8x57 cartridges. I do not know if these were standard cartridges, either special training cartridges with adjusted powdercharges/bullet weight. It forms however a cheap way of training with much cheaper 8x57 rifle cartridges over the more expensive 47mm ORFA d’instruction rounds.
Picture 10 :
The “cartouche d’exercise”, or exercise cartridge. It exists of a normal shellcase in which a dome shaped wooden nosepiese is fixated with screws. The wooden dome is painted black. It has the text “Exercise” painted in white on the black dome.
Picure 11 :
When transported from the factory / storage area to the front, a transport plug is placed, to avoid the fuze well and thread from fouling. It exits of a felt pad locked up between two thin steel discs held together by a wingnut shaped wire.
The OEFA, (picture 8), the subcalcalibre training round (picture 09) and the Exercise cartridge (picture 10) are still missing in my collection (as a cutaway model) . If anybody can help me on these cartridges, please let me know.
A big thank you to BLU-97 , Chris and Yodamaster for their great help and support on this posting
Regards, DJH
Within the C47 gun two types were available and in use; the model 1932 (pict 12) and the model 1936 (pict 13). The difference between the two guns was that model 1936 was the shorter gun version, making it more suitable for use in bunkers.
Weight of the towed gun : 525kg.
Elevation : -5 to +20.
Traverse : 20deg.
Rate of fire : 18rpm.
Effective range of the gun : 2000 mtrs.
Shellcases are brass made and 280mm long. A percussion primer with a black powder magazine is placed in the base of the shellcase. The most common base stamp is C.47 (12 o’clock), 1937 (year of manufacturing at 3 o’clock), FN (Fabrique National at 6 o’clock), and the lot number which is placed at 9 o’clock.
Nine types of cartridges were available;
Left on picture 01/02 :
The “cartouche a OEA” (cartouche a Obus Explosive En Arcier / High explosive cartridge with a steel projectile body) cartridge of which the projectile is fuzed with the “Fusee detonateur percutante de 24/31 R.Y.G Mle 1918- instantane”. The HE projectile weighs 1.665kg and has a Vo: 450m/s to a 5400m max. range. The complete cartridge weighs 2,435 kg.
The powdercharge in the shellcase exists of two packages of powderstrips, each package tied together with strings; All strips are 14,3 mm wide and appr. 0,5mm thick. In the lower package the strips are 134,3mm long, in the upper package the strips are 65,7 mm long. The total weight of the propelling charge is 0.155 kg.
The projectile body is hot pressed and machined and is made of mild steel. When pressing the projectile body over a rod while manufacuring, the chance exists that microscopic small cracks appear in the base. To prevent hot gasses from the propelling charge to reach the 0,175 Kg TNT charge in the projectile body upon firing, a 0,5mm thick steel disc is brassed to the base of the projectile. This acts as a gasket and so prevents the projectile from premature explosion. The projectile body is threaded on the inside in top to receive the sheet metal transport bushing, which is placed in the cast explosive TNT charge. All types of 47mm C47 projectiles have a red copper driving belt. The colour of the HE projectile is ocre/yellow with black ink stenceling.
Picture 05/06/07 :
Functioning of the fuze “fusee detonateur percutante de 24/31 R.Y.G Mle 1918- instantane”:
This fuze is a instantanious impact fuze with an –according to the instructionbooklet- 0,001sec delay between impact and activation. It exists of a long brass body (A) with a protruding mushroom shaped aluminium dome (B) on top. The booster (C) is screwed in the base. The firing cap (D,red) is placed in the firing cap housing (E) . This is a long tube with grooves machined in the upper part which also houses the firing pin (F,white). Two bushings are placed over the top part of the tube. Both bushings are kept in upward position by a spring. The inner bushing (G,blue) has six longitudal lips with grabbing hooks on the inside, the lockingbush (H,green) has a rim on the inside that forces the lips into their inner position when in locked position. In this safe position –before firing-, the firing pin (white) cannot reach the firing cap, even if the aluminium dome on top is fully pressed downward (5mm). Upon firing, inertia moves down the lockingbush, -riding the spring (J)-, followed by the inner bushing (blue), the hooks slipping over the lower grooves. At a certain moment both bushings are in their lowest position, and as soon as the lockingbush starts moving upward again, the hooks of the inner ring (blue) are locked in the lower groove, preventing it from moving upward again. As accerleration of the projectile has now stopped, the weaker lower spring (K) will force the tube with the interlocked bushings –in lower position- forward, moving the firing cap(red) forward to just a few tenth of a mm below the point of the firing pin (white). Upon impact, the aluminium dome is hammered inward, pushing the firing pin into the firing cap. As can be expected this fuze is very sensitive.
Second from left on picture 01 / right on picture 02 :
The same “cartouche a OUA” (cartouche a Obus Explosive Arcier / High explosive cartridge with a steel projectile body) cartridge of which the projectile is fuzed with the “Fusee detonateur percutante de 24/32 Modele 1899”.
Picture 03/04:
Functioning of the fuze “Fusee detonateur percutante de 24/32 Modele 1899”:
Upon firing, inertia moves back the upper arming ring (3) inside the nose cap (2), riding the spring (4). The three inward bent lips of the locking ring inside the upper arming ring grip over the rim of the firing pin masking fork (5)below it. The upper arming ring is locked in lower position and cannot move upward again.
Also upon firing the lower arming ring (6, light green) moves back, riding the spring below it. Around this lower arming ring another ring with inward bet spring lips is placed (7, light blue) which prevents the firing cap housing (8) from moving forward. When the lower arming ring (6) is moved back by inertia upon firing, it bends the lips of the outer ring (7, light blue) outward, releasing the firing cap housing (8). The lower arming ring is locked behind the rim of the firing cap housing and cannot move up again. The only thing that now hold back the firing cap housing (8) is a light pull type spring (10) that is screwed in a thread in the firing cap housing , as well as a thread in the flange below. Upon impact, the firin cap housing is thrown forward –stretching the spring (10)- , as well as the firing pin masking bolt (5) which is thrown forward, releasing the firing pin (red). The firing cap (blue) is driven into the firing pin. The flame of the firing cap is led through black powder booster pellets (9,11) which boosts the flame into the detonator (12). This will explode the booster in the projectile as well as the main charge.
In this cutaway one side of the firing pin masking fork (5) has been cut off (dark green surface) to make the firing pin (red) visable.
Picture 08 :
There is also a practice version of the High Explosive projectile, the OEFA (Obus Explosive Fonte Arcier / High explosive cartridge with cast iron projectile body). The projectile was –according to my calculations- 159,5mm long (against 190mm for the HE) and filled with firmly pressed black powder. The projectile colour was red. It was used with the “fusee detonateur percutante de 24/31 R.Y.G Mle 1918- instantane”.
Third from the left on picture 01 :
The “cartouche a ORPT” (cartouche a Obus Rupture Pastille Tracante / cartridge with armour piercing projectile and tracer element). The projectile exists of a steel projectile with a hardened nose. A machined aluminium windshield is screwed on top of the projectile. A pressed steel cup –containing the tracer mixture- is kept in place with four indentations in the base of the projectile. The projectile weighs 1.56kg and has a Vo: 675m/s. The complete cartridge weighs 2,61kg.
The powdercharge in the shellcase exists of two packages of powderstrips, each package tied together with strings; All strips are 14,3 mm wide and appr. 0,5mm thick. In the lower package the strips are 134,3mm long, in the upper package the strips are 65,7 mm long. The total weight of the propelling charge is 0,315 kg.
Penetration: 57.7mm face hardened steel plate at 0 deg @ 300mtrs; 47.5mm facehardened steel plate at 30deg @300 mtrs.
The colour of the projectile is grey with black ink stenceling.
Third from the right on picture 01 :
The “cartouche a ORFA d’instruction” (cartouche a Obus Rupture en Fonte Arcier d’instruction / practice cartridge with Armour piercing projectile from cast iron). This is a practice armour piercing shot that was made of cast iron. It was not hardened. The tracer mixture is placed in a drilled hole in the base of the projectile.
The powdercharge in the shellcase exists of two packages of powderstrips, each package tied together with strings; All strips are 14,3 mm wide and appr. 0,5mm thick. In the lower package the strips are 134,3mm long, in the upper package the strips are 65,7 mm long. The total weight of the propelling charge is 0,315 kg.
Second from the right on picture 01 :
The flatnosed projectile. The projectile is made of cast iron and has a flat nose. It may be a short range practice projectile, either a high pressure test cartridge. A pressed steel cup –containing the tracer mixture- is kept in place with four indentations in the base of the projectile.
The powdercharge in the shellcase exists of two packages of powderstrips, each package tied together with strings; All strips are 14,3 mm wide and appr. 0,5mm thick. In the lower package the strips are 134,3mm long, in the upper package the strips are 65,7 mm long. The total weight of the propelling charge is 0,315 kg.
Right on picture 01 :
The “SM” (Salvo en Manoeuvre / Blank). It has no projectile. It has a powdercharge of 100 grams B.C.N.1 powderstrips, tied together in a package, placed in the base of the shellcase. On top, two three mm thick cartboard discs are placed. Two other 3 mm cartboard discs are placed appr. 12 mm below the top of the shellcase mouth. The space between these discs is filled with pressed saw dust.
Picture 09 :
The “Douille d’instruction amorcee”, subcalcalibre training round. The cartridge exists of a shellcase with a round brass cap fixed to the top. In the base a steel ring is placed, which houses a short barrel that protrudes through the top of the round brass cap. The cartridge used in this subcalibre training device are the 8x57 cartridges. I do not know if these were standard cartridges, either special training cartridges with adjusted powdercharges/bullet weight. It forms however a cheap way of training with much cheaper 8x57 rifle cartridges over the more expensive 47mm ORFA d’instruction rounds.
Picture 10 :
The “cartouche d’exercise”, or exercise cartridge. It exists of a normal shellcase in which a dome shaped wooden nosepiese is fixated with screws. The wooden dome is painted black. It has the text “Exercise” painted in white on the black dome.
Picure 11 :
When transported from the factory / storage area to the front, a transport plug is placed, to avoid the fuze well and thread from fouling. It exits of a felt pad locked up between two thin steel discs held together by a wingnut shaped wire.
The OEFA, (picture 8), the subcalcalibre training round (picture 09) and the Exercise cartridge (picture 10) are still missing in my collection (as a cutaway model) . If anybody can help me on these cartridges, please let me know.
A big thank you to BLU-97 , Chris and Yodamaster for their great help and support on this posting
Regards, DJH
Attachments
-
01 - six different types of 47mm C47 cartridges.jpg -
02 - HE projectiles for 47mm C47 gun.jpg -
03 - Fusee detonateur percutante de 24-31 Mle 1899 with numbers.jpg -
04 - dwg-pic fusee detonateur percutante de 24-32 Mle 1899.jpg -
05 - Fusee detonateur percutante de 24 31 RYG Mle 1918 instantee with numbers.jpg -
06 - Fusee detonateur percutante de 2431 RYG Mle 1918 instantee.jpg -
07 - safety mechanism Fusee detonateur percutante de 24 31 RYG Mle 1918 instantee with numbers.jpg -
08 - OEFA (Obus Explosive Fonte Arcier d instruction.jpg -
09 - drawing 8x57 mm subcalibre training device for 47mm C47 gun..jpg -
10 - 47mm C47 exercise cartridge.jpg
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