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Post-Wwii Infantry & Artillery Training Film " Firepower Versus The Pillbox " 17204


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#21 DougRichards

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Posted 08 January 2020 - 1756 PM

"But wouldn't the HE shell of the M10 have less paylaod than the 75 mm? Or did that only apply to the 76 mm and not the 3 inch gun on the US M10s?"

Yes, but if you put it right into the bush the Pak40 is hidden in it doesn't matter. Both gun's ballistic were identical. The 76mm was the new and much lighter version of the 3". I think the ammo wasn't interchangeable though.

Hogg notes that the 3" AT gun fired the same HE round as the 3" AA gun, with a filling of .86lb of TNT.  He also notes that the 76mm AT gun used the same projectiles as the 3" AT gun (different cases). 

 

The US 75mm tank guns (and the 75mm howitzer) fied an HE round with 1.47lb TNT filling.


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#22 Inhapi

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Posted 08 January 2020 - 1821 PM

No, the M12 and its French origin 155 field gun wasn't a low velocity howitzer (howitzer ny nature are low velocity), who says so? And what is your point?

But when WWII tanks were fitted with howitzers - usually 75-105mm in place of their original medium to high velocity the reason behind is often quoted as "bunker busting". An example could be the M4 which in some numbers had the 75mm M3 medium velocity tank gun replaced by a 105 mm howitzer. And most of them I suppose produced after the film was made (1943?).

 

But if the results claimed in the film are valid, the 75 mm medium velocity gun would be much better in busting bunkers than the 105 mm howitzer.

 

Perhaps "concrete pillboxes" wasn't a very big concern and "bunkers" rather meant sand bags and logs - ie. field fortifications?

I think that is the case. field fortifications could be very numerous and quickly constructed from the moment the front stabilised for a while, while real heavy bunkers (thick concrete walls with heavy rebar reinforcment and armoured parts) were actually quite rare to very rare outside established fortified lines. These lines were usually build before the war, there is no way you can quickly build a series of Maginot line strength bunkers when the front moves. (lots of logistics and planning for long lead order items needed, also the thick concrete takes ages to cure properly)

Yes you hear about quickly build fortified lines (like in Britain in 1940), but these were usually pillboxes with very thin concrete walls and little rebar and no armoured cupolas/turrets/embrasures.


Edited by Inhapi, 08 January 2020 - 1825 PM.

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#23 DougRichards

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Posted 08 January 2020 - 1954 PM

 

No, the M12 and its French origin 155 field gun wasn't a low velocity howitzer (howitzer ny nature are low velocity), who says so? And what is your point?

But when WWII tanks were fitted with howitzers - usually 75-105mm in place of their original medium to high velocity the reason behind is often quoted as "bunker busting". An example could be the M4 which in some numbers had the 75mm M3 medium velocity tank gun replaced by a 105 mm howitzer. And most of them I suppose produced after the film was made (1943?).

 

But if the results claimed in the film are valid, the 75 mm medium velocity gun would be much better in busting bunkers than the 105 mm howitzer.

 

Perhaps "concrete pillboxes" wasn't a very big concern and "bunkers" rather meant sand bags and logs - ie. field fortifications?

I think that is the case. field fortifications could be very numerous and quickly constructed from the moment the front stabilised for a while, while real heavy bunkers (thick concrete walls with heavy

Yes you hear about quickly build fortified lines (like in Britain in 1940), but these were usually pillboxes with very thin concrete walls and little rebar and no armoured cupolas/turrets/embrasures.

 

Or broken down Covenanter tanks.  :P


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#24 Inhapi

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Posted 09 January 2020 - 1129 AM

 

 

No, the M12 and its French origin 155 field gun wasn't a low velocity howitzer (howitzer ny nature are low velocity), who says so? And what is your point?

But when WWII tanks were fitted with howitzers - usually 75-105mm in place of their original medium to high velocity the reason behind is often quoted as "bunker busting". An example could be the M4 which in some numbers had the 75mm M3 medium velocity tank gun replaced by a 105 mm howitzer. And most of them I suppose produced after the film was made (1943?).

 

But if the results claimed in the film are valid, the 75 mm medium velocity gun would be much better in busting bunkers than the 105 mm howitzer.

 

Perhaps "concrete pillboxes" wasn't a very big concern and "bunkers" rather meant sand bags and logs - ie. field fortifications?

I think that is the case. field fortifications could be very numerous and quickly constructed from the moment the front stabilised for a while, while real heavy bunkers (thick concrete walls with heavy

Yes you hear about quickly build fortified lines (like in Britain in 1940), but these were usually pillboxes with very thin concrete walls and little rebar and no armoured cupolas/turrets/embrasures.

 

Or broken down Covenanter tanks.  :P

 

 

They were not even good for that, much to thin armour for static positions. Logs with a layer of earth will withstand arty better than the thin steel of a Covenanter (especially on top)


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#25 Inhapi

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Posted 09 January 2020 - 1156 AM

OTOH:

 

Quickly build, rather tough fortifications were not entierly impossible: An example is the German armoured machine gun nest, which could case a lot of trouble; And the modified Panther turrets sometimes mounted on log bunkers.


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#26 R011

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Posted 09 January 2020 - 1425 PM

I think the Panther turrets were placed mostly where they had the time to prepare fortifications, like in Italy.  I don't think they had much time to place them in NW Europe given the fluid conditions, and I don't recall hearing of them there.


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#27 Stuart Galbraith

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Posted 10 January 2020 - 0305 AM

Speaking of the UK, they used a variety of materials and different types. They certainly used concrete, Im also fairly certain ive seem some made out of red brick. There was also some specialized types made in the southeast that were almost like a concrete garage, and could mount a 2 pdr, or possibly even a 6pdr antitank gun.

 

Ive not see pictures of Panther turrets emplaced outside Italy either. Did they use them on the Eastern Front? Strikes me as a waste of effort there.


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#28 DougRichards

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Posted 10 January 2020 - 0535 AM

Speaking of the UK, they used a variety of materials and different types. They certainly used concrete, Im also fairly certain ive seem some made out of red brick. There was also some specialized types made in the southeast that were almost like a concrete garage, and could mount a 2 pdr, or possibly even a 6pdr antitank gun.

 

Ive not see pictures of Panther turrets emplaced outside Italy either. Did they use them on the Eastern Front? Strikes me as a waste of effort there.

A reasonable number of ex US 75mm were received some of which were pedestal mounted.  It is not hard to believe that a number of these received some protection rather than being left out like the proverbial shag on a rock. They were considered to be 'coastal artillery equipment' but were really for beach defence.

 

About 8k from my home are some WW2 concrete emplacements for otherwise obsolete 18pdr guns that gunners arranged concrete mountings, overhead and other concrete cover.  This was nominally to protect Port Botany from attack by Japanese torpedo boats... (yeah sure, 8000 kilometres from Nippon to Sydney).  More likely to defend the nearby 9.2in battery from shore parties from Japanese submarines or cruisers.

 

The artillery personnel sent to this little battery were from an anti-tank unit to train local choco soldiers (chocolate - melt in the sun, nothing racial) in using emplaced 18pdrs against moving targets.

 

I am sure that the Brits / Cannucks / Kiwis had similar things happen.

 

The place was Henrys Head

 

http://postcardsydne...tional-Park.jpg

 

A few years ago I was walking one of my annual pilgrimages to the site when I encountered two 'young' women

(well they were young to me) asking about the bushwalk to Henrys Head.  They had taken a wrong turn and had walked onto a local unofficial nude beach, where the Henry's Head that they expected was not as expected....)  I walked them to the proper place and gave them some history along the way.

 

henrysheadbatterypano_wm-640x360.jpg


Edited by DougRichards, 10 January 2020 - 2041 PM.

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#29 Inhapi

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Posted 10 January 2020 - 0653 AM

Found this interesting page on the Pantherturm, with drwings of different types of mounting: concrete, steel box and wood. In the picture gallery you can see that these were used on the eastern front.

 

https://ww2-germanar...213-pantherturm

 

IIRC there is one still in existence in a museum on the Siegfried line and one in a Museum in Poland, but of both of these i am not sure wether these are in the original position. The one in Poland IIRC has at least the Iron structure of a Pantherturm emplacement under it, so it is not a re-purposed turret from a tank.


Edited by Inhapi, 10 January 2020 - 0657 AM.

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#30 Markus Becker

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Posted 11 January 2020 - 0427 AM

https://postimg.cc/gallery/18r46v6ea/

Irrel, Germany. From the 2014 I&I, though that one has been put there post war as decorations.
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#31 CaptLuke

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Posted 11 January 2020 - 1318 PM

A more or less similar message comes from the US XIX Corps study called "Breaching the Siegfried Line"  This is, in turn, fairly consistent with anecdotal evidence from US operations in Aachen and Metz where the M12, though ponderous and vulnerable in direct fire, was revered for taking down reinforced structures with a few rounds.

 

The effect of direct artillery hits on the pillboxes, except the 155mm SP gun and possibly heavier calibers, was not sufficient to destroy the box or prevent its future use. The concussion by a direct hit certainly discouraged not too strong-hearted defenders. The 57mm anti-tank gun, 75mm and l05mm were, except for direct hit in the embrasures itself, ineffective. They could remove the camouflage but little else. The 155mm howitzer required an uneconomical number of rounds to secure direct hits. The 155mm SP guns at ranges between 2000 and 4000 yards with a concrete bursting fuze penetrated the 6 feet of reinforced concrete with 3 to 5 hits. The 8 inch howitzers at 8000 yards could average a direct hit per 5 rounds, and penetrate after 5 hits. 

 

One other interesting comment that pops up is that the M12 was less effective at ranges under 2000 yards because the higher impact velocities caused the shell to break up before full penetration was achieved.  At least one unit started training gunners to stop using the highest charge for short range direct fire to reduce impact velocity.


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#32 shep854

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Posted 11 January 2020 - 1853 PM

"What tanks did the Canadians have in Afghanistan?

"The Royal Danish Army had a platoon of Leo 2s in Afghanistan and I know they were very valued for their 120 mm HE shells and often settled the matter by just showing up." --Redbeard
The Canadians had some Leo 1s, replaced by 2s. The 1s were popular for their 105mm HESH, and both versions were liked for their long-range accuracy, allowing a tank in good overwatch to cover fairly large areas with effective direct fire. IIRC, Franko's first tour was in Leo 1s. The same held for the Danish tanks as well, without a doubt.
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#33 DougRichards

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Posted 11 January 2020 - 2114 PM

A more or less similar message comes from the US XIX Corps study called "Breaching the Siegfried Line"  This is, in turn, fairly consistent with anecdotal evidence from US operations in Aachen and Metz where the M12, though ponderous and vulnerable in direct fire, was revered for taking down reinforced structures with a few rounds.

 

The effect of direct artillery hits on the pillboxes, except the 155mm SP gun and possibly heavier calibers, was not sufficient to destroy the box or prevent its future use. The concussion by a direct hit certainly discouraged not too strong-hearted defenders. The 57mm anti-tank gun, 75mm and l05mm were, except for direct hit in the embrasures itself, ineffective. They could remove the camouflage but little else. The 155mm howitzer required an uneconomical number of rounds to secure direct hits. The 155mm SP guns at ranges between 2000 and 4000 yards with a concrete bursting fuze penetrated the 6 feet of reinforced concrete with 3 to 5 hits. The 8 inch howitzers at 8000 yards could average a direct hit per 5 rounds, and penetrate after 5 hits. 

 

One other interesting comment that pops up is that the M12 was less effective at ranges under 2000 yards because the higher impact velocities caused the shell to break up before full penetration was achieved.  At least one unit started training gunners to stop using the highest charge for short range direct fire to reduce impact velocity.

Interestingly, the divisional 155mm piece, that is, the 155mm howitzer M1, was not supplied with a piercing round, but given the comment about the M12 being used with just the base charge (1,955ft/sec) the M1 howitzer with max charge was not short of that at 1,850ft/sec. 

 

The piecing round used by the GMC M12 and the Gun M1 155mm was a coastal defence projectile intended to pierce 6.5 inches of homogeneous armour at 1000 yards.

 

Given that Germany managed to put a 15cm howitzer on a medium tank chassis (ie Hummel), was it sheer short shortsightedness that meant that the US did not put the M1 155mm howitzer on a chassis adopted from the M3 or M4 medium series?   It was only in July 1944 that a SP equipment, on a hull based on the M24 light tank, was authorised.  A bit late for Europe. 

 

The 105mm howitzer on the M3 / M4 ie M7 Priest was a good equipment but was a lot of vehicle for the gun, given that Germany managed to put a 10.5cm on the Panzer 2 hull and chassis.


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#34 Markus Becker

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Posted 12 January 2020 - 1658 PM

Self propelled above 105mm seems not to have been a thing in the US Army. First just 100 M12 were made and then used for training before ending up in combat eventually.

I'm sure they must have had their reasons. No idea what they were. 105 and 155mm howitzers aren't that much different, the 155mm gun is but with that range it doesn't need to be able to go cross country to get to a target?
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#35 17thfabn

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Posted 12 January 2020 - 1910 PM

Self propelled above 105mm seems not to have been a thing in the US Army. First just 100 M12 were made and then used for training before ending up in combat eventually.

I'm sure they must have had their reasons. No idea what they were. 105 and 155mm howitzers aren't that much different, the 155mm gun is but with that range it doesn't need to be able to go cross country to get to a target?

 

In addition to the M12 Gun Motor carriage using the old M3 Lee tank hull mounting the older French 155 MM cannon, the U.S. Army also had the M40 Gun Motor.

 

The M40 used the newer M4 hull  and M1 155mm gun. 

 

If the M3 and M4 hulls could carry the 155 mm gun, carrying the 155 mm howitzer would be easy.

 

There was a thought in the U.S. Army Field Artillery that self propelled artillery had significant downsides. The thinking was, if the self propelled mount breaks down the gun is out of action. If the prime mover of a towed gun breaks down you can get another vehicle to tow it. 


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#36 Inhapi

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Posted 13 January 2020 - 1550 PM

Self propelled above 105mm seems not to have been a thing in the US Army. First just 100 M12 were made and then used for training before ending up in combat eventually.

I'm sure they must have had their reasons. No idea what they were. 105 and 155mm howitzers aren't that much different, the 155mm gun is but with that range it doesn't need to be able to go cross country to get to a target?

 

When the army asked for more M12's there were no 155mm GPF left to build them.

 

Since the exisitnig M12 could not take the weight(and recoil) of the new M1 gun, a whole new SPG based on the M4 had to be designed/tested/build. This new SPG (T93/M40) with the 155 M1 gun was ready for production only in feb. 1945 and subsequentely 418 were build. On the same chassis the 203 M1 howitzer could also be mounted (T89/M43), 576 T 89/M43 were ordered but the end of the war reduced the production run to 48. (Hunnicutt) Note , the M43 could switch its barrel and ammor racks to the M1 155 mm gun.

 

So it seems that after initial combat with the M12 the US army was very keen to get mor of this type of weapon system.

 

There were also ofc the 203 mm gun and 240 mm howitzer on modified M26 chassis, but these were too late for the war.

 

The 155mm howitzer was to be mounted on a modified M24 chassis to make for a lighter system, but again this design was ready too late for the war. (only prototypes build)


Edited by Inhapi, 13 January 2020 - 1604 PM.

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