# Mechanization



## tomo pauk (May 15, 2012)

The ww2 saw many of the tecnical developments, one of those was a strong trend towards mechanization of ground forces (for the countries that could afford such thing, of course). Starting with tanks, introducing SP artillery, AAA, infantry transporters, amphibious vehicles, logistical vehicles - all based on either full- or half-tracked platforms. 
Could the things be sped up? British were experimenting with 'Birch gun', an SP piece that combined hull of medium tank and armed with 'all elevation' 18pdr cannon. Soviets were experimenting with APCs based on the T-26. Early in ww2, Germans used 15cm infantry gun and the 4,7cm ATG on the Pz-I chassis, and 7,5cm gun on the Pz-III chassis (StuG-III). So lets see, in an alternate history layout, what could happen when, say, British don't discard the 'Birch gun' concept and decide to explore it further.

to be continued


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## davebender (May 15, 2012)

Certainly. It's just a matter of how a nation decides to spend their military budget. Spend the money for mechanized equipment plus logistical support and you will have it. Something else will get a budget cut at the same time.


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## tomo pauk (May 15, 2012)

To start with alt history time line:
In 1936, the idea of a 'regular' artillery piece carried on tracked chassis was embraced once again, this time with determination to really introduce the new equipment to the Army. 
The gun to be carried was the 18pdr, while companies offered their tracked hulls as the platforms. In 1937, the 3 proposals that were chosen for pre-series production of 6 vehicles each were the Bren Carrier, Vickers LT Mk VI and the modification of the Vickers 6 ton tank. The trials revealed shortcomings: Carrier was judged as a too light vehicle, not allowing for any useful numbers of round to be carried, the LT Mk VI was also far away from a comfortable vehicle, while the 6 ton tank conversion was not that fast as the LT conversion, and absence of the tank from the British Army ranks was weighted also against it. So it was decided to install wider combat compartment at the rear hull of the Mk VI , providing the more room for crew and ammo, and the Bren MG is to be installed to provide a form of self-defense. In order to provide more ammo, each SP piece can tow a limber from the towed 18pdr.

Picture, you say? This is a historical conversion of a captured Mk VI, sporting the German 10,5cm LefH 16 howitzer ( a ww1 left-over); note the ground brake:


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## davebender (May 15, 2012)

What is being cut from the RAF and/or RN to pay for an increase of the British Army budget?


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## davebender (May 15, 2012)

France probably has the best chance for SP howitzers at the start of WWII. By the mid 1930s they had a mature tank industry and they had a newly installed communist government that voted a massive increase in military spending. With different spending decisions a large portion of French Army 105mm light howitzers could be mounted on a tracked chassis. They could also produce APCs based on one of their existing light tank chassis.


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## tomo pauk (May 16, 2012)

What is being cut from the FAF Marine Nationale to get such stuff?



davebender said:


> What is being cut from the RAF and/or RN to pay for an increase of the British Army budget?



Nothing - part of the the hulls of the LT Mk VI is used for the SP artillery (= less light tanks), the Britain is awash with 18 pdr guns in the 1930s.


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## Shortround6 (May 16, 2012)

tomo pauk said:


> What is being cut from the FAF Marine Nationale to get such stuff?
> 
> 
> 
> Nothing - part of the the hulls of the LT Mk VI is used for the SP artillery (= less light tanks), the Britain is awash with 18 pdr guns in the 1930s.



Please Tomo, I expect better of you. _Britain is awash_ is not a phrase I would have thought you would use 

Britain hasn't made an 18pdr since about 1919. There are two rather distinctive 18pdrs. The older ones with the recoil system on top of the barrel have rather limited elevation and traverse and are the older style, meaning that if any large number have not already been scrapped they are due for it. Mounting barrels with a good part of their useful life already gone on new tracked carriages in peace time is a sure way to start a scandal in the press. 
many of the newer ones with the recoil system under the barrel are slated to be rebored/relined from 83.4mm to 87.5mm to make 18/25pdr guns as the treasury is too cheap to buy new 25pdr field guns. 

Mounting the guns on the MK VI chassis is also a mark of desperation. Better than using a team of horses perhaps but putting the barrels on a tracked chassis is just the start of the equation. You need ammo, and battery command posts, and radio links and wire parties and so on. Standard British doctrine was to have 142 rounds of 25pdr ammo in the first line of supply for towed guns, 114HE 16 smoke and 12 AP. More ammo is in the 2nd and 3rd echelons of supply. Please note that the German Wespe is not as "efficient" as some people make it out to be. Every 4 gun battery had another two chassis acting as ammo carriers.


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## tomo pauk (May 16, 2012)

--continuation--

When the trials of the modified SP piece were conducted in 1938, the Army had more confidence to continue. 
It was decided to move on with larger heavier vehicle, the one that would be as armored as tanks the Army was purchasing, bolstering their punch when used together. For a short time it was considered to build tank's versions that would've featured short howitzer in turrets, but that was discarded since it was felt that a shell of decent both weight and muzzle would come in handy. With the new gun, the 25pdr, wanted as main armament, arming the turret of the tanks in production was out of question, so the designers proposed a more refined gun layout of the French Char B1 for the new 'tank'. In 1939, the boxy superstructure (called 'ugly' by many of the people that saw it) was added instead of the turret at the hull of the A9 tank. Hull MG turret were deleted, one MG mounted at the roof. Superstructure was featuring overhangs above tool boxes, and was armed with 18pdr instead of planned 25pdr. 
Another hull considered for the same role was from the Matilda II. 
A rough sketch how should the A9 version looked: 

--tbc--


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## davebender (May 16, 2012)

The Wespe was a dirt cheap wartime improvisation to take the place of the cancelled Sd.Kfz.165/1. Without the desperate wartime need for lots of low cost equipment the Marder SP AT gun and Wespe SP 10.5cm howitzer would not have produced.

Peacetime production should plan for something better.


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## tomo pauk (May 16, 2012)

Shortround6 said:


> Please Tomo, I expect better of you. _Britain is awash_ is not a phrase I would have thought you would use



May I plead to be a non-original speaker? 



> Britain hasn't made an 18pdr since about 1919. There are two rather distinctive 18pdrs. The older ones with the recoil system on top of the barrel have rather limited elevation and traverse and are the older style, meaning that if any large number have not already been scrapped they are due for it. Mounting barrels with a good part of their useful life already gone on new tracked carriages in peace time is a sure way to start a scandal in the press.
> many of the newer ones with the recoil system under the barrel are slated to be rebored/relined from 83.4mm to 87.5mm to make 18/25pdr guns as the treasury is too cheap to buy new 25pdr field guns.



Well, it could go this way: not everyone (that was in charge for this or that) was a 'true believer' into the SP artillery case, so not many of those were built, maybe one hundred by the time UK declared the war?



> Mounting the guns on the MK VI chassis is also a mark of desperation. Better than using a team of horses perhaps but putting the barrels on a tracked chassis is just the start of the equation. You need ammo, and battery command posts, and radio links and wire parties and so on. Standard British doctrine was to have 142 rounds of 25pdr ammo in the first line of supply for towed guns, 114HE 16 smoke and 12 AP. More ammo is in the 2nd and 3rd echelons of supply. Please note that the German Wespe is not as "efficient" as some people make it out to be. Every 4 gun battery had another two chassis acting as ammo carriers.



Not a 'mark of desperation', but more of 'the war might be starting; if works in real combat - fine, we'll build more (and/or better stuff); if not - we did not spent too much of money, and the hulls guns can be reused'.  
I've already stated that the limber would be towed behind (80 rounds, if I've counted correctly), and some quantity of the ammo can be carried on board. The dedicated ammo vehicle could be used, and it was used in German units operating the 10,5/Mk VI combo; it was based upon the Mk IV itself, and was also towing a trailer. The German version was not towing a limber, so the separate ammo vehicle was necessity; the 10,5cm ammo being more voluminous anyway.
The artillery units will get what it takes to be proper units: command posts, radio links etc.


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## Shortround6 (May 16, 2012)

tomo pauk said:


> Well, it could go this way: not everyone (that was in charge for this or that) was a 'true believer' into the SP artillery case, so not many of those were built, maybe one hundred by the time UK declared the war?
> 
> 
> 
> ...



If you haven't seen it yet try this web site;

British Artillery in World War 2

Many pages and while you might not agree with everything it does provide a very good over view of artillery in general. 

There is a distinct difference between an armored gun used for direct fire assaults and self propelled artillery or "mechanized" artillery. For an artillery battery or battalion to be truly "mechanized" not just the guns but a very large part of the battery/battalion must be mechanized. It does no good to get the guns across 20 miles of sandy dessert if half of the radios, field phones, and meteorological section are left behind. Every sub unit or section in the Battery/battalion needs the same mobility. 

Somebody once said the shells are the weapon, the guns are just the delivery system. An artillery howitzer or gun is expected to fire 5000-10,000 rounds before needing a new liner. Towing un-armored trailers of ammo behind the tracked armored SP gun is a sure indicator that something wasn't planned well. Granted proper use of even armored SP guns calls for them to thousands of yards from the front lines.
Artillery fire often calls for time fuses and in the case of howitzers instead of guns, zone charges. towed guns have 6 or more in the gun crew in order to handle all the tasks, A _GOOD_ SP artillery piece is going to have room for a gun crew of 4-6 men to work and serve the gun including ammo preparation. This means more than one loader. One man cannot unpack, fuse, adjust fuse timing and load the gun while keeping up any sort of rapid fire rate. Having to adjust the zone charges on Howitzers just adds to the confusion/slows the rate of fire. 

Armored boxes on the top of tank hulls are fine for putzing around but as the British found with the Bishop: Bishop (artillery) - Wikipedia, the free encyclopedia

They are far, far from ideal. The Sexton may have been less than ideal ( no top cover, not as much ammo as desired, height made bombing up difficult, more?) but a battery of Sextons could provide fire to a much, much larger area than even several batteries of Bishops. Which is the better buy? 

In peace time take the time to get it right, To much time,effort, and money was spent on half-**sed solutions that were "cheap" but of dangerously limited actual ability.


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## tomo pauk (May 17, 2012)

> There is a distinct difference between an armored gun used for direct fire assaults and self propelled artillery or "mechanized" artillery. For an artillery battery or battalion to be truly "mechanized" not just the guns but a very large part of the battery/battalion must be mechanized. It does no good to get the guns across 20 miles of sandy dessert if half of the radios, field phones, and meteorological section are left behind. Every sub unit or section in the Battery/battalion needs the same mobility.



I've tried to respond to the similar question raised, by:
-The artillery units will get what it takes to be proper units: command posts, radio links etc.-
That means that the supporting parts of the unit will travel either by gun-less SP gun platforms, and part of them can travel on the 'Bren' carriers.



> Somebody once said the shells are the weapon, the guns are just the delivery system. An artillery howitzer or gun is expected to fire 5000-10,000 rounds before needing a new liner. Towing un-armored trailers of ammo behind the tracked armored SP gun is a sure indicator that something wasn't planned well. Granted proper use of even armored SP guns calls for them to thousands of yards from the front lines.



Good call on the unarmored trailer being a fair game to threats that would not harm the vehicle towing it (the SP in question gun should provide horizontal protection vs. artillery splinters up to the rifle/LMG fire). The cure might be the trailer with same level of protection (even if it need to carry only 60 rds, to allow for weight of the armor), while introducing a dedicated ammo carrier (based on same vehicle as the SP gun).



> Artillery fire often calls for time fuses and in the case of howitzers instead of guns, zone charges. towed guns have 6 or more in the gun crew in order to handle all the tasks, A GOOD SP artillery piece is going to have room for a gun crew of 4-6 men to work and serve the gun including ammo preparation. This means more than one loader. One man cannot unpack, fuse, adjust fuse timing and load the gun while keeping up any sort of rapid fire rate. Having to adjust the zone charges on Howitzers just adds to the confusion/slows the rate of fire.



The German version was served with 4 men (+ driver).



> Armored boxes on the top of tank hulls are fine for putzing around but as the British found with the Bishop: Bishop (artillery) - Wikipedia, the free encyclopedia
> 
> They are far, far from ideal.



I'm gearing the A9 'Stug' more towards direct fire role (they would serve instead of historical CS tanks).



> The Sexton may have been less than ideal ( no top cover, not as much ammo as desired, height made bombing up difficult, more?) but a battery of Sextons could provide fire to a much, much larger area than even several batteries of Bishops. Which is the better buy?



Hold your horses, we are still in 1939 here. The LT Mk VI based SP gun will serve in artillery units, not the A9 based one.



> In peace time take the time to get it right, To much time,effort, and money was spent on half-**sed solutions that were "cheap" but of dangerously limited actual ability.



I could not agree more. 


If I was not clear above, this time line is not about the 'ideal SP artillery' for different countries, but a time line that would include trial and error, ups and downs, while some ideas would be adopted by other coutries. If I was to propose 'ideal' stuff, I'd went with 15-20 ton 75-105mm SP artillery, and 25-30 ton 115-155mm stuff.


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## yulzari (May 17, 2012)

The German army had less of a trend to mechanisation and more of a trend to equitation with horse power remaining a crucial large part of their transport and artillery. 

The British army began the war as the most committed to mechanisation, having all but eliminated horses in european operations. Though it found a worthwhile role for mules in poor ground conditions such as french mud, italian mountains and burmese jungle and was grateful for indian and cypriot muleteers amongst others.

The russians would have been hard pressed to mechanise their transport without american lorries which were the most vital support sent to russia.


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## davebender (May 18, 2012)

Not so sure about this.

The BEF was mechanized but that was only a small part of the total British / UK army. For instance I doubt the large British controlled Indian Army was mechanized.


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## Shortround6 (May 18, 2012)

Tomo, a more "practical" SP gun for 1938-39 would be to take the A9, and much like the Archer 17pdr, turn it around so that the gun is pointed back over the engine deck. Use the 18pdr MK V Mount so you have 25 degrees traverse each way (or within vehicle limits) without moving the vehicle. 8 degrees of traverse is a joke. Now you have the room from the turret and mg turrets (and driver vacating his seat) for the gun crew to work. Much more room than a MK IV light tank lashup. More ammo on the vehicle. 
When the Germans were converting those left over British and French chassis, not only did they not have enough tracked chassis of their own, or trucks, they didn't even have enough horses go around. Any way of moving a gun was an improvement over not moving it. 
Much artillery fire is not done at the maximum rate of fire but limiting your peak rate of fire because of a too small vehicle is a problem that _CAN_ be avoided in peace time. 

While the entire ammunition supply doesn't need the same mobility as the guns there is usually a lot more ammunition than people think. In 1914 the "official" ammo supply for an 18pdr gun was 24 rounds on the gun limber, 152 rounds on ammo wagons in the battery, 76 rounds in the Brigade ammunition column, 126 rounds in the Division ammunition column for a total of 378 rounds on transport. A further 150 rounds were in Divisional ammunition parks and another 472 rounds in ordnance depots. These was supposed to be the allotment per gun _in the field_ and not including storage in home depots or factories. How close they came I have no idea and a number of revisions happened as to what ammo was kept were as the war went on.


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## davebender (May 18, 2012)

That would be useless for direct fire and the 18 pounder shell is too small for effective indirect fire. You would be further ahead to install an inexpensive 120mm mortar on an outdated tank chassis.


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## Shortround6 (May 18, 2012)

Yes it would be useless for direct fire but if you are using the divisional artillery assets for direct fire the situation has gone to pot in a big way and total disaster is imminent. 

The M7 Priest and the Sexton were never intended for the direct fire role. Like wise the US M37 self propelled 105 was never intended for the direct fire role nor the post war M-108. The M-12 155mm was only intended for the direct fire role in the rarest of circumstances, as was the M-40. The M-55 and M-109s are not direct fire weapons. The M-41 was not a direct fire weapon. 

As far as further ahead????

The 18pdr could range to 11,000yds with 38 degrees of elevation, given an observer in a good position (or aerial) it could sit thousands of yards out of range of the 120mm mortar and pound it to destruction. 

If you want rebore/reline the the gun to take 25pdr ammunition as was done to around 1000 towed guns, not quite the range of a regular 25pdr (due to elevation limit) but th e traverse of the 18pdr MK V mount may make up for it.

18pdr HE shells of WW II weighed 18.5 lbs and carried 1.1 lbs of explosive. While not 105 howitzer rounds they are a step above 75mm rounds. 

Your a bit too obsessed with cheap weapons. Cheap is good in some cases but carried too far results in the loss of capability. Russians equipped entire battalions with stamped sheet metal sub-machine guns and hand grenades, worked in cities and in the open with lots of t-34 tanks as close support. In the open without the tanks??? 
How much do the tanks cost in relation to the "normal" battalions heavy weapons?

Somebody once claimed the Germans would run from "cold steel" (bayonet charge) on the Russian front. A cynic replied they only ran after the machine gun ran out of ammunition.
Bayonets are really cheap. Machine guns are expensive. We know how most armies wound up voting.


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## davebender (May 18, 2012)

If you are going to that trouble why not just develop a modern 105mm light howitzer?


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## Shortround6 (May 18, 2012)

Just maybe because were talking about the British army before WW II. Developing special guns "just" for the mechanized troops that took different ammo was a luxury nobody could afford. 

The British did rebore/reline 1422 18pdrs to 25pdrs from 1937 to1941 while production of the "modern" 25pdr was organized and under taken, First "modern" 25pdr being made in 1940.


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## tomo pauk (May 18, 2012)

Shortround6 said:


> Tomo, a more "practical" SP gun for 1938-39 would be to take the A9, *and much like the Archer 17pdr, turn it around so that the gun is pointed back over the engine deck.* Use the 18pdr MK V Mount so you have 25 degrees traverse each way (or within vehicle limits) without moving the vehicle. 8 degrees of traverse is a joke. Now you have the room from the turret and mg turrets (and driver vacating his seat) for the gun crew to work. Much more room than a MK IV light tank lashup. More ammo on the vehicle.
> When the Germans were converting those left over British and French chassis, not only did they not have enough tracked chassis of their own, or trucks, they didn't even have enough horses go around. Any way of moving a gun was an improvement over not moving it.
> Much artillery fire is not done at the maximum rate of fire but limiting your peak rate of fire because of a too small vehicle is a problem that _CAN_ be avoided in peace time.



I have a vehicle like you're describing on the pipeline, it would not take much for the British to come out with one 
IIRC the cause for artillery not firing on max rate was the barrel's imminent overheating, after a minute or two of firing at max rate?



> While the entire ammunition supply doesn't need the same mobility as the guns there is usually a lot more ammunition than people think. In 1914 the "official" ammo supply for an 18pdr gun was 24 rounds on the gun limber, 152 rounds on ammo wagons in the battery, 76 rounds in the Brigade ammunition column, 126 rounds in the Division ammunition column for a total of 378 rounds on transport. A further 150 rounds were in Divisional ammunition parks and another 472 rounds in ordnance depots. These was supposed to be the allotment per gun _in the field_ and not including storage in home depots or factories. How close they came I have no idea and a number of revisions happened as to what ammo was kept were as the war went on.



Thanks; as they say, logistics is the key


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## davebender (May 18, 2012)

> Developing special guns "just" for the mechanized troops that took different ammo was a luxury nobody could afford.


The mechanized chassis costs a lot more then a 105mm howtizer. If Britain cannot afford to purchase light howitzers then how are they supposed to purchase SP artillery of any type?

Price examples.
16,400 RM. 10.5cm leFH18 howitzer.
22,000 RM. Sd.Kfz.11 towing tractor. Normal tow vehicle for a 10.5cm howitzer.
about 50,000 RM. Panzer II. The smallest possible chassis that can carry a 10.5cm howitzer.


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## Shortround6 (May 18, 2012)

British had been working on the 25pdr for a number of years. They weren't going to adopt a 105 howitzer in 1938-1940 no matter what.


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## Shortround6 (May 18, 2012)

tomo pauk said:


> I have a vehicle like you're describing on the pipeline, it would not take much for the British to come out with one
> IIRC the cause for artillery not firing on max rate was the barrel's imminent overheating, after a minute or two of firing at max rate?



For the 25pdr the firing rates were 

Rates of fire---------Gunfire------Intense------Rapid------Normal--------Slow--------Very slow

Rounds/Minute------6 to 8---------5------------4----------3------------2--------------1

I haven't found the firing rate/s for the 18pdr yet but I would be very surprised if it was under 12 rounds a minute for it's max rate of fire and may have been as high as 15-20rpm with prepared (fused) ammunition. Shell was crimped to cartridge case so one piece loading with no charge adjustment.

A US 105 howitzer was supposed to do 8rpm for the first 1/2 minute, 4 rpm for 4 minutes, 3 rpm for 10 minutes and 100 rounds an hour. If the crew has time to prepare ammo and lay it out (zone charges adjusted and shells fused) then having a single loader ammo handler might not be too bad, depending on far from the gun breech the rounds are after the first 10 or so. That is assuming they want 25-30 fused shells laying about. If fuses have to be fitted and zone charges adjusted while firing one man is going to be overwhelmed. 

While too heavy a chassis is a waste too light a one reduces accuracy or rate of fire. Recoil spades help but too much gun for the chassis means a lot of bounce between firing and the gunner has to re-aim the gun more often, or at least check the aim. Some towed guns suffered from this.


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## davebender (May 19, 2012)

Rate of fire is nice but having enough HE filler in the shell to defeat field fortifications such as concertina wire is more important for indirect fire artillery. That lesson should have been learned during WWI. I'd rather be supported by 120mm mortars then 25 pounder field guns. Not as accurate and range is shorter but at least they have enough punch to get the job done.


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## Shortround6 (May 19, 2012)

Problem being that if your opponent has 25pdr field guns and a competent spotting group you won't have your 120mm mortars very long. 

If you are depending on 120mm mortars to defeat field fortifications then your divisional and corp artillery are not doing their job. 

How much effort did the Germans put into lengthening the range of their 105 howitzer from 10,675meters to 12,325 meters?


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## tomo pauk (May 19, 2012)

davebender said:


> The mechanized chassis costs a lot more then a 105mm howtizer. If Britain cannot afford to purchase light howitzers then how are they supposed to purchase SP artillery of any type?
> 
> Price examples.
> 16,400 RM. 10.5cm leFH18 howitzer.
> ...



In British case, they will initially use the guns that are already produced, or are being produced; the artillery branch will use a chassis priced between the Bren carrier and Pz-II (while it would be produced less 'real' light tanks), while the tank branch will not buy historical CS tanks, but the SP assault guns (main task providing HE support for 2pdr armed tanks accompanying infantry). 



Shortround6 said:


> For the 25pdr the firing rates were
> 
> Rates of fire---------Gunfire------Intense------Rapid------Normal--------Slow--------Very slow
> 
> ...



Many thanks for the fire rates.
The LT-based SP vehicle should have 2 loaders, commander, aimer and driver (as it was the case for the German conversion). Once in the firing spot, the driver can assist the loaders.
The A9 based vehicle will fire as fast/as slow as the StuG-III with long 7,5cm.



> While too heavy a chassis is a waste too light a one reduces accuracy or rate of fire. Recoil spades help but too much gun for the chassis means a lot of bounce between firing and the gunner has to re-aim the gun more often, or at least check the aim. Some towed guns suffered from this.



Comparing the British conversion with German, the shell weight is some 45-50% less in the British example, MV being about the same, so the recoil is about a half of what was the case for German conversion. 

Once more, I agree that too light/small a vehicle can hamper the performance, but once more I repeat that British*, in this thread, are still learning about the finesses of the SP artillery. Some 3 years earlier than historically 

*didn't even started with others yet


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## Shortround6 (May 19, 2012)

Tomo, the German conversions of the MK VI tank used a WW I left over howitzer, not the standard howitzer. Barrel was about 300mm shorter, top velocity with the zone 5 charge was 395m/s. max range 9225 meters. 4 degrees of traverse (?) 2 to each side of centerline.


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## tomo pauk (May 19, 2012)

Thanks for the correction; I knew that the 10,5cm lefh 16 was in question, but assumed that MV values are similar. 
So, if I'm calculating it correctly, the 10,5cm shell has the momentum equal to 5846 kgm/s vs 4132 for the 18pdr, or, the 18pdr has a recoil of some 72% of the lefh 16?


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## davebender (May 19, 2012)

> How much effort did the Germans put into lengthening the range of their 105 howitzer from 10,675meters to 12,325 meters?


None.

The 10.5 cm leFH 18/40 change was intended to lower production cost. A bit more range and higher rate of fire was just a bonus.


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## Shortround6 (May 19, 2012)

tomo pauk said:


> Thanks for the correction; I knew that the 10,5cm lefh 16 was in question, but assumed that MV values are similar.
> So, if I'm calculating it correctly, the 10,5cm shell has the momentum equal to 5846 kgm/s vs 4132 for the 18pdr, or, the 18pdr has a recoil of some 72% of the lefh 16?



Could be, 70-80% should be in the area ( weight of propellant times escape velocity of the gasses). The German conversion was done by/for a second line unit that probably couldn't even get enough draft horses.


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## Shortround6 (May 19, 2012)

davebender said:


> None.
> 
> The 10.5 cm leFH 18/40 change was intended to lower production cost. A bit more range and higher rate of fire was just a bonus.



Try looking at the changes from the 10.5 cm leFH 18 to the 10.5 cm leFH 18M. New shell, new propelling charge, muzzle brake and changed valving in the recoil system. The 10.5 cm leFH 18/40 had nothing to do with it. 

Of course those changes were totally unnecessary as the Germans should have been using 120mm mortars with1/2 the range, right?


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## davebender (May 20, 2012)

There's more then one way to solve a military problem. The 10cm Kanone was the Heer solution to counter battery and other such long range artillery missions. 

Welcome to Landships! - A site for WW1 Military Hardware WW1 Military Modelling
10cm Kanone M14. 724 produced 1914 - 1917.
10cm Kanone M17. 192 produced 1917 - 1918.
10cm Kanone M18. about 1,500 produced 1934 to end of WWII.
.....19km max range.
During 1941 to 1945 the 10cm Kanone was supplemented by about 350 of the more powerful 17cm Kanone.

This has nothing to do with general infantry support missions which were accomplished using howitzers with shorter maximum ranges.

Before designing a SP artillery piece we first need to determine it's mission. I am thinking in terms of general infantry support which means being able to defeat field fortifications such as concertina wire. Apparently you are thinking of a long range counter battery weapon to suppress enemy artillery fire.


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## tomo pauk (May 20, 2012)

I would suggest that the mortar vs. howitzer debate should be located to some other thread. Thank you.


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## Shortround6 (May 20, 2012)

ALL artillery and mortars can be call upon to fire in counter battery mission. The Infantry battalion will attempt to silence the enemy mortars with their own mortars. If they cannot reach the target then a request will be passed up to regiment or brigade or Division. Where ever the next longer ranged ordnance is held. 

The same goes for Regimental guns, howitzers and heavy mortars held at the regimental brigade levels. The unit involved tries to see it the job can be handled by it's own assets and if it can't requests help from a higher echelon.

Equipping units with substandard weapons because they are _CHEAP_ and expecting to get needed support from Corp or Army echelon weapons whenever needed is a surefire way to to suffer high causalities and failed missions. 

This applies to self propelled weapons or mechanization as well. 

As far as Mechanization and infantry support goes I would suggest taking a very good look at the German Stug batteries in France. The Stug used an artillery style periscope sight, used though and opening in the roof. They were issued in batteries of 6 vehicles and had specialized ammo carriers (Sd Kfz 252 and Sd Kfz 250/6) attached to the batteries along with one _VERY_ special addition, The Sd Kfz 253 light armoured observation post, later replaced by the Sd Kfz 250/4. Strange that what many people view as a direct fire weapon system had at least one armoured forward observation post vehicle issued for every 6 gun vehicles? 

I would agree with Mr. Bender on this "Before designing a SP artillery piece we first need to determine it's mission"

Are we looking for a SP anti-tank gun? A support weapon for a tank company or battalion (in the British army to replace the support <smoke> tanks)? A SP divisional support weapon ( placing the normal divisional artillery on tracks)? 

A major advantage of tracked artillery ( that _NEVER_ shows up in civilian war games) is it's ability to keep up with a fast moving advance ( or retreat), not so much in the sense of being able to drive along side tanks through mud, snow or sand but in the fact that the tracked battery can get out of a firing position, drive to a new firing position, set up and commence firing much faster than a towed battery can. This means the advance (or rear guard) is without artillery support for much less of the time than if the artillery was all towed. 

Now if you are trying to mechanize an army in 1937-40 where are you going to get the most "bang for your buck"? Mechanizing some special purpose guns/mortars/whatevers or mechanizing some/all of the mechanized brigade/division's regular artillery component?


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## davebender (May 20, 2012)

The weapon costs the same whether it's towed or SP. So it comes down to the cost of a tow vehicle vs the cost of tracked vehicle sturdy enough to handle howitzer recoil.

In the German Army a Sd.Kfz.11 towing tractor costs about half as much as the lightest possible armored vehicle chassis (i.e. 10 ton Panzer II). In addition the towing tractor can be used for supply missions when the howitzer is stationary. So if you want "bang for the buck" a towed howitzer wins every time.

If money is no object then SP howitzers are preferable for reasons already stated. Faster to set up and faster to bug out for the purpose of evading counter battery fire. 

Armored divisions are the exception to the rule. All division elements including artillery must keep pace with the tanks. Artillery support is crucial for suppressing enemy AT guns and your tanks need it immediately if they are to survive.


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## tomo pauk (May 20, 2012)

@ SR6



> Equipping units with substandard weapons because they are CHEAP and expecting to get needed support from Corp or Army echelon weapons whenever needed is a surefire way to to suffer high causalities and failed missions.
> 
> This applies to self propelled weapons or mechanization as well.



For the 3rd time: in this thread, the British are aware of the incoming war. They are experimenting with an novelty, an SP gun for their artillery arm, with intent to use it in indirect fire role (the A9 'stug' is to be used in tank units, instead of historical CS tanks). As an experiment, it uses an affordable chassis and an already produced artillery piece. If the experiment fails, it was not costing them too much. If it works, they would produce more examples, either same type, or improved, or substantially better designs. The 18pdr is an useful piece, and implying it's 'substandard' is way out of mark.



> As far as Mechanization and infantry support goes I would suggest taking a very good look at the German Stug batteries in France. The Stug used an artillery style periscope sight, used though and opening in the roof. They were issued in batteries of 6 vehicles and had specialized ammo carriers (Sd Kfz 252 and Sd Kfz 250/6) attached to the batteries along with one VERY special addition, The Sd Kfz 253 light armoured observation post, later replaced by the Sd Kfz 250/4. Strange that what many people view as a direct fire weapon system had at least one armoured forward observation post vehicle issued for every 6 gun vehicles?



Thanks for the information. BTW, any info about the max elevation of the early StuG-III gun?
It's obvious that LT-based SP gun would need observation posts/units, they can use the 'Bren' carrier, or maybe another LT based vehicle.



> I would agree with Mr. Bender on this "Before designing a SP artillery piece we first need to determine it's mission"
> *Are we looking for a SP anti-tank gun? **A support weapon for a tank company or battalion (in the British army to replace the support <smoke> tanks)? ***A SP divisional support weapon ( placing the normal divisional artillery on tracks)?


Think I've covered this before, but anyway:
*Not yet (prior Sept 1939).
** Yep, the A9 based vehicle, firing both HE smoke shells.
***That's one of the aims, LT-based SP piece being sorta proof of concept.



> A major advantage of tracked artillery ( that NEVER shows up in civilian war games) is it's ability to keep up with a fast moving advance ( or retreat), not so much in the sense of being able to drive along side tanks through mud, snow or sand but in the fact that the tracked battery can get out of a firing position, drive to a new firing position, set up and commence firing much faster than a towed battery can. This means the advance (or rear guard) is without artillery support for much less of the time than if the artillery was all towed.



Agreed.



> Now if you are trying to mechanize an army in 1937-40 where are you going to get the most "bang for your buck"? Mechanizing some special purpose guns/mortars/whatevers or mechanizing some/all of the mechanized brigade/division's regular artillery component?



The 1937-40 is out of question for an completely mechanized army, even if that's the British (small size, but heavily on the path of motorization (and it will remain there when army starts a steady grow), so the mechanization would require just an 'extra mile' effort, contrasted with, say, German army (big army, but even the motorization is out of question). So just a smaller part of the army would be initially mechanized, growing more as the war progresses (providing the beligerent don't collapse prior, of course). 
A 'free' gun plus a cheap/free/mass produced chassis would make the best 'bang for buck'. So having, say, 1/3rd, or 1/4th of the army being mechanized would be an asset. Implementing the combined arms approach, that should involve the mechanization of AAA, AT infantry units, too.


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## davebender (May 20, 2012)

Then you need a weapon with enough punch to do the job.

105mm howitzers are tried and true. Favorite size for general infantry support for the past 100 years (Soviet Union excepted). That's good enough for me.


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## Shortround6 (May 20, 2012)

davebender said:


> The weapon costs the same whether it's towed or SP. So it comes down to the cost of a tow vehicle vs the cost of tracked vehicle sturdy enough to handle howitzer recoil.



You continue to misunderstand. If you have limited funds and have to chose between mechanized divisional artillery of your "mechanized" division/s or mechanized "special purpose" artillery vehicles and towed divisional artillery which is the better buy?


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## Shortround6 (May 20, 2012)

davebender said:


> Then you need a weapon with enough punch to do the job.
> 
> 105mm howitzers are tried and true. Favorite size for general infantry support for the past 100 years (Soviet Union excepted). That's good enough for me.




British did not switch to the 105 until the late 1950s. But then they don't count do they?? 
British gun makers were selling 105s to other nations since the early 1920s. 

105s WERE NOT the favorite size for general infantry support for the last 100years. They only became the favorite size from the middle of WW II on, about 70 years. While the US adopted the 105 howitzer in the early 30s they didn't make more than a couple dozen until 1941. Which is why the forces in the Philippines used 75mm guns. Many other nations used a mixture of 75-76mm guns and 100-105 howitzers as divisional artillery. Often in a ratio of 2 or 3 batteries of 75-76mm guns for every battery of 100-105 howitzers. The 75-76mm gun and the 100-105mm howitzer were the heaviest weapons that could be moved as "field artillery", that is keep up with marching infantry when horse drawn. Anything bigger, 90-105mm guns or longer ranged 120 howitzers (or short ranged 150mm howitzers) were part of the heavy artillery and while mobile could NOT move the same distance per day as an infantry unit in the march. 
Granted things got much easier with motor transport but only the British army and the Americans were motorized (not mechanized) in 1939. 

By the way, from about 1910-1940 there were around a 1/2 dozen 12cm howitzers in use by a number of smaller (and larger, Russia) nations that were about the same weight as a 105 Howitzer. They used shells of about 20-23kg but had ranges of about 6-7 km. These were made by Krupp, Rheinmetall, Schneider and others.


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## Shortround6 (May 20, 2012)

tomo pauk said:


> For the 3rd time: in this thread, the British are aware of the incoming war. They are experimenting with an novelty, an SP gun for their artillery arm, with intent to use it in indirect fire role (the A9 'stug' is to be used in tank units, instead of historical CS tanks). As an experiment, it uses an affordable chassis and an already produced artillery piece. If the experiment fails, it was not costing them too much. If it works, they would produce more examples, either same type, or improved, or substantially better designs. The 18pdr is an useful piece, and implying it's 'substandard' is way out of mark.



Sorry but the substandard was in relation to 12cm mortars, however it applies to some extent to the 18pdr depending on model and year. There are 2 different 18pdr barrel and recoil mechanisms and 3 rather different carriages. there is also a modernized HE shell. AS to the carriages I am not referring to the the type of wheels or brakes but wither it had the pole trail carriage, the box carriage or the split rail carriage. The carriage affects the elevation and traverse limits for a simple conversion ( cut the wheels off, cut trail/s down and mount on/in vehicle) Building new elevation/traverse mechanisms tends to run up the cost. The problem here is that the most desirable carriages for conversion to SP guns (the MK IV box trail and MK V split trail) are also the most desirable for the British to convert to 25pdrs as towed artillery. as an example 704 of the converted 18/25pdr guns were lost in France along with 216 18pdrs. The least desirable guns for conversion were the pole carriage guns. These had an elevation limit of 16 degrees with rather limits the range. They also had a total of 8 degrees of traverse. the box trail offered 30 degrees of elevation and the Split trail offered 37.5 degrees. The box trail equipment was sometimes given a turntable like the 25pdr for easier large arc traverse movement. 

There were 90 of the 25pdr MK II (the "standard 25pdr")in England in May of 1940 and none are supposed to have gone to France. 

For your experiment the 25pdr MK I (18/25pdr) is as good as it gets (from 1937 on), the guns/mounts to be turned into the 25pdr MK I are second best and perhaps spoken for but available in small numbers. The older guns with pole carriage, recoil cylinders on top of the barrel and so on are the "cheapest" they are also slated for scraping or training commands, have limited range about 6000 meters (the change from 16 degrees to 30 degrees was worth 2600yds) have a different breech mechanism ( a slower two motion breech instead of a single motion breech). 
The Experimental Birch guns used the later 18pdr barrels, breeches and recoil systems and that was in 1925. there were experimental gun carriers in the First World War based on the Big British tanks. The British played with the Birch guns fot 6 years. 

the French had built 8 different prototype SP guns by 1919 and the US had built 12 different models by 1922. The Idea was not novel but exact doctrine and technique needed a lot of work. 




tomo pauk said:


> Thanks for the information. BTW, any info about the max elevation of the early StuG-III gun?
> It's obvious that LT-based SP gun would need observation posts/units, they can use the 'Bren' carrier, or maybe another LT based vehicle.



Stug elevated to 20 degrees. 
The OP unit needs to mount the standard OP optics (not much of a problem) a small map area, (not much of a problem) and a decent radio set ( a bit more of a problem). The First German OP unit mentioned Sd Fkz 253 actually had thicker armor on the front than the standard half track. It might be better to use the LT chassis rather than go cheap with the "Bren" carrier. 



tomo pauk said:


> Think I've covered this before, but anyway:
> *Not yet (prior Sept 1939).
> ** Yep, the A9 based vehicle, firing both HE smoke shells.
> ***That's one of the aims, LT-based SP piece being sorta proof of concept.



an A9 "Stug" doesn't really have the armor to take part in the direct fire battle, the A9 itself didn't have the armor. A10 maybe.
If you have this kind of influence (  ) get the British to make and issue an HE round for that 3.7in smoke mortar _and_ an HE round for the 2pdr. 

The concept is already somewhat proven, what is needed is a "practical" vehicle to carry it to the next step. Small vehicles with limited ammo storage, limited firing arcs (if used with 8-9 degree traverse mounts) limited working room and some what limited cross country performance (step and trench) are NOT needed in any numbers. The MK VI light tank also had a primitive steering system. It used the clutch and brake system which was OK on the level and climbing hills, it would reverse steer descending a hill unless the engine was under load (accelerating). To steer the 'inside' track was de-clutched and if needed was braked as the outside track continued to be powered causing the tank to slew (turn). going down hill on a trailing throttle as soon as the 'inside' track was de-clutched it ' free wheeled' (free tracked ?  ) and the normally driven track held back causing the vehicle to turn in the opposite direction intended. Not great in any vehicle, in a top heavy SP gun?? 

Part of the British resistance to SP guns in the late 30s was not so much cost but mistaken tactical beliefs. Like the tank was invulnerable (even with 30mm or less armor) and so didn't need artillery support to suppress enemy defenses.


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## tomo pauk (May 21, 2012)

Great posts; many thanks, SR6 



> The Experimental Birch guns used the later 18pdr barrels, breeches and recoil systems and that was in 1925. there were experimental gun carriers in the First World War based on the Big British tanks. The British played with the Birch guns fot 6 years.
> 
> the French had built 8 different prototype SP guns by 1919 and the US had built 12 different models by 1922. The Idea was not novel but exact doctrine and technique needed a lot of work.



I stand corrected wrt. SP guns being a novelty in late 1930s.



> an A9 "Stug" doesn't really have the armor to take part in the direct fire battle, the A9 itself didn't have the armor. A10 maybe.
> 
> Part of the British resistance to SP guns in the late 30s was not so much cost but mistaken tactical beliefs. Like the tank was invulnerable (even with 30mm or less armor) and so didn't need artillery support to suppress enemy defenses.



As it was the case, the belligerents will learn the stuff hard way, despite the new (or 'new') hardware. They are cautiously moving in the direction towards an army that is well mechanized, purchasing the stuff that is affordable, while available without much of delays.



> The concept is already somewhat proven, what is needed is a "practical" vehicle to carry it to the next step. Small vehicles with limited ammo storage, limited firing arcs (if used with 8-9 degree traverse mounts) limited working room and some what limited cross country performance (step and trench) are NOT needed in any numbers.



Now, how much fun discussion would we have with, say, 1944 hardware, if I 'gave' the belligerents the best stuff feasible for 1939? So far we have some very informative posts (and other that are not so informative  ), with just 2 vehicles 'designed' - unlikely so in case of 'ideal' stuff? Maybe we need a thread that would cover the 'best possible feasible' for different war's years? Maybe a thread covering the prototypes you are mentioning (if it's not already in the ww1 sub forum?); even the gun-armed rhomboid tanks could be called SP guns. French SP guns on Holt chassis are much sorta 'primitive Stug'.



> Stug elevated to 20 degrees.
> The OP unit needs to mount the standard OP optics (not much of a problem) a small map area, (not much of a problem) and a decent radio set ( a bit more of a problem). The First German OP unit mentioned Sd Fkz 253 actually had thicker armor on the front than the standard half track. It might be better to use the LT chassis rather than go cheap with the "Bren" carrier.



Looks like the British will have in France, May 1940, (between other) a force consisting of 120 SP guns, 40 ammo carriers and 20 OP units.


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## Shortround6 (May 21, 2012)

take the Birch gun and scale it back. NO anti-aircraft fire and NO 360 degree traverse 

The MK VI light tanks speed of 35mph might be a bit much for an SP gun too. 

This was on the drawing boards in the US in 1944 as they were not happy with the M7. 

M37 SP 105mm

I think the A9 chassis is a good start. Powered by a bus engine (how much cheaper do you want to get?) Getting rid of the rotating turrets ought to make it a bit cheaper too, Somebody once claimed the Stug was about 30% cheaper than the equivalent tank. 

here is an interior shot of an M7







Not real sophisticated. But it shows what is needed and what common sense would dictate. Room for ammo and room for the gunners to work.

The German conversion of the MK VI light was both ingenious and desperation. It was done by a Garrison unit on the coast of France. Germany was short of horses and a 6 gun battery of even WW I left over howitzers would suck up 36-48 horses just for the guns. Dropping to 4 horse teams might mean to slow a movement. With the British chassis just sitting in a depot and not much hope of getting anything better why not go for it? 

But to base a peacetime purchase or deployment of a number of batteries on such a limited chassis seems like false economy.

The Amercans in the early part of the war tried to but just about every type of gun they had on just about every chassis. Some worked a whole lot better than others.


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## Shortround6 (May 22, 2012)

Tomo, consider the Russian SU-76 and the T-70 tank. The SU-76 was almost 60 cm longer, with an extra road wheel, and about 40cm wider than the T-70. Compared to a MK VI light tank the SU -76 is 88cm longer and 65cm wider. 

The Su-76 carried about 60 rounds for the main gun. The gun is offset and according to some sources the traverse is 16 degrees left and 20 degrees right. Much more useful than 4 degrees each way but not as good as 30 degrees each way. 

If you want anything approaching a decent SP gun for a 83-88mm gun/howitzer it is going to be around a 15 ton or better vehicle.


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## davebender (May 22, 2012)

> If you want anything approaching a decent SP gun for a 83-88mm gun/howitzer it is going to be around a 15 ton or better vehicle.


I agree. Using a smaller chassis should be considered only as a wartime emergency measure.

*Sd.Kfz.165/1 10.5cm SP Howitzer*
Achtung Panzer! - Prototypes !
18,000 kg
188 hp engine.
60 rounds of 105mm ammunition.
30mm frontal armor. 14.5mm armor on sides and rear.
.....IMO something like this should be your objective. If you want the option to engage targets with direct fire then armor should be twice as thick. Which will push weight up to about 22 tons.


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## tomo pauk (May 24, 2012)

With the weight going to 22 tons, the 188 hp engine is lacking. It also sucks more fuel. Install the bigger engine to keep the power to weight ratio, the weight goes again up, so we will bulk up the transmission, suspension track-work; the bigger fuel tanks also demand more volume -> the weight goes up again. So before you know it, it's a 30 ton vehicle, akin to Sherman 105mm.

------
-- a new chapter --

After the fall of Poland, it was clear to the Army planers that German tank force was something that is ought to be stopped. The AP ammo was issued for the 18 25pdr cannons, while another AFV entered the service, the 2pdr cannon mounted on the 'Bren' carrier. Also the French 25mm ATG was used in such a fashion.
British armor gave a good service during the campaign of 1940, especially during the counterattack around Arras, where only the timely arrival of the Luftwaffe 8,8cm Flak, halftrack mounted, managed to forestall the advance. 

After the fall of France, the British Army has undertaken a deep analysis of both their and enemy hardware employment of it. The invasion seemed imminent, so no time was wasted.
Out of German hardware encountered, the most formidable was a version of the Pz-III tank, an assault gun equipped with long 7,5cm cannon (such a vehicle, armed with shorter 7,5cm gun was deemed as less of a danger). Unknown to the British, the longer 7,5cm cannon was an ordnance from the field gun 7,5cm lefk 16nA, and managed to make a notable impression on both infantry and tank units of the B. Army.
One of the AFVs that was seen as a lesser threat was the Pz-I body armed with 47mm cannon, of Czech origin. 
Both that one, and the half tracks with 8,8, were judged as an easier target, but only if enough of the artillery fire can be accurately laid on those.

The 18pdr on the LT chassis was found wanting, and the vehicle to be replacing it needed to be of greater size, with enough of room for crew to work, and plenty of ammo to be carried. The 25pdr is to be the weapon, and, if possible, the new 4,5in. One of the experiences from the BoF was that the ammo vehicles were often used to evacuate the wounded soldiers from the fluent front line, so someone proposed that it might be a good idea to use the modified ammo vehicles to carry the soldiers into battle. Sort of a better 'Bren' carrier.
The A9 SP gun was too easy a target, even for the 37mm ATG, and a better protected vehicle is needed. Since the new vehicle is to encounter enemy tanks, up close personal, a gun far better than the 2pdr and 18pdr is needed.

For all of those new, shining toys to make any effect, the Luftwaffe need to be either far away, or sufficiently suppressed. So the SP AAA is to be produced, while the RAF must do it's part in the future.


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## Shortround6 (May 25, 2012)

Uh, Tomo, the "new" 4.5in British artillery piece was a replacement for the 60pdr gun and weighed about 3 times what a 25pdr did, it would need a chassis in the 40-50 ton range unless you resort to the same "chassis" method the US did with the M7 and the M12. M12 carried the gun while the accompanying M30 (same chassis) carried the gun crew and ammunition. 

"The 18pdr on the LT chassis was found wanting..." It should have been found wanting on Salisbury Plain and not in combat. The Officer who authorized any purchase of such equipment past the first one or two should serve the rest of his career serving in a weather station in Nepal. 

The MK VI light tank was with in a few inches in width and a foot in length of a Bren or Loyd carrier and offered no real advantage in either load carrying or passenger carrying ability even with a new body. Armies tended to dislike (intensely) APCs that would not support the standard infantry squad structure or something close to it. If the "standard squad/section" was ten men then an APC that would hold 10 men (dismounts) was wanted (or maybe nine men). An APC that held 6 men (dismounts) was not wanted as it meant both new squad tactics/drills and much increased confusion in action. 

The British 2pdr gets a bad reputation because it was forced to carry on well past it's normal due date. In actual fact it could see off quite well most any German tank until well into 1941. One major failing was it was not provided with decent ammo for a good part of the time. The Muzzle energy of the Germany 37mm with normal AP ammo is 200,000 joules. The German short 50mm gun had 404,000 joules while the 2pdr with AP shot was 392,000 joules and with APCBC shot 382,000 joules. Unfortunately the British do not get the APCBC shot in production until the end of 1942. Please note that APCBC shot/shells were being used in Naval warfare by 1914 so this is not exactly "new stuff". APCBC shot would have gone a looong way in taking out the face hardened German tanks in 1941-42. Need to actually _issue_ HE ammo has been gone over before. British 2pdr HE ammo, when it did show up, carried about 2 1/2 times the explosive of a German 37mm tank HE shell. 

18pdrs as AT armament is nothing short of desperation. AP shot was made and issued but much more in the line of self defense. The effective range is short (much shorter than the 2pdr) and rate of fire (and more importantly, the rate of _engagment)_)is much lower. 

There is a lot of controversy about when the 6pdr should have been introduced but the 2pdr could have been much more effective in 1940-41 with different projectiles even without going to _new types_ like APCR or APDS. 

These are not mechanization issues as such but changing the chassis under the guns or using (misusing?) odd ball guns on new chassis isn't really going to change things much.


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## tomo pauk (May 25, 2012)

> Uh, Tomo, the "new" 4.5in British artillery piece was a replacement for the 60pdr gun and weighed about 3 times what a 25pdr did, it would need a chassis in the 40-50 ton range unless you resort to the same "chassis" method the US did with the M7 and the M12. M12 carried the gun while the accompanying M30 (same chassis) carried the gun crew and ammunition.



No quarrels here, the 4,5in will NOT share the same chassis as the new SP 25pdr 



> "The 18pdr on the LT chassis was found wanting..." It should have been found wanting on Salisbury Plain and not in combat. The Officer who authorized any purchase of such equipment past the first one or two should serve the rest of his career serving in a weather station in Nepal.



He is going to Malaya 



> The MK VI light tank was with in a few inches in width and a foot in length of a Bren or Loyd carrier and offered no real advantage in either load carrying or passenger carrying ability even with a new body. Armies tended to dislike (intensely) APCs that would not support the standard infantry squad structure or something close to it. If the "standard squad/section" was ten men then an APC that would hold 10 men (dismounts) was wanted (or maybe nine men). An APC that held 6 men (dismounts) was not wanted as it meant both new squad tactics/drills and much increased confusion in action.



The ammo carrier based APC will look slightly different than the ammo carrier itself.



> The British 2pdr gets a bad reputation because it was forced to carry on well past it's normal due date. In actual fact it could see off quite well most any German tank until well into 1941. One major failing was it was not provided with decent ammo for a good part of the time. The Muzzle energy of the Germany 37mm with normal AP ammo is 200,000 joules. The German short 50mm gun had 404,000 joules while the 2pdr with AP shot was 392,000 joules and with APCBC shot 382,000 joules. Unfortunately the British do not get the APCBC shot in production until the end of 1942. Please note that APCBC shot/shells were being used in Naval warfare by 1914 so this is not exactly "new stuff". APCBC shot would have gone a looong way in taking out the face hardened German tanks in 1941-42. Need to actually issue HE ammo has been gone over before. British 2pdr HE ammo, when it did show up, carried about 2 1/2 times the explosive of a German 37mm tank HE shell.



Thanks for sharing that.



> 18pdrs as AT armament is nothing short of desperation. AP shot was made and issued but much more in the line of self defense. The effective range is short (much shorter than the 2pdr) and rate of fire (and more importantly, the rate of engagment))is much lower.



Yep, more of 'we will encounter them, so let's be prepared' stuff, than something active 'let's hunt the panzers'.



> There is a lot of controversy about when the 6pdr should have been introduced *but the 2pdr could have been much more effective in 1940-41 with different projectiles* even without going to new types like APCR or APDS.



Easy to agree on that.



> These are not mechanization issues as such but changing the chassis under the guns or using (misusing?) odd ball guns on new chassis isn't really going to change things much.



The Brits would made a better show further on, but so will the others


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## Shortround6 (Jun 2, 2012)

For your consideration:

MK VI AA tanks. 











A Vickers 6 ton AA vehicle:






A Vickers 6 ton artillery tractor also known as a Dragon:






And a model of a 40mm on a truck, notice the jack stands:


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## tomo pauk (Jun 5, 2012)

Thanks for the contribution. Currently I'm working, flat out, so my posts in this thread would be postponed, maybe until September.


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## Shortround6 (Jun 5, 2012)

We will miss you. take care of your self and your family. Hope the work goes well.


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## tomo pauk (Jun 6, 2012)

Thanks for the wishes, we're all okay (and expecting a new family member  ). The work is really awesome this year.
I'll be able to spare a half an hour daily to check out the forum; you won't get rid of me so easlily


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