WesWorld

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Originally posted by Red Admiral

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Originally posted by Vukovlad
Another strange statement...

Not really. Don't see many high velocity 75mm guns before then. The Japanese Type 96 is a T-34++ with armour around twice as thick, massively increased speed and a high velocity 75mm gun. A bit better than a T-34/85 and similar to a Panzer V. Definitely 1944 territory.

Gothia Works seems to be going the same way with high velocity 75mm guns.

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From my understanding of the situation re: upgunning tanks, there are a couple different limiting factors.

Recoil and weight aren't that big factors unless its a very light tank. Weight isn't much, even for a modern 105mm its only about 1200kg. Medium velocity 75mm is around 300kg. This is from a nice little book on AFV design I have borrowed. Counterweights on the breech end take up volume and may be more of a problem. Internal space in the turret is the largest problem. How much the gun elevates/depresses depends on what height you have the trunnions and external fittings. Then there is the recoil length and the need to push a new round into the breech. The 88L71 was able to fit into the Panther's Smallturm, but its an interference fit and barely able to load ammunition.

Interesting so you dont consider AA guns High velocity weapons nor of course the 75/70 or the 17 pounder. Even the Swedish Strv M/42 was supposed to have a long 75 initially

What are you on about? Tanks with the 75/70 and 17pdr don't appear until late 1943 of OTL. Not 1936. A heavy AA weapon mounted on a truck isn't the same as a tank, and weren't that common anyway.

I guess new Italian tanks will have to upgun from the 47/32 to the 65/64 at least over the next year or two.

You said no HV guns before 1944, now its no HV tankguns before 1943 and of course the Truck mounted 75+mm guns used since WW1 have now become unusual.. looking forward to the next statement. Btw shouldn´t Italy stick to MGs on tanks in this period?

I was referring to the entire package of highly sloped thick armour, considerable speed and a high velocity large calibre gun. The pieces themselves exist before they all come together. Here they are all coming together in 1936 instead of 1944 or 45 after 5 years of war experience, when here there is very little.

An AA gun mounted on a truck isn't a tank. Here the emphasis is on getting a high velocity gun to shoot at tanks, not planes. The two things are very very different.

How many tanks did Gothia Works produce in OTL? Theres got to be some leeway, but at the moment when we're out by almost a decade things are a bit too much.

True Gothia Works didnt produce tanks OTL just aircraft and
ships... It might be early for HV tankguns but were do you come up with this 1944 crap? You said that NO HV guns were around before 1944. We have very short lead in time in WW so my guess is that it wouldnt take 3 years for the 17 pounder to get into production as OTL (design starting 1940, first service 1943) nor do we have to worry about disrupting production or draw incredibly wrong conclusions.
Nor would every nation base its tanks ton LT-38 or BTs. The Swedish Army that hadnt fought a war for 130 years ordered a Tank with a HV 75mm gun in 1941 (later changed to a shorter gun as it was seen more appropriate for fighting in wooded terrain).

Its not that the guns don't exist, a large calibre high velocity gun wasn't mounted in a tank until then. The long lead team on the 17pdr was from production focusing on the 2pdr and then 6pdr following the massive loss in equipment at Dunkirk. Here things might go a bit smoother. Tanks here don't have to be based on OTL designs, but should be roughly comparable, not a giant leap forwards for little reason.

Until massive tanks with thick armour come along there is no need for a long calibre HV gun.

Such massive tanks won't come about until bigger AT guns pose a threat and until the current lighter designs prove to be hazardous the the crew's health. Which as yet they haven't.

The 17pdr in WW might not be needed until 1945, who knows. WW is not a case of "lets have all the tech of 1944 and move it forwards five years" its more a case of "what do I need now to meet the needs of 1936 without hindsight from our 2008 standpoint." There is a difference.

And we have seen the need for 40kT battleships and 300 MpH fighters how? NWM as I stated before getting jumped by RA the guns were to be introduced after that the Legionaries are slaughtered on the plains (if I read the plans correctly) and having rejected RA suggestion of going down in caliber that has never ever happened on a production tank.

The Legionaries were destroyed because they ran out of fuel and were forced to fight statically and the RSAA tanks worked round the flanks and easily knocked them out at quite close range. There was no opportunity for long-range slugging it out. Even so the Legionaries 75mm guns took a toll on the enemy, even more so at close range.

The roots of the problem lie with the historical Type 90 75mm field gun and the Type 88 75mm AA gun used by the IJA and the way I looked at them. The field gun was a 38.4 caliber weapon and the AA gun was a 44 caliber weapon. I thought it would be better to use the Model 1930 gun (which was going to be used on many warships) for the field gun and AA gun. This seemed logical to me since that would mean that just one 75mm gun model would have to be produced for use on the field gun mount or the AA gun mount by the IJA or the DP gun mount by the IJN. That meant that when I went for the T-34 clone, it made more sense to use the mass produced 75mm/50 cal gun rather than to produce a different shorter 75mm gun to match the historical T-34 tank.
... also it helps make it look somewhat different from the actual T-34/76.

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Not really. Don't see many high velocity 75mm guns before then. The Japanese Type 96 is a T-34++ with armour around twice as thick, massively increased speed and a high velocity 75mm gun.

I never really paid any attention on that, but now that you mentioned it and I have looked around, I think I might have accidentally used the data from the wrong model (i.e. not the Model 1940 but one of the later T-34/76 models). Also looking at the data, the speed is probably a typo (either from me of from where I got the data) and it should have been metric, not imperial.
-_-;;

Data should roughly match the Model 1940 now.

I must make a note: "Remember where you get your data from." because I can't remember where I got the data from in the first place.

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Originally posted by Rooijen10
The roots of the problem lie with the historical Type 90 75mm field gun and the Type 88 75mm AA gun used by the IJA and the way I looked at them. The field gun was a 38.4 caliber weapon and the AA gun was a 44 caliber weapon. I thought it would be better to use the Model 1930 gun (which was going to be used on many warships) for the field gun and AA gun. This seemed logical to me since that would mean that just one 75mm gun model would have to be produced for use on the field gun mount or the AA gun mount by the IJA or the DP gun mount by the IJN. That meant that when I went for the T-34 clone, it made more sense to use the mass produced 75mm/50 cal gun rather than to produce a different shorter 75mm gun to match the historical T-34 tank.

The problem I see here is that the requirements for an AA gun and a field gun are not the same. Yes, making only one weapon IS a savings, but at what cost? If the field gun is really an AA gun on a different mounting, it will be heavier (from the longer barrel and higher recoil) and more expensive than it needs to be, and hence more problematic to deploy and use in the field.

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Originally posted by Vukovlad
And we have seen the need for 40kT battleships and 300 MpH fighters how? NWM as I stated before getting jumped by RA the guns were to be introduced after that the Legionaries are slaughtered on the plains (if I read the plans correctly) and having rejected RA suggestion of going down in caliber that has never ever happened on a production tank.

Re: 40t BBs and 300mph fighters
As for 40t battleships, the historic South Dakota class, laid down in 1920, was to displace 43,200 tons normal, but was cancelled due to the Washington treaty, as was the 48,400t 9x16 G3s. Of course the 42,670t Hood was completed. We are not pushing the curve here.

As for 300mph airplanes, that is not unusual for mid 30s aircraft. Now, you will find some WW designs at 400mph but until recently there was a +5 year tech limit for piston engined aircraft. And you do find things like the P-38 hitting 400mph around 1940.

Re: Downgunning
Actually, I was the one that suggested downgunning. It is the most logical approach at this time. When the concept was challenged as ahistorical, RA simply confirmed that the Brits did in fact do this, swapping down from a 95mm how to a 6pdr. In consideration of the Pz-IV, the Germans used the Pz-III for the primary anti-tank role, and did explore fitting the 50mm to the Pz-IV, but it was not necessary at that time. Only after a couple years of war was the Pz-IV redesigned to sport a 75L43.

The problem the Legionnaire may face is that the 75L26 is adequate at short ranges, but the penetration and accuracy drops off at long ranges. The solution is not to rearm it with a 75mm HV gun, that is unneeded and problematic. For all current tanks a 47-57mm gun should be sufficient as an antiarmor weapon. Further, a 47-57mm weapon should be fit in the current tanks as a replacement for the 75L26 without requiring modification to the design.

There is also the issue of the turret ring and turret size pointed out. A webpage on the Challenger discusses how the tank was made just big enough for a turret ring (66 or 70 inches) to support the 17pdr, which the 57inch Cromwell could not, even though there was a 95mm Cromwell CS. Eventually the tank was enlarged to into the Comet with a 64inch turret ring to take the 77mm.

When I developed the Lt-35, I looked up bunches of things trying to make it reasonable. As I recall I copied the Sentinels 138cm (54in) turret ring as the Sentinel was successfully fielded with the 6pdr and the 25pdr- which matched my desire for a AT and IG versions, but was not satisfactory when experimentally fitted with a 17pdr (at least from my perusal).

The legionnaire is already a large, heavily armored and armed tank, privately developed and oddly superior to most nations and private companies tanks. I find it unlikely that the designers would have chosen to fit an oversized turret ring to allow upgunning further. After all, larger turret rings and larger turrets mean greater weight and a need for a wider hull, again meaning more weight for the same armor thickness. This leads to more stress (or redesign) on the suspension, lower speeds for the same HP, and reduced mobility. The physical dimensions of the Legionnaire would seem to support this notion, as the Legionnaire is not as wide as the Lt-35. Note that the Pz-IVG was even wider at 2.88m.

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Originally posted by Vukovlad
NWM as I stated before getting jumped by RA the guns were to be introduced after that the Legionaries are slaughtered on the plains (if I read the plans correctly) and having rejected RA suggestion of going down in caliber that has never ever happened on a production tank.

Lets refrain from taking things so personally shall we?!

Dont know why i bother since no one seems to read.

The brits did NOT go down in caliber the development of British tanks went 40-57-75-76 (17lbs & 77mm HV). I you had bothered to check out the 77mm HV you would have noticed that it is the 17lbs with a more compact breach and chamber firing the same ammo as the 17 lbs necessiated by the need not to delay production (see also the 17/25 lbs AT gun). In WW we dont have to take that into consuderation. That the germans planned an 50mm Pz IV is hihly unlikely as the Pz IIIF was using that weapon and both the Pz III & IV were planned to be upgunned after the experiences in France. With your comment about the 95mm CS it is obvious that you need to read up on differences between howitzers and guns. OTL it was was always a trade off between availability and performance.

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Originally posted by Vukovlad
Dont know why i bother since no one seems to read.

The brits did NOT go down in caliber the development of British tanks went 40-57-75-76 (17lbs & 77mm HV).

Believe me the exasperation is mutual at this stage.

The British fielded the 57mm and the 95mm in the same time period. With the Churchill you see the turreted 95mm prior to the turreted 57mm. According to RA's info tanks fitted with the 95mm could be fitted with the 57mm barrel. This provides a historical precedent for the downgunning from a LV howitzer gun to a HV antitank gun.

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I you had bothered to check out the 77mm HV you would have noticed that it is the 17lbs with a more compact breach and chamber firing the same ammo as the 17 lbs

The point of that is the 77mm had lower MV and pressures, thus requiring a smaller turret ring, as outlined.

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That the germans planned an 50mm Pz IV is hihly unlikely

From Wiki : In March 1941 a prototype Panzer IV Ausf. D was fitted with a Krupp 50 mm KwK 39 L/60, which was effective against most tanks of the era. The prototype did not enter production.

Perhaps I should have said "explored" or "considered" instead of "planned", but it was certainly something they explored. Of course the 50L60 proved lacking in the east, so *then* they went to the HV 75mm.

I think I am sufficiently acquainted with the differences between howitzers and guns, but thank you for your concern.

Edit :

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The gun mounted on the Comet tank had a smaller breech block to enable it to be fitted inside the turret and cartridges from the 3" AA gun were used. The weapon fired the same projectiles as the regular 17pdr but as the cartridge was different the ammunition was not interchangeable, although the same calibre as the 17pdr the gun was named the 77mm HV in order to prevent confusion over ammunition supplies. The smaller cartridge meant a lower muzzle velocity and thus a decrease in performance compared with a regular 17pdr.

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Originally posted by Vukovlad
Dont know why i bother since no one seems to read.

Apparently your correct if by "no one" you intend to throw yourself into that lot.

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Originally posted by VukovladThat the germans planned an 50mm Pz IV is hihly unlikely as the Pz IIIF was using that weapon and both the Pz III & IV were planned to be upgunned after the experiences in France.

When designing the Panzer III the Germans explored the idea of a heigh velocity 50mm gun. In fact they designed the turret ring to mount this weapon but in the end adopted the 37mm gun because the infantry had just accepted the 37mm AT gun and opted to standardize.

I have several sources that cite this, its no shock that the design later upgunned in the Ausf F version to the 50mm with ease. The Ausf H acctually predated the F and G versions and was designed from the start to mount the 50mm gun. These designs were conceptualized in 1935 and began production in 1936 so to see 50-57mm guns in this timeframe is about historical. 75mm guns at best would be low velocity guns for the purpose of fire support.

Since its the consensus of the board the will be no rearming of Legionaires since I cant bring my self to take an route that has never been taken by any nation but is much favored by WW. I will now try to pursaude my friends that the Centurion AVRE (165mm) and M728 are "Upgunned" Centurions and M-60

No pursuasion (or sarcasm) nessassary really.

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The problem I see here is that the requirements for an AA gun and a field gun are not the same. Yes, making only one weapon IS a savings, but at what cost? If the field gun is really an AA gun on a different mounting, it will be heavier (from the longer barrel and higher recoil) and more expensive than it needs to be, and hence more problematic to deploy and use in the field.

Actually, if you look at the ships that carry it, you know that it is a Dual Purpose gun on a different mounting and not an AA gun (but probably just as bad).

You are right though. I have no doubts that there might be problems, but at least there is a good reason as to why Japan is doing that, even if it turns out that the logic behind it is totally flawed when the material is really put to the test in a conflict (in which case Japan would have to rethink their idea of using just one model gun). At least it is not the reason of "If he is doing that then I will do that as well".

Looking at the data now, I think that waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaay back when I started out with designing the Japanese ships for the start of Wesworld, I looked too much at the US 3"/50 guns (Mark 2 and Mark 22 and all the 3"/50 guns in between) which resulted in the whole Japanese 75mm series used on warships (starting with the Model 1912) being 50 calibers long rather than the 40 calibers that the historical Japanese 3"/8cm guns were. Why I did that? I have absolutely no idea. If I had stuck to the 40 calibers length of that gun, then it would have been a 40 caliber long weapon used on warships, as field guns and AA guns and in the tanks...

... but now I am stuck with that 50 caliber long gun...