Polish Projects and Prototypes - 1939

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Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-01-29 04:00, Monday

Howdy all y'all.

I'll stick to English due to not everyone speaking Polish out on this forum. If need be I can do bilingual posts.

I've looked around some forums - DWS, Odkrywca, some websites, the wiki of course as well. Many hours of digging over the last several days...
:thud

Then this site: https://www.commonwealth-triumphant.com has some interesting what if...? vehicles - some were being worked on, some I'm pretty sure are fake.

What I did find was a gold mine of information, I'll share it here. It's image heavy, but rather images than a thousand words each.

This has nothing to do with making a mod for OG at all, absolutely.

I'll go from the stuff that was most realistic to the "there were design discussions in the design bureau", to a few feasible but what I'm convinced fictional.

So first off, the 7 Ton Polish (7TP) tank was up for an upgrade. Some say it already entered service.
Others that it was to be the production run due to enter service in early 1940 was to be the first one of the new type.

It was commonly known as the 9TP due to its increased weight, and per the wiki, one of the early units is the one that doesn't look like the others in this pic:
Image
Image

There was also the 14TP tank in development, which was to be armed with the 37 mm Bofors, but upgunned with a 47 mm gun when the gun became available:
Image
There was a prototype tested of a Christie type tank, the 10 TP, but the wheel+track system was too complicated, so this design was upgraded to tracks only and the prototype for that was never finished before the war.
This is the 10 tonner:
Image

The PzInż 303 scout car had an armored version in the works....
Image

Image
Is it realistic to assume that this car would get an AA MG mount during development? This was getting very popular with Polish designs at this time.

A bit further down the road there was the 25TP tank. 75 mm gun.
Image

Image
This tank apparently had a wooden mockup built, and the mockup along with the documentation was lost. The above is a recreation of what it would have looked like. This was one fun forum topic to read through.
https://forum.odkrywca.pl/topic/323402- ... /#comments

I'll skip the multi-turret tanks that are found in WoT, those I know for a fact were cancelled, and I mean there's already a tank that fits between the Pz IV H and the Sherman 76 just mentioned, so the multi turrets were thrown out for good reason.

Then there is the kind of sort of iffy category. From what I found, these would not be pursued for further development.
Is it realistic to assume that since the chassis was made, and prototypes were tested for a couple years, that this family of vehicles would be approved for production, at least until the better designs are ready? It seems that this family of vehicles was to be just testbeds, because the newer and greater things were to be ready in just a couple of years.
Let's say WW II breaks out, but due to an Obrona Chęstochowy and a Cud nad Wisłą Poland is not conquered, and now needs equipment to deal with Pz II's and BT-5's due yesterday.


There was the family of PzInż 130 (amphib tank), 4TP (scout tank), PzInż 152 (arty tractor) and PzInż 160 shown below:
Image

Now for the "design discussions" category:

PzInż 160 - there was a big move to replace main guns on tanks from the 37 mm Bofors to the 47 mm Pocisk.
If the 160 went into production after all, what are the chances it would get upgunned? It was a good meter longer than the TKS-D, so it should be able to fit the 47.
Further speculation from me - what about the 65 mm mountain gun? There was a push with the TKD and Carden-Loyd to put a field gun on a self propelled chassis, and while the TK series won against the 160 because it was cheap, it was later decided that those tankette gun carriers are too lightly armored.


PzInż 342.
Image
There was a project of this truck to be an AA gun portee. I was not able to find what gun it would carry, I doubt it was a 75 mm.
Anyways, that ground clearance, those tires. :yes

I found similar info about the PzInż 202:
Image
This one was also to be an SP AA gun. I assume a 40 mm? Or could it carry the 75 mm wz 36?

After that there was the PzInż 222, a smaller half track, on which there was an armored version in the design discussion stage:
Image

Image
There was also talk (or so some smart people on the internet wrote), that this vehicle would come in a fire support variant with a twin 20 mm.

The 7TP was also to be developed into an AA tank with a twin FK 20mm gun.

Pure and total speculation zone below.

Now in the end, a few questions.
Did anyone ever run into anything about a tank destroyer on the 14TP?
By "anything" I mean either mentioned by historians, or in the archives or some other reliable source. I'll be happy with just draft notes, memoirs, etc, don't need prototypes. After all, when designing an alternative history, some things will simply not fit with the original timeline anyways.
This would be akin to German E-Series tanks and such. Never fully developed, but with enough info to make an educated guess on their looks and capabilities.

It would be very similar to the Hetzer in size, weight and capabilities if armed with one of the 75 L/50's that were available.
Image
This one uses the wrong chassis (should have 4 road wheels per side, but it still looks cool).

The site also has a 120 mm gun/mortar SPG on the 14TP:
Image

Then there is a cherry on the top that I found on a Russian website:
Image
A 25TP tank destroyer armed with a 90 mm gun wz.39.

Oh yeah - after looking at that tank destroyer I found out that such a 90 mm gun actually totally existed:
Image
So there is at least some grain of truth in the TD drawing.... :)

What about armored gun trucks? I know of Kubuś, but that was a one off.

And finally - what about a 7TP or C7P mount for the 75 mm "Schneider"? Something in the same spirit as the TKD, only bigger and better.


The only SPG I know of was the 75 mm AA gun mounted on a truck chassis, and these were not only shooting air targets:
Image
Image

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Re: Polish Projects and Prototypes - 1939

Post by sympatyk » 2024-01-29 11:42, Monday

:howdy
I have no idea where this information is, but I can inform you that there are also campaigns that use September hardware first, then prototypes, then move on to hypothetical hardware --> you can play it and see how effective it is --> G45 campaign on e- Gustlik e-file and several others

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Re: Polish Projects and Prototypes - 1939

Post by randowe » 2024-01-30 01:01, Tuesday

Great post @RoyalBengalTiger. There are some interesting prototypes and hypothetical vehicles. While i have some of them already in the efile i may add some more :lol The self-propelled guns are very tempting. No correct icons available though.
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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-01-30 03:57, Tuesday

I'm figuring out the icons... and also an eFile as well.

This may take a while though. I used to be around on this forum, but I see that something happened a couple years ago and I had to re-create my account.

And also - I would want to stick as close to realistic as I could, note I did not add any 155mm SPG's, or heavy tanks, or some high level AA gun (I think the Bofors 40 half track will be the top).
I looked the internet far and wide and I am pretty sure that any such projects did not exist.

I'm pretty sure the re-armed PzInz 160 will exist in the mod I'm building, as well as the vehicles I know were discussed...
Same will go for airplanes, artillery as well.

I'm very much on the fence regarding the 14TP variants - the TD and the SPG, and same with the 25TP tank destroyer.
I think they're too far removed from reality, even though both the chassis and the guns were either designed or existing.
It's just that they were never combined.
On the other hand there is the argument of this whole scenario being an alternative history anyways...

:dunno

I'll have to play a couple campaigns to see what others did. I'm not the first to do this.

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Re: Polish Projects and Prototypes - 1939

Post by sympatyk » 2024-01-30 09:18, Tuesday

Wiemy doskonale, że po 1939 roku wojsko polskie jako jednolita nacja przestało istnieć --> część, która walczyła na zachodzie otrzymała tamtejszy sprzęt, ci na wszchodzie - sprzęt rosyjski
To jest gra - tu można stworzyć nację, która ze sprzętu prawdziwego przechodzi do prototypów i projektów
Następnie dalej sprzęt hipotetyczny (fikcja) ..

We know perfectly well that after 1939 the Polish army ceased to exist as a unified nation --> some who fought in the west received local equipment, those in the east received Russian equipment
This is a game - here you can create a nation that moves from real equipment to prototypes and projects
Then further hypothetical equipment (fiction)..

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-01 04:49, Thursday

Alright, I am doing further research...

This one is in Polish, sorry non-Polish speakers:
https://www.youtube.com/watch?v=kZwUzlrvNx0

I will base off the above documentary, with the "what if" scenario actually taking place.

The premise is that general Kutrzeba (who was in charge of an army that was not attacked by Germany - they bypassed it and went around its south flank) would go rogue, knowing that Warsaw is detached from reality, and do an offensive on September 4th (when Warsaw did come up with orders a couple days later, the orders were to fall back). Historically Kutrzeba followed orders, knowing that there is a great opportunity for a counter attack early on being missed. This lead to the Battle of Bzura being a s**tshow.

At the time Kutrzeba wanted to perform his sudden maneuver, the Polish Air Force still functioned, Łódź was still in Polish control, and the German flank would already be opened. German command was not expecting an operation like this.
If Kutrzeba got through the German flank, the front would get stabilized, and Germany loses the initiative on the West approach.
This buys time for the first shipments of tanks, artillery, weapons and other goodies to make it to Romania - and then Poland.

Ah yes, Romania.

https://en.wikipedia.org/wiki/Polish%E2 ... rld_War_II
Poland declined Romanian military assistance

I only learned of this yesterday. :shock

This is the second point of departure from actual history.
Poland did not update the defensive strategy to include a German attack from Czechoslovakia.
Czechoslovakia is right around where Poland borders with Romania. Over the month of September, Romanian units would deal with the brunt of the fighting in Silesia, as in my "what if" campaign, Polish command is not too proud to ask for help immediately and energetically.
Now when the Soviets invade, there is a quarter million extra dudes to plug the gaps.

It is also a well known fact that Russia's Army, in all its might, can be stopped indefinitely by the use of a well placed traffic jam.

P.S. I'll make some icons. I have an idea or two how to make new icons look good without a PhD in in pixelated engineering drawings in multi-angle perspective views. But that's for next time - I'll need to try it out to see how good it works.

I'll go with the hypothetical vehicles too, so long as both the chassis and the main armament would exist, and similar vehicles were created using similar weapons and chassis during this timeframe. So there won't be anything heavier than a 25TP chassis. Nothing bigger than the 90 mm wz. 39S for tank guns.

Sorry, never designed. Never suggested. That's the cutoff.

I found rumors that there were discussions of developing the 14-tonner into different versions, and Poland did experiment with SPG's and TD's and SPAAG's.
Thus the 14TP could do anything the Pz38(t) and Hetzer variants could do though, so the tank, tank destroyer, howitzer/mortar SPG and even an AA variant to replace the actually proposed 7TP with a twin 20mm are I think realistic (the 7TP was on its way out and Polish designers knew this).
I guess the twin 20mm could fit on the 4TP chassis to make for a lighter and cheaper AA tank.

P.S. 155mm wz 40 on a 25TP chassis anyone?
Image

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Re: Polish Projects and Prototypes - 1939

Post by sympatyk » 2024-02-01 08:40, Thursday

Może wyważasz otwarte drzwi?
Temat sprzętu dla ROP - to osobny temat na naszym forum
Powstało sporo ikon - są wykorzystywane w polskich kampaniach

Może warto się z tym zapoznać i porozmawiać z Waldziosiem (odpowiada za sprzęt)
Na tym forum nie wiem, czy ktoś jest zainteresowany ....
Lepiej zjednoczyć siły - no chyba, że chcesz działać indywidualnie ?

Masz już upatrzony e-fil na którym zrealizujesz swoją kampanię/scenariusz?

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Re: Polish Projects and Prototypes - 1939

Post by randowe » 2024-02-01 12:57, Thursday

RoyalBengalTiger wrote:
2024-02-01 04:49, Thursday
P.S. 155mm wz 40 on a 25TP chassis anyone?
Image
Why not :evil

Thanks to your post i even found an error in my efile (which i took over from older efiles). I think they were confused why Poland had (prototypes) a 155mm gun and thought it must be something they got from the western allies in 1944. I will correct that.
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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-03 01:37, Saturday

sympatyk wrote:
2024-02-01 08:40, Thursday
Może wyważasz otwarte drzwi?
Temat sprzętu dla ROP - to osobny temat na naszym forum
Powstało sporo ikon - są wykorzystywane w polskich kampaniach

Może warto się z tym zapoznać i porozmawiać z Waldziosiem (odpowiada za sprzęt)
Na tym forum nie wiem, czy ktoś jest zainteresowany ....
Lepiej zjednoczyć siły - no chyba, że chcesz działać indywidualnie ?

Masz już upatrzony e-fil na którym zrealizujesz swoją kampanię/scenariusz?
Jak zobaczyłem po istniejących ikonkach to...
14TP miał 5 kół jezdnych na stronę. 10TP miał 4, a 14-ka była modyfikacją 10-ki. Zawieszenie po 2 koła na wspólnym mocowaniu. Z resztą tak jak 4TP.
25TP miał 5 kół jezdnych, powinno być 6. The same problem.
7TP widziałem że jest wersja z 4x 20mm, ale z tego co doczytałem były założenia do projektu z podwójnym 20mm tylko.

Także ikonki się przydadzą nowe. Na razie tworzę mniej więcej dość dokładne (wystarczająco żeby ikonki zrobić) modele 3D, używając Sprocket. :)
Potem zrobić screenshots pod każdym potrzebnym kątem żeby mieć z czego przerysować.

E-File, jeszcze nie wiem, z którego bazować, ale na pewno będzie trochę modyfikacji.

Short story long in English:
I looked through icons and found that the 14TP and 25TP had the wrong number of road wheels, among other issues. Was 5 per side, should be 4 and 6 respectively, with wheels mounted in pairs to the chassis. The 7TP I only know of a proposed 2x 20mm design, while there is am icon with 4x 20mm, so that one needs a modified version too.
So I'll make some icons. Right now I'm creating an approximate (close enough to work) version of the Polish vehicles in Sprocket.
Then I will take screenshots at the necessary angles and I will have templates to do the icons.

Regarding the e-file - I don't know where I'll base off from, but I'll have to do modding anyways.
randowe wrote:
2024-02-01 12:57, Thursday
RoyalBengalTiger wrote:
2024-02-01 04:49, Thursday
P.S. 155mm wz 40 on a 25TP chassis anyone?
Image
Why not :evil

Thanks to your post i even found an error in my efile (which i took over from older efiles). I think they were confused why Poland had (prototypes) a 155mm gun and thought it must be something they got from the western allies in 1944. I will correct that.
There was absolutely a 155.
And it was impressive too, it outranged the Long Tom that I posted on the Sherman chassis before.
Maximum range: 27600m

Here's what it looked like, the prototype in 1939-ish:
Image

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Re: Polish Projects and Prototypes - 1939

Post by randowe » 2024-02-03 02:10, Saturday

RoyalBengalTiger wrote:
2024-02-03 01:37, Saturday
There was absolutely a 155.
And it was impressive too, it outranged the Long Tom that I posted on the Sherman chassis before.
Maximum range: 27600m
A fine gun indeed. I already corrected the error in the efile :cool

The name was correct even, wz. 40, but it was only available from summer 1944. That's why i speculate that people must have tought it must be some allied 155mm gun.
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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-04 03:44, Sunday

So...
I'm in a pickle here.

This is the 10TP tank, actual photo:
Image

Notice the continuous frontal sloped armor, with the exception of 2 "boxes" on the sides and the machine gun.

Now this is the 14TP, actual engineering sketch, per Tanks Encyclopedia:
Image

The armor is a step.

Here it is in WoT (I guess with the 47mm gun it would eventually get):
Image

From what I found out, nobody knows what the "boxes" are for, but possibly to access the steering mechanism to run without tracks.

The pickle I am in is that was the 14 ton to have a continuous sloped front like the 10 tonner, or should it have a 2 piece front?
It may be that the 14TP sketch is actually for the 10TP, only mislabeled, being that one is built off the other.
The single sloped plate would give better resistance for its given weight, and I know for a fact they did not need to bulge out the upper front to fit the crew, as they already fit on the earlier prototype...

Here's a Tanks Encyclopedia sourced drawing of a 14TP with a continuous slope, where the "boxes" are removed and otherwise the config is like the 10TP:
Image

I'm going with the TE interpretation, not the WoT one, but :dunno

Image
This is still like a 15-20 min of work before I have enough details right to make an icon, but it's close...

Anyways, there was talk about making a collaboration.
Can Waldzios or someone make icons if I supply screenshots from all the correct angles?
That should help getting this released a lot quicker.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-04 17:07, Sunday

PzInż 160 with 37 mm Bofors:
Image

Reconstruction sketch of the original:
Image

Hypothetical PzInż 160 with 47 mm wz. 39 Pocisk:
Image

The gun:
Image

And hypothetical PzInż 160 with 65 mm wz. 08 mountain gun:
Image

le gun:
Image

Just a few more to go, the 14TP TD, SPG and SPAA, and then the 25TP TD and SPG.
Then I can take pictures from the correct angles, shrink them down and have templates to make accurate icons.

I don't have anything for OG yet, but this is soooo satisfying to look at already.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-05 04:26, Monday

Update:

So I was doing the tank destroyer on the 25TP chassis, and I just could not make it work the way I'd want to.
There was no project, no design, no discussion even. Was stuck, and did not want to create something totally fake.

I did want to put the 90 mm L/50 on that tank...
I looked at the turret ring diameter, the reconstruction I have is at 1.65m and there is a bit of room by the edges of the hull. The hull could be a bit wider too before the tank exceeds Poland's railroad gage.

165 cm is the same ding diameter as the Sherman and larger than the Panther. The Sherman fit the 90, and the Panther also had a powerful gun.

So I gave the 90 mm a muzzle brake, similar to the one on the 47 mm Pocisk, and here it goes:

75 mm wz. 36 (as designed):
Image

90 mm wz. 39ST (hypothetical upgunning):
Image

There was also a plan to put a twin 20 mm on the 7TP. I know main guns would be shared between that and the 14TP - with it starting out using the 37 mm.
So let's make a mid/late war version of the twin 20 on the 14 tonner chassis.
But what about the turret? I looked far and wide and found nothing at all.

Except for...
Image

So here is a similar 8 sided turret with a rectangular gun mantlet mount:
Image

Now for the more difficult part - I read somewhere the 14TP was to be a base for self propelled guns.
What would Habich do?

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-07 06:17, Wednesday

So just a few more to go and then time for some icons.

This time it's more of the speculative vehicles. The 14TP gun carriage versions.

The guns used are my SWAG, I was not able to find any info on what would be used IRL, but the 14TP is just a couple tons of weight lighter than the Hetzer and it's also a bit larger than the Mareșal, so that's where I went to to figure out what firepower to use.

I used the design of the PzInz 160 as a template to make this vehicle look like what would be the logical next step in the design bureau, due to the lack of any drawings.
Up to the superstructure this vehicle did exist in the form of the 10TP, and the unfinished 14TP that was a development of it.

Image

Image

Image

So here's a tank destroyer:
Image

It would use the 75mm L/50 main gun as found on the 25 ton tank:
Image

...and here's an artillery piece:
Image

This version would be armed with the 120 mm mortar wz. 40.
Image
This mortar was a breach loader, so could be used in an assault gun given a adopted mounting.

Hope all y'all like it.
Any comments? Suggestions? If all is well then up next something from the 25TP family. Now that I was able to make a PzInz 160 on steroids and I think it looks very believable I think I can make something fitting for the large chassis.

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Re: Polish Projects and Prototypes - 1939

Post by randowe » 2024-02-07 15:00, Wednesday

Great job once again :cool

Maybe some sort of self-propelled artillery like a Hummel or Wepse for the 25TP family? Or one that could be used in direct and indirect role.
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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-08 05:04, Thursday

Regarding the mortar/howitzer:
Moździerz 120 mm wz. 40 ST
Prędkość pocz. pocisku 295 m/s

https://pl.wikipedia.org/wiki/120_mm_mo ... _wz._40_ST

That's muzzle velocity of 295 m/s. Absolutely a direct fire gun if mounted on a tonk. I'll have to change the model to have the gun point forwards, as is the OG convention for direct fire guns.
That's even less than the earliest StuG III or Pz IV. So direct fire with 1 field range lol.
But 120 mm should have a high soft attack stat, and the 14TP was to have up to 50 mm armor @ 45 deg, and a 300 HP engine, so I think it has merit as a system.

For the Wespe I'll use the 14TP and this elusive 100mm howitzer:
http://www.1939.pl/uzbrojenie/polskie/a ... index.html

I will have to make the assumption that they have a typo - that the range is not 14 000 m, but 10 400.
First argument - it was to be an upgraded version of an older gun with a 9 600 m range, this one:
http://www.1939.pl/uzbrojenie/polskie/a ... index.html
Image

Then it had a 420 m/s MV, which compares to this other 100 mm howitzer that had 430 m/s and a range of 10 600 m:
https://en.wikipedia.org/wiki/10_cm_houfnice_vz._30

After looking around I think the 100 mm Polish howitzer would look like this, even though this one labeled as the old type on the website:
Image

Then for a field gun mount on a tracked chassis, I'll use the TKD as an inspiration:
Image
Note - the above had 2 prototypes built and the project was canned due to the gun not having enough anti-tank performance.
Poland was not really into having SPG's as field artillery, only tank destroyers.

So yeah, getting into World of Tanks level historical accuracy:
Image

Now the 25TP is coming soon.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-08 06:25, Thursday

Soon I mean right now.

So I looked around again, with the 25TP being designed with the 75 mm AA gun, and then I noted that the 90 mm would fit as well so we have 2 versions - early and late...
But what about a gun too big for a turret?

Well...

Nothing says "take your silly little tanks and go home" like a 120 mm gun that fires a 24 kg AP shell at 900 m/s:
Image
Armata morska 120 mm wz. 36 L/50 Bofors - Naval gun 120 mm wz. 36 L/50 Bofors

Compare to the IS-2 with 25 kg @ just 800 m/s.

This gun was not even produced in Poland, it was ordered from Sweden and used as the main caliber on destroyers, and also for shore defense. Unless Poland got a license to build it, or the Baltics got cleared of the Kriegsmarine, the following vehicle would probably have a hard time coming into existence.
Just a disclaimer, yes the gun existed (although was not in common use), yes the chassis (almost) existed, but no this was not designed and is a purely "what if".

Anyways...
Image

But wait, you might say, that tank is only the size of a T-34, how can it carry a gun that they needed the IS-2 to carry?
This ain't realistic, it ain't believable!
Image

I'll have the indirect fire version with the yuuuuge 155 mm as promised.
Soon.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-10 07:10, Saturday

Howdy all y'all,

Revision on the 14TP-H (haubica - howitzer).
The 100 mm will be replaced by this 105 mm:
Image
105mm wz 29

Reasoning being:
Made since 1936, rather than being prepared for production in 1939.
Range of 15 200 m vs 10 400 m.
MV 550 m/s vs 420 m/s.

So it's a slightly better gun for the job. I think the 100 mm was in the works because there was a stockpile of ammo, it would have been lighter and cheaper to make.
It would have been a waste of chassis to use the less capable gun.

New:
Image

Old:
Image

Now for the 25TP-H.

The 155 mm cannon is ridiculous. It's an L/52, so same caliber and barrel length as the Panzerhaubitze 2000
Image

Fitting that into a 25 ton tank is holy balls difficult. Poland never designed a SPG where the engine was moved from the rear to the center, and then the gun could be mounted in the rear (like any other power that had large SPG's did - US with the M40 posted before, Germany with the Hummel, etc).
This is the only precedence I can work with:
Image

Frustrating AF.

After a long time of failing to make it work, here it is:
Image

This is already a rework - the original would not have the hull roof with crew hatches, the gun was more forward. I made the superstructure as far back as I could before running into the engine deck. It'll occupy the space where the turret was.
The TKS-D was built on a stretched variant of the TK tankette, so I did the same over here, by 40 cm.

There is room for more than 1 meter for the breach behind the gun shield, and another 1+ meter for recoil before the engine deck is hit. I think it would work.

I still think it's front heavy, but it fits with the design conventions of the time of the same design bureau and the same engineers.

I'm looking around for any "normal" artillery, and it's like either very old stuff, or things the 14TP could carry.

Any takers for a 130 mm Modèle 1924?
Image
That would make a good intermediate level SPG, even though it's using a not very common gun if actual history is to be considered (this is a mid-30's French naval gun used on a few Polish ships). It is possible this would be delivered in numbers from France, where quite a bit more were used.
Also, note the difference in the wheel arrangement here, where the normal hull is used.

So now I'll go and do icons for all of these. Then I think a couple armored cars and half tracks would need to be added as well. We'll see, maybe there are good icons, but from what I checked, all half tracks have visibly different suspension, even at the resolution of the icons.
I hope some of those would be mods of existing icons so it's easier.

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Re: Polish Projects and Prototypes - 1939

Post by randowe » 2024-02-10 12:15, Saturday

Hehe yeah, the barrel length of the 155mm SPG looks unreal. The 130mm looks much better and more realistic :cool
The 105mm SPG looks great too!
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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-10 17:14, Saturday

Image

Image

Yeah, so that's the early vs the final attempts.

Errors on the early version:
-gun barrel was 6 meters (maybe even 5.5), and since the gun's total length is 8.1 meters I think the proper mounting should have 6.75 meters sticking out and about 1.25 meter plus breach being inside . That's about the proportions of how it was mounted on its trailer on the original photos.
-The gun was mounted over 2nd set of roadwheels. This would make it front heavy and out of balance. Now it's close to the 3rd roadwheel, and the chassis is stretched too for better balancing.
-Chassis of normal length would not give room for recoil if I mounted the gun closer to the center (I actually made a simple box 2 meters long to check I have enough room when updating).
-Redid gun shield as the first version did not look close to any original design.

Further considerations:
-This will have to be a specially built derivative, not just a re-used tank chassis. It would probably have to be like 20 mm thick all around rather than with the original armor thicknesses. Hummel was quite a bit less armored than the Pz IV (and weighed 24 tons, so very much same category). Defense points will be lower on this one than the other versions. Polish artillery tractors based on tank chassis did not have tank armor either.
-Ammo storage would be rather small.
-It would still be overweight, and thus underpowered, so it's mobility score will have to be less than that of the normal versions. I'll estimate it at closer to 30 tons than 25.
-Hummel's range is 13 325 m, the 25TP-H z 155 wz. 40 would be 27 600 m. That's right, more than twice the reach. That's a lot of hexes, and that's the saving grace of this design, which will otherwise not perform well in any task.

Just making a model is easy, but making one look believable not so much. And the PzH 2000 weighs 55.8 t loaded, but the gun is the same...
Sure not having a turret (or even enclosed superstructure) cuts off a lot of weight, but it's pushing it.

But then I'll point at the USA:
Image
175 mm L/60 (10.5 meter long barrel!!!), total vehicle weight 28.3 metric tons (combat).

Anyways, I'll now take my time to update some details on all the models now that I'm familiar with Sprocket's freeform modelling functions (and I have 2 weeks more worth of researching the archives and finding websites with good info), figure out some tricks in GIMP, and I will be back soon with icons.

Expect a couple surprises too.

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Re: Polish Projects and Prototypes - 1939

Post by randowe » 2024-02-10 17:34, Saturday

Here's an Italian prototype: Semovente da 149/40 with a 149mm gun with a range of 23.700m mounted on the back.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-11 07:24, Sunday

An attempt at making this:
Image

... on the 14TP:

Image

I know there was no design, but for s***s and giggles I built it anyways.
The logic is that a proper turret for a twin would never fit on this chassis, so it's sort of a Mobelwagen, only without the armor plates fixed to the hull around the gun.

I'll make a more serious attempt at something later on.
There were actual plans for the PzInz 202 and 222 half tracks, as well as one of the off road trucks to be armed up (check original post for their photos).
And the 202 might actually fit this twin 40 (I have the 3D model now so I can experiment and see, I also can check the load capacity and compare to the weight of the twin mount too).
The 222 would end up with a 20 mm (there was a project for it to be sort of an armored fire support vehicle equipped with just that).
The truck will probably enjoy doing AA work with a single 40 mm.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-12 05:49, Monday

Image

Say hello to the PZInz 152. It's a chassis shared with the 4TP, the swimming PZInz 130 and the PZInz 160 tank destroyer.

Image

55 km/h
3270 + 500 kg (vehicle weight + load capacity)
100 HP engine
5000 kg towing capacity

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-13 06:01, Tuesday

Image

PZInz 130. Swimming little tonk.
Version armed with a machine gun.

Image

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-14 02:30, Wednesday

So, the 20 mm is like less than a pixel wide and I need to do some touch ups so that it's even visible at all.
Image

That's the 20 mm equipped PZInz 130.

Now for the 4TP...

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-14 05:51, Wednesday

Image

Image

4TP
Doesn't float, but has both a 20 mm and a machine gun.
Also this thing has 22 HP/ton and goes 55 km/h.
That compares to the PSW 231 at 19.4 HP/ton and 85 km/h.
Recon movement - yea/nay?

Also question - does Open General have tech descriptions for units?
I could write a thing or two for each of these (and then info about the hypothetical vehicles too - where the grounds in reality are for their designs for instance).

More tomorrow. I think I have the hang of this now.

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Re: Polish Projects and Prototypes - 1939

Post by randowe » 2024-02-14 11:53, Wednesday

RoyalBengalTiger wrote:
2024-02-14 05:51, Wednesday
Also question - does Open General have tech descriptions for units?
I could write a thing or two for each of these (and then info about the hypothetical vehicles too - where the grounds in reality are for their designs for instance).
Yes, it is possible to have a unitpedia. Information and a picture can be stored for every unit at efile level and displayed in the game.
If i remember correctly LXF and NOKORP efiles use this.
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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-15 06:16, Thursday

That's pretty cool, I'll have to look into it at the next step.

Anyways,

PZInz 160 (oh BTW - since this gun carriage is on the same chassis as the 4TP, should it not be known as the 4TP-D, in analogy to the TKS-D and TKS?)

37 mm gun - this is as designed.
Image

65 mm version - hypothetical light assault gun with mountain gun (I doubt anything bigger would fit, I mean my car is bigger than this)
Image

And finally the 47 mm. This is hypothetical based on the fact the 47 mm would be replacing the 37 as a tank gun.
Image

I'm also looking through the development of tanks and I found that the 7TP twin turret version had a slightly longer hull than the single turret, so this was not just done when going from the TKS to C2P to TKS-D, but was more common. I feel better with the yuuuuuge 155 mm gun on the stretched 25TP now.

Speaking of the 25 tonner - the 7TP had an upgraded version called the 7TP wzm (wzmocniony - strengthened), aka the 9TP. Armor 25 mm sides, 40 mm front, vs 13 and 17 mm.
The 10TP was developed into the 14TP. 35 – 50 mm armor up from 16 – 20 mm.

Thus I will call the 25TP as the 25TP wzm. from now, and it'll have slightly better armor stats. It's been historically done twice - and in both cases with a significant increase.
So it would not have 40 - 60 mm, but maybe 50 - 80 or something...
Still looking for how thiccc Poland could make an armor plate (I know somewhere in the Polish historical forums this was talked about, but I did not pay attention at the time). I'll also need to do a weight estimate using its approx size and some steel plate weight calculators and then think about if it makes sense (so adds only a couple tons max).
There was also design work for a home grown engine, the PZInż R.W.A. This was to have 300 to 400 HP. Guess what I'm considering for the 25TP wzm. :)

This PZInż R.W.A engine is actually mentioned in the 14TP tank wiki article. The upgraded 14TP will also be a bit faster than the initial version with the 37 mm.
Since the 14TP already is the up-armored version, whatever defense stats it gets it will keep. And 35-50 will rank it with like a mid/late version of a Pz III.

Anyways, more icons soon.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-17 07:12, Saturday

Alright, not more icons, but yes more archeology.

As I wrote in the previous post, I was looking for how thick Poland could make armor plate in the '30s...

Here's the answer:
Image

These reached nearly 200 mm of thickness, nearly 2 meters in diameter, and were cast in one giant piece.

So I can say that the 25TP wzm. will have 80 mm front and 50 mm sides, rather than the design 60 mm front and 40 mm sides as was the actual original design.
This also adds only about 2 tons of weight, so I declare it a believable update for the late war period. The weight is not excessive, the industrial capability was there, the earlier tanks made by the same engineers in the same design bureau were up-armored and up-gunned so this is very very nice.

25TP wzm. ("official" stats):
Armor: 80 mm front, 50 mm sides & rear
Engine: 400 HP (I'll take the upper estimate of the R.W.A engine that was under development, I could not find why it was designed for 300 to 400 HP, I can only speculate that there was an option for a turbo or something)
Main gun: 90 mm L/50
Weight: I guess about 28 tons.

This compares close to the T-44 which was similar size and weighed 32 tons with 75 mm side armor, and 90 mm hull front and 120 mm turret front.

But wait, there's more!

The quest to find that answer reminded me of the cast turret 25TP drawing:

Image

Now the hull for this sketch comes from this tank:
https://tanks-encyclopedia.com/polnisch ... agen-t-39/

But what about the turret?
I originally thought it was just someone's creativity, but now I think such a turret shape may be very realistic... It looks as if the top part of a fort cupola got chopped off, and then slapped on the tank's hull. The chief engineer - Habich - did note they wanted to make a tank with a flat and wide turret, originally welded, but eventually made as a casting.

So I dug deeper into Polish fortifications of the 1930's, and these armored castings existed as immovable cupolas, but also some forts had rotating gun turrets:
Image
This one is from Fort #38 of Kraków Fortress.

Now big question - I'll be using the welded turret design because it was well researched and reconstructed to the best of the ability of folks who knew what they were doing, but does anyone want the cast turret version as an extra icon?
It would be similar logic to what I think the sketch above used - a bunker cupola on the 25TP hull. I'd call it close enough to be believable, especially as this was actually planned. This will not be the official design, as no actual drawings exist, nor do any serious reconstructions.

Yea/Nay?

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-18 04:34, Sunday

Update!

First off, I hope nobody is using the previous icons yet, the 4TP family is about 10% larger on the icon than what it should be.
I only found out now when I'm doing the 14TP family, which should come out a bit bigger, but is not by much.
I'll have to do a cheap and dirty fix and just scale down the existing views in the previous icons. Soon.

The fact that I used the Hetzer and the Pz 38 for reference did not help...
One is 2.6 m wide, the other is 2.1 m wide, but they are about the same width on icons.
:doh

Secondly, it seems like I'll have to touch up the yuuuuge 155....
Image
The two guns are about the same length, only the reference is 203 mm caliber. The 25TP howitzer is in almost the same scale on the icon view as the normal tank will be. The T93 is actually a larger vehicle, and its gun is shortened on the icon.
Image

I noticed a similar shortening here (not just the barrel, but the front part of the chassis is way out of proportions too):
Image
And this gun is exactly the same in both caliber and barrel length as the Polish 155.
Image

I'll do my best here, but it seems there is just not enough room on the icon file to not either scale down the whole vehicle, or shorten the barrel...

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-20 05:44, Tuesday

And another update.

Icons are actually quite inconsistent in size, so I'll just go by the convention that:
Vehicles about 2m wide become 18px wide.
Vehicles about 2.5m wide = 20px.
Vehicles about 3m wide = 22px.
This sort of works, and the 4TP family from before just so happened to scale down to 18 pixels wide. In other words, I'll just leave them the way they are and not fix anything.

Also, here's the hypothetical 14TP as armed with the twin 20 mm cannon that was in design/proposed for the 7TP.
Image
This would be a later war adaptation to put the proposed twin 20 on a more modern and much faster chassis.

I'll also have this turret on the 7TP of course, so expect a few modded icons and not just original ones.
The 7TP did not only have a proposition for a twin 20 AA, but also to be a gun carriage, so...

Here's a similar one that existed - Soviet AT-1:
Image

And here's a model of what I'll be aiming at:
Image

Historical note: I did not find any source of what gun this vehicle would even carry, only that it was being suggested in PZInż along with the twin 20mm as sourced by IIRC odkrywca.pl historical forums. I'll just assume it's the Schneider 75 mm wz. 97, as it was used not only for fire support, but also for direct fire (including anti-tank work).
Image
The thinking at the time in Poland when arming vehicles was was gun can shoot tanks = good, gun can't shoot tanks = bad.
It was also in plentiful supply, so an early war retrofit makes sense here to fill up the gaps before the cooler gear shows up.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-21 06:19, Wednesday

Image
Had to do a bit of a touch up, updated twin 20 mm AA.
I have a feeling I might revisit a couple icons a bit later when I know what I'm doing better.

Image
This is the initial version of the 14TP. This was in reality a partially complete prototype. Armed with the 37 mm Bofors.

Image
And that's the version with the Armata przeciwpancerna kal. 47 mm wz. 39 "Pocisk". This was the planned upgrade, so is historically accurate.
Since the guns, scaled down vary only by like 3 pixels, I added a radio antenna to make it a bit easier to tell them apart (again - I may revisit these icons and put better coloring or something so some of the details are easier to see).

Historical note:
Radios in tanks was also something planned for the early 40's. In fact the 25TP, which I'll be making icons for soon, was supposed to have a powerful radio to allow it to "do independent work", or in other words, to not be tied down to supporting infantry.

Now for the hypothetical versions on the 14TP chassis - the SPG and TD - those are coming up next.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-22 06:19, Thursday

Update.

The 14TP-D:

Hypothetical tank destroyer, the enlarged version of the PZInz 160, on the 14TP chassis, and armed with the 75mm gun that was planned for the 25TP.
Also, Hetzer.
Image

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-23 06:16, Friday

Image
14TP-DS (działo szturmowe = assault gun).

This is the assault gun version armed with an adapted breach loading mortar, 120 mm caliber, to supplement the tank destroyer from the previous post.
The chassis did exist, the gun did exist, but I do not know of any plans to have them both combined.
This one will be comparable in firepower to the SU-122, only its barrel is about a full meter shorter, so it would have low shell velocity and therefore will get only 1 hex of range.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-24 07:06, Saturday

I now present the 14TP-H (haubica = howitzer).

105mm wz 29 armed SPG, an overgrown TKD on the 14-tonner's chassis.

Image

This marks all vehicles on this chassis, except maybe for an artillery tractor (it would be called C14P, there is a need for a 300 HP tractor as the C7P had about 100 HP and was to be upgraded to 150).

Up next - the 25TP.

I will change one of the versions, the 25TP-H SPG with the 130 mm will have its gun replaced with the Canon de 155 mm GPF
Image
It's a 155 mm L/38.2

Reasons for change:
It's a French gun that was built by the hundreds.
Poland bought both guns and licenses to produce from France.
It seems like many more of these were built than the 130 mm that I currently have modeled (adapted from one class of Polish Navy destroyers).
The GPF's were used as towed artillery and as guns mounted on vehicles.
The Americans used this gun on a Sherman based chassis, so there's precedence that this gun was used on a same weight class vehicle.
Poland used this gun as the Western Free Polish army.
I'll make the assumption that these guns would be sent to Poland should Poland not fail in 1939 (they were issued anyways in reality, see above).

Based on these arguments, I think this would be a more realistic choice for an SPG main gun for a hypothetical Polish SPG of the early 40's.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-24 22:19, Saturday

And another update.
Almost done with the PZInz tracked vehicles...
I'll be back with those either later today or maybe tomorrow.

Then I'll do the 7TP AA (twin 20 FK-A) and assault gun (Schneider 75). This one will need a hull model, so it will take a bit, or I'll just Frankenstein a couple existing icons together.

Then I'll look at the half tracks and trucks I guess. I will need to figure out half tracks and wheeled vehicles in Sprocket, so this may take a bit longer. Either that or modify existing similar icons.

Also, request for help.

I noticed that the following airplanes do not have their own icons (or they do, but the icons do not have all perspective views and some are copies of others like the PZL-38):

https://pl.wikipedia.org/wiki/PZL.38_Wilk
Image
Image
Note how the same view is used for 2 different angles several times.
Might be time to do an upgrade so each angle has its own perspective view.

https://pl.wikipedia.org/wiki/PZL.49_Mi%C5%9B
Image
This one has no icon at all from what I can find.

https://pl.wikipedia.org/wiki/PZL.48_Lampart
Image
Image
Same issue with views here...

https://pl.wikipedia.org/wiki/PZL.50_Jastrz%C4%85b
Image
No icon.

https://pl.wikipedia.org/wiki/PZL.56_Kania
Image
No icon.

https://pl.wikipedia.org/wiki/PZL.46_Sum
Image
No icon.

I unfortunately do not know of any PC game similar to Sprocket, only for designing airplanes.
If there is one, then it's possible to do a 3D art and then take screenshots to make accurate icons..
If I'd have to make these, I'd have to simply find the most similar planes and change some pixels around. This would take a few weeks though, especially with them waiting in line for the other stuff.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-25 05:15, Sunday

Update:

Image
25TP, as designed.

75 mm L/50 main gun, armor 40 to 60 mm, 300 HP engine.

Image
25TP wzm - hypothetical upgrade using the 7TP to 7TP wzm (aka 9TP) upgrade as precedence.

90 mm L/50 gun, 50 to 80 mm armor and 400 HP engine.

Then the tank destroyer counterpart will follow shortly.

Since this is the top of the tech tree so to speak, I'm looking for an anti-tank gun, or one that could be adopted as such, so the 25TP-D can have 2 variants - an early showing up with the base 25TP tank, and then a wzm version which would have the 120 mm naval/coastal defense gun.

This is also all the fully tracked chassis that were ever designed, using all the guns that were designed, and in all configurations that ever existed or were worked on or even discussed in late 1930's Poland.
There were no 8" howitzers, no heavy tanks, no rocket artillery (alright, prove me wrong :) ), not one self propelled mortar - even as a proposed design.

That said, using existing prototypes, designs and then making hypothetical versions of existing designs using larger vehicles and larger guns as the starting points should give quite a wide selection of stuff to work with.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-26 05:55, Monday

Alright, I figured out a thing or two.
Poland purchased 75 mm AA guns from France, these were for coastal defense originally, but then were to be adopted to be the main gun of the 25TP. They then started building their own 75 mm L/50.
They purchased a license to produce and made their own modification of the 90 mm L/50 gun for AA work, this is the upgraded tank gun, following the logic of AA guns adapted to tanks, only with modernized equipment.

France had a 100 mm gun caliber in use as well.
Poland had 2 (two) of these, 100 mm Canet wz. 1891 and these were in the coastal defense battery - Bateria „Canet”. Now with 2 (two) guns there is not much to put on a tank destroyer, as there could only be 2 (two) ever built. They were also outdated and not very impressive in terms of performance. There were also a couple 100 mm French guns used on Polish subs, but they were with their barrels cut a bit shorter.

So I looked at what the then modern equivalent would be and found the 100 mm/45 Model 1932, to follow the existing trend.
Image
15 kg shell at 755 m/s.
The gun is known to have a semi-AP shell, but I could not find its performance in terms of armor penetration.
I had to play with an armor penetration calculator to make an estimate.
That 15 kg shell should get through some 135 mm @ 1km @ 90 deg, so it's comparable to the 17 pdr, only with more kaboom.

Early (100 mm, will complement the tank with a 75 mm - penetration @ 1km @ 90 deg of about 135 mm and 105 mm)
Image

Late (120 mm, will complement the tank with a 90 mm - penetration @ 1km @ 90 deg of about 200 mm and 135 mm)
Image

Icons soon of course.
Sorry I don't have any right now, but to make this realistic it takes a lot of time to research.
I'm also on the fence whether to use this model, or just make a 90 mm for the early tank destroyer and then have an analog to the SU-85 and T-34-85.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-02-29 03:52, Thursday

Image
25TP-D.
100 mm main gun, as I was writing before, this would be a French delivered surplus gun.

Image
I had to actually shorten the barrel a bit in a couple frames to make it fit, and also it is larger than some big guns, but then the whole vehicle is quite a bit smaller than say the Jagdtiger, so the gun is a little out of proportion in some views.
It is what it is.
120 mm L/50, old guns off the Blyskawica when that goes and gets rearmed in GB. Some such guns were used for shore defense and then there some more on order from Bofors.

Up next - the SPG versions.
Hope all y'all like it. :)

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Re: Polish Projects and Prototypes - 1939

Post by randowe » 2024-02-29 16:29, Thursday

This is how BT018 looks in the game right now.
[EDIT: the background hast to be unicolor. There are pixels with a slightly different color.]

Image
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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-03-01 01:16, Friday

I'll do edits and fixes when I get through the last few. These ones are more difficult due to having to touch up each one for radio antennas, AA machine guns, the gun barrel sticks out a lot, so they take more time to complete.
Then there's the fact that it's a bit harder to stitch together the front, center and rear in the side on view, and the left, center and right in the front and rear views when perspective plays games, and these views are supposed to not have perspective in them.
I'll make a tutorial how to make an icon from a 3D model later on, using the way I figured out.

I'm also adding a C14P (ciągnik 14-tonowy Polski - tractor, 14 ton Polish) and a C25P, based off the 14 ton and 25 ton tonk respectively, in addition to the 25TP artillery variants.
So that makes it 4 more icons and I'll clean everything up, before going for the wheeled and half tracks, but there won't be that many of those.

IIRC it's just a scout car, a 4x4 truck and 2 half tracks, with maybe 2-3 variants each. Most of everything else is already well represented in OG.

Also - 018 is the tank destroyer on the 25TP with the naval 120 mm, its hull should be about the size of a T-34, and its gun should be a bit longer than the one on the IS-2.
Does it compare correctly?
I tried to get close to some existing icons, but I'm also using a fairly accurate 3D representation of what the original would have looked like, and it's a bit of a balancing act as not everything in OG is scaled proportionately...

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-03-17 17:18, Sunday

Greetings all,

Sorry for no update for several days, but I was out on vacation.
I'm building a unitpedia for all the goodies I'm making, which will show up when I release something or another, but I did not touch icons when I was out.

I of course also did some more reading. It seems like there were plans to fill in light artillery brigades with a new 75/100 mm gun/howitzer (same towed chassis, but could use different barrels, so depending on the needs the gun could even be swapped in the field). This would free up the 75 mm Schneiders which were still in working order.

There also seems to have been discussions about a 7TP and a 14TP self propelled gun.

I'm already working on the 7-tonner, but now I have some reason to believe that a Schneider 75 was also to be mounted on the 14TP. Expect this one soon too. It'll supplement the existing TD and SPG as the entry level vehicle. Since it was to be a fire support vehicle and not tank destroyer, I think I'll use the open top SPG setup, only with the small gun instead of the 105 as I already created before.

Other changes - I'll use a stretched chassis for the 120 mm version of the 25TP-D. The logic is as follows:
The TKS tank was stretched to make the C2P tractor. This stretched version was then used for the TKS-D tank destroyer. In other words something similar has been done.
I also think that the gunnery crew might need more room.
Here's what the bullets looked like:

Image

Up next - I don't think the 155 mm wz. 40 would work on the 25TP in the form it was in (i.e. center mount). I just don't think it's realistic enough. I can clean up and release the icon though, as an Easter egg.
I still did not find any self propelled artillery projects by pre-war Poland, where the gun would be mounted on the rear of the chassis, so I won't go that route to make a 25TP SPG with the 155 wz. 40.

The 25TP, stretched and unarmored, will make for the C25P artillery tractor which will tow these giant guns (so just a supersized TKS evolution).
The extra space from stretching the hull can be used for cargo, and it was not uncommon for Polish artillery tractors to have a few hundred kg's of gear on them too.
It is true that Poland was going to design a more powerful artillery tractor than the C7P, but if it was a 14-tonner or 25-tonner or maybe a heavy half track chassis is anyone's guess, so I just need to make my own interpretation here.

The only SPG on the 25TP will be the one with French 155 GPF's which were historically issued to Polish troops when they made it to France in late '39. Still a good gun, and this one would fit in a center mount on a stretched 25TP chassis. Guns of similar firepower were mounted this way, such as the Soviet SU-100Y mounting a 130 mm naval gun or the Jagdtiger.

Regarding weapons delivered by the Western Allies - Poland had MS-406 and Hawker Hurricane fighters on order, they wanted to buy the Somua S35's (but France only sold the Hotchkiss H35's historically), of which only one shipment was ever delivered (the other was a bit too late and would have been ready by October '39).
In other words, gaps in equipment would be filled using British and French gear until domestic production can keep up.

More soon.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-03-21 05:02, Thursday

Alright, here's a non-stretched 25TP chassis with a cab over it:

Image

This would be the C25P, or ciągnik 25-tonowy polski (tractor, 25-ton, polish). Stretched out it just didn't look good, and all the bigger tank based artillery tractors and prime movers were just the normal hull, and the cab is already more than 3m long so it would fit the crew and some crates with goodies...

It'll mimic the existing vehicles:

C7P:
Image

PZInż 152:
Image

C2P:
Image

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-03-31 18:53, Sunday

Sorry for being away, but I had a busy week.

Small update.

I wrote previously of a fire support vehicle being planned for the 14TP, with surplus 75 mm Schneider guns as its main armament.

Here's the model:
Image

Compared to the 105...
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Now that I'll have probably several weeks without any extra events, so I think I'll be able to get more done here finally.

Also, Happy Easter.
Image

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-04-03 02:34, Wednesday

Sorry for no icons today, but those interested in the long lost and forgotten weapons...

Armata 75mm wz. 31 St i wz. 38 St, as well as Haubica 100mm wz. 38 St.

These are cryptic artillery pieces with not much info - and no photos or drawings.
http://www.1939.pl/uzbrojenie/polskie/a ... index.html
http://www.1939.pl/uzbrojenie/polskie/a ... index.html

So the above articles are mostly correct, but they get a thing or two wrong.

The 100 mm is listed at a max range of 14000m, but its muzzle velocity was just 420m/s, rather slow.
I did a bit of a sanity check.

The comparable Czech 100 mm:
https://en.wikipedia.org/wiki/10_cm_houfnice_vz._30

...had a 430 m/s muzzle velocity but only a range of 10.6 km. Something was wrong, a slower shell cannot fly further if launched at the same angle.
I later found somewhere that the 14 km range was for the 75 mm wz. 38, not the 100 mm wz. 38 when I was reading through historical forums.

Then I remembered that the Starachowice factory (who's guns are denoted by the St in the identification), also made the 75 mm AA gun.
This AA gun had a max range of 14.5 km against ground targets, so close enough to the 14 km of the artillery piece (that value was from the memoirs of a soldier who saw the artillery gun tested).
Now I put the puzzle pieces together and it makes all the sense in the world.

The 75 mm L/50 wz. 36 St AA gun from Starachowice must have been a close relative of the 75 mm wz. 38 St artillery gun. I now think they used the same barrel, due to the same caliber, same factory, same era and same max range.
So the 75 mm wz. 38 will be represented as such.
There will also be a 75 mm wz. 38 St ppanc (przeciwpancerna - anti-armor), a hypothetical variant of the field gun to be used against tanks. It was common for AA guns and arty guns to be used as AT guns during this time period (Poland used the 75 mm Schneider in all these roles), so I am not pushing the boundaries for realistic and believable too much. This is especially as the 25 TP tank was to have an adaptation of a 75 mm AA gun as its main armament.

The 100 mm version will have a range comparable to the Czech gun. Just over 10 km.

I know I'm nerding out over here, but it seems I discovered something.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-04-14 04:19, Sunday

Alright, I had to revise my dreams of the greatest guns on the greatest vehicles, with a great Polish army in OG.
https://www.youtube.com/watch?v=BMdQaVZDUno
That's a vehicle mounted GPF, on the M3 Grant chassis. This is about the weight class of the 25TP.
It's mounted in the rear and the vehicle digs in to put the recoil into the ground. The gun moves like 2-3 meters backwards when it's fired.

There's no way this gun could ever be fired from a tank, mounted amidships in the configuration I had for the 25TP-H. It would recoil right into the engine deck, the SPG would get pushed back if not anchored to the ground, and that would be the end of it.

Since Poland only ever had front or mid mounted guns on their SPG's, I had to scale things down.
The M7 Priest was a 105 mm mounted in the center of the M3 chassis and I think that's among the biggest guns ever mounted in such a way.
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Here is a 25TP-H with the 105 mm wz 29:
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This will replace the one on the 14TP. I think that more weight is needed to absorb the recoil of this gun. The 105 wz 29 is in fact a longer range, higher velocity gun than that of the M7. 11.2 km range vs 15.2.

And as a bonus, here's the 25TP with the 155 mm wz 17:
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This is a much shorter barrel, much less recoil compared to the GPF or wz 40, but gives an option for larger shells to be delivered.

The 14TP was to be a carrier for the 75mm Schneider, which was to be replaced by the 100 mm and the 75 mm I wrote in the previous post.

Here's the 75:
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Here's the 100:
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While stronger than the Schneider 75, these guns would still not kick back as hard as the 105.

I think my work with the tracked vehicles is now finished. Just need to check if I'm missing any details and make the extra 5 or so icons. I'm happy with built ones, the planned ones, and the hypothetical ones as well.

Sorry for teasing with the 155 mm wz 40, I just did not know as much as I do now about these really big guns. I only thought about if the vehicle was going to tip over from the weight of the barrel, but the weight of the gun is not a big deal compared to recoil forces.
It's all for the best though. I'd rather scrap stuff and spend an extra couple weeks to get it right than to have something that would definitely never work. I'm aiming for realism here.

Bonus point is that all of the above guns were made in Poland.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-04-21 01:07, Sunday

75 mm Schneider on the 14TP:
Image

75 mm wz 38:
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and 100 mm wz 38:
Image

The 25TP heavy artillery coming soon.
It's also quite a bit of work for just a few pixels different in the end, but it is what it is.

*EDIT: Had the 75 and 100 backwards.

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-04-22 04:38, Monday

Having a bit of fun. This one will need a bit of touch up (paint glass color for windows, tarp color over cargo compartment, etc)...

Image

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...but when I get the proportions good enough, it'll make for a nice little addition.

The closest existing icon I can find is this:
Image
And it does not nearly have that off road monster truck feel to it, so I figured I'll try to at least fake a wheeled vehicle in Sprocket. We'll see how it goes.

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Re: Polish Projects and Prototypes - 1939

Post by randowe » 2024-04-22 09:20, Monday

Which truck is that in the photo?
Image Slava Ukraini!

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Re: Polish Projects and Prototypes - 1939

Post by RoyalBengalTiger » 2024-04-22 12:40, Monday


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