COMPETITION Steel Chariot of The Prairie: The Lone Free State's First Battle Tank (2247)

[Sturgeon]

Just now, A. T. Mahan said:

 

I did it the other way around last time, it's not that bad -- the millimeter is already defined as 1/25.4 of an inch.

 

So something specific to firearms engineers is that being "bi-lingual" is a must. So, for example, my documents are all set on metric. But every dimension is conceived in inches. Fortunately, Solidworks provides for this, so I end up typing "in" a lot.

[Sturgeon]

Just now, A. T. Mahan said:

Shhhhhhhh

As a USC man myself, I understand.

[A. T. Mahan]

I mean, I've just always set NX to inches. I will say, I'm looking forward to getting the hull finished enough tonight so that I can post a screenshot, then start on the turret. Sizing the turret properly is being a pain in the ass, especially in the weight regime I'm working in, as well as getting the under-armor structural shape done right to balance the gun nicely.

[Lord_James]

2 hours ago, Sturgeon said:

Quintuple power posting: This competition does have a "gimmick" btw. It's not secret, it's built into the spec you've already seen.

 

It might be fun for you guys to guess what it is!

Fuel armor? The long distances that are required would necessitate a lot of fuel, which could be used as armor if arranged correctly. 

[Sturgeon]

Starting to look like a real hull:

[A. T. Mahan]

 

The hull is coming along nicely so far -- I have all the gubbins modeled, I just need to make up an NX assembly for them. I'm dreading linking up the tracks again, that took me like two damn days last time.

 

 

And with the armor array in place. Zero guesses for how much of a NATO box tank this thing is going to be. 

[Sturgeon]

Imagine working with flat surfaces.

[A. T. Mahan]

Just now, Sturgeon said:

Imagine working with flat surfaces.

 

I'm way better at weldments than I am at casting. Plus there's this bigass rolling mill lying around.

[Sturgeon]

2 minutes ago, A. T. Mahan said:

 

I'm way better at weldments than I am at casting. Plus there's this bigass rolling mill lying around.

Hahahaha I'm role playing as a foundry.

[A. T. Mahan]

 

Hey, presto! Tracks and wheels and a dozer blade and auxilliary fuel drums!

[A. T. Mahan]

A quick update on the gun, the current iteration of dart is doing north of 16" RHAe at 2000 yards. It seems that the decision to use an auto-loaded 5" gun was not especially unwise, although it seems to be larger than the guns discussed previously. That should provide substantial margin for growth.

[Toxn]

I spent far too long last night designing a gyro-stabilized gun sight, but in the process I was able to find a cute application that allowed me to rough out the configuration of planes, mirrors and lenses:

https://ricktu288.github.io/ray-optics/simulator/ 

[LoooSeR]

13 hours ago, Sturgeon said:

I thought it was the inch was defined in millimeters.

Looking forward for misreading those.

[N-L-M]

As I am a judge on this competition, I cannot win, and therefore I feel free to make a bit more of a joke submission.
I considered the fully upgraded Norman, as a totally-not-industrial-espionage-honest-guv deal, or a set of 3, 2-man tanks under a tarp, one with an ATGM for the armor performance, one with an RR for the anti infantry performance, and one with an autocannon (and all with both fixed and coax MGs) for that sweet sweet automatic firepower.
I ended up deciding on something which is both more ridiculous and yet also much more sensible, stay tuned.

[Sturgeon]

18 hours ago, A. T. Mahan said:

A quick update on the gun, the current iteration of dart is doing north of 16" RHAe at 2000 yards. It seems that the decision to use an auto-loaded 5" gun was not especially unwise, although it seems to be larger than the guns discussed previously. That should provide substantial margin for growth.

 

I'd honestly be surprised to see any guns under 120mm.

[A. T. Mahan]

42 minutes ago, Sturgeon said:

 

I'd honestly be surprised to see any guns under 120mm.

 

Fair enough. I don't see a huge advantage to going much bigger than 120/125/5" unless it's for a pure HEAT-chucker -- even with armor protection where it stands in 2021, it's still possible to make suitable gun and dart in 120mm caliber that provides sufficient performance. Further, the armor penetration requirements are more than suitably met with a ~125mm caliber HEAT charge, even a high velocity one, with substantial growth margin as improvements in warhead design come to fruition, and it's a pain in the ass to manhandle anything bigger than about 5" into the tank. Even 105mm dummy rounds are kind of a pain in the ass, from personal experience. 

[Sturgeon]

8 minutes ago, A. T. Mahan said:

 

Fair enough. I don't see a huge advantage to going much bigger than 120/125/5" unless it's for a pure HEAT-chucker -- even with armor protection where it stands in 2021, it's still possible to make suitable gun and dart in 120mm caliber that provides sufficient performance. Further, the armor penetration requirements are more than suitably met with a ~125mm caliber HEAT charge, even a high velocity one, with substantial growth margin as improvements in warhead design come to fruition, and it's a pain in the ass to manhandle anything bigger than about 5" into the tank. Even 105mm dummy rounds are kind of a pain in the ass, from personal experience. 

 

Pretty much every contestant knows they're trying to beat the Norman, and on top of that everyone else. The Norman comes out of the gate with a 105 and it's public knowledge that @N-L-M planned a semi-canon 125mm for it. So while you could technically qualify with a ~4 inch gun, I anticipate that everyone will blow all the requirements out of the water - which is very normal for an SH competition.

[Sturgeon]

4 minutes ago, A. T. Mahan said:

 

Fair enough. I don't see a huge advantage to going much bigger than 120/125/5" unless it's for a pure HEAT-chucker -- even with armor protection where it stands in 2021, it's still possible to make suitable gun and dart in 120mm caliber that provides sufficient performance. Further, the armor penetration requirements are more than suitably met with a ~125mm caliber HEAT charge, even a high velocity one, with substantial growth margin as improvements in warhead design come to fruition, and it's a pain in the ass to manhandle anything bigger than about 5" into the tank. Even 105mm dummy rounds are kind of a pain in the ass, from personal experience. 

 

At the same time, as you point out, guns bigger than 5-inch are a hard sell. They virtually demand an autoloader (and in the back of their heads people expect Texas to field these guns with caveman HE, it's just their style), and the compromises get out of control fast on a tank that already demands quite a bit of internal volume.

[A. T. Mahan]

41 minutes ago, Sturgeon said:

 

At the same time, as you point out, guns bigger than 5-inch are a hard sell. They virtually demand an autoloader (and in the back of their heads people expect Texas to field these guns with caveman HE, it's just their style), and the compromises get out of control fast on a tank that already demands quite a bit of internal volume.

 

Actually, on that, do we have statistical information on how big the average Texan tanker is and what the SDs and max allowable height is? I'm sure I can accommodate a corn-fed good ol' boy but it would be easier to not have to

[Sturgeon]

1 hour ago, A. T. Mahan said:

 

Actually, on that, do we have statistical information on how big the average Texan tanker is and what the SDs and max allowable height is? I'm sure I can accommodate a corn-fed good ol' boy but it would be easier to not have to

 

Yes they're 6'1". Max allowable should be 6'6".

[Sturgeon]

Hull is starting to look handsome, in the way that gigantic brown slugs do.

[Sturgeon]

I guess I didn't post the massively over-detailed suspension here yet:

[Sturgeon]

I dub thee, Sir Greeblebutt

[Sturgeon]

So basically if you aim for my engine cylinders from the side you can just go get fucked:

[N-L-M]

Behold, the first images of the Howling Retriever:


The armor packages are... not small.
The weight of the structure and armor do however converge to a reasonable all up weight, as I planned.

For those not aware as to what a Howling Retriever is, well, it's a pre-war breed of canine from the Texas region, known for its aggressive tendencies: