COMPETITION Brawling Bobcat: Armored Truck for the Lone Free State (2245)

[N-L-M]

To defeat the Norman in the frontal arc you'd need around 300mm KE or around 400-450mm CE pen.

This translates to around 115mm BM-6 and around 80mm LP HEAT or 100mm HP HEAT.

At least as long as the Norman hasn't gotten its uparmor package yet...

[Toxn]

1 hour ago, Xoon said:

I am curious, what would be needed to penetrate the Norman at 1-2Km range?

Speaking about both HEAT and KE.

Would a 120mm be sufficent?
Or would a 150mm be needed?

I think it depends on whether it's the original version (probably the version current for this competition) or the hypothetical up-armoured ones, and whether you're talking frontal arc or a side shot.

 

A quick look at the original submission shows 200mm LOS RHA, an air gap and 60mm LOS HHA. So around 350mm RHA penetration equivalent should do it. This equates to about a 100mm HEAT-FS or a really, really beefy gun firing AP. Like, significantly more potent than the M58. Given the limits of APFSDS in this competition, you'd probably be looking at something in at least the 125mm range if that's what you want to sling.

 

For side shots you're looking at something like 160mm RHA equivalent penetration to get into the turret, which puts you in the realm of super-hot 75s and the 90mm M3

[Kal]

Would the 120mm wombat's HESH round be suffice vs Norman?  Its a 12.8kg projectile supposedly rated at 400mm RHA. (27.2 kg complete round)

Apparently there was also a Flechette round.

[N-L-M]

The Norman is basically covered by spaced armor all around, so HESH would be incredibly ineffective. Slinging HEAT from the same gun would however work.

[Toxn]

58 minutes ago, N-L-M said:

The Norman is basically covered by spaced armor all around, so HESH would be incredibly ineffective. Slinging HEAT from the same gun would however work.

Agreed. It would peel off HHS plates, but leave the base armour relatively unmolested.

[N-L-M]

So I booted up the Norman model. Turns out that thanks to the needlenose shape and being specced for the wide frontal arc, from directly ahead the Norman's cheeks are hilariously thick:

of course the center of the needlenose, where the mantlet is, is significantly more sane.

 

cheek section at 30 degrees to the right

 

Section at the mantlet.

 

 

The Norman is a really tough nut.

[Sturgeon]

So it turns out that for the upper bound we're shooting for, the 3 stock rim sizes are far too small. I am adding 28in and 32in rims, as a result.

[Sturgeon]

BULLETIN

GOVERNMENT RELEASE OF NEW ORDNANCE FOR CITIZEN APPLICATION WITHIN THE LONE FREE STATE OF TEXAS

The Lone Free State of Texas government has developed an advanced new cannon which can meet both the needs of current citizen-settler militias and the Texas government law enforcement agencies moving forward. The new gun is 3-inch caliber, far larger than previous conventional cannons provided for Texas militias, and incorporates the most advanced barrel, mounting, and ammunition technology available to the Lone Free State. 

 

Find enclosed the following figures and specifications:

 

3in G-41 L/59 cannon

Mass (no mantlet): 1,975 lbs
Rifling: 12-groove polygonal

Twist rate: 1:17 calibers
Recoil system: Concentric
Breech: Vertical sliding block

 

 

 

 

 

 

Ammunition:

3in-23 G-141

 

 

G-141B HVAP-T
Projectile weight: 12.7 pounds
Core: Tungsten Hard Alloy (WHA) Class 4

MV: 3,770 ft/s

V1000yd: 3,501 ft/s

V2000yd: 3,217 ft/s

Penetration, RHA, 1,000 yd: 10.4"

Penetration, RHA, 2,000 yd: 9.2"

 

 

 

G-141D HVAP-DS-T

Projectile weight: 12.9 pounds (in-bore), 10.0 pounds (in flight)
Core: Depleted Uranium

MV: 3,820 ft/s

V1000yd: 3,583 ft/s

V2000yd: 3,362 ft/s

Penetration, RHA, 1,000 yd: 11"

Penetration, RHA, 2,000 yd: 10"

 

 

 

 

G-141A HE-T

Projectile weight: 14.0 pounds
High Explosive: 2.7 lbs RDX

MV: 2,800 ft/s

 

 

I will be releasing the files for this gun shortly (once it's completely finished), and it may be used by any entrant, should they so choose. It also provides a reference of what sort of technology the Texan government is capable of producing, gun-wise.

[Sturgeon]

I've been posting this over on the discord, figured I'd update the thread too. You've all seen the G-41 gun of course, but the truck itself is coming along alright too:

[Sturgeon]

Crew (and passenger) layout:

 

 

 

those three guys are having a great time in the back, trust me.

[Sturgeon]

I was able to cut 8" of hull height and over 3100 lbs of weight without negatively impacting crew working volume:

[Toxn]

While waiting for the competitors to continue their work, I got bored and decided to produce a design at the other end of the scale:

This is the Maxcat, an experimental heavy wheeled AFV which uses a rather insane hydraulic drive system which uses three engines to power the 14 individually-articulating road wheels (each provided with hydraulic motor). The drive system is a power hog, and requires the use of an elaborate hydraulic control system to make it all work. The final wrinkle is that the inner set of wheels need a complex geared torsion bar system to provide the correct amount of travel using stubby torsion bars. 

 

The results are impressive, however: the Maxcat sports a 120mm/L60 gun with the same ballistics as the pre-war M58 (including a useful APDS round based on the one used in the old British L1A2), and has impressive survivability thanks to the large distances between the outer hull and the major components. The hull front has respectable KE resistance (260-350mm RHA equivalent depending on the angle and the region targeted) and frankly insane CE resistance (well over 1000mm of RHA equivalent in some places). The turret front is actually less protected over all, but still manages up to 270mm/750mm KE/CE resistance depending on the angle and area hit. The brow armour is also notable, and gets around 300mm/>1000mm KE/CE resistance against attacks from the front. The Maxcat weighs in at just under 70st unloaded, and hits the minimum range requirement by dint of six massive fuel tanks with a maximum capacity of just over 1150 gal. It hits 90km/h on roads, and will try to do the same offroad if the driver is foolish enough to open the throttle.

 

With all of the above, the Maxcat is designed to be an MBT in all but name - meant to take on all comers head-on and win. It would probably be an expensive, resource-devouring maintenance queen at base, but while out in the field it would be an unholy terror to anything foolish enough to get in its way.  

[N-L-M]

3 hours ago, Toxn said:

The turret front is actually less protected over all, but still manages up to 270mm/750mm KE/CE resistance

That kind of CE resistance is still enough to flat out stop the Mormon 2"/4" tandem warhead, if the armor is properly arranged.

Very impressive beast.

[Toxn]

54 minutes ago, N-L-M said:

That kind of CE resistance is still enough to flat out stop the Mormon 2"/4" tandem warhead, if the armor is properly arranged.

Very impressive beast.

Tandem charges are tricky. The Mormon weapon sneaks through from the front (0.63"/16mm residual penetration into the fighting compartment) if shot at a very specific point on the upper hull. However, adding another 1.5"/38mm RHA spaced armour layer midway down the tunnels on either side of the driver (the most vulnerable area of the upper hull front) allows it to defeat the tandem HEAT pretty effectively across the entire 30' aspect. 

 

There's also a bit of growth potential in the design - around 9.7st (8.8mt) before the vehicle bumps over the loaded ground pressure requirement, with generous space in the hull front, hull sides, turret interior front and turret exterior sides for NERA.

 

The final thing to note is that the dimensions of this thing are simply hilarious: 26'/2.9" (8m) long without the gun, 41'/6" (12.65m) with, 16'/4.9" (5m) wide and 13'/1.9" (4.01m) high. The Maxcat is house-sized, yet cramped.

 

Edit: the turret is very tricky to work out, as the ERA is arranged at two angles and there's a lot of ways it can get hit. As near as I can tell a shot from the 2"/4" directly from the front and hitting the side panel ERA, turret skirt, air gap and front armour still gets in.

[Sturgeon]

5 hours ago, Toxn said:

While waiting for the competitors to continue their work, I got bored and decided to produce a design at the other end of the scale:

This is the Maxcat

 

I think my favorite part about this is the insane drivetrain used just to get reasonable ground pressure with wheels, when there is no explicit requirement in the solicitation to even use wheels.

[Toxn]

29 minutes ago, Sturgeon said:

 

I think my favorite part about this is the insane drivetrain used just to get reasonable ground pressure with wheels, when there is no explicit requirement in the solicitation to even use wheels.

There's the option to build a wheeled death trap and I'm taking it.

 

Don't worry though - I'm sure I'll get bored in a week's time and try to design a half-track that can do highway speeds or something.

 

Edit: or a 60-tonne convertible drive tank.

[Sturgeon]

Anyone looking to use the G-41 cannon, I've had to update the penetration figures as I was using the wrong core diameter for my comparator in DeMarre.

[Toxn]

A more aesthetic picture of my creation:

 

I'm imagining shitty 90s toy commercial faux-rock playing in the background.

 

Edit: here are some of the vital stats:

 

Length: 26'3" (hull), 41'6" (gun forward)

Width: 16'5"

Height: 13'2" (top of commander’s cupola)

 

Engine: 3 12-cylinder liquid-cooled turbodiesel, 2,368 ci displacement each, 2520hp total

Transmission: hydraulic drive system, 120hp motors on each wheel

Suspension: swing-arm, torsion bars/geared torsion bars

PWR: 32.1hp/st loaded (note: due to inefficiencies, only around 25-26hp/st makes it to the ground)

Ground clearance: 4'2"

Max road speed: 56mph

Max recommended offroad speed: 22mph

Operational range (on road/offroad): 435mi/170mi

 

Base hull thickness:

Hull front: 2" sloped at 60' from the vertical

Hull sides, rear, bottom, inner compartments: 1.5"

Turret front: 5.9" sloped at 20'

Turret sides: 1.5" sloped at 20'

Mantlet: 6.1"

Turret floor, roof: 0.8"

 

Protection (ERA fitted, no fuel, KE/CE):

Upper hull front: 12"/>39" RHA equivalent

Upper hull sides (30’ arc): 14"/>39" RHA equivalent

Upper hull sides (60’ arc): 5.9"/8.7" RHA equivalent

Upper hull sides (90’): 4.9"/6.3" RHA equivalent

Turret front: 10.6"/12.9" RHA equivalent

Turret 30’ arc: 10.2"/29.5" RHA equivalent

Turret sides (90’): 4.3"/4.3" RHA equivalent

 

Turret ring diameter: 98.4"

Main gun: 120mm L/60 medium-pressure gun

Ammunition stowage: 52 rnds complete

+22/-6 degree elevation (-12 if not facing forwards).

 

Ammunition:

4.7x34.6" propellant charge (56.7lb max weight)

AP (M358): 50.9lb, 3480ft/s, 11.8" RHA penetration at 110yd, 10.6" RHA penetration at 1090yd

HEAT-FS (M469): 31lb, 3480ft/s, 15" RHA penetration (reduced charge propellant case)

HEAT-FS (advanced): 31lb, 3480ft/s, 17.3" RHA penetration (reduced charge propellant case)

HE (M356): 50.3lb (10.25lb fill), 2490ft/s, 1.8" RHA penetration (normal or reduced charge propellant case)

APDS (tungsten core): 16.8lb, 4890ft/s, 14.2" RHA penetration at 110yd, 13.8" RHA penetration at 1090yd

 

Secondary weapons:

.50 cal coaxial MG (800 rnds)

.50 cal loader’s MG (600 rnds)

.50 cal commander’s MG (600 rnds)

 

[Beer]

How do You change the inner wheels? 

[Toxn]

40 minutes ago, Beer said:

How do You change the inner wheels? 

You build a small shrine to the crewmen of late-war German tanks and then get to work taking the outer suspension units off.

 

Edit: I should say inner suspension units. Taking the outer units off would certainly make it easier though. This is made more complex by the fact that each swing arm actually has hydraulic cabling running through it, so you'd probably want to just run on flats until you can get back to depot and change out there. Sort of the same principle as modern MBTs and their torsion bars - if one breaks the most common thing is just to run on it until you have the option of going back in to have it properly looked at.

[Sturgeon]

 

The competition is discontinued due to lack of interest. It's my fault. I substantially undermined one of the contestants due to petty concerns which were not relevant to the competition at large, and which I could have handled more gracefully. I chose not to do so and this has resulted in the tacit withdrawal of many of the entrants. I am sorry to those who have put in the effort.

[Sturgeon]

I've been talking with people and it seems there is still some interest in the Texas car competition. I don't think it was properly structured initially, and I'll be reviewing it and rebooting it (likely picking up where we left off, but with maybe a different judge structure. Last time some judges really wanted to participate but weren't able to because of da ruuruus). 

However, right now I don't have the time to do that, so in the interim we're running a mostly discord-based mini competition, see the thread for that.

[CharlieAlphaVictor]

Hi everyone, long time lurker, first time poster. Any update as to when the competition will resume? I was really looking forward to making a submission! 

[Sturgeon]

5 hours ago, CharlieAlphaVictor said:

Hi everyone, long time lurker, first time poster. Any update as to when the competition will resume? I was really looking forward to making a submission! 

 

We're currently looking at rebooting it in the next few weeks. The biggest problem is that I have a newborn and very little free time.

We would love to have you participate, though!

[Sturgeon]

5 hours ago, CharlieAlphaVictor said:

Hi everyone, long time lurker, first time poster. Any update as to when the competition will resume? I was really looking forward to making a submission! 

Are you on the discord?