Military Ground Vehicles of Your Nation Mk X

[Fordorsia]

I didn't know the T-28 was a scaled up version of a teeny tiny T-28 from WWI

[Gallia-]

Breaking news: Hollywood artists don't know anything about tanks' time periods!

[Fordorsia]

What a bunch of losers

[Gallia-]

What a bunch of losers

You literally have no standing with which to say this, Gigapanzerite. At least that artist used a real life tank for their picture.

The real shame is that DC EU's films are rubbish but their games are good. Injustice is cool. It's the inverse for Marvel EU.

[Theodosiya]

Realistically, that should've been the British Mark *insert roman numerals* or A7Vs...

[Purpelia]

Basically I am not quite sure what I want to do for the period as far as tanks go. Like, I'll just throw everything out here in one big post and like bullet point it.

1. My first tank ever, designed in 1917 is actually a tank destroyer. The thing is basically a mix between the whippet and the FT-17 but armed with the 2cm Johanson machine gun for infinite AT dakka.
2. My second tank, arriving at about the same time is a monstrosity based off the St. Chamond but with british style rhomboidal tracks and a pair of ball mounts on the sides for machine guns. Really big ball mounts.

3. In the aftermath of WW2 my military abandons the 7.8cm infantry field gun as useless. The simple logic they have is as follows: (in character quote)
The 7.8cm field gun is a technological and doctrinal dead end. It's shells offer too little in terms of firepower to defeat heavy fortifications, wire or entrenchments. And its combination of limited range and low trajectory force it to be deployed in full line of sight of the enemy. When you combine this with the size and weight and thus immobility of such a weapon we have a device that is slow to reach battle, quick to die in it and ineffective in the interim.

Instead they focus on developing heavy long range guns and light field guns. The later of which will eventually in 1935 culminate with the dual purpose 4cm AT/infantry support gun. This becomes the primary armament of my early war tanks.

This also results in the lack of a good tank gun in the 7.5cm range for my army forcing them to use support guns derived from mountain guns and eventually design from scratch resulting in the overuse of the 63mm caliber.

4. So reaching WW2 I want a light tank of some sort. But like really light. Like Panzer I levels of light. For basically being a tracked armored car.

5. I also want a medium tank of some sort. Now, here I actually have an idea. Like take the engine from the BT-7, put it in a larger (think Panzer III) sized vehicle with a 1.6m wide turret ring. Armor is to be about 20-35mm depending on the surface and heavily sloped in the French style. Also a large French style commanders cupola/tower. Also a support variant with a 63mm L20ish gun derived from a mountain pack gun in the turret. Also a 1940ish variant inspired by the T-34-57 that in my case uses a 63mm L66 gun for ultimate penetration.

6. Some sort of Char B1 style tank for the infantry. But like doctrinally it's a stug. So the hull gun is the main weapon and what ever is in the turret is just secondary. So I am playing around with ideas such as a MG only turret for the commander. Also it needs to use the same engine as #5 and be late in the game enough that the hull can be repurposed later to make an actual tank some time down the line in the 40's.

Both #5 and #6 would be 1937 vintage tanks (introduction).

[Chinevion]

What a bunch of losers

You literally have no standing with which to say this, Gigapanzerite. At least that artist used a real life tank for their picture.

The real shame is that DC EU's films are rubbish but their games are good. Injustice is cool. It's the inverse for Marvel EU.

Agreed Hollywood has done worse, *ahem gunsights on backwards Ahem*

[Taihei Tengoku]

Would an M777 tube on a soft-recoil mounting (cf. XM204, Hawkeye) be able to fit on a FMTV or similar medium truck?

[Purpelia]

You literally have no standing with which to say this, Gigapanzerite. At least that artist used a real life tank for their picture.

The real shame is that DC EU's films are rubbish but their games are good. Injustice is cool. It's the inverse for Marvel EU.

Agreed Hollywood has done worse, *ahem gunsights on backwards Ahem*

Aren't gunsights just two pieces of metal that you line up visually so as to get a reference for the line along which your weapon is pointed? Like you line both sticks up so that you only see one stick and no badguy and therefore you know the badguy is in front of your rifle? So like what's wrong with them being on backward unless its like one of those odd adjustable things that you use to volley fire at long range or something.

[Fordorsia]

What a bunch of losers

You literally have no standing with which to say this, Gigapanzerite.

Well I do cause even I wouldn't take a tank from the 30s, stupidly put it in a WWI setting and then shrink it down in a bad photoshop. I'm smaht

[Purpelia]

You literally have no standing with which to say this, Gigapanzerite.

Well I do cause even I wouldn't take a tank from the 30s, stupidly put it in a WWI setting and then shrink it down in a bad photoshop. I'm smaht

WW1? Now I am confused. What's wonderwoman doing in WW1 throwing around tanks when everyone who used tanks in any significant number was on the same side as america? Like aren't all the "good guy" superheroes supposed to be american and not fight against america? Or is she like special or something?

[Fordorsia]

Who knows I don't know about you kids and your superheroes

Wouldn't be surprised if she's meant to be fighting the Germans which would make the picture even more hilarious

[Purpelia]

Who knows I don't know about you kids and your superheroes

Me neither. Like, my knowledge of her is entirely based off several episodes of a batman cartoon. And from what I know she is a female superhero that goes around in a bikini painted like the american flag and her superpowers are apparently super strength and tying people up with a rope. And I was not sure about the super strength until I saw that image just now.

Wouldn't be surprised if she's meant to be fighting the Germans which would make the picture even more hilarious

Maybe it's a Soviet tank bought up as surplus after WW2 by a mysterious collector who turned out to be a moon nazi who dropped it back in time so that Germany could win WW1!

[Dostanuot Loj]

I didn't know the T-28 was a scaled up version of a teeny tiny T-28 from WWI

My favorite part is how it's anti-gravity. The tracks slack upwards between the return rollers. Also none of the unlocked hatches or covers have fallen open.

[Kouralia]

Who knows I don't know about you kids and your superheroes

Wouldn't be surprised if she's meant to be fighting the Germans which would make the picture even more hilarious

I mean, isn't she proper tight with an American pilot? She's also punching germans in the trailers.

[Fordorsia]

Maybe it's a Soviet tank bought up as surplus after WW2 by a mysterious collector who turned out to be a moon nazi who dropped it back in time so that Germany could win WW1!

They lost nearly all of them in the first few months of the German invasion so I think the only ones left after the war were all broken down or largely irreparable. I don't think there were any surplus T-28s. Must be a well-off moon Nazi to be able to restore it to fighting condition.

I didn't know the T-28 was a scaled up version of a teeny tiny T-28 from WWI

My favorite part is how it's anti-gravity. The tracks slack upwards between the return rollers. Also none of the unlocked hatches or covers have fallen open.

lmao

Also 30 tonnes supported on two high heels on a pile of rubble.

[Kouralia]

A hollywood movie about superheroes isn't caught up in concern for the technical accuracy of whatever random war-thing the superhero is punching?!

Colour me surprised

[Fordorsia]

:O

A hollywood movie about superheroes isn't caught up in concern for the technical accuracy of whatever random war-thing the superhero is punching?!

Colour me surprised

For being supposedly grounded in reality, they're not very grounded in reality.

[Chinevion]

Agreed Hollywood has done worse, *ahem gunsights on backwards Ahem*

Aren't gunsights just two pieces of metal that you line up visually so as to get a reference for the line along which your weapon is pointed? Like you line both sticks up so that you only see one stick and no badguy and therefore you know the badguy is in front of your rifle? So like what's wrong with them being on backward unless its like one of those odd adjustable things that you use to volley fire at long range or something.

Correction, the scope, on backwards.

[Austrasien]

Aren't gunsights just two pieces of metal that you line up visually so as to get a reference for the line along which your weapon is pointed? Like you line both sticks up so that you only see one stick and no badguy and therefore you know the badguy is in front of your rifle? So like what's wrong with them being on backward unless its like one of those odd adjustable things that you use to volley fire at long range or something.

No

Sights are calibrated so the angle of depression between the first post/blade/loop/notch whatever near the eye and second post on the muzzle compensates for the expected gravity drop at a certain range. If you reversed them even on weapons with fixed sights you would shoot the sky.

[Purpelia]

Aren't gunsights just two pieces of metal that you line up visually so as to get a reference for the line along which your weapon is pointed? Like you line both sticks up so that you only see one stick and no badguy and therefore you know the badguy is in front of your rifle? So like what's wrong with them being on backward unless its like one of those odd adjustable things that you use to volley fire at long range or something.

No

Sights are calibrated so the angle of depression between the first post/blade/loop/notch whatever near the eye and second post on the muzzle compensates for the expected gravity drop at a certain range. If you reversed them even on weapons with fixed sights you would shoot the sky.

I see. Well I guess that explains why the things can some times go up and down. But like how does it work for those that don't like those funky rings on HK weapons?

[Kouralia]

No

Sights are calibrated so the angle of depression between the first post/blade/loop/notch whatever near the eye and second post on the muzzle compensates for the expected gravity drop at a certain range. If you reversed them even on weapons with fixed sights you would shoot the sky.

I see. Well I guess that explains why the things can some times go up and down. But like how does it work for those that don't like those funky rings on HK weapons?

Those on the L85 are basically on two screws, and you use a tool to alter the height of the front post or the left-right position of the rear aperture.

[The Akasha Colony]

Nothing here since Monday?

Guess I'll put something down, then.

So... tank engines?

Carthage's current tank currently uses a 1,000 kW low-heat rejection oil-cooled diesel, essentially the Cummins XAV-28 as developed for the AIPS program but slightly downscaled and with some fancier modern gizmos like a hybrid turbocharger. This is coupled with a 600 kW permanent magnet motor in a power-split configuration to drive the tracks. The motor is fed by a 200 kWh battery pack that can be charged both regeneratively and by the engine when the tank is idling. Thus, maximum output into the transmission is 1,600 kW for a tank with a base weight of ~65 tonnes (the cooling system is electric and can thus be run separately without detracting from power to the sprocket).

Because of the battery pack and the relatively fuel-efficient engine, the original idea was that no APU would be necessary; the tank could run on batteries while idle and simply start the engine every now and then to recharge the battery pack as needed. This is also because the powerpack was already getting pretty complex and cramming in a second engine would have made it even more so. It was also expected that the engine could be designed for rapid start/stop capability like a modern hybrid car and it could be shut off whenever the tank is not in motion. As a result of the smaller, lower-output engine and some acoustic damping measures, the acoustic signature should be somewhat lower than a regular diesel-powered tank with a 1,200+ kW engine, but still noticeably higher than a gas turbine tank.

There's a heat-recovery system in the exhaust to both extract additional electricity as well as help cool the exhaust to make it safer for troops to stand behind the tank. One of the design goals of the tank is also to eliminate diesel smoke, although since the tank usually burns jet fuel anyway this shouldn't be a major concern.

The downside of this arrangement is that it is quite complex, requiring both an electric path and both a transmission and an epicyclic gear to merge the output of the motor and engine. It would also place a substantial cyclic load on the battery which would have a negative effect on the battery's longevity. It's also almost certainly rather pricey. The upside is that it should be rather fuel efficient with a lower noise signature than a pure diesel and with reduced air requirements, requiring less armored grating for ventilation.

This is a bit of a climbdown from the original *NS* version which used first a swing-piston engine and then an OPOC engine back when RRoan was pushing OPOCs hard, and the complex power-split arrangement is because Forza was adamant at the time that a series hybrid arrangement was not practical for the torque output required of a tank (at least, not without being significantly more expensive, less efficient, and/or heavier than a power-split or mechanical transmission). I think he may have become more amenable to the idea of series hybrids shortly before he went inactive, though. And I think others have mentioned them as a more viable option since. But I haven't seriously reexamined the engine in years.



So I guess the question is: is it a viable arrangement? Or are there better alternatives? Are turbines still on the table if fuel efficiency is still a concern?

Fuel efficiency is something of a priority both for logistics but also for political reasons; the government has committed itself to across-the-board fuel efficiency measures to reduce fossil fuel consumption and reliance on oil imports. Beyond that, the requirements are basically the same as would be expected of any other modern MBT: provide an acceptable P:W ratio, sufficient torque for good acceleration in combat, relatively compact size and acceptable weight, robust and capable of field servicing or replacement, and the ability to power the tank's substantial electronics load with room for both weight growth and growth in electrical demands.

I'm not averse to somewhat more exotic engines but I'm not rushing to seek them out, either.

(inb4 muh camless engine)

[Austrasien]

• I think having a heat recovery system is probably more trouble than its worth. Heat exchangers tend to be expensive and/or bulky.
• Forza was correct AFAIK, an electrical transmission is heavier and more expensive than a mechanical transmission or hybrid, but he might have oversold the point a bit.
• Personally I am skeptical of batteries as an APU alternative because the size/weight is pretty unfavorable unless the main power plant is running quite a lot.

[Taihei Tengoku]

Turbine engines' fuel efficiency issues come from idle. At full power they aren't any less efficient than diesels (roughly 2 gallons to the mile for both) but turbines need lots of airflow to spin the blades fast so when it is only using a little air and spinning the blades slow t's not as efficient as a piston engine where the efficiency of the individual ignitions aren't as affected. I also basically failed out of mechanical engineering before switching majors so take it as you will.

For the Type 18 I wrote a series hybrid electric transmission where the engine only produces electrical power rather than doing any mechanical work on the drivetrain. Previously I had two gas turbines, one so that in low-speed cruising or powered idle the crew could just turn one off and also to split up the powerpack for a rear egress tunnel like Merkava. When I get around to rewriting it I'll probably move the tunnel to the side like Achzarit and either have a cramped over-the-motor egress or put the sprockets up front.

Alternatively, a Deltic where each crankshaft directly feeds into an electric transmission