What would replace/be the next evolution of tanks in the future

Question

What would tank design or even replacements look like in the far future. The proposed tech level is something akin to the expanse, but for hand wavy reasons ships in orbit cannot just bombard enemy positions from orbit or drop fighters/jets into orbit behind enemy lines. Thus a ground war of sorts will exists w/ two sides vying for control over a planet or a moon or a rock etc. What would the next evolution of tanks or even there replacements look like in a situation like this. Taking this a step further and assuming that there are multiple planets in a solar system like earth that can sustain human life perfectly (some contain lots of jungles, others are more uniform in environment types, others are more flat like deserts/plains etc, but all are more than capable of sustaining human without much terraforming needed). How would a faction develop a replacement for tanks that could work on multiple terrain and celestial bodies. At present current tank design doctrine is based around earth and the assumption that tanks will be deployed in areas where they are best suited/against countries where they are best suited (cold war tank design for example played into this). Ideally the replacement should be a basic pattern that is modular, such that the use of specific vehicles for every different type of environment becomes unfeasible.

Edit: I should have been more clear about this, but by something on the tech level of the expanse, I mean that humanity has the capability to traverse the solar system and colonize it. The technology of the expanse can be best described as near future, as there are no FTL/warp drives. Almost everything is mechanical in nature, space travel exists, but its still very dangerous and an absolute pain. Things still require fuel, there is no anti gravity, the only way to get 1g in your ship is to move at 1g, else you will be weightless or pulling hard Gs. Sending and receiving messages takes a time delay, there are no mega laser cannons like in star wars or stargate. Rather the weapons are still very much kinetic based with the likes of rail guns and torpedo's. Though in my setting early weaponized laser systems are being developed for anti ship combat but they are filling in a niche roll that's not been completely developed yet. The existence of multiple planets w/ earth like conditions generates a lot of interest in space travel early on so there wasnt a need to develop heavily armed and armoured space warships because the first concern was getting large ships to carry humans out there in the first place, and have smaller ships with maybe a single gun on it for patrol against piracy or hijacks. This means that the ships are rather weak in there armor, its not like they can tank a lot of damage: mines, small space based rail gun platforms, boxes of just torpedo's/ sentries free floating in space, or even ground to space/orbit weaponry like heavy railguns or missiles would do significant damage to a ship trying to sustain orbit around a planet or attempt to bombard from space. Essentially ships are like glass cannons at the start of the conflict. As for drones and planes, they would still be able to fly, its just that they can be affected by existing countermeasures or just plain shot down, deploying them from an air base is just safer. Its just that for a ship to carry a bunch of drones or planes to position above an enemy in orbit then deploy those drones is very risky as it has a high risk of being shot down (this problem extends to transports and replacements for both parts and soldiers which is a major part of the story). Essentially once a planet has a pretty good ground to space defense setup, approaching it for both sides is a suicide run for a good part of the war.

Answer 1

I'd say the tank is going to stay.

What a tank is?

A mobile, protected platform for heavy weapons.

Tank track seems to be the most efficient way to provide vehicle with all terrain mobility. The ground pressure of the tracked vehicle is simply incomparable to any other chassis. And track is relatively easy to repair and maintain in difficult conditions. So unless you can cheaply produce anti-grav devices, tracked vehicles will be used in difficult terrain for the years to come.

Protection, as @PcMan mentioned is more and more difficult. But tanks never were made to be completely impervious to any weapons. They were made to protect from the most abundant weapons enemy has. Unless common rifle can pen any armour, armoured vehicles will still be part of the military.

And there will be always need for heavy weapons on the battlefield.

So if those above are to stay, what will change?

1. Crew reduction. Absolute minimum for efficient tank crew is 3 - driver, gunner and commander. Loader is still more efficient than loading mechanism, but SciFi tech could take care of that. You can't really cut the crew below 3 without compromising something important (either you can't shoot on the move or properly judge situation and command other tanks).

2. Crew could be replaced by remote pilots... Unless enemy has tech to block connection or, worse, hack into system. Then you would suddenly regret it.

3. Most probable IMHO would be either AI controlled tanks or tanks with commander only, with rest of the functions performed by AI. Commander would be there to give orders and just in case you need someone to press a mechanical switch off button.

4. You can't remove too much armour as you want engine, ammo and crew/computer protected. That stuff is too expensive to be made completely expendable. This protection will be dropped only if:

• common trooper can pen it with basic weapon.
• terrain is so difficult that even tracks cant support properly armoured vehicle. Even today lightly armoured tanks are used in countries with a lot of jungles and other bad terrain.

Answer 2

There won't be one single solution. On a world with lots of rivers and sea's you are better off with boats, ships and amphibious vehicles. On a large flat planet tracked and wheeled vehicles would be key. On a planet with mostly hills and mountains you would use multi-legged vehicles.

If you still want a generalistic answer then multi-legged vehicles will likely be the most superior for land use. There is little use in bringing a wheeled/tracked vehicle to a planet where you can't use them for most of it's land surface area, but a multi-legged vehicle would still be useful in those environments and have far more mobility in hills and mountains where even tracked vehicles can only reasonably pass if roads have been constructed.

Archelaos's answer mentions that tanks have the lowest ground pressure but misses that this is a requirement for tanks to exist and that legged vehicles can surpass them if you engineer the feet like a real-life designer rather than a game developer. To turn most of the tank tracks slide across the ground, if the pressure is too high the tank will both rip the ground/road to pieces and it's turning rates will be debilitated, hence why tanks are required to have such specifically low ground pressure rates and few tanks will have smaller tracks. This makes sense, tank tracks are some of the most vulnerable parts of the tank and would best be as small as possible, the only reason to keep them this large is because it's necessary.

The feet of legged walkers can be engineered to have a large surface area as well. For simplicity imagine a non-turning track at the end of the foot, turned sideways and pointing to the center of the vehicle. The suspension adapts the foot to any uneven ground it tries to rest on, the fact that the track is pointed inwards means the vehicle template wont be ridiculously large and the feet don't get in each other's way and it means that a 6-legged mech could have more track to stand on than a regular tank reducing it's surface area even more.

Naturally having current tracks for feet would be inefficient. It is just to illustrate the point that feet design as shown in games and movies is done by people who have no experience designing support surfaces. They would never have designed a leg prostetic like this: https://www.google.com/search?q=leg+prostetic+carbon&oq=leg+prostetic+carbon&aqs=chrome..69i57j0i8i13i30j0i8i13i30i457j0i8i13i30l2.11427j0j7&client=ms-android-samsung&sourceid=chrome-mobile&ie=UTF-8#imgrc=KZF842-EttKNJM

Feet design would include things like spikes along the bottom to better get traction when climbing steep terrain or ram them into mountainous area's to get into places a tracked vehicle can't even dream off. It could also use suction and earth compaction with each step to increase it's chances of passing over the terrain.

Multi-legged vehicles do not have to be the slow, lumbering vehicles portrayed in movies and games either.

Having multiple legs also means redundancies. A tank with a blown track is disabled, an 8-legged Mech of 50 tons could still be moving if it lost 3 or 4 of it's legs, although it's speed would be decreased.

A common idea is "just shoot the legs". That is a court-martial offense if mechs were real. Unlike wheels and tracks a leg can be completely armored, legs are also the parts that move and shift the most. Anyone with a weapon capable of damaging a tank would fire for the hip-joints. Those joints are the largest, attached close to each other so a miss could mean you hit another one instead and even if you miss all joints there is a good chance of damaging other components on the main body. This means that a mech would be inbetween wheeled and tracked vehicles in terms of vulnerability of their locomotion. A wheeled vehicle can lose more wheels and doesn't damage the vehicle if all wheels are destroyed, a tracked vehicle is disabled faster but it doesn't damage the vehicle to lose the tracks, and a legged vehicle does suffer from crashing to the ground if too many legs are destroyed (assuming you haven't lowered the chassis by then to reduce a potential catastrophic loss) and the legs are the most armored and resiliant compared to the other two.

Legged vehicles would have the most jack-of-all-trades capabilities and would be the best if you had to stick to one and one alone. However anyone smart would bring everything they've got, boats, ships, wheeled, tracked, legged and even hover tech.

Answer 3

The one tank is very popular with the top brass. It is often horrifically unsuited to its current applications.

Consider the Sherman tank in ww2.

https://archives.library.illinois.edu/blog/poor-defense-sherman-tanks-ww2/

The M4 Sherman was the primary tank utilized by the United States army during World War Two. It also became the main tank of the other Allied countries, except for Russia. The popularity of the Sherman was not due to its superior design, but its availability and mass production. On the contrary, this tank suffered from serious design flaws. Perhaps it is more appropriate to say that it was the soldiers within these tanks that bore the brunt of the Sherman’s problems.

In your world, the tanks used in every military endeavor on every planet are essentially the same tank designed for a war 40 years prior. There are a lot of these tanks and a lot of resources committed to making them. They are hometown favorites and imbued with patriotic fervor. The persons in charge of purchasing and the military-industrial complex are committed to making this tank.

It is the best tank and that is that. And it was a fine tank in its time. It was good for its original uses. Every now and then the current generation can see why the machine was so popular. But now this tank is mostly a source of great frustration to its end users. End users have standard hacks and modifications that they put on new tanks when they show up, trying to fit the square peg of this tank into the round holes that are the various planets where they are deployed. Hacks and mod are idiosyncratic and one can often identify a tank brigade by the mods on their tanks. Tank crews battle their own tanks as much as the enemy.

---

For one, this is historically a thing that happened. But more importantly, conflict makes for an interesting story. An optimal tank does not offer much conflict. If your characters are wrestling with their archaic machine at the same time they are battling the enemy, that will make things more interesting.

Answer 4

Modular Machines:

No one machine will ever do all the things on the battlefield that are needed to be done. A tank fights big things better than anything else. A military truck will haul equipment better than a tank or anything else. An APC will always be needed in any environment where humans are present and significant to the battlefield. So to say anyone can have one vehicle that can go everywhere is silly.

You hit it on the head to say the design needs to be modular. I'll take that a step further, and say your battlefield will be populated by EMP-shielded mostly autonomous AIs mounted to a chassis. The engines, armor, and weapons will be mated up to the chassis to fulfill whatever role is needed (or based on what's available for parts, but that's every war). The AI and base chassis should be small enough to mount within an armored frame that can fit down an average human hallway or through a human door. The same chassis can mount to a truck, firetruck, VTOL/STOL vehicle, etc. If you want to give the AI a human-like personality, go ahead. It isn't needed, but this is the only way "humans" would be relevant.

Most of any of these vehicles that do fighting will be a simple conveyance with a gun large enough to destroy targets on the field. The specifics of the weapon will be constantly changing depending on what you need to fight and the capabilities of the weapons available. The conveyance will be unique to the environment (either selected or modified on-sight to match local needs). So it could be anything from a small VTOL drone with a rocket launcher to a "small" armored fusion reactor on treads spewing plasma.

Armor will still be relevant, but heavy armor won't be. If you fail to armor your vehicle at all, then the smallest, weakest weapon on the field can defeat it. But the nature of the armor will be highly variable and likely directed largely towards protection from light, routine threats and the environment.

The point is, the vehicles will never look the same, but they will have the same independent operating system (AI + chassis) will run every component on the field that needs to be involved in the fight.

• PS. Upvoting PcMan's answer; it's similar, but different enough to be a separate answer (and everything I said would be too much for comments, anyway).

Answer 5

troop transport, less armor more cargo, The terrain advantage of tread but built for capacity or speed, that is tanks geared to troop transport. The big advantage of tread is the ability to transverse a wide range of terrain with ease because of the huge contact surface. The future will be more and more about how fast you can get assets on site, and you can't send troops by UAV, tread handle a much wider range of terrain than wheels but are much faster and support more weight than legs. You can see slower more conventional set ups of high speed lightweight ones like the ripsaw. The basic concept of an armored box to put troops, or anything important in during transport looks even more enticing in the age of drones and robots.

Mobile heavy weapon platforms. We see this use often now tanks with little armor but uses the advantages of a heavy tread platform to move heavy weapons in to position. look at the M270 or M982A1 in use now. basically you will see tanks that act as mobile platforms for missiles, rockets, armillary, drones launch, or other unusual weapons that are too heavy or large to be fit on smaller lighter platforms.

Mobile sensor arrays. We see tanks being used more and more for this, tanks as a mobile platform resistant to opportunity attacks make great places to set up monitoring and communications equipment, whether manned or drone. We already see small drone tanks being used for this, the ripsaw is a drone scout tank.

Main Battle Tanks. in conflicts between major powers you will still see main battle tanks in use, this of course depends on the political situation of your future. MBT are very expensive, but also very effective in war focused on holding ground.

Armored construction vehicles. lets face it construction vehicles in combat situations are both often necessary and enticing targets. the only effective way to armor them is to use treads. conventional construction machines are fine away from combat but anywhere near actually fighting they are rolling bullseyes, which is why we use armored construction vehicles today.

Answer 6

Think: Spot the Dog on steroids.

Given that the power supplies of the future will be able to deliver huge power/weight rations, scale Spot up to a size where a human would fit into the belly.

Now, add tank treads to its belly. But not just any tank treads, wheels that can convert to tank treads. So when spot lies down, he can move using the wheels, but when the going gets tough, the wheels become treads. When there is a wall or such, Spot rises up o his legs and climbs over.

Oh, did I mention the jets in the legs, so for very limited distances he can 'fly' like those jet-kite guys in Dubai?

That really neat arm that opens doors would serve double-duty as a rail gun/rocket launcher.

As a final touch, make Spot amphibious, so he can swim across rivers and such.