Tanks make their apperence in the Civil War (RAR!)

[Zor]

In this scenario it's October of 1862, the US Civil is going on and is beginning to look to be a long nasty fight. However to Lincoln's surprise a Team composed of a wealthy Frenchman and his English Wife both of which are skilled engineers and staunch abolitionists along with a team of a couple dozen technicians and laborers shows up in New York with a strange object that takes some effort to get out of the ship which rolls forward down the street under it's own power, making a lot of commotion even after they informed the US military of their intent. It is called The Liberator, though we would call it a Tank.

The Liberator is 2.4 meters wide, 7.4 meters long, weighs in at ten tonnes and rolls along on a pair of iron tracks. It is powered by a steam engine which provides 35 Kilowatts of power in it's rear burning mainly pulverized coal with a range of 40 km with a top speed of 5km/h. It has 8-16mm of iron plate. It's primary armament is a 3 pounder Armstrong Gun, but it also has a small 25cm breachloading rifled gun in a small hand cranked turret on top as well as gunports from which the crew can shoot out. The vehicle has a crew of five. It works reasonably well and they have brought along a fair number of spare parts, though it is a maintenance hog.

The couple offer the Liberator to the United State Army as a gift to the US in the War Against Slavery. They also say that they can set up a factory which can make three of said vehicles a month in a year's time at a cost of $20,000 a unit.

What happens?

Zor

[Zor]

Ghetto Edit...

ll 25cm breachloading rifled gun

This is 25 millimeters.

Zor

[U.P. Cinnabar]

Edwin Stanton expresses firm opposition to the idea, but Lincoln is intrigued enough by it to have Kiberator pressed into immediate service with the Army of the Potomac, where, like the early historical tanks, it encounters difficulties away from Virginia's roads, and requires constant maintenance from the inventors and crew of techs, requiring them to be in the field, exposed to the enemy.

Stanton's skepticism is echoed by his generals and many others in Lincoln's Cabinet, with calls to cancel the project and withdraw Liberator from the field.

Until Liberator. comes into its own during the Battle of Antietam, where it's mobility and firepower proves devastating to Lee's forces, resulting in a decisive rout rather than a bloody stalemate. This is enough for the Union to authorize the production of more Liberators, just in time for the Battle of Gettysburg, where these machines, with improvements based on experiences in the field, ambushes the Army of Northern Virginia, spooking Lee's cavalry, and making short work of his infantry.

In time, the inventors and their team train others to build and maintain the Liberators, utilizing Irish and freed black laborers in doing so, especially as more slaves are freed, leaving them with a trade and sought-after skills.

The success of the Liberators means more will be deployed, the offensive against the South ramps up. They may even make an appearance at the siege and reduction of Fort Pulaski and any subsequent offensive against Savannah, spearheading a March to the Sea in reverse, possibly in conjunction with Sherman's Atlanta Campaign.

In sufficient numbers, they may even shorten, if not completely eliminate the later Siege of Petersburg.

[U.P. Cinnabar]

Liberators success will also usher in the age of the automobile that much earlier post-war.

[Esquire]

Pulverized coal dust, you say? In 1862?

A lot of people are going to die when tank-fuel plants inevitably explode. As to the tank itself... it can't actually use that speed strategically, because nothing else in 1862 (except, possibly, trains on well-maintained express lines) can move that fast. I'm also extremely skeptical of its reliability, given the abysmal reliability of real-world tanks built with an extra 50 years of industrial expertise. It'll be useful enough reinforcing stressed positions, but can't actually attack at much above infantry speeds for fear of destruction (or worse, capture). It might do good work reducing sieges, if it doesn't prove too vulnerable to emplaced artillery or mines (CSS Virginia had armor that was, at minimum, more than three times thicker than this contraption, and which also had a rather significant slope).

Basically, I think this will turn out like CSS Huntley - a leap much too far; historically tantalizing but not actually that useful on the battlefield.

[Elheru Aran]

If it can turn a battle or two, it might be worth it even if they just serve as mobile turrets. That said, I'm largely with Esquire above; the technology probably has more promise in terms of post-war advancement than actual tactical or strategic improvements, particularly given that they probably won't move fast enough to be able to avoid heavy artillery fire the moment one of them comes into range of any fortified positions.

[Batman]

Excuse me? Nothing but express trains can move faster than 5 kph?

[The Romulan Republic]

Depends how fast they can start producing them in large numbers, and if there is the political will to do so (though my guess is yes- the Union produced a lot of technical innovations throughout the war, and if the tank is deployed in battle, it will quickly prove its value unless it suffers technical malfunction or something).

If its deployed in significant numbers in time for Antietam, Lee gets curb-stomped, as UP Cinnabar noted. At that point, there is really little to stop the Army of the Potomac from marching straight into Richmond by the end of '62 under even a moderately competent general. Sadly, if there is one man who can piss away this advantage, its George McClellan, but in that case Lincoln just sacks him as per the original timeline (this is hopefully the case, really, because a victorious McClellan might successfully challenge Lincoln for the Presidency in '64, and the cowardly, racist, pro-slavery McClellan would be an awful President to handle Reconstruction, albeit probably not worse than Andrew Johnson). At worst, the end of the war in Virginia is delayed into spring of '63 or so. If they aren't deployed in time for Antietam, then they are likely used to reinforce a spring campaign to push towards Richmond, and the war in the east likely ends sometime in '63. The Emancipation Proclamation presumably gets issued following the Union victory at Antietam, as per the original timeline. However, the speedier end of the war may leave slavery intact in at least the border states for a little longer- we might see a more gradual abolition and move towards black civil rights in the post-war era.

Out West, Grant's army will be moving on Vicksburg by '63. IIRC, they were marching in some pretty rugged terrain, so keeping in mind the mobility issues raised in this thread, the tanks likely have little effect on that campaign, other than possibly freeing up troops from the East to reinforce Grant, or terminating the war outright by forcing a Confederate surrender before Vicksburg.

Gettysburg never happens, because Lee has been crushed in '62. Grant likely becomes little more than a historical footnote, with credit for the Union victory going to McClellan or his replacement (historically, IIRC, Burnside), along with Lincoln.

Presuming the butterfly effect prevents Lincoln's assassination, Lincoln likely wins a victory in the '64 election, though it is possible that a victorious McClellan (shudder) or Burnside could run against him successfully for the Presidency. If Lincoln wins, and survives, he can preside over Reconstruction. That will probably turn out better than Reconstruction being the subject of feuding between a traitorous Southern sympathizer in the White House and a vengeful radical Republican Congress.

Within a few years, other militaries start adopting tanks. The US likely turns them lose on indigenous populations in the West. The long stalemate of trench warfare in Europe in WW1 never happens, which means World War II and the Soviet Union may never happen. Knock-on effects of that could include the absence of the Cold War (although some confrontation of that sort will likely happen once nuclear power is discovered), which may affect the development of space flight. Other technological developments are likely advanced or affected as a result.

Hard to predict beyond that.

[Esquire]

Excuse me? Nothing but express trains can move faster than 5 kph?

Good catch - I somehow misread it as 40 km/h, not a 40 km range. Underlying point stands, since they're not faster than infantry in the first place.

[Eternal_Freedom]

If this is indeed to be a way to defeat infantry/cavalry warfare, wouldn't it make sense to fit them with those new Gatling guns rather than shell-firing cannon?

[Vendetta]

Excuse me? Nothing but express trains can move faster than 5 kph?

Good catch - I somehow misread it as 40 km/h, not a 40 km range. Underlying point stands, since they're not faster than infantry in the first place.

Bear in mind that's what the first tanks actually were for.

This Union Tank however may have a couple of extra problems. First is it won't go 5kph on a 35kw engine. The Mark 1 had twice that engine power for a tank of roughly similar dimensions and therefore weight and only did 2. Chances are it's going to be slower than infantry, if it's mobile at all under combat conditions, especially as it will have a very significant weight of fuel and water.

Also, armament layout is going to matter a lot. Given that it's only mentioned as having one main armament I'm surmising it's front mounted like the A7V, rather than sponson mounted like the Mark 1. That's a problem because the primary job of the tank is going to be to do what the Mark 1 was for, overrun and fire into rifle trenches. That means it should have sponson mounted weapons and the turret gun will be basically unable to engage anything (this is going to be a tall vehicle, like A7V).

[Vendetta]

Ghetto edit: Mk. 1 did 6kph not 2

[The Romulan Republic]

Excuse me? Nothing but express trains can move faster than 5 kph?

Good catch - I somehow misread it as 40 km/h, not a 40 km range. Underlying point stands, since they're not faster than infantry in the first place.

Bear in mind that's what the first tanks actually were for.

This Union Tank however may have a couple of extra problems. First is it won't go 5kph on a 35kw engine. The Mark 1 had twice that engine power for a tank of roughly similar dimensions and therefore weight and only did 2. Chances are it's going to be slower than infantry, if it's mobile at all under combat conditions, especially as it will have a very significant weight of fuel and water.

Also, armament layout is going to matter a lot. Given that it's only mentioned as having one main armament I'm surmising it's front mounted like the A7V, rather than sponson mounted like the Mark 1. That's a problem because the primary job of the tank is going to be to do what the Mark 1 was for, overrun and fire into rifle trenches. That means it should have sponson mounted weapons and the turret gun will be basically unable to engage anything (this is going to be a tall vehicle, like A7V).

So without modifications, their main use is likely to be as well-fortified, slightly mobile artillery batteries?

[Esquire]

Not even batteries; they've got one (very) light artillery piece, an antimateriel rifle, and whatever the crew can fire out the sides without choking themselves with powder smoke.

[Jub]

This thing is a nightmare for its own side if it's ever actually deployed. It's a neat idea that could lead to WWI style tanks early but probably won't be of much us on the battlefield with its stated specifications.

Even if we assume it comes out to exactly ten metric tons fully loaded, a figure which is almost certain to be rather on the light side, we're talking ~4.27 hp/ton. Even the notoriously immobile tanks of WWI had better power to weight ratios than this thing. As an example Mk VIII had an hp/ton ratio of between ~8.11 and ~8.92 (the US and UK used different engines) and they bogged fairly often and could rarely reach their rated top speed. Thus, even assuming that this Liberator gets as much power from its engine to its tracks as the Mk VIII did this thing is going to absolutely crawl any time it has to move under its own power.

Steering is also likely to be an issue given the limitations of the day. Look at the first tracked vehicle that came out IRL, it steered with a front wheel and was more of a half-track design. Your LIberator is stated to have two tracks with no wheels for steering listed. It might be possible to get this thing to turn jerkily while in motion but it seems more likely that you'll have to stop, change gears, turn, change gears and start off forward again. This is going to make you a large slow target for every bit of artillery that can be pointed your way. Given the mobility restrictions, you're not driving this thing anywhere and so you're stuck moving it via rail and hitching it up behind a team of horses if you want to get anywhere near a fight. Neither of those methods are exactly fast, easy, or convenient so your tank may actually slow down the march of the unit it's attached to.

So you have an armored box that's harder to move than a cannon, slows down your army, and requires a massive logistical tail and we've only touched on mobility thus far.

The crew inside of this thing are going to be miserable. WWI tanks were noted for nearly killing their crews from carbon monoxide and other gases coming off of the engine. This thing is going to be hotter and sootier than any WWI tank, though it'll likely be slightly less noisy for whatever good that'll do. I'd imagine that it ends up parked at the back with the rest of the artillery park with the doors and hatches wide open and the boiler off in any reasonable combat scenario.

The real kicker is that unless you're very careful with mounting your guns this vehicle's weaponry accuracy is going to be lower than a traditional field gun. Your rate of fire is also going to be slower unless they really nail ammo storage and IRL that took a lot of work and practical experience to really get right.

TLDR; this thing is an immobile target that shoots worse than a normal field gun and gases its crew whenever they have the misfortune of needing to actually drive the thing. All for the upside of having two guns in protected positions with the pipe dream of actually getting this thing to trundle at the enemy if the stars align and it's working, ready, and in position with a fresh crew as your army is in a position to attack into the enemy.

[Caiaphas]

All for the upside of having two guns in protected positions with the pipe dream of actually getting this thing to trundle at the enemy if the stars align and it's working, ready, and in position with a fresh crew as your army is in a position to attack into the enemy.

Would this be that well-protected, anyways?

I mean, the typical Confederate field artillery piece was apparently the "light" 12-lb Napoleon, firing a 4.1 kg shell with a muzzle velocity of 440 m/s (according to the wiki). Assume we're firing solid iron shot, so it's roughly a sphere with a volume of 520cm^3, so a sphere just under 10cm across. Since I have no idea about the actual dynamics of impact physics, let's assume that it deposits all its energy into a "hard" target in the span of time it takes to travel its own length (because frankly I imagine that if it travels more than its own length into the armor then the armor has catastrophically failed), so about 0.25ms, gives us a force of 7.22MN to slow the shot to a stop and a stress of 920MPa over the area that it hits. Young's modulus of iron is 170MPa according to Engineering Toolbox, so the armor is experiencing a strain of about 5.4, or in other words it's changing its length five times over. Obviously this isn't the most rigorous analysis and it's probably wrong somehow (and I'd appreciate if someone more knowledgeable could correct me) but it looks like to me that the armor just doesn't stand up to a direct hit from field artillery, and it's likely to attract fire from such once the Confederates get over the shock of seeing it.

...although now that I think about it, USS Monitor took fire from similar guns on the Virginia, but if you look at pictures of its turret the armor's barely dented. Wiki gives the thickness of armor on the turret to be between 20 to 30cm of iron, so maybe that's a baseline for how thick you'd need the armor to be to provide any real protection.

On a bit of a tangent, would such a tank as proposed in OP be at all feasible for the Union to have conceived of and built? I mean, obviously the idea of armored vehicles with turreted weaponry was there, just look at the USS Monitor.

[Jub]

Would this be that well-protected, anyways?

It should be proof against anything lighter than Confederate field guns and it could have mounting points for logs as additional armor. Given that once emplaced it likely won't move the added weight shouldn't hurt too much. Of course, that idea relies on it getting there ahead of the battle and having time to set up so how practical it would be and how much added log armor would help is very much an open question.

[Caiaphas]

Would this be that well-protected, anyways?

It should be proof against anything lighter than Confederate field guns and it could have mounting points for logs as additional armor. Given that once emplaced it likely won't move the added weight shouldn't hurt too much. Of course, that idea relies on it getting there ahead of the battle and having time to set up so how practical it would be and how much added log armor would help is very much an open question.

In which case why not just use regular field guns in fortified positions? You can certainly drag around one of those just as fast, can't you?

[Caiaphas]

Ghetto edit to my post above: I screwed up, iron's Young's modulus is 91 GPa according to Engineering Toolbox, its ultimate tensile strength is 170 MPa. So it won't deform that much, but it'll probably get a chunk torn out of it by the shot.

[Jub]

Would this be that well-protected, anyways?

It should be proof against anything lighter than Confederate field guns and it could have mounting points for logs as additional armor. Given that once emplaced it likely won't move the added weight shouldn't hurt too much. Of course, that idea relies on it getting there ahead of the battle and having time to set up so how practical it would be and how much added log armor would help is very much an open question.

In which case why not just use regular field guns in fortified positions? You can certainly drag around one of those just as fast, can't you?

That's pretty well the point I was making. This thing simply isn't useful because at the best of times it can barely move and when it can move infantry can likely outpace it while not being gassed constantly.

[Elheru Aran]

And, particularly if it's going up against a fortified position like Vicksburg or Petersburg, there's going to be heavy enough artillery emplaced against it that they can blow the thing apart once they've got the range. It might be able to hold up against mobile field guns for a few shots before losing operational effectiveness, but against fixed artillery, no.

[The Romulan Republic]

It should be proof against anything lighter than Confederate field guns and it could have mounting points for logs as additional armor. Given that once emplaced it likely won't move the added weight shouldn't hurt too much. Of course, that idea relies on it getting there ahead of the battle and having time to set up so how practical it would be and how much added log armor would help is very much an open question.

In which case why not just use regular field guns in fortified positions? You can certainly drag around one of those just as fast, can't you?

That's pretty well the point I was making. This thing simply isn't useful because at the best of times it can barely move and when it can move infantry can likely outpace it while not being gassed constantly.

I suppose the armor gives it some additional survivability against artillery, and virtual immunity to infantry fire for the gun crew.

I guess its usefulness will be determined largely by whether the additional survivability granted by the armor outweighs the additional cost compared to standard artillery.

A model optimized for overrunning enemy trenches would be damn useful in a Vicksburg, Wilderness Campaign, or Petersburg situation.

[Imperial528]

Can enough Liberators be built to even matter?

The Liberator shows up in late 1862. Peak troop strength for the Union was over 600,000 in January 1863, which did not drop significantly over the remaining years of the war. Confederate troop strength peaked at around half of that at the same time, and had dropped to 200k by 1865.

By the OP, the factory that makes these vehicles will take a year to build, so October 1863 at the earliest. That single factory will make three such vehicles in a month, meaning that factory will only be able to produce fifty-four such vehicles before the IRL end of the war, for a total run cost just over a million dollars, not counting the cost of the factory itself.

Fifty-four vehicles at the start could make a difference if used decisively, but they will be coming out at a trickle compared to other materiel in the war effort and at much greater cost. For the price of a single unit, the Union could afford 30 12-pdr. napoleon guns, a hundred 10-pdr. parrot rifles, or 44 10-pdr. ordnance rifles. Or pay the wages of roughly a hundred enlisted men for a month.

For the cost of an entire production line, the Union could purchase nearly four Monitor Ironclads, all of which could be built well before any single Liberator production line would reach fifty-four units.

All of which would be much more capable of adding to the war effort, especially considering that the infrastructure they rely on already existed. Frankly, relying on these to contribute significantly to the war effort would only help the Confederacy given how expensive they are.

[The Romulan Republic]

It still might be worth it if they could break the Petersburg siege and end the war in the summer of '64, though.

[Jub]

It still might be worth it if they could break the Petersburg siege and end the war in the summer of '64, though.

How would they do that? They can't move, at least not reliably and even then only under nearly perfect circumstances, they can't take hits from most artillery and they'll surely be targets for such firepower, and they can't fight better than a regular field gun because of worse visibility, worse reloading times, and less access to ready ammo. Not to mention the extra supply train you're needing to worry about for this one machine.

If you're claiming this thing can do anything, you're going to need to lay down why you think this may be the case.