M551 Sheridan

Airborne!

"Always make the enemy think you know more than you really know."

– Gen. Phillip Sheridan

The M551 Sheridan was an American Light Tank Airborne Assault Vehicle that was rushed into service to meet the demand for armored vehicles in Vietnam. Unique for its time, the 152mm main gun was able to fire anti-tank guided missiles FROM THE BARREL. Although the missile option was never used in Vietnam and were ultimately replaced with the more ubiquitous BGM-71 TOW missile launcher. Instead, the Sheridan was primarily an infantry support vehicle, using its low-velocity cannon to fire HE Shells.

In Team Yankee

The Stats

The Sheridan is the only tank that you can take as part of the Huey Infantry Combat Team since it was the only tank you could throw out of the back of an airplane where the airborne needed it most.

The M81 152mm gun is an interesting weapons system. At close ranges (out to 16") it uses a HEAT shell with AT 21 and a firepower of 1+. Yes, you can one-shot T55s from the front, and with the brutal rule infantry and other units without an armour save have to reroll their successful saves. Unfortunately, you only have a ROF of 1 when moving or halted, although with a Stabilizer, you don't get +1 to hit for moving. For ranges in excess of 16" (because you physically cannot shoot it less than that), you can use the MGM51 Shillelagh (Shill-lay-lee) Guided Missile. The Shillelagh is an AT 22, firepower 3+ missile that can smack targets out to 48" away. However, you can't fire the Shillelagh on the move.

Now since the difference between AT is negligible, and the firepower disparity is the difference between killing a target 2/3rds of the time and killing it every time, you might wonder why would you ever use the Shillelagh. Well, it mostly comes down to defences. The M551 only has a front armour of 4, so basically, any AT weapon is going to cut right through it like it wasn't even there, and 30mm autocannons from the BMP-2 and the Scimitar will shred you, but 4 armor might suffice against NATO IFVs in field exercises. However, you should keep the enemy at an arm's length and use concealment to avoid taking fire: it might be stronger than an M113 but it dies when tanks look at it funny. This method will extend the lifetime of your Sheridan, but you can't utilize the HEAT shell.

You also get a pair of MGs for dealing with infantry, of which the .50cal can be used for air defense.

The M551 Sheridan is the cheapest NATO tank weighing in at only 2 points per vehicle and can be taken in platoons ranging from 2 to 5 tanks.

IRL

EAT THIS IVAN!

God, where to begin with this one? The M551 was a cursed design on so many levels it becomes funny so tragic it is...

As with most such cases, one has to look to the immediate post-WWII and the Korea War to see where it all started. During that period, the US Army was fielding the M41 Walker Bulldog as a light tank. Except... the M41 wasn't exactly light: a compromise between mobility and firepower, it was... ultimately lacking on both parts: too heavy and not mobile enough for the role of a light tank, and undergunned for the role of a medium.

Fast-forward tot the early sixties: the Army is pushing for a successor to the M41. This time, they want a proper LIGHT tank for doing light tank duties, and there's a promising prototype, the T92... And then those goddamn red bastards have to come and ruin the day as they start fielding air-droppable, amphibious and ATGM-equipped 'light tank' designs. The Army saw, took duly note, and decided that whatever the Reds had; they had to have too! Exit the T92, as while it can be made air-droppable it cannot easily made to be amphibious, and the Army adamantly believed their light tank needed to do both to oppose those dirty commies. This however got them into a pinch: having switched to the MBT doctrine and already pouring massive budget in the MBT-70 project (another can of worms best left opened for another day and place), the Army simply could not ask for more budget for yet another tank. So they elegantly reclassified the new project as an "Armored Reconnaissance/Airborne Assault Vehicle" instead, and pushed it through with the alluring sales pitch the vehicle would be lightweight, amphibious, air-droppable, and able to use both state-of-the-art caseless munitions and ATGMs. In theory, the perfect lightweight jack-of-all-trades to support the bigger full-fledged tanks currently in development.

Sadly enough, in practice the Sheridan turned out to be a complete and utter master-of-none. It was air-droppable and amphibious, yes, and its light structure made it less at risk to bog down or throw tracks than his bigger M48 and M60 cousins. But for the rest. Nothing. Worked. As. Intended! The Sheridan served as a machine gun/howitzer pillbox in Vietnam as its ATGM was buggier than an iPhone, its gun was such a high caliber for its size that every time it fired the vehicle bucked backward and all the fucking electronics had to go through a full reboot. The tank might have been air-droppable, but the ATGM's WEREN'T, as the solid rocket fuel tended to crack during drop testing. The Sheridan's in Vietnam simply weren't issued any ATGMs, limiting them to chuck their caseless HE at footsloggers; which got them REKT when the northern commies sent proper MBT's into the dance. The 152mm gun did have an antipersonnel flechette round available late in the war, and records of its use in Cambodia make it sound highly effective It is sad/hilarious that of the over 80.000 produced ATGM's, no more than a dozen were ever fired at a real enemy over the entire lifespan of the M551. Part of the problem was that due to limitations of the guidance system, designed in the 1960s, a Shillelagh ATGM could not be fired at closer than 730 meters, held by some to be greater than the distance to which the main gun could be fired with any accuracy. It took that long to stabilize and begin accepting guidance input from the gunner. The Army's performance demands from Ford Aerospace for the missile circa 1963 were audacious--too audacious for 1960s or 1970s technology, not if it was going to be mass produced. In 2021 we could do much, much better.

As final nail in the poor Sheridan's coffin, in their stupidity the US Army retired it during the 90's without a proper replacement. Projects like the RDF LT were launched and many companies opened private ventures. The latter of which is now being introduced into the game. Today the Army is holding a competition for a new Light Tank. With the big three (General Dynamics, BAE Systems and Raython) offering up their own platforms for the program as the Stryker based M1128 Mobile Gun System isn't up to the task. Insult to injury, when the Sheridan was retired from active service, the National Training Center picked up a couple and dressed them up as Soviet Bloc vehicles (T-72s, T80s, and BMPs) to help train US servicemen in identifying possible enemy tanks.

...theoretically the current vehicle in the Sheridan's role is the M1128 Mobile Gun System version of the Stryker BTR clone, I mean, armored car. It has a 105mm gun with a carousel autoloader in the turret. On paper this should make it highly effective. But, like so many prior attempts, the MGS is top-heavy and more prone to flipping over than a 1988 Suzuki Samurai. The long gun barrel does not allow for much in the way of traversal while navigating narrow Middle Eastern streets--this turned out to be pretty important because the Fedayeen Saddam and Al-Qaeda in Iraq didn't bring a lot of tonks with them to the fight, just AK47s, RPGs, suicide bomb vests, and suicide truck bombs, so the light armored vehicle with the big crew-served direct-fire gun was called upon for infantry support in urban warfare, instead of duking it out with the Eighth Guards Tank Army in the Fulda Gap--and it is horribly overweight, prone to bogging down and bottoming out in soft sand, one of the few problems the Sheridan didn't have. Despite its excessive weight a sixty-year-old RPG is still capable of turning it into a mobile crematorium for its crew from any angle, though I suppose it is unfair to expect light AFVs to protect their crews as well as MBTs do. The ammo loadout for the main gun is not large. And unlike the Sheridan, it's NOT air-droppable. The problems are sufficient that the Big Army has suspended further orders and is looking around, again, for a Sheridan replacement, again, like they've been doing since the Carter Administration.

You know what would be cool? Bring back the Sheridan, but fix the problems with the missiles--through-the-gun-tube long-range laser-guided ATGMs are being mass produced right now in China and India, for fuck's sake. Buy it from them, put it in a styrofoam sleeve to hold it centered in the 152mm gun breech, and there you go. Or design a new ATGM and put that big fat 152mm caliber to use, with something like a really big, modern, 21st Century dual-charge tandem warhead, and build fire-and-forget capability in, like the Javelin has had for 25 years now. Give the commander and gunner modern thermal sights. Add a laser rangefinder and modern ballistic computer for the unguided rounds from the gun. Use the vehicle for infantry support in the streets of places like Baghdad and Fallujah like they use the MGS--only with that stubby gun tube, it can actually rotate its turret while sitting between buildings. Give it a nice big fat 152mm HE round for infantry support, one with some nice notched wire frag coils for preformed shrapnel. I'm sure the blueprints for those flechette rounds they used in the 'Nam are still sitting around somewhere too, but if flechettes aren't PC now, how hard could it be to give it WWI style canister antipersonnel round filled with ball bearings? There. It'd be no worse than the MGS, and modern electronics and a modern missile wouldn't have all the problems the Sheridan had 55 years ago.