M551A2 Sheridan

[ChalkLine]

This is the final of my Sheridan revisions for combat in T2K. It assumes that the 82nd Airborne and the NTC VisMod vehicles are returned to store for upgrade.

At rearmament the US army had insufficient cavalry divisions, and in 1999 and the reintroduction of the draft the 61st, 63rd, 64th, 65th and 66th cavalry divisions we reactivated. As these were third echelon units they were primarily issued with older equipment drawn from storage. These 'Twilight Divisions' drew on mothballed stocks of equipment modernised to meet the challenges of the third world war.

M551A2 Sheridan Armoured Reconnaissance Vehicle.

No longer amphibious or air-droppable, the M551A2 is a light combat vehicle utilising the hull, turret and suspension of the M551A1 TTS. The M8E1 rifled gun/launcher, the M219 coaxial TMG, the 6V53T diesel power pack and drive train is removed and placed in storage.
These systems are replaced with the M119A3T modified howitzer, M240T coaxial machine gun and the 6V53TIA diesel power pack and drive train.

The M119A3T is a rebuilt M119 Hamel 105mm howitzer, cut down and simplified using the same techniques with which the M3 105mm Howitzer was made from the M2/M101 105mm howitzer. The barrel is shortened by 700mm which reduces trunnion stress by roughly 1/3rd, and the M8E1 recoil system modified to take the less violent weapon. Recoil length is still roughly 400mm. The same elevation of +19.5° to -8° is maintained, and the weapon is direct fire only. Because the weapon is not designed for indirect fire the propellant charges are pre assembled using only Charge 3 rating. As such the weapon maintains similar ballistic and range characteristics as the M8E1, even though a new sighting system is used. Firing this weapon still exhibits a large muzzle flash, partially alleviated by the M119 double flange muzzle brake, but the considerably less violent recoil is absorbed by the chassis without lifting road wheels or slewing the turret, as was formerly the case.
The old M219 coaxial machine gun was known for its extremely poor reliability, despite being a 'Browning' weapon. The replacement with the M240T and its Egress Package containing a polymer butt, foregrip, heat shield and bipod gives the gunner a reliable weapon to back up the main gun.
With the total 6V53T power pack production needed for M113A3 replacement and upkeep, the newer 6V53TIA with its superb new transmission is available to upgrade the already nimble vehicle. For the first time the M441 would have a transmission capable of dealing with the power output of its power pack. The increase of power from 275 bhp to 400 bhp is important to maintain agility despite the weight of the up armour package.

The hull sides are removed and the flotation screen discarded. In place of the thin sides M113 armour sections cut from wrecked vehicles are installed, adding spaced panels 45mm thick to the sides of the vehicle. The 25mm mine floor package is standard already on the M551A1 that the new vehicle is based on. Applique 45mm Rolled 5083/5086 H32 aluminium armour plates are attached to the glacis, hull front and vehicle rear, also sourced from M113 wrecks. New spaced turret armour is installed adding 22mm of RHA. ERA lugs are installed over the front arc.
The turret is stripped out of its former obsolete electrical wiring and new solid state control modules installed. Main gun ammo capacity is upgraded from the former extremely volatile 30 combustible rounds to 45 wet-store 105mm howitzer ammunition. Finally, a spall liner is installed throughout the crew compartments.

While some turrets are fitted with excess M19 commander's cupolas from the M60A3, this is not an authorised modification and only the 66th cavalry receive these vehicles.

The M551A2 is a dedicated reconnaissance vehicle, and relies on its companion vehicles and air support for ant tank capability. Although the designated ammunition load includes L42 HESH rounds, engaging MBTs is still not recommended.

The following uses Paul's vehicle format:

M551A2
Price: $223,463 + $75,000
Fuel Type: D,A
Load: 600kg
Crew: 4
Maintenance: 6
Night Vision: Passive IR, Starlight (x8/x12), Thermal
Radiological: Shielded
Travel Move: 150/95
Combat Move: 30/21/3
Fuel Capacity: 598 litres
Fuel consumption: 110
Configuration: Tracked
Suspension: T4
Armour: TF20 TS8 TR8 HF30 HS6 HR6
Fire Control: +3
Stabilisation: Fair
Armament: M119A3T, M240T, M2HB
Ammunition: 45 x 105mm Howitzer, 3080 x 7.62mm, 1000 x 12.7mm

Weight: 17 tonnes
Length: 20.6 ft (6.3 m)
Width: 9.1 ft (2.8 m)
Height: 7.5 ft (2.3 m)
Crew: 4 (Commander, gunner, loader, driver)
Engine: General Motors 6V53TIA, 6 cylinder, supercharged diesel 400 hp (300 kW)
Power/weight: 22 hp/tonne
Suspension: Torsion bar
Operational range: 348 mi (560 km)
Speed: 100 km/h (60 mph)

[lombardoslegion]

This is a great write up. I am defin itely going to use this in my game.

[pmulcahy11b]

Somewhere along the line (mid-1980s, IIRC), experiments were done with the turret of the M-551 replaced with the turret of the Cadillac Gage Stingray. It was designed as a competitor in the quest to come up with a replacement for the M-551, but I don't think the project went beyond prototype state. (TR had it on his site.)

[jester]

Thats a good write up, one of the things I like about the game, the modifications one can make to vehicles.

I would also think there would be a return to armored cars as well like the old style M-8 of WWII with some modern upgrades. Just a standard scout car with a big gun and coax as a cheap alternative to adding something to the post war vehicle assembly line.

The write up also got me thinking of how long such a makeover would take. I am thinking of my time in the Brigade motortransport maintenance section, and the time it took to refit standard rolling vehicles humvees and dueces and a few others. I am thinking with all the changes and all the assets available one could have it done in about a week from start to finish. Of course they would be working in stages, one gang doing the prep work, one doing the weapons, one the electrical, one the drive train, one the armor and one the finish work. Alot of them being doing simulatiniously, while others when done after a day or half a day will begin the next vehicle, I would say again under optimal conditions a week to 5 days with all the personel, equipment, shop facilities and replacement parts.

It makes me think what other vehicles we could change or upgrade.

[Abbott Shaull]

You know it always amused while in the 82nd Airborne Division that we had an Airborne Deployable Tank Battalion. I always thought it would be easier to take an airfield that was capable of C-5s and C-17s to land and off load M1s if you needed serious Anti-Tank capabilities. Yes, I know it expensive and move, as well as costly to supply this way, but I always thought when you need the best weapon, bring them to you, if you can. Otherwise pray that the Anti-Tank systems that were airdropped in with the Division work as stated in theory.

With that said, it does look like it would fit in nicely as an alternative, to give units tool to use. Making the vehicle that was practical purposes.

[Raellus]

Chalk, as such a big Sheridan fan, I recommend that you pick up a copy of Osprey's title on the subject. There is some stuff in there also on the various vehicles intended to replace the Sheridan (none of which actually "made it").
I've thumbed through it a couple of times at the local bookstore and it looks pretty cool.

http://www.ospreypublishing.com/stor..._9781846033919

Amazon has it too. And no, I don't work for Osprey. Wish I did, sometimes!

I like your idea, BTW.

Anyone know if the U.S. has any other older AFVs sitting around (c. '97 or before) in decent enough conidition to return to active service (probably in the CONUS only, but who knows) either as-is or modified in like fashion? I'm thinking of M60s, M48s, Cadilac Gage armored cars.

[copeab]

To be contrarian ...

I'd be tempted to keep the 152mm gun but drop the missile capability. Yes, I know you could only carry around 30 shells (converting missile space to shell space) and that the gun had heavy recoil for such a light chassis, but the edge the 152mm has in destructiveness over the 105mm seems worth it to me.

Also,I doubt I would up-armor the M551 to the point where is can't float, since that's one of it's few positive assets. You can't armor it well enough to survive direct hits from a TG or ATGM anyway, so you're doing a lot of work just to create another burning wreck.

[Raellus]

Originally Posted by copeab

To be contrarian ...
Also,I doubt I would up-armor the M551 to the point where is can't float, since that's one of it's few positive assets. You can't armor it well enough to survive direct hits from a TG or ATGM anyway, so you're doing a lot of work just to create another burning wreck.

Fair points. Taking away it's swimming ability limits its capabilities as an "armored reconaissance vehicle". In the CONUS, I don't think it's going to need a whole lot more armor. Unless it's going up against armor from another faction (CivGov vs. MilGov) or facing the Soviets in Alaska or Texas or going up against Mexican Armor (IRL, not much of a threat), it's not going to be facing the kind of weaponry that can take out armored vehicle with one or two hits.

[ChalkLine]

Originally Posted by copeab

To be contrarian ...

I'd be tempted to keep the 152mm gun but drop the missile capability. Yes, I know you could only carry around 30 shells (converting missile space to shell space) and that the gun had heavy recoil for such a light chassis, but the edge the 152mm has in destructiveness over the 105mm seems worth it to me.

Also,I doubt I would up-armor the M551 to the point where is can't float, since that's one of it's few positive assets. You can't armor it well enough to survive direct hits from a TG or ATGM anyway, so you're doing a lot of work just to create another burning wreck.

A few points;

- It takes 20 seconds to cycle the gun. The breech is locked, purges, and slowly opens. It's all automated, so there's nothing you can do about it to hurry it up.
- The 152mm rounds destroy the barrel after 200 shots.
- The floatation system was removed in 1979, only the screen remains
- As it stands, it cannot survive strikes from a 30mm autocannon, the minimum required to be a useful recon vehicle.

[copeab]

Originally Posted by ChalkLine

- It takes 20 seconds to cycle the gun. The breech is locked, purges, and slowly opens. It's all automated, so there's nothing you can do about it to hurry it up.

That's not why I'd remove the missile system. To my understanding, the gun/launcher was severely flawed. Firing a missile badly fouled the barrel for the shells. Firing a shell often knocked the missile targeting system out of alignment, making it useless. Given a choice, I'd rather fire shells than missiles.

- The 152mm rounds destroy the barrel after 200 shots.

Didn't know this. However, I think it's worth asking how many M551's will last long enough to fire 200 shells, uparmored or not, on a T2K battlefield.

- The floatation system was removed in 1979, only the screen remains

This is something I'd want to put back on. More than added armor, more than a new gun.

- As it stands, it cannot survive strikes from a 30mm autocannon, the minimum required to be a useful recon vehicle.

I doubt if such a requirement would be observed in the desperate situation of the later years of the Twilight War, nor would the expense (materials, labor, time) likely be considered worth it by the Army, who would be desperate to field as many AFVs as quickly as possible.

[ChalkLine]

All good points.

But if we look at probably the only ever nation to endure T2K-like conditions, the tanks German put out in 1945 were five times more armoured than they manufactured in pre-war peacetime. They up-armoured light vehicles progressively during the war, as has every other combatant in armoured vehicle history. When something doesn't work, you just whip it out and put something in that does. A short 105mm howitzer has a commonality of munitions with the support weapons, the M119 Hamel howitzer. The canister round is impressive (as the Australian gunners at firebase Balmoral in Vietnam will attest to, when they fired their M110 howitzers over open sights at assaulting NVA and VC troops) and the vehicle is going to be simpler, faster firing and longer lived. You get easy access to reloads anywhere there's NATO supply, and when your local ammo runs out you don't have to discard a useful vehicle.

Honestly, I've always liked the M8E1 gun. It wasn't until I read the field manual for the gun that I realised how flawed it is. The caseless cartridges are highly flammable, and the slightest penetration resulted in catastrophic explosions. There's no extraction device on the gun, so if you get a misfire (and it's an electrically fired round, misfires were common) you couldn't get the round back out. If you have a missile or a shell loaded and need something else, under combat conditions you had to fire it off because you couldn't get it out of the gun. Worse still, if you open the breech of the launcher with a missile loaded and neglect to flip over the lock switch - only used when firing a missile - the breech screw rips the backside off the missile and scatters explosive propellant through the fight compartment. This stuff explodes if you stand on it! If you fire the MG while this stuff is in the tank, you'll probably blow the whole thing up.