Renegade334

For some reason, 1-2SBCT tweeted this picture of StrykerX, with the caption: "This is Heavy!" - Marty McFly Not sure why. V--- what the OMFV contenders might look like. Not exactly the latest graphics in date, but better than nothing?

I suppose GDLS is going with the contender it previously submitted. What was it again -- the Griffin III with 50mm autocannon? Speaking of GDLS: Source: General Dynamics Land Systems receives $712 million order for Stryker DVHA1 vehicles – General Dynamics Land Systems (gdls.com) --------

^--- That's the Thumper indeed. And I stand corrected about the photo. I unfortunately don't own either book, but the cited years do place that M1 testbed smack dab within the same time period as the Thumper (1988)...which, incidentally, was built out of a M1A1 from Anniston Depot, rather than a M1. The only possible photo we might have of CATTB Phase I, now that I think about it...might be this: Why? Well, because it has the exhaust grille for the AGT-1500. The CATTB Phase II with the XAP-1000 AIPS should look like this: Also, note the different track pads (the new track had single 25in-wide shoes instead of the two 9in-wide shoes side by side) on the P2. The plan was to double the service life to something like 5,000-6,000 miles. The P1 used the telltale T156 tracks. Unless of course they sent the CATTB P2 back to the factory for an AGT-1500 refit, which would involve cutting the back of the hull and removing the new compartment bulkhead/divider (XAP-1000 was smaller than AGT-1500, which freed up 3.5m³ of hull volume for non-ready [mechanically autoloading] ammo storage). I must nevertheless confess that I do not know if the XAP-1000 was supposed to be removable from the powerpack compartment the same way the AGT currently is (opening the grille doors and sliding the engine out with the help of a crane) or if it's more of a Leo2 engine replacement-type procedure with a crane-powered vertical travel. Another possibility is that there were two different hulls and the engineers at Aberdeen simply swapped the turret around with the help of a crane.

Thumper was originally meant to receive the 120mm-barreled XM291, but there is PM-TMA documentation (20181815MNBT989112214F167098I011.pdf, which I previously linked here in this thread and the ballistics board) that indicates that the Thumper also trialed the 140mm ammo variety, achieving precision equal to that of a M1A1, but with penetration values well capable of defeating a notional FST-3's frontal aspect (speculated to be ~1m thick, but who knows which model TACOM used). All that was needed was a barrel change. Static test firings for 120mm were done in a crewed Thumper, but the 140mm were done remotely, uncrewed. Dynamic 120mm test firings were also conducted, but no mention of the 140mm. The ATAS ATD project was supposed to have two vehicles, ATD I and ATD II, but the pictures of we have of the final vehicles (93/94) show some differences: - ATD I was supposed to be built on a M1A2, not a M1. - ATD I was supposed to have a 120mm XM291 gun and no autoloader (ergo, no need for a modified turret). ...Speaking of which, does this mean this picture is actually of ATD I, which might have mutated into CATTB Phase I? (I believe most pictures we have of the CATTB duo are of the Phase II vehicle) ---V ^--- Short turret storage baskets point to a M1 turret. The "stain" on the right turret cheek could possibly indicate an externally-welded weight simulator. And, yeah, that looks like a XM291 (the bore evacuator doesn't have sloping extremities like the M256's), though I have seen here and there claims that this is a picture of a M1 testbed with a 55-caliber M256E1. Barrel thickness seems (YMMV) consistent with 120mm. Possible issues with my theory of this being ATD I/CATTB Phase I: - no panoramic turret with laser designator on the space reserved for the future CITV, as planned for ATD I. Only a M240 mount for the loader's topside station. - no sign of the CMRS (Continuous Muzzle Reference System) atop the mantlet. - tarp around the gun muzzle, not allowing us to see the planned combination collimator/mirror mount. I'm also not sure which year was this taken. If it was in the 1990s, odds are this shows ATD I/Phase I. The ATAS ATD II, on the other hand, was the most radical of the ATAS vehicles, clearly providing the basis for CATTB Phase II...but there were once again differences between the (now publicly available) plans and the final prototype we saw: - No panoramic turret on the reserved CITV space. - Gunner sight doghouse still there instead of a second panoramic turret (think AbramsX's pair of PASEO turrets). - Still an M1 hull, not a M1A2. - Still no CMRS atop the mantlet. ^--- Note the retaining rings on the drive sprockets and the trapezoid, rearmost side skirt segment - indications that that this is an original M1, not a M1A1 or M1A2. Though the presence of both parts could been mandated to prevent the roadwheel-concealing tassels from getting snagged by the sprockets' teeth. That said, I don't see any reason to build such a large turret bustle for Phase II unless TACOM intended for it to house the exceptionally long 140mm ammunition rounds. If it was only supposed to get the normal 120mm ammo, the XM91 cassettes could simply have been shortened, allowing for the use of a simple M1A1/A2 turret. Obviously, plans (and budget allocations) changed in the meantime.

^--- Looks like it belongs in a Toho Godzilla movie where it gets vaporized after firing a few Estes rockets. And, yes, this was a Japanese project. ^--- Apparently, the Fort Moore Armor Curator (Mr. Rob Cogan), informed Ronkainen that "XM1302" was indeed the designation for the prototypes. Hmmm, don't see this often (no cringey joke intended) ---V

Apparently, this UA Bradley incurred a direct ATGM hit on the turret and caught fire; the soldiers on board were nevertheless able to evacuate and the driver managed to take the vehicle back behind cover to extinguish the flames. No wounds sustained except for one contusion. EDIT: not an ATGM, but a 122mm Grad.

Follow-up to my previous post on this SPH. Apparently, there is also interest in building a M109A7 version of the M109A6+ on top of fielding four regiments' worth of XM1299s ERCAs ---V

o_-;;

If you're referring to the M256 vs XM291 comparison, it can be found here: 20184655MNBT989107254F026170I002.pdf | DocDroid Speaking of Abrams variants -- once upon a time, a certain duo made of Asher H. Sharoni and Lawrence D. Bacon (yes -- the very same pair who cooked up the Abrams AGDS with the twin Oerlikons and ADATS missile launchers) doodled another paper tank: the Abrams L52 Howitzer Concept. Obviously, this went nowhere as it was merely a what-if concept -- besides, the Army was already busy developing the ultimately ill-fated XM2001 Crusader. Anyway, this article was published in the Armor magazine, November-December 95 edition. ... ... ...While skimming through it, I was quite horrifyingly reminded that this was the same magazine where a certain...M113 Simp...I mean, Mike Sparks, also penned down his fever dreams (in Nov-Dec 95, it was an argument to make a HMMWV version of the recoilless rifle-slinging M38A1C...and, a few pages further, there was also a rebuttal, by a Ft Lewis captain, of Sparks' love for the M113, his opinion of how Bradleys should be used as well as his arbitrary use of the name "Gavin"). Now, if you'll excuse me, I need to find some Clorox for my eyes?

Here's the whole thread:

^--- I gotta say, that's a nice-looking camouflage pattern and netting right there.

I'm mainly referring to ammunition weight and the increases that potentially come with bigger rounds...and all the architectural shenanigans you have to indulge in to accommodate them inside the vehicle. I'm fully aware that some rather radical designs like FASTDRAW were even supposed to be lighter than the regular M1A1's bustle ammo rack they were designed to replace, so I'm not gainsaying anything here about autoloaders being potentially lighter than their elbow grease-powered counterparts. And, yes, size is a concern if we're exploring the 130/140mm ecosystem: Per the following article in Jane's_International Defense Review, 1990 vol.23 issue 12, the XM964 APFSDS measured at least 1.5m long and weighed 38.5kg each (the M829A4 is around 940mm and according to some sources, weighs up to 25.4kg - though I'd advise to take that last number with a grain of salt). The XM291's chamber volume was twice that of a M256. Obviously the loader's going to get major lumbar pains trying to manhandle those beasts into the breech. An autoloader is the way to go - no contestations from me here. The ASCALON, Rh130 and the British 140mm (in the ENT tank) all resulted in serious cartridge growth, and in the XM964 and the British 140mm's cases, the rounds had to be broken up into two parts connected by a snap joint so that they could be stored inside the hull. In the UK's ENT tank, they even had to resort to a T-72/T-90-style carousel (see the Britons are in Trouble thread), with a non-ready hull ammo rack close to the driver. The Rh130 ammo appears to be single-piece, which casts doubt on the feasibility of hull storage and puts much if not most of the onus on the bustle storage point. The KF51 only has 20 or 22 rounds of 130mm ammo, though I suppose this could be increased if they got rid of those loitering suicide drone launchers atop the turret to increase bustle size. Lower ammo count wouldn't make weight increase that bad, though some would argue that a max loadout of 20 or 22 rounds is not acceptable for most combat missions. The CATTB, however, went all out with one bustle autoloader (ready storage, rounds already telescoped) and two, vertically stacked hull carousels (non-ready, with the rounds divided into 2 parts, each one occupying a single cassette), which gave it a humongous 39 rounds capacity in its 140mm configuration (5 less than a M1A1's - not bad) - one ton and a half worth of ammunition. Better yet, when it switched to 120mm, the CATTB could reach 50 rounds capacity (17 in bustle, 33 in hull), six more than a M1A1's. But if that document @alanch90 posted is still representative of what the US Army wants for its Decisive Lethality Platform (or whatever it'll finally be called), 130mm seems to be the biggest caliber (explicitly) considered, with 120mm retained albeit with different chamber dimensions.

The 140mm 47-caliber XM291 weighed around 6,600 pounds, 200 pounds lighter than the M256, which was quite the achievement. It did however encounter some problems such as stabilization, vibrations, massive recoil (due to the chamber volume and muzzle energy measuring twice that of a M256's), but the guys at Watervliet and Aberdeen did manage to narrow down the target impact dispersion (TID) to that of a M1A1, with successful overmatch of the theorized FST-3's frontal armor. The development of the 140mm was nevertheless stopped chiefly due to political reasons (end of Cold War) rather than technical. And then the EX36 (later on XM36 and finally XM360) emerged as the more alluring lighter alternative to the M256. That said, embarking on the >120mm bandwagon means committing to the autoloader route (plus the issues that come therewith: potentially lower ammo capacity, bigger turrets and serious weight increase) and, for some reason, despite I don't know how many programs to test multiple prototypes (both built and computer-modelled), USAR is still reluctant to go there. ...Mayhap it's the resulting price tag that's giving them second thoughts, who knows.

157mm for cartridge diameter? Just about sounds like the current 120mm cartridge case's dimensions (the [stub] base's diameter being, IIRC, 169mm - dunno what the actual diameter of the casing is), but without the necking.

Once upon a time... The swing chamber cannon launcher - MRAAS - for the Future Combat System. https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2002/gun/smith.pdf

Mobile Protected Firepower prototypes (both BAE's and GDLS') are now known as XM1302, pending final type classification and formal naming. Little thread on Abrams's weight growth: I swear those names are getting more comic bookish or video-gamish as time goes by ---V

https://emu.usahec.org/alma/multimedia/378862/20181815MNBT989112214F167098I011.pdf Old PEO Armament TMAS brochure on the Thumper and the ATAS ATD, which seems to have evolved into the CATTB. It also shows the intended technical differences between ATD I and ATD II, which became CATTB Phase I and Phase II, respectively. https://emu.usahec.org/alma/multimedia/401640/20184655MNBT989107254F026157I004.pdf https://emu.usahec.org/alma/multimedia/401705/20184655MNBT989107254F026170I002.pdf

BAE Systems successfully tests guided projectile | BAE Systems

Follow-on to Challenger...with a T-72/90-style carousel and autoloader:

...That's not American. But this is:

Still waiting for Nick Moran's take on this.

Regardless of whether there are blowoff panels and/or whether composite armor, ERA or the Iron Fist APS can negate KE and CE threats, it is still a curious place to position the non-ready storage. It doesn't even look accessible from inside the turret basket or the driver's compartment. If the tank crew wishes to replenish the ready storage mid-combat, it means the vehicle has to disengage and find sizable cover, have the driver jump out of his seat, pop open the glacis side door and then start handing the rounds, one by one, to the TC or gunner perched on top of the mantlet. It would be so much simpler if that task could be done from the inside, even if it means doing weird body contortions and, later on, experiencing big lumbar pains.