M4A3 (90 mm) HVSS, Operation Coronet, 1946

[kerick]

Thanks all

That would have taken me months.

Oh, this took me ... (checks the dates on the photos) ... from 25 January 2021 to 3 April 2021. So call it two months — which is pretty quick for me, especially considering I began building a medium tank M3 around the time the basic paintwork on this model was finished but before I built the tracks and did the weathering etc. Though, of course, it being two years ago is why I could post the whole thing here in just a few days

I've got a few other finished models I intend to post about here, and am still thinking about how to do an M247 Sgt. York what-if ... US Army M247A1 with Stingers? Israeli with Merkava tracks? South Korean with skirt plates? Something else yet?

I had the old Sgt York kit a loooong time ago. Tamiya I believe. Never figured out what I did with it. Would be a nice build as I was at Fort Hunter-Liggett when the Army tested it. What a turkey. Would make a nice in service whiff.

[Wardukw]

The best part..2 best parts were the M48 chassis and the 40mm Bofors ..the rest ..total waste of time and money..US thought they could build a better SPAAG ..nope.

[Jakko]

I had the old Sgt York kit a loooong time ago. Tamiya I believe. Never figured out what I did with it. Would be a nice build as I was at Fort Hunter-Liggett when the Army tested it. What a turkey. Would make a nice in service whiff.

That's the plan — I built the Tamiya kit 20+ years ago, then bought the Academy clone of it maybe ten years ago, intending to correct its glaring errors (the whole engine deck/hull rear, mainly). Because of the work involved I never did get round to that, but when Takom announced its version I sold on the Academy kit and bought the Takom one recently.

Doing some reading up on it, I get the impression that was killed off the M247 was not so much it being a bad design, but bad press and politics. Sure, it wasn't the greatest SPAAG of its time, but most of its issues seem to have been teething problems that just required a bit more work to fix. Much of the criticism levelled against it since seems to be repeating the same sensational newspaper reports (second-, third- and more-hand, of course) that hyped up its problems and were one of the causes of the M247 being withdrawn.

The most ironic part of the whole thing is that one of the four initial entries for the programme was a PRTL turret on an M48A5 hull, which the US Army rejected even before contracts for prototypes were being awarded. Fast-forward about 40 years and its non-identical twin proved very effective in Ukraine ... So the US could have had the best SPAAG of its generation and beyond, on a hull it had the logistics to support already, and probably for cheaper than the M247 turned out to be ... but NIH, I guess.

[Wardukw]

The Gepard has been considered a top level SPAAG system since day and even today its still a formidable weapons system..yeah a ton of work the York could have been a player but the biggest and most stupid thing was the chassis..the M48 is done..still used with the M88 but even that's starting to have issues.. that's why I built a M88 which sits on a M1A1 chassis 
The M48 has been around since the Vietnam War and using the chassis which has to work with the M1 and M1A1 Abrams was a mistake in the first place..it would never keep up with the M1..which ya mentioned the army never wanted..that straight away would raise the eye brows of the boys in the head shed ..from there it takes quite alot of work to convince them otherwise.
There was repeated issues with all the electronics with systems not talking to each other..tracking and targeting systems need to work perfectly...they didn't.
I think part of the problem was it being rushed ..let's use
off the shelf parts and expect them to work right from the get go . Don't work like that at all .
You can't just slap a engine from a 79 Stingray into a MK4 Cortina and expect everything to gell..it don't.. trust me on that..Chevs don't mate to Ford gearboxes without work.
It was a good idea just executed in all the wrong ways possible.
If I remember and don't quote me here    one of the radars was takin from a F16 which was never designed for a armoured vehicle but likeni said..no quoting 

[Old Wombat]

I think the biggest issue was the guns being close together on the centre line of the turret, right under the radar which started tracking the out-going projectiles far too early in their ballistic arc, as they left the barrel (a point where most projectiles "kick" slightly before settling into their true trajectory), which fudged all the targetting computations.

The Gepard, with its wide-spaced guns doesn't start tracking the out-going rounds until they're a little way out from the guns & settled into their ballistic trajectory.

This allows the computers to correctly calculate the intersection of the out-going projectiles & the incoming target, which the Sgt York couldn't do (unlike the real, WW1 Sgt York ).

The other issue was using old-school clip-fed guns, when belt-fed chain-guns would have maintained the steady supply of rounds to the weapon & created a fixed RoF.

[kerick]

There were so many things wrong with that system it was ridiculous. Plus the fact that Ft Hunter Liggett was known as the place things were sent to fail. I remember watching aircraft and helicopters flying around it while it was supposed to be tracking them and the stupid thing never moved. And that was without firing a shot. And if the bathroom fan story was even half true it's still ridiculous. I recall a news story about how the 40mm gun barrels leftover from WW2 had laid on the shelves for so long they were all bent enough the guns wouldn't shoot straight. If they had really wanted a gun system they could have just bought the German one.

[Jakko]

the biggest and most stupid thing was the chassis..the M48 is done

Um ... no? In the early 80s, sure, many M48 hulls were getting a bit long in the tooth, but that's a maintenance issue, and given the large parts commonality between the M48 and M60 series, the latter of which was still very much in front-line service at the time, it would not have been a big problem to keep them running perfectly well for an anti-aircraft vehicle.

it would never keep up with the M1..

It wouldn't need to have kept up with the M1 Abrams and Bradleys dashing across the battlefield, which is another misunderstanding that keeps being repeated It was a Division Air Defense system, not a Company one

which ya mentioned the army never wanted..

I meant they didn't want the PRTL turret. The M48A5 hull was specified by the US Army, because they had them aplenty at the time. If this had been ten years later they would probably have specified the M60 hull instead, but like I said above, those were still in front-line service and none could yet be spared for conversion.

I think part of the problem was it being rushed ..let's use off the shelf parts and expect them to work right from the get go . Don't work like that at all .

True, this was one of the major issues. It feels like it's a good idea: marry up proven parts to make a working system faster than designing stuff from scratch would have taken. In practice with a system as complex as this, it was about as much work as designing the important bits from the ground up would have been.

If I remember and don't quote me here    one of the radars was takin from a F16 which was never designed for a armoured vehicle but likeni said..no quoting 

The tracking radar was from the F-16, yes. Something else that keeps getting repeated is that with the guns at maximum elevation, their barrels would get in the way of that radar — which seems illogical, because the radar would be pointing in roughly the same direction as the guns ... I suspect the mid-80s journalists mixed up the tracking and surveillance radars.

The other issue was using old-school clip-fed guns, when belt-fed chain-guns would have maintained the steady supply of rounds to the weapon & created a fixed RoF.

The M247 used automatically-fed guns. There were four magazines, two in the bottom of the hull and two in the front of the turret, holding 502 ready rounds in total that were fed to the guns via flexible chutes that dropped the rounds into modified standard Bofors ammo hoppers (cut down to two-round capacity, basically). Using two magazines per gun meant it could be very quickly switched between two ammo types, the idea being to load one with point-detonating and the other with proximity-fused rounds.

And those proximity-fused rounds were the primary reason to go for the XM247 rather than the XM246, which had the same 35 mm guns as the PRTL and Gepard: its rounds were too small to have proximity fuses with early 1980s tech. And you know the US military mindset: if we can solve a problem with higher technology or with better understanding and training, always go for the former!

if the bathroom fan story was even half true it's still ridiculous

According to one of the pilots playing target in the tests, it wasn't a latrine fan, as was widely reported, but the fan on a trailer full of test equipment. To which you can say, of course, "what's the difference?" but calling it a latrine makes more sensational journalism — which isn't exactly unbiased reporting, then. But as he puts it:

It was designed to look for things that rotate (like helicopter main rotor systems) and prioritize them for prompt destruction.

I recall a news story about how the 40mm gun barrels leftover from WW2 had laid on the shelves for so long they were all bent enough the guns wouldn't shoot straight.

Which is stupid, but not a detractor of the system as a whole — assuming they didn't use the bent barrels on production vehicles, anyway. Even then, you can change a Bofors gun barrel in minutes if you have to.

If they had really wanted a gun system they could have just bought the German one.

True. Well, the Dutch one, as that was the one actually being offered.