TokyoMorose

Real odd choice in engines, IMHO - BAE's spec sheet lists the C32 ACERT. Has no compatibility with anything else in the fleet, and isn't outside of the power range of further-upraded AVDS-1790s. Seems like uprating the 1790 would be far less work.

It really is incredible how much of a mimic of the ATACMS the new missile is (I've heard it rumored as KN-25 under DoD codenames, which has been seen before in texts but nobody has seen a 'KN-25' so this may be it) - they even seem to have aped the M270 launcher design for this and the new heavy MLRS they showed off...

On 6/23/2016 at 5:26 AM, Collimatrix said:

Forczyk mentioned in his T-34 vs panther book that there was some loon in the German armor development bureaucracy who was completely obsessed with torsion bars and interleaved road wheels, and would basically reject any design that didn't have them.  This is apparently why the DB panther design gained them later in development.  But it's not clear to me why this guy had so much say in tank design, and why everyone around him didn't point and laugh.

I know I am late here, but the loon wouldn't happen to be Ernst Kniepkamp would it? I know with the half-tracks and Panzer III he was directly the guy responsible for those elements - and the Tiger I work at Henschel was also his pet project of the time.

And wait, I have Forcyk's book.... and yep it is Kneipkamp. Head of all tank projects at the Wehrmacht, and had been the chief army engineer even before the Nazi takeover when it was the "Military Automotive Department". Even the tiny Kettenkrad has the interleaved wheels, and yep the patent on that is "E. Kneipkamp".

6 minutes ago, Clan_Ghost_Bear said:

I think they need to get rid of the PT-91 and T-72M1s before reserving any of their Leopards.

Oh I agree wholeheartedly. But my question was that since the Leo2PL project is funded separately from the T-72 replacement: If it is cheap enough and there are enough available at the cheap price, it might be worth diverting the 2PL funds to replace the 2A4s *as well* as the old T-series tanks.

While I take the M1A1SA rumor with approximately 500t of salt, if they do get a good price on those and sufficient volume is available... does this not rather take the wind out of the Leo2PL program? It's hard to see how the 2PL would be a better machine overall due to the limited scope of the upgrades on it, and unless the 2PL is *suuuuper* cheap wouldn't it make more sense to spend the money on SAs and just consign the ancient 2A4s to training & parts hulk duties?

2 hours ago, David Moyes said:

Warrior hulls are too worn-out for upgrade so now the plan is to make entirely new ones.

That... that is impressively pointless. I'd wager by the time you've built the limited run of new hulls you're nearing the total cost/vehicle as the Ajax but while still being limited to ye olde chassis.

25 minutes ago, skylancer-3441 said:

although its kinda cramped (well, entire vehicle is) with internal height from floor to ceiling of like 3 feet 11, and some 19.5 inches of width per dismount.

I understand that, it's made clear in the article - but at 3'11" you're gonna have to be crouching - and I don't think that 19.5" per dismount is enough width to actually fit guys in - that's similar in size to notoriously cramped economy class airline seats, which aren't going to fit an infantryman, crouching, in combat gear.

5 hours ago, LoooSeR said:

     Front engine, ~55 tons, 6 dismounts, crew of 3, supposedly 30 rounds in turret and 10 more in hull for the main gun.

If they are using an unchanged T-80UD/T-84 turret, where are the dismounts seated? The turret basket is going to take up most of the space in there, and it seems to be too wide relative to the hull to allow BMP-3 type seating *around* the turret basket. Poor guys in there have to be basically vacuum sealed...

On 5/12/2019 at 1:03 PM, AssaultPlazma said:

 

I'll elaborate a little, I guess the premise just seemed odd to me because the HMMWV was never designed to eat IED's and take the fight to folks in heavy urban street fighting. As a basic utility vehicle there's nothing wrong with it besides being old at this point.  

As true as this is, the age is honestly rather cause enough for replacement. The things are slow, maintenance intensive, not particularly stable, and lack some "creature comforts" that have rather proven to be necessary in certain operations (the classic case being no effective AC in desert fighting...). You might be able to get away with a deep overhaul, but likely for the same costs as a newer design.

22 hours ago, Ramlaen said:

Upgrading a Humvee fleet (that you have many thousands of) to JLTV is a lower priority than upgrading MBT, IFV, artillery etc. The US Army doesn't have infinite money and has to make choices.

 

If a situation requires the use of 'battle buses' then the US Army has more MRAPS than it knows what to do with.

I thought one of the ideas of JLTV was to actually save money in the long run by allowing the vast mishmash of hurriedly-acquired MRAPs to be liquidated in favor of one standard family of machines. Seems a bit like hurting yourself in the future to save money now by keeping all of the different humvee & MRAP configs in use. It's just odd because so many of the other procurement decisions being made seem to focus on this rebuilding-for-the-long-term prioritization and cutting back of interim/stopgap work (such as Bradley/Abrams upgrades getting scaled back in favor of additional NGCV funding, and Chinook F Block II getting axed for a bump in FVL funds)...

The goal of groups like GAO is specifically to be as critical as humanly possible. A hypothetical issue like a poor service life on a tire, while not impeding the function of a vehicle, can have it stated to be "not operationally suitable".

The only pieces of equipment that are "fully operationally suitable" have either been through decades of use & refinement... or only exist on powerpoint presentations. Poor training & manuals, even if legit criticisms, are hardly reasons to prevent acquisition of a vehicle. I heavily doubt the GAO would have found the M3 Medium Tank's Training and Manuals operationally suitable as the US was desperately trying to build up an armored force in early WW2.

11 hours ago, LoooSeR said:

Tankoff once again found interesting thing - 2TV373Ch engine for groung vehicles

 

 First 2 engines are using 2 axial turbine turbochargers with 2 air coolers, "O" engine uses 2 turbochargers with centrifugal turbine + 2 air coolers, last 2 are using unspecified type of turbochargers (2) and 2 aircoolers with "battery type fuel system".

A) I wonder what vehicles that first engine could be planned for.

B) "Battery Type Fuel System" sounds like a fancy high-pressure common rail. Would allow improvements in fuel flow and control to achieve the better performance.

I would be quite frankly astonished if the current Sprut 2S25M had ammo restrictions - autoloaders capable of handling the longer ammo have been around for far longer than the Sprut's development program, and there's no other possible technical reason it couldn't fire any 2A46M compatible ammo (just comparing the 2A75 to the other 2A46M derivatives)... the worst that may happen IMHO is it getting knocked back a bit.

On 2/16/2019 at 1:43 AM, SH_MM said:

Nozh works as advertised, just the claimed efficiency is way too high.

I was referring to that thread, and from the evidence in there the performance seems dismal enough to say it's not working as advertised and certainly no improvement over Kontakt 5 outside of a few hypothetical edge cases.

15 hours ago, heretic88 said:

Somewhat surprising from Hlopotov, he defends the T-64. And actually, he is right! This "T-64B3" upgrade is indeed better than the T-72B3.

https://zen.yandex.ru/media/gurkhan/tankist-vsu-rasskazal-o-svoem-tanke-t64bv-obr2017-goda-5c64372b84e0ea00aebfadf9

 

Is he though? One of the key points for saying it is better is that the new T-64 update mounts Nozh instead of the old Kontakt-5 applied to the B3s, but Nozh doesn't work as advertised. I thought the general consensus of evidence is that K-5 is better than Nozh given its multitude of issues?

2 hours ago, EnsignExpendable said:

All I see is 

 

I'll back up EE here, that's what I've been seeing for some time now as well. I didn't bring it up as I figured Loooser would notice.

4 hours ago, Serge said:

Yes, they are. 

And if you look at the Swedish politics history, they are not sweat harts. 

Come on, Serge - that is an exceedingly silly thing to say. As if the French or pretty much any nation are wonderful sweethearts who only deliver fin-stabilized sunshine & rainbows.

On 1/24/2019 at 7:35 AM, Collimatrix said:

 

My books on armor metallurgy disagree.  As an example, if you could eliminate all of the bonding dislocations in a piece of mild steel, its tensile strength would be 20 times higher.  Modern steels aren't anywhere near their theoretical maxima.

 

Entirely novel steel metallurgy has been developed in the last 10 years, including armor steels with bainitic microstructure, TRIP and TWIP steels.  Additionally, ultra high hardness steels are being developed that may be viable alternatives to ceramics.

Oh, I'm entirely aware of what has been produced in labs or in 1 or 2 pound test batches, but I was more generally speaking about mass-produced armor steel that they could build a large number of turrets right now out of. Some of the maraging sintered alloys that have come out are remarkable (well over 700 Brinell!), but these haven't moved to mass production of plates and likely wont for some time.

8 minutes ago, RoflSeal said:

Oh, so going from cast(?) to welded, just like the Challenger 2?

As I say, even if the original turret was welded, the new turret will use different steels for weight saving.

 

And even then, going back to M1->IPM1, you definition of a new turret is arbitrarily restrictive. And extended frontal armour wasn't the only difference.

Steel is basically steel. RHm can claim newer steels, but to be honest the improvements in most regards are in the order of 1-5% over the last 20 years - it's mostly marketing wank. Steel metallurgy is simply mature and has been some time, so with the exception of niche alloys/properties major improvements just aren't going to happen. That said, I do agree that re-use of sub-components does not make a new turret merely a variant of an old one. The earliest batches of 76mm Sherman turrets re-used the vast bulk of sub-components with the then-current 75mm turret models, and nobody says it isn't a new turret. The Keiler-derived Leopard 1A3 turret initially shared most sub-components and systems with the 1A2 cast turret, and nobody says they are different variants of the same thing.

1 minute ago, Ramlaen said:

The original M1 did have a different turret than later models.

Correct, the M1IP introduced the "Long" turret compared to the earlier "Short" turret on the M1 Vanilla. It re-used most subsystems and was based on the same overall design, but was structurally an all-new unit.

15 minutes ago, SH_MM said:

Always find it ridiculous how people decide to speak about "the three best Western tank" (or four in this case) and then include the Challenger 2 over the Leclerc...

At least nobody puts the C1 in that competition!

7 minutes ago, Ramlaen said:

 

Even though your own math disagreed with you?

But my own math didn't? The only math I did was comparing BFSC of the V908 with a representative figure for a current fielded-in-number diesel. And I just realized there was a major flaw in my math too (this is what I get for getting nosleep...), the V908 power figured I used was in Gross, not Net. Which is going to knock a good deal off of it. It's actually a pain to get the exact fuel consumption figures for that old thing. I did no math comparing the new engines simply because there's no way to.

I'd love to see the BFSC numbers of the new engine, but they don't exist - and their only claim for "improved efficiency" is end-user efficiency (i.e. Bradley will be 25% more efficient with the engine, which could likely be met with zero increase in thermodynamic efficiency, instead merely getting rid of parasitic drag and having a more engine reserve power so it isn't constantly floored amongst others...).

2 hours ago, Ramlaen said:

 

Didn't you initially assert that it was less efficient than a generic modern turbodiesel, not that turbodiesel on the drawing board are just as good?

But it is, the turbodiesel improvements aren't drawing-board level things. It's small improvements like coatings and the like. Which this engine doesn't currently have either because they aren't production ready. The current state of the engine is I'm 100% certain less efficient than a current standard engine, and the final production engine will be less efficient than a 2020 or whenever year engine. The improvements aren't really design related that are coming.

1 hour ago, Collimatrix said:

This slide explains that opposed piston diesels have a small inherent efficiency advantage due to lower surface area/volume ratio.  

They do have a heat rejection advantage, but they come with many other issues with incomplete combustion, lubricant in the combustion chamber, and lots of extra gears or levers to mate the piston cranks to a common output shaft that all hurt efficiency. There's a reason in an age of ever increasing efficiency, no major company has gone into the two-stroke piston business despite this technology being nothing new.

Just now, Ramlaen said:

 

So at 20%+ it is actually a greater improvement than a modern diesel design? (without accounting for the other improvements in the Achates/Cummins engine)

No, it's not really, considering it's not production ready yet and conventional diesels are already planning improvements that'll be ready by the time this is. The only big upside to this engine over say "Generic V8 Turbodiesel 2020 #23436448" is really the power density from the very compact layout.

1 hour ago, Ramlaen said:

 

Perhaps I am misunderstanding your math but 222 to 190 is roughly 15%.

Which is within a few percent of their 20% claim (always account for PR puffery), and that's just with improving the combustion efficiency of the old design. Many other things contribute to overall "end-user" efficiency, and improvements in those should drive the numbers way up. As I've said, commercial diesels have gone further just in the last 20 years already overall.

8 hours ago, Ramlaen said:

 

What do you think is an appropriate level of fuel efficiency a current tech engine should have over a V903? (without accounting for the other improvements)

Honestly, I'd say at least 50% - and that's just looking at other mass-produced diesels through the years. In the last 20 years, we've seen alone total >20% improvements in fuel economy, so given this is a half-century old design (it's a low-pressure fuel injection design!) there are tremendous savings to be had.

Based on some simple math, the V903 has a (at peak efficiency) brake specific fuel consumption of 222 grams per kilowatt-hour. Modern diesels are capable of a peak ~190, and that's just pure core thermodynamic efficiency changes more or less meeting their changes. Of course, a 1000hp engine will be more lightly loaded, and won't be pushed much beyond the peak compared to the old engine. It also won't be pushed as hard running all of the accessories. That said, I do believe the goal of this engine is power density, not pure efficiency. The better efficiency is merely a byproduct of it being a modern design.

Honestly, if they want better agility/lower weight at the cost of armor, the CV90-120 does make more sense than the LeClerc or really any other vehicle - the CV90 is operated in large numbers throughout the force, and is a domestic product.

But other than that, the only hot lines are indeed the Leopard 2... and the M1, and I don't see any case where they decide to operate both.