PUMA - Ultimate IFV presented
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Because at that time when greater energy was needed it was easier to increase the diameter instead of handling the increase in pressure that would have been needed. It always is.A larger diameter offers a gun though a relative greater penetration potential. Why do you think that the 120mm replaced the 105mm as the NATO standard MBT caliber
But today as we understand material technology and simulation etc. much better, you can go for bigger propellant charges rather than bigger diameter.
It's a question of how much pressure your gun tube and breech can handle, and that as an alternating load when firing multiple rounds in automatic mode.
I'm not working with Rheinmetall but I guess that 2 decades ago the 120mm L55 gun would not have been doable with reasonable effort. Today it is.
Actually I didn't want to contradict you at all, my remark was more of an addition... Speaking of penetrating power, a more powerful 30mm would be feasible. Concerning the other points, well that's another matter.Firn said:
Well I admit I was just being polemik about the PUMA contra CW90, the reason for that is what I see as the fundamental disaster and, I think, ultimately the undoing of most of Europe's defense industry: Narrow national centric industrial interests, that leads to uncompetiative and wastefull production of units in small quantities by too fat companies.
The US army can do with one MBT, One IFV one LAV-platform etc, it should be possible for the totality of european forces to do the same. In this dream state of perfection (yet how unrealistic it sounds, still a necessity for europe to step out of the shadow of "irrelevance") the PUMA could very well and possibly be the system of choise.
The meassure of succes of the Puma shouldn't, in my line of thinking, be the engineer's assesment of it's technical qualities (which I think looks great and second to none) or the panzergrenadier's assesment of it's operative qualities (that's not my field), but instead be meassured alone by it's succes as a sale item on it's home market - which ofcourse is not just "Germany" but "Europe". In the sale, the technical and operative qualities are ofcourse paramount, but so is f.ex. "timing", "cost" and "relevance".
In that light, dispite being a beautifull machine, I do have my doubts about the PUMA.
The US army can do with one MBT, One IFV one LAV-platform etc, it should be possible for the totality of european forces to do the same. In this dream state of perfection (yet how unrealistic it sounds, still a necessity for europe to step out of the shadow of "irrelevance") the PUMA could very well and possibly be the system of choise.
The meassure of succes of the Puma shouldn't, in my line of thinking, be the engineer's assesment of it's technical qualities (which I think looks great and second to none) or the panzergrenadier's assesment of it's operative qualities (that's not my field), but instead be meassured alone by it's succes as a sale item on it's home market - which ofcourse is not just "Germany" but "Europe". In the sale, the technical and operative qualities are ofcourse paramount, but so is f.ex. "timing", "cost" and "relevance".
In that light, dispite being a beautifull machine, I do have my doubts about the PUMA.
More to the point, if your projectile is fast, it looses much more energy due to air friction, which means that it has to be fired with a larger initial kinetic energy than a low velocity projectile (to deliver a given quantum of energy at a given distance) that means a bigger/better gun able to handle the increased chamber pressure, at which point you could just as well save the gunpowder and add mass (leads to adding calibre) to the projectile - given that you are happy with the balistic performance. The air friction works against the high velocity gun, and when you are satisfied with the ballitics, it's typically much better gun design to add mass and not speed.
As you yourself had admitted the european market is not as dependent upon the excellence of the product and market forces as it is with the political decisions each armed forces must cope with regarding purchasing the locally built alternative even if it is inferior. So it's a bit harsh to then turn around and say that as the Puma has not been sold all over europe that it should be judged in light of this lack of success. In short it is not a widespread european sales hit NOT because it isn't arguably the best IFV in the world but because of domestic politics.
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Isn't the motto of the EU "United in diversity"?
I personally see the diversity in the market place as a strenght - as long as there is a common market. While there still a lot of politicing in each procurement process, but I think that in the last 10-15 years things have moved into the right direction. Large European companies have grown through mergers, success and acquisitions. European products are successfull on a international market, even if they are handicapped by very limited access to the largest one. In fact the USA is in many regards in defense matters not a good example for the EU or European countries.
Ironically there are quite a bit of very important areas where the smaller European companies have proven to be far more innovative and creative then their US-american companies. Take for example the field of the wheeled APC and IFV, mine-protected IMV, RWS, turreted mortars to name just a few.
But this a topic about the Puma so I will leave it there. The Puma is a new expensive vehicle which should be a big step forward into the IMHO right direction. If it works well enough and the circumstances are right other countries might buy it. The CV90 is a cold war vehicle which right now enjoys a string of successes because there is nothing comparable available on the market and the costumer feel the need to have a such a product now or in a few years.
I personally see the diversity in the market place as a strenght - as long as there is a common market. While there still a lot of politicing in each procurement process, but I think that in the last 10-15 years things have moved into the right direction. Large European companies have grown through mergers, success and acquisitions. European products are successfull on a international market, even if they are handicapped by very limited access to the largest one. In fact the USA is in many regards in defense matters not a good example for the EU or European countries.
Ironically there are quite a bit of very important areas where the smaller European companies have proven to be far more innovative and creative then their US-american companies. Take for example the field of the wheeled APC and IFV, mine-protected IMV, RWS, turreted mortars to name just a few.
But this a topic about the Puma so I will leave it there. The Puma is a new expensive vehicle which should be a big step forward into the IMHO right direction. If it works well enough and the circumstances are right other countries might buy it. The CV90 is a cold war vehicle which right now enjoys a string of successes because there is nothing comparable available on the market and the costumer feel the need to have a such a product now or in a few years.
The Puma is a superb vehicle, however some armies do not like an unmanned turret configuration. The UK/ US (reinforced by experiences in Iraq/A-STAN) prefer a more traditional two-man turret (commander & gunner), allowing the crew to sit high up and utilise the mark-one eyeball through the turret hatches to observe their surroundings instead of relying wholly on the technical/electronics surveillance fit. Correct me if I'm wrong but If I was using the Puma in the recce role and wanted to survey my surroundings with the naked eye I would have to exit the vehicle or use one of the hull roof hatches?Isn't the motto of the EU "United in diversity"?
I personally see the diversity in the market place as a strenght - as long as there is a common market. While there still a lot of politicing in each procurement process, but I think that in the last 10-15 years things have moved into the right direction. Large European companies have grown through mergers, success and acquisitions. European products are successfull on a international market, even if they are handicapped by very limited access to the largest one. In fact the USA is in many regards in defense matters not a good example for the EU or European countries.
Ironically there are quite a bit of very important areas where the smaller European companies have proven to be far more innovative and creative then their US-american companies. Take for example the field of the wheeled APC and IFV, mine-protected IMV, RWS, turreted mortars to name just a few.
But this a topic about the Puma so I will leave it there. The Puma is a new expensive vehicle which should be a big step forward into the IMHO right direction. If it works well enough and the circumstances are right other countries might buy it. The CV90 is a cold war vehicle which right now enjoys a string of successes because there is nothing comparable available on the market and the costumer feel the need to have a such a product now or in a few years.
One assumes however that the Puma chassis can be fitted with a manned turret though as customer spec'd alternative.
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It seems that there are a lot of different POV and arguments by experienced members on the issue, see LAV III: turret or RWS?. Note that towards the end the ever better SA of the newer RWS stations and their supreme accuracy and control and seems to deemed important. Still the naked eyeball and "feel" out of the hull is still seen as great asset, as long the dangers of IEDs and other threads is no too high . The Puma has anyway the biggest and most complete amount of integrated optics (cameras, vision blocks, periscopes, etc) up to date, given the whole team possibly unmatched under armor SA.
We will see how things play out...
Well as in the equation for kinetic energy the velocity gets squared in comparison to mass, you'll get much more out of it, since we're talking about penetration power with APFSDS (=kinetic energy) rounds.
I'm sorry I'll leave my hands of air friction at that speeds, I only had one semester of fluid mechanics and we were mainly dealing with sub- and transsonic speeds
But certainly you'll have to balance characteristics according to your intended use.
Pro's and con's for both arguments, however as mentioned in the linked blog having to exit a IFV/MRAP to clear or reload your RWS in a heavy engagement might warrant the immediate issuing of a VC.
In the pure recce role in places like A-STAN were you may end up crossing wide open spaces or patrolling parallel to existing MSR's where the likelihood of being hit by a concealed IED is more remote (by not following predictable routes) I would prefer from an operational point of view to be sitting in a manned turret, with the added option of being able to sit high-up viewing my surroundings using the naked eye / bino's. No matter how good the current range of optics are you always lose a sense of depth, SA and peripheral vision. also if you are positioned in a static position providing overwatch at major junctions / choke points, being able to sit high and observe heavy traffic / pedestrian movement with a clear 360 view of your surroundings seems to me to be advantageous. RWS are ideal for wheeled MRAP vehicles, where they already tend to have good built-in all round vision through reinforced glass viewing panels.
Fallstaf
It quickly gets complicated with ballistics and special properties of the penetrator, the impact itself etc. Though in general, at impact one would expect that it doesn't matter whether you store your kinetic energy in mass or velocity. Though if you went for high velocity you will get penalised by the air resistance, which, like the kinetic energy, has a squared dependence on velocity, meaning that if you double the velocity, you quadruple the air friction. So if you and I (world famous gun designers) were to qaudruple the "power" (at a certain distance) of a gun, we could chose to double the velocity, keeping the mass constant, but doubling the velocity would also quadruple the air resistance, so we would need to add extra gunpowder and higher velocity to zero that, though that velocity increase would also unfavorably add to the air resistance so we would need a little bit more than that.
If we vent the other way and kept the speed constant but increased mass (practically that'll be, we increase the borediameter), we would only incur an extra airresistance porportional to the increase in the cross section of the projectile, necessary to quadruple the mass of the projectile. and that is likly much better for our design, since we need less gunpowder and chamber pressure.
Adding in ballistics, shell size, cannon size and other practicalities you arrive at conditions for optimality for a cannon designed to do a certain job. If you need to have your cannon to be more powerfull, You can increase the power by adding more gunpowder, but really quickly you end up with a gun which is suboptimal next to a larger callibre optimally design to do that larger task. So the 30mm can probably be "boosted" to do the job of 35mm, but the 35mm would probably be a superior gun (smaller, easier, cheaper etc). Today we have a pretty good idea how our projectile will behave it self when we fire it, in WW2 some german engineers figured out that the old well known 76mm cannon, was underpowered, and by adding a lot more power (velocity) and higher angular momentum, you transformed this old weapon into an easy to handle powerpack very well suited to defeat tanks. It featured both high penetration power at practical distances and the trajectory had a flat curvature, which made it easy to aim. And the gun stayed relatively small which was good for the anti tank crews handling it on the ground or the tank designers trying to fit it in the turret of some tank. An example of a very good gun design, striking a good compromise between range, callibre, power, balistic-path, handling, size etc. to do a given job.
It quickly gets complicated with ballistics and special properties of the penetrator, the impact itself etc. Though in general, at impact one would expect that it doesn't matter whether you store your kinetic energy in mass or velocity. Though if you went for high velocity you will get penalised by the air resistance, which, like the kinetic energy, has a squared dependence on velocity, meaning that if you double the velocity, you quadruple the air friction. So if you and I (world famous gun designers) were to qaudruple the "power" (at a certain distance) of a gun, we could chose to double the velocity, keeping the mass constant, but doubling the velocity would also quadruple the air resistance, so we would need to add extra gunpowder and higher velocity to zero that, though that velocity increase would also unfavorably add to the air resistance so we would need a little bit more than that.
If we vent the other way and kept the speed constant but increased mass (practically that'll be, we increase the borediameter), we would only incur an extra airresistance porportional to the increase in the cross section of the projectile, necessary to quadruple the mass of the projectile. and that is likly much better for our design, since we need less gunpowder and chamber pressure.
Adding in ballistics, shell size, cannon size and other practicalities you arrive at conditions for optimality for a cannon designed to do a certain job. If you need to have your cannon to be more powerfull, You can increase the power by adding more gunpowder, but really quickly you end up with a gun which is suboptimal next to a larger callibre optimally design to do that larger task. So the 30mm can probably be "boosted" to do the job of 35mm, but the 35mm would probably be a superior gun (smaller, easier, cheaper etc). Today we have a pretty good idea how our projectile will behave it self when we fire it, in WW2 some german engineers figured out that the old well known 76mm cannon, was underpowered, and by adding a lot more power (velocity) and higher angular momentum, you transformed this old weapon into an easy to handle powerpack very well suited to defeat tanks. It featured both high penetration power at practical distances and the trajectory had a flat curvature, which made it easy to aim. And the gun stayed relatively small which was good for the anti tank crews handling it on the ground or the tank designers trying to fit it in the turret of some tank. An example of a very good gun design, striking a good compromise between range, callibre, power, balistic-path, handling, size etc. to do a given job.
@ Palnatoke
I think this sums it up pretty well. The essence of this problems have troubled humankind for couple of thousend years. The efficiency of a given bow to transform the stored work into kinetic energy to give an arrow an initial momentum changes greatly with the weight of the arrow. Certain types of bows were overall more efficient then others but had usually different "efficiency curves/relationships". This is still true in the modern "cannon" context.
Of arrows and rounds
Arrows designed to have a higher chance to pierce armor were usually relatively heavy (more efficient energy tranfer, high intial momentum and a very high relative one at longer ranges) and were tipped with heads with a small, sturdy and elongated cross section (reduced plastic deformation, reduced cross section) which allowed it all in all to impact with a relative high sectional densitiy and high momentum.
The drawbacks compared to "standard" arrows were:
(i) bulk and weight of the projectiles allowing fewer arrows to be carried
(ii) a low velocity and a high ballistic arc, no good for mobile single targets
(iii) a arrowhead with greatly reduced wounding capability
So while very light arrows in huge quantities were excellent for the Scythian horse archers with their small recurved composite bows in the 6th century BC heavy arrows or bolts were a must to hope to make at least some impression in an dismounted retainer in a fine crafted full steel plate armour.
So what?
If we look now at modern cannons we see that Palnatoke made a pretty good overview of this dilemma. The modern Rheinmetall L44 tank gun was first of all intended to deliver a projectile with very high sectional density with a high enough momentum to penetrate all the potential targets in the foreseeable future at very long range while trying to keep the component speed in the equation as high as possible to flatten the trajectory and to reduce the time in flight.
Machine cannons face further dilemmas as they were/are designed for a wider spectrum of sometimes conflicting tasks.
@ Falstaff: A short flirt with physics at the uni or a longer love affair?
I think this sums it up pretty well. The essence of this problems have troubled humankind for couple of thousend years. The efficiency of a given bow to transform the stored work into kinetic energy to give an arrow an initial momentum changes greatly with the weight of the arrow. Certain types of bows were overall more efficient then others but had usually different "efficiency curves/relationships". This is still true in the modern "cannon" context.
Of arrows and rounds
Arrows designed to have a higher chance to pierce armor were usually relatively heavy (more efficient energy tranfer, high intial momentum and a very high relative one at longer ranges) and were tipped with heads with a small, sturdy and elongated cross section (reduced plastic deformation, reduced cross section) which allowed it all in all to impact with a relative high sectional densitiy and high momentum.
The drawbacks compared to "standard" arrows were:
(i) bulk and weight of the projectiles allowing fewer arrows to be carried
(ii) a low velocity and a high ballistic arc, no good for mobile single targets
(iii) a arrowhead with greatly reduced wounding capability
So while very light arrows in huge quantities were excellent for the Scythian horse archers with their small recurved composite bows in the 6th century BC heavy arrows or bolts were a must to hope to make at least some impression in an dismounted retainer in a fine crafted full steel plate armour.
So what?
If we look now at modern cannons we see that Palnatoke made a pretty good overview of this dilemma. The modern Rheinmetall L44 tank gun was first of all intended to deliver a projectile with very high sectional density with a high enough momentum to penetrate all the potential targets in the foreseeable future at very long range while trying to keep the component speed in the equation as high as possible to flatten the trajectory and to reduce the time in flight.
Machine cannons face further dilemmas as they were/are designed for a wider spectrum of sometimes conflicting tasks.
@ Falstaff: A short flirt with physics at the uni or a longer love affair?
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I pretty much agree with it. You might read this excellent article to see just how important a independent "hunter" sight is, which the LAV III lacks. To gain partly of this capability (plus some others) the commander of LAV III has to get out with his binos. This is seemingly often not advisable due to IEDs and intensive enemy fire.
Lesssons Learned said:
The Puma has vastly better SA than the Leopard - you have to take a look. Plus he has the eyes of his section in our out his hull to gain further SA. The whole vehicle is quite well presented, we will see who much it is like.
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I agree
I don't "admit" that "the european market is not as dependent upon the excellence of the product and market forces as it is with the political decisions" that's one of the things I see as the disaster of european defense industry and procurement.
And it is harsh on the Puma, but that's how it is. The Puma is arguably the technically best, but that doesn't mean much, if you can't sell it because nobody demands it for the time. the CW90 is probably an inferior IFV, but those who offered that one for sale got two important things right (by calculation or Chance-I don't know, and it doesn't matter): "Timing" and "relevance": there were a demand.
Ofcourse one could say; well equipping the bundeswehr is the criterium of succes - or rather since we know that no matter what it will equip the Bundeswehr, the real criterium is to build a fantastic machine to serve the bundeswehr to the very best. I consider that as a very defensive buisness strategy that leads to one place and that's nowhere.
Btw should european defense procurement live up to the standards of the common market, I am pretty sure that KMW and RM would have had some nice buisness opertunities in certain large european nations, because it's obvious that they are the best in europe at what they do.
Defense industry&procurement in Europe reminds me of Greenland. As you probably know it's a danish dependency, and the greenlandic economy is the following: The fish some fish, get a huge subsidy from Denmark, spend money and when they run out of money they phone for more money in the danish treassury. As you can imagine Greenland is the place in the world where, if you know the right people, lazyness, incompetence and very modest education and intellectual cababillites are no hinderence for reaching to the stars. And things do work in Greenland, the cost is just very high, and everything is very expensive.
Fortune has it that the EU is a relative large market with some 500 million people in it. Yes still large parts chunks of the defense market are sheltered by a dear nanny called state but overall it has and is increasingly providing European and international actors - with various efficiency - good and excellent products. Looking at the whole it seems that Germany is the one country who has gained most of the more open markets as the products of its companies a by far the most wide spread ones. Great performer with "timing" and the fitting "relevance" like the LAV by MOWAG (now General Dynamics) or the CV90 by Hagglund (now BAE) also greatly profited from it.I agree
Defense industry&procurement in Europe reminds me of Greenland. As you probably know it's a danish dependency, and the greenlandic economy is the following: The fish some fish, get a huge subsidy from Denmark, spend money and when they run out of money they phone for more money in the danish treassury. As you can imagine Greenland is the place in the world where, if you know the right people, lazyness, incompetence and very modest education and intellectual cababillites are no hinderence for reaching to the stars. And things do work in Greenland, the cost is just very high, and everything is very expensive.
Personally I think that the Puma has the chance to become also a great performer on the international market. Already a CV90 with modern upgrades is no longer that far away from the price of a Puma. But the inherent weaknesses compared to the Puma in quite a few aspects can only be mended by a new design. That is the way of the world. Anyway in twenty years we will know
@ Falstaff: So I will only wish you a good marriage and a not too demanding wife
@Palnatoke & Firn
I'm sorry guys but there is nothing to be discussed here, just to be stated.
The penetration power of a APFSDS round with a given shape at a given angle largely depends on the kinetic energy you can deliever on the target, and here you can gain much more from the velocity than from weight.
Air resistance or friction along with all the overlaying aerodynamical problems won't negate the advantages from that when handled correctly, remember we're talking about specifically shaped projectiles with a very small cross section.
Apart from that I don't remember saying that this is the one and only or better solution, I only said it can be done (and is done). In my opinion, this the more difficult but also more elegant way to go. I even remember saying that you'll have to balance the characteristics. Didn't I?
I'm sorry guys but there is nothing to be discussed here, just to be stated.
The penetration power of a APFSDS round with a given shape at a given angle largely depends on the kinetic energy you can deliever on the target, and here you can gain much more from the velocity than from weight.
Air resistance or friction along with all the overlaying aerodynamical problems won't negate the advantages from that when handled correctly, remember we're talking about specifically shaped projectiles with a very small cross section.
Apart from that I don't remember saying that this is the one and only or better solution, I only said it can be done (and is done). In my opinion, this the more difficult but also more elegant way to go. I even remember saying that you'll have to balance the characteristics. Didn't I?
You did mention it. Anyway it is a too complex topic to be discussed in this thread. For a armor penetration it comes down very very roughly to the question if momentum or kinetic energy of the projectile (among other factors mainly connected to the characteristics of it) are the better indicators for penetration power.
I and seemingly Palnatoke tend to see the first indicator as more relevant as the second one while keeping the other in mind. You tend to regard the second one as a better one while appreciating the first one.
IMO the momentum can't be an indicator because the material failure process that leads to the penetration isn't a matter of (Newton's) motion mechanics.
Well, enough of that. It's OT and as you said, too complex. I enjoyed the discussion though
IMO the momentum can't be an indicator because the material failure process that leads to the penetration isn't a matter of (Newton's) motion mechanics.
Well, enough of that. It's OT and as you said, too complex. I enjoyed the discussion though
As a post OT...
I don't sufficiently understand the physics behind "penetration"
to give a definate oppinion, though I feel that flagstaff is correct vis a vis the energy aspect. I don't think momentum, is so important here. (edditted out some physics, that I'm not sure about)
Energy is the integral of force wrt position, so if you have the energy, you are saying something about the magnitude of forces that have acted across the path of action [namely the forces avaliable to dislocate material] (correct? It's a long time ago..).
This must be the interesting meassure when we try to push a dart through some material.
momentum is the integral of force wrt time, so knowing the momentum (change) only tells us that this much force have been required to bring the dart to a stop in this time interval.
Energy, force and momentum have a lot to do with each other.
Though flagstaff, regardless of the porportion between mass and velocity I think my argumentation holds since it concerns the total kinetic energy delivered, thus the kinetic energy avaliable for the penetration process.
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