Finally i have a bit of work-free time to write something. Let start :1) The ever open question of Probability to Hit of a MBT equipped with a modern FCS and importance -or lack of it - of target's surface area for this crucial parameter
An advanced, modern FCS ,provided with all the necessary chrono-spatial and environmental information (precise range from target ,accurate measure of its motion's vector, overall environmental temperature, wind speed, specific humidity, barrel level of thermal expansion and its level of structural fatigue etc..etc..)can effectively allow a modern MBT to find a fire solution and reliably hit a relatively small target -smaller than the frontal projection of a MBT- at long range (in the right conditions even more than 3000-3500 meters), but what is almost always, strangely, "forgotten" is that ,at medium-long range (2000 m and over) considering actual HEAT and APFSDS rounds ,all that remain true only against stationary/near-stationary targets or those changing theirs motion vector in a proportional way
Image an engagement attempt against a target at 2200 meters moving at 36 Km/h (10 meter/second), for simplicity we can image this target moving perfectly perpendicular to the barrel's axis of the shooting tank (choosing therefore the most advantageous geometry for the shooter); from the processed data and the precise instant of the found fire solution to the moment of the APFSDS arrival on the computed point of interception, taking into account: gun collimation ,fire initialization, velocity and gravity drop of the round and travelling time long the parabolic trajectory to this point 2200 m far, elapse about 2 seconds for a round like M829A3 (1540 m/s at gun exit).
Now any change of the target motion from the vector computed by the FCS at the instant of fire solution capable to modify the actual spatial position of the silhouette's centre of a distance superior to its semi-projection
(half of the projection of its target area at the shooting point) will cause an assured miss
, anyone can easily realize as a variation as small as +/-15 Km/h in the target speed or a simply turn ,even of only few degrees, or even the effect of some terrain morphology is more than sufficient for a tank with an average silhouette to cause a miss by part of the named round at this range.
What is very important to point-out is that what now expressed remain totally valid independently from the FCS's sophistication
(unless someone will manage to create a future-reading FCS
) because those variations of target's vector in the mentioned time window are totally arbitrary
,therefore completely out of the computing capabilities of any data processing system in the past ,in the present or in the future.
The unique factors, conversely, capable to influence a similar engagement sequence against a target randomly changing its motion's parameters are : round's speed, distance from target, target capability to quickly change its motion vector, round average dispersion at this date range, and size of the target actual aspect projection from the shooting point.
Now anyone can easily realize as even small variations in a MBT's area projection (in the order of some dozen of cm ) produce a disproportionate effect in the related PtH -Probability to Hit- parameter for engagements at 2000-2500 m ,or over, between randomly moving opposing MBTs not employing guided ammunitions, because those features allow both to increase the time window useful for initialize a motion variation capable to cause a miss and/or mitigate the "required" entity of the same motion's variable.
We must also add that a MBT with a smaller silhouette show, almost always, also a smaller internal volume and a significantly lower inertial mass, elements that don't allow only to maintain a greater armoured-mass-to-surface index but also a far better capability to quickly change direction and speed in the unitary time segment of reference , one of the variables in the Probability to Hit function for medium-long range engagements.
The operational factors previously described wouldn't be simply important but literally crucial
in any major MBT's engagement between peer opponents employing armoured brigades ,both in offensive and in defensive missions, in theirs classical CONOPS and even more considering modern concepts of adaptive ground manoeuvring warfare.
Naturally, one more time, Gulf War, with Iraqi ground forces employing theirs MBT as....fixed pillbox/field artillery pieces
....have generated a lot of low level platitudes (among which capability to engage enemy MBT with APFSDS or HEAT at 3 km or over “thanks to advanced FCS” )very difficult to eradicate from common immaginary and completely irreconcilables not only with physical reality but with what would actually happen ,or would have happened, for example, in the highly mobile engagement in the Thar Desert between India and Pakistan armoured forces (or, in the past , in the Fulda Gap and the Great European Plain between URSS and NATO) where the heavy effects of lower probably to hit triggered by lower target area and lower inertial mass of some of the MBTs involved would generate an huge impact on the final attrition ratio .2) The question of K-5 efficiency against various menaces
I want to begin this response pointing out that defeating mechanism of the so called second generation heavy Soviet ERA has obviously variable effects against specific type of menaces at the variation of some of theirs parameters but
,one more time , in way completely different
(often even at the exact opposite) from some ridiculous ideas circulating on the subject
For KE rounds against this type of ERA ,a topic very often debated in open media, main factors involved in deciding the residual penetration power of the rod after ERA action are : penetrator speed, geometry of round incidence, length to diameter ratio of the penetrator (in a paradoxical way) ,speed of the ERA plates in the inducing action (in a paradoxical way) ,ERA plates spatial configuration, KE penetrator’s main mechanical characteristics, critical plastic strain limits and tendency to bend/deform, degrees of the yaw angle .
Among the named variables, experimental emergences have proved that those characteristics of the KE penetrators codifying for a prolonged interaction between ERA plates (in particular rear plates) with the rod increase ,often even dramatically, the efficiency of the defeating mechanism of K5-like type of ERA .
What is interesting and important to point out is that some of those “negative” characteristics of KE penetrators in the interaction with dynamic reactive armours are conversely just those required to increase penetration capabilities against modern ,ever growing, multilayered passive armour of MBTs .
I should still have somewhere the link to a pair of scientific publications on that specific subject in English (two others i own are in paper books in other languages) when i find them if will add here; all what said will appear surely more clear and simple.
Ok , found the first link to one of the scientific publications
Worth a mention are : the increase of length to diameter ratio
: this element increase the interaction time with the ERA plates greatly “aiding” the neutralization capabilities and effectiveness of oblique plate side action of the K-5-like ERA ,the increase of L/D ratio is a forced trend among world KE penetrator’s designer ,induced obviously by the necessity to maintain a certain capability to penetrate at operational useful distances ever growing frontal passive armour level of modern MBT (and not, of course to better defeat heavy ERA ,against which it become effectively even a negative characteristic ! -where increased diameter and shortening length would be the “paying” design choices- ) ; speed of the penetrator
: also here we see a clear trend for heavier and longer APFSDS with a contextual loss of speed at barrel exit and an increase of speed drop - one more time a design compromise required by the implementation of characteristics useful at improve performances against fast improving protection levels of modern passive armour but lowering efficiency against dynamic protection systems ; employment of DU core
: also here the different level of adiabatic shear band formation, representing an advantage in the tunnelling action against majority of dense materials of multilayered passive armour, is linked, to the other side, to significantly lower threshold for plastic deformation and an higher tendency at tangential particle ablation and mass loss, one more time characteristics “aiding” the defeating mechanism of heavy ERA .
At the end of day we can assert that, at the contrary of what commonly repeated in low level speculations, several features of KE round design implemented in the latest APFSDS rounds show physical capabilities the efficiency of which are at the exact antipodes for interactions with multilayered passive armours or modern ERA dynamic protection systems; therefore the most rational option remaining to the designers remain only to optimize the KE round for the best performances and penetration capabilities against composite and spaced passive armour considering that : ERA tiles never cover the entire surface of a MBT , almost always them work only for a single APFSDS hit in a particular spot and that several MBT don’t employ them at all. 3) K-5’s versions or modernizations and level of protection
Kontakt-5 ERA has received in the years only secondary modifications (mostly aimed at reduce the required explosive charge , geometry and specific arrangement of the system for a specific platform and a moderate retarding of rear plate reaction sequence ), but the fundamental of the system are remain unchanged .
What is more interesting is point out ,as already exposed in other mine intervention, the substantial difference between the export version of K-5 offered aboard ,with a capability to increase the level of protection of existing passive armour of 1,2 [ 20% ] against Kinetic Energy rounds and 1,7 -1,8 [70 %] against Chemical Energy rounds and ,conversely, the last Russian internal version with claimed capabilities in specialized publications of about 1,5 -1,6 against KE [50-60%] (equal or better than the actual performances of Relikt ERA now offered for export !) and 2 [100%] against Chemical Energy rounds.
For render much clear the actual point make and those previously exposed ,i find that an article from "Tehnika i Voorujenie" of November 2006 by Colonel S. Tupitsyn and A. Tarasenco can be truly enlightening (edit note : appear that Cyber has almost magically mentioned the same article i have pointed out while i was writing ,in any istance with my link you can read it entirely in first person and with it, hundreds of others -
Please go at this link and download in PDF the issue n 11 of 2006 and open at pag 10-15 (in link format it don't work here : simply copy and paste)
Some interesting informations from the article on internal russian versions of notorious systems and some westrn ones that someone would find surprising :
1) The gun shooted 9M119M1 has a penetration power of 900 mm RHA against not ERA equiped target
, in the computations of the developers more than sufficient for penetrate and destroy modern version od Leopard-2 and Abrams
2) The increase resistance to armour level offered by internal Kontakt-5 ERA is
,as previously mentioned, 1,5 - 1,6 against KE penetrators and 2 against CE ammunitions
3) Is present a table with the velocity drop of several russian and western APDS (3BM42,3BM42M, DM53 from L44 and L55 gun, M829A2 )
4) Protection level of M1 Abrams of 1980 against APDS round was about 350-380 mm of RHA and 500 mm for the M1A1 vesrion
5) APFSDS with a minimum guaranteed penetration level of 300 mm RHA at 60 degrees at 2 km (therefore about 600 mm at usual penetration route length) was already introduced in Russian armoured forces.
6) In a report by L. Mann in "Deutsche Airspace" of 1993 on tests effectuated on T-72M1 resulted a frontal turret armour level of 420-480 mm against the best 105-120 mm Federal Republic of Germany rounds available at the time.
7) An M1 Abrams had a frontal projection more than 25% bigger than a T-72 -5,1m2 against 4 m2-
(do you remember the question of PtH in mobile engagement at 2000m + range?) The level of frontal protection of the Soviet T-72B
(likely like those tested by L Ness and M. Held after Germany reunification) was 550 mm RHA against APFSDS increased at more than 750 mm against APFSDS when fitted with K-5 ERA !!
9) Semiactive baffle plates and ceramic layers with high tensile proprieties are employed in T-90. Even more advanced fillers was implemented in the welded turretts of domestic T-90 and on export T-90S for India .
10) In several tests conducted in front of Indian delegation using latest foreign munitions of the M829A2 type conducted from 250 meters against T-90S devoid of the normal built-in reactive armor the turrett resulted completely impentrable !!
(that can give an idea of the level of protection reached by modern russian 10 layer composite passive/semiactive armour in the frontal sector and aid us also to avoid to remain surprised in front of the figures for armour level -850 mm against APFSDS and 1200 against CE - provided for frontal sector of the new export T-90MS ).
That absurd resiliency to enemy fire (systematically proved by Russian MBT any time live tests was conducted in the past on any not-monkey model specimen....with good peace of ignorant claims of "tanks not designed to sustain hits" !!!
) resulted ,at the end, as one of the most crucial selling point for T-90S MBT to India.
11) Even only tyhr physical thickness of T-90 turrrett armor is in the range of 70-95 cm ,with 45 cm in the firing port area, a Leopard -2A5 show a physical thickness for the same area of 65 cm and 35 cm in the area of gun mantlet